Synthesis, structure, and reactivity of ruthenium carboxylato and 2-oxocarboxylato complexes bearing the bis(3,5-dimethylpyrazol-1-yl)acetato ligand

Article abstract of DOI:10.1021/ic8000224

A series of ruthenium(II) acetonitrile, pyridine (py), carbonyl, SO ₂, and nitrosyl complexes [Ru(bdmpza)(O₂CR)(L)(PPh ₃)] (L = NCMe, py, CO, SO₂) and [Ru(bdmpza)(O ₂CR)(L)(PPh₃)]BF₄

Full text of DOI:10.1021/ic8000224

Inorg. Chem. 2008, 47, 9624-9641
Synthesis, Structure, and Reactivity of Ruthenium Carboxylato and
2-Oxocarboxylato Complexes Bearing the
Bis(3,5-dimethylpyrazol-1-yl)acetato Ligand
Stefan Tampier,†,‡ Rainer Mu¨ller,‡,§ Andrea Thorn,† Eike Hu¨bner,† and Nicolai Burzlaff*,†
Inorganic Chemistry, Department of Chemistry and Pharmacy & Interdisciplinary Center for
Molecular Materials (ICMM), UniVersity of Erlangen-Nu¨rnberg, Egerlandstraꢀe 1, D-91058
Erlangen, Germany, and Department of Chemistry, UniVersity of Konstanz, Fach M728, D-78457
Konstanz, Germany
Received January 4, 2008
A series of ruthenium(II) acetonitrile, pyridine (py), carbonyl, SO2, and nitrosyl complexes [Ru(bdmpza)(O2CR)(L)(PPh3)]
(L ) NCMe, py, CO, SO2) and [Ru(bdmpza)(O2CR)(L)(PPh3)]BF4 (L ) NO) containing the bis(3,5-dimethylpyrazol-
1-yl)acetato (bdmpza) ligand, a N,N,O heteroscorpionate ligand, have been prepared. Starting from ruthenium
chlorido, carboxylato, or 2-oxocarboxylato complexes, a variety of acetonitrile complexes [Ru(bdmpza)Cl(NCMe)(PPh3)]
(4) and [Ru(bdmpza)(O2CR)(NCMe)(PPh3)] (R ) Me (5a), R ) Ph (5b)), as well as the pyridine complexes
[Ru(bdmpza)Cl(PPh3)(py)] (6) and [Ru(bdmpza)(O2CR)(PPh3)(py)] (R ) Me (7a), R ) Ph (7b), R ) (CO)Me (8a),
R ) (CO)Et (8b), R ) (CO)Ph) (8c)), have been synthesized. Treatment of various carboxylato complexes
[Ru(bdmpza)(O2CR)(PPh3)2] (R ) Me (2a), Ph (2b)) with CO afforded carbonyl complexes [Ru(bdmpza)(O2CR)(CO)-
(PPh3)] (9a, 9b). In the same way, the corresponding sulfur dioxide complexes [Ru(bdmpza)(O2CMe)(PPh3)(SO2)]
(10a) and [Ru(bdmpza)(O2CPh)(PPh3)(SO2)] (10b) were formed in a reaction of the carboxylato complexes with
gaseous SO2. None of the 2-oxocarboxylato complexes [Ru(bdmpza)(O2C(CO)R)(PPh3)2] (R ) Me (3a), Et (3b),
Ph (3c)) showed any reactivity toward CO or SO2, whereas the nitrosyl complex cations [Ru(bdmpza)(O2-
CMe)(NO)(PPh3)]+ (11) and [Ru(bdmpza)(O2C(CO)Ph)(NO)(PPh3)]+ (12) were formed in a reaction of the acetato
2a or the benzoylformato complex 3c with an excess of nitric oxide. Similar cationic carboxylato nitrosyl complexes
[Ru(bdmpza)(O2CR)(NO)(PPh3)]BF4 (R ) Me (13a), R ) Ph (13b)) and 2-oxocarboxylato nitrosyl complexes
[Ru(bdmpza)(O2C(CO)R)(NO)(PPh3)]BF4 (R ) Me (14a), R ) Et (14b), R ) Ph (14c)) are also accessible via a
reaction with NO[BF4]. X-ray crystal structures of the chlorido acetonitrile complex [Ru(bdmpza)Cl(NCMe)(PPh3)]
(4), the pyridine complexes [Ru(bdmpza)(O2CMe)(PPh3)(py)] (7a) and [Ru(bdmpza)(O2CC(O)Et)(PPh3)(py)] (8b),
the carbonyl complex [Ru(bdmpza)(O2CPh)(CO)(PPh3)] (9b), the sulfur dioxide complex [Ru(bdmpza)(O2-
CPh)(PPh3)(SO2)] (10b), as well as the nitrosyl complex [Ru(bdmpza)(O2C(CO)Me)(NO)(PPh3)]BF4 (14a), are reported.
The molecular structure of the sulfur dioxide complex [Ru(bdmpza)(O2CPh)(PPh3)(SO2)] (10b) revealed a rather
unusual intramolecular SO2-O2CPh Lewis acid-base adduct.
Introduction
ligands and thus have been subject of two very recent reviews
by Otero and Pettinari.1,2 Complexes of these N,N,O donor
ligands with various transition metal complexes reveal their
potential in organometallic and coordination chemistry as
scorpionate ligands closely related to Tp.1,2 Lately, we
reported on ruthenium(II) complexes bearing the bdmpza
Bis(pyrazol-1-yl)acetic acids, such as bis(3,5-dimeth-
ylpyrazol-1-yl)acetic acid (Hbdmpza) introduced 1999 by A.
Otero,1 are available in a broad spectrum of chiral and achiral
* To whom correspondence should be addressed. E-mail: burzlaff@
chemie.uni-erlangen.de. Phone: +49(0)9131/85-28976. Fax: +49(0)9131/
85-27387.
†
University of Erlangen-Nu¨rnberg.
Both authors contributed equally to this work.
University of Konstanz.
(1) Otero, A.; Fernan´dez-Baeza, J.; Antino˜lo, A.; Tejeda, J.; Lara-San´chez,
A. Dalton Trans. 2004, 1499–1510.
(2) Pettinari, C.; Pettinari, R. Coord. Chem. ReV. 2005, 249, 663–691.
‡
§
9624 Inorganic Chemistry, Vol. 47, No. 20, 2008
10.1021/ic8000224 CCC: $40.75  2008 American Chemical Society
Published on Web 09/19/2008

Ruthenium Carboxylato and 2-Oxocarboxylato Complexes
ligand such as [Ru(bdmpza)Cl(PPh3)2] (1).3 Because of the
sterical hindrance of the bdmpza ligand, one of the PPh3
ligands and the chlorido ligand can easily be exchanged for
carboxylato or cumulynidene ligands.3,4 Other ruthenium
complexes bearing the bdmpza ligand have recently been
reported by Cao and Otero.5 The carboxylato complexes
[Ru(bdmpza)(O2CR)(PPh3)] (2a: R ) Me; 2b: R ) Ph) and
the 2-oxocarboxylato complexes [Ru(bdmpza)(O2C(CO)R)-
(PPh3)] (3a: R ) Me; 3b: R ) Et; 3c: R ) Ph) showed
significant tendencies for a hemilabile κ1O1-behavior regard-
ing the κ2O1,O1′-carboxylato and κ2O1,O2-2-oxocarboxylato
ligands.3 As a proof for these hemilabile ligands, we recently
reported on a water adduct [Ru(bdmpza)(O2CMe)(OH2)-
(PPh3)] (2a × H2O) and an acetonitrile complex [Ru-
(bdmpza)(O2C(CO)Ph)(NCMe)(PPh3)] (3c × NCMe).3b Ru-
thenium(II) complexes with hemilabile ligands, as well as
with coordinated solvent molecules, are often key compounds
in inorganic syntheses or catalytic reactions. A recent
example is the ruthenium hydridotris(pyrazolyl)borate (Tp)
complex [RuTpH(NCMe)(PPh3)], which exhibits catalytic
activity for the hydrogenation of CO2 to formic acid and is
easily derived from [RuTpCl(NCMe)(PPh3)].6 Thus, inspired
by [RuTpCl(PPh3)(MeCN)] we decided to study the coor-
dination of acetonitrile and pyridine by various ruthenium(II)
complexes bearing the bdmpza ligand. Furthermore, 16 VE
complex fragments coordinating small molecules often allow
the syntheses and stabilization of otherwise highly reactive
molecules in the complex environment. As an example the
synthesis of sulfene complexes starting from ruthenium SO2
complexes should be mentioned.7 Therefore, here we study
also the coordination of small molecules CO, NO, and
especially SO2 that might act as π acceptor ligands L in
ruthenium complexes [Ru(bdmpza)(O2CR)(L)(PPh3)] (L )
CO, SO2, NO).
δ values are given relative to TMS (1H), solvent peaks (13C) or to
triphenylphosphine at -4.72 ppm as internal standard (31P). FAB
MS: modified Finnigan MAT 312. Elemental analyses: Analytical
Laboratory of the Department of Chemistry, University of Konstanz
or Euro EA 3000 (Euro Vector) and EA 1108 (Carlo Erba) (σ (
1% of the measured content). A modified Siemens P4 and an Enraf-
Nonius CAD 4 Mach 3 diffractometer were used for X-ray structure
determination. The syntheses of [Ru(bdmpza)Cl(PPh3)2] (1), the
ruthenium carboxylato complexes [Ru(bdmpza)(O2CR)(PPh3)] (2a:
R ) Me, 2b: R ) Ph) and the ruthenium 2-oxocarboxylato
complexes [Ru(bdmpza)(O2CC(O)R)(PPh3)] (3a: R ) Me, 3b: R
) Ph, 3c: R ) Et, 3d: R ) CH2CH2CO2H) were reported recently.3
To remove last traces of thallous carboxylate the acetato and
benzoato complexes 2a and 2b were recrystallized from CH2Cl2/
pentane. All the 2-oxocarboxylato complexes used for experiments
had been synthesized by using this crystalline complex 2a.
Acetonitrile and pyridine have been distilled prior to use. Nitrogen
oxide, carbon monoxide, carbon dioxide, nitrogen and sulfur dioxide
were used as purchased. For differentiation of the NMR data the
signals of the bdmpza ligand next to the PPh3 ligand are marked
without an apostrophe.
Method A: General Procedure for the Syntheses of Aceto-
nitrile Complexes. The chlorido, acetato, or benzoato complexes
1, 2a, or 2b were dissolved in acetonitrile, and the reaction mixture
was stirred at ambient temperature. The progress of the reaction
was monitored by IR spectroscopy. After the reaction was
completed, the solvent was reduced in vacuo until precipitation
occurred. Precipitation was completed by adding pentane. The
product was filtered off and dried in vacuo.
[Ru(bdmpza)Cl(NCMe)(PPh3)] (4). Reaction of [Ru(bdmpza)
Cl(PPh3)2] (1) (0.428 g, 0.471 mmol) with acetonitrile (20 mL) for
4 h according to method A but with heating under reflux afforded
[Ru(bdmpza)Cl(NCMe)(PPh3)] (4) as a yellow crystalline powder.
Yield 0.301 g (0.438 mmol, 93%). mp 230 °C (dec.). IR
(CH2Cl2): ν˜ ) 2275 w (Ct N), 2254 vw, 1660 vs (CO2-), 1647
sh, 1565 w (C)N), 1483 w, 1463 vw, 1434 m, 1420 w cm-1. IR
(KBr): ν˜ ) 2269 w (Ct N), 2247 vw, 1657 vs (CO2-), 1642 sh,
1583 vw, 1561 m (C)N), 1483 w, 1460 vw, 1433 m, 1416 vw
cm-1. UV/vis (CH2Cl2): λmax/nm (log ε) ) 237.0 (4.34), 267.0
(3.91), 274.0 (3.90). FAB-MS (NBOH-matrix): m/z (%) ) 686 (10)
[M+], 645 (100) [M+ - MeCN], 610 (33) [M+ - MeCN - Cl],
566 (29) [M+ - MeCN - Cl - CO2], 363 (38) [M+ - MeCN -
Experimental Section
All experiments were carried out with Schlenk technique under
an argon atmosphere. Solvents were dried by distillation over
suitable drying agents [THF (Na), Et2O (Na), pentane (LiAlH4),
hexane (Na), CH2Cl2 (CaH2)] prior to use and were stored under
Argon. IR: Biorad FTS 60, CaF2 cuvets (0.5 mm) or KBr matrix.
1H NMR and 13C NMR: Bruker AC 250, Bruker DRX 600 Avance
and Varian Unity Inova 400. 31P NMR: JEOL GX 400 and Varian
Unity Inova 400. 2D NMR experiments: Bruker DRX 600 Avance.
1
Cl - bdmpza]. H NMR (CDCl3, 400 MHz): δ ) 1.88 (s, 3H,
NC-CH3), 1.88 (s, 3H, C3′-CH3), 2.47 (s, 3H, C5-CH3), 2.51 (s,
3H, C5′-CH3), 2.71 (s, 3H, C3-CH3), 5.89 (s, 1H, Hpz), 6.04 (s,
1H, Hpz′), 6.51 (s, 1H, CH), 7.26 (m, 6H, m-PPh3), 7.28 (m, 3H,
p-PPh3), 7.30 (m, 6H, o-PPh3) ppm. 13C NMR (CDCl3, 100.5 MHz):
δ ) 3.67 (NC-CH3), 10.9 (C5′-CH3), 11.4 (C5-CH3), 14.4 (C3′-
(3) (a) Lo´pez-Herna´ndez, A.; Mu¨ller, R.; Kopf, H.; Burzlaff, N. Eur.
J. Inorg. Chem. 2002, 671–677. (b) Mu¨ller, R.; Hu¨bner, E.; Burzlaff,
N. Eur. J. Inorg. Chem. 2004, 2151–2159.
(4) Kopf, H.; Pietraszuk, C.; Hu¨bner, E.; Burzlaff, N. Organometallics
2006, 25, 2533–2546.
(5) (a) Ortiz, M.; D´ıaz, A.; Cao, R.; Otero, A.; Ferna´ndez-Baeza, J. Inorg.
Chim. Acta 2004, 357, 19–24. (b) Ortiz, M.; D´ıaz, A.; Cao, R.;
Suard´ıaz, R.; Otero, A.; Antino˜lo, A.; Ferna´ndez-Baeza, J. Eur.
J. Inorg. Chem. 2004, 3353–3357.
(6) (a) Chan, W.-C.; Lau, C. P.; Chen, Y.-Z.; Fang, Y.-Q.; Ng, S. M.;
Jia, G. Organometallics 1997, 16, 34–44. (b) Yin, C.; Xu, Z.; Yang,
S.-Y.; Ng, S. M.; Wong, K. Y.; Lin, Z.; Lau, C. P. Organometallics
2001, 20, 1216–1222. (c) Ng, S. M.; Yin, C.; Yeung, C. H.; Chan,
T. C.; Lau, C. P. Eur. J. Inorg. Chem. 2004, 1788–1793. (d) Lau,
C. P.; Ng, S. M.; Jia, G.; Lin, Z. Coord. Chem. ReV. 2007, 251, 2223–
2237.
4
CH3), 15.0 (C3-CH3), 69.1 (CH), 108.6 (d, C4′, JCP ) 2.8 Hz),
3
108.8 (C4), 124.0 (CN), 127.4 (d, m-PPh3, JCP ) 9.2 Hz), 129.0
(d, p-PPh3, 3JCP ) 1.8 Hz), 134.3 (d, o-PPh3, 2JCP ) 9.5 Hz), 134.7
1
5
(d, i-PPh3, JCP ) 40.7 Hz), 140.3 (d, C5′, JCP ) 1.0 Hz), 141.6
(C5), 155.2 (d, C3′, 3JCP ) 2.6 Hz), 158.4 (C3), 167.6 (CO2-) ppm.
31P NMR (CDCl3, 161.8 MHz): δ ) 48.8 ppm. Anal. Calcd for
C32H33ClN5O2PRu (687.14): C, 55.93; H, 4.84; N, 10.19. Found
C, 55.87; H, 4.76; N, 10.06.
[Ru(bdmpza)(O2CMe)(NCMe)(PPh3)] (5a). Reaction of
[Ru(bdmpza)(O2CMe)(PPh3)] (2a) (0.134 g, 0.200 mmol) with
acetonitrile (10 mL) for 5 h according to method A afforded
(7) (a) Schenk, W. A.; Urban, P.; Dombrowski, E. Chem. Ber. 1993, 126,
679–684. (b) Schenk, W. A.; Bezler, J.; Burzlaff, N.; Hagel, M.;
Steinmetz, B. Eur. J. Inorg. Chem. 2000, 287–297.
Inorganic Chemistry, Vol. 47, No. 20, 2008 9625

Tampier et al.
[Ru(bdmpza)(O2CMe)(NCMe)(PPh3)] (5a) as a yellow crystalline
powder.
romethane was added pyridine. The reaction mixture was stirred
at ambient temperature and the progress of the reaction was
monitored by IR spectroscopy. After the reaction was completed,
the solvent was reduced in vacuo, and the product was precipitated
with n-pentane. The precipitate was filtered off and dried in vacuo.
[Ru(bdmpza)Cl(PPh3)(py)] (6). Reaction of [Ru(bdmpza)Cl(P-
Ph3)2] (1) (0.308 g, 0.339 mmol) in CH2Cl2 (15 mL) with pyridine
(0.271 g, 3.43 mmol) for 3 days according to method B afforded
[Ru(bdmpza)Cl(PPh3)(py)] (6) as a yellow crystalline powder.
Yield 0.237 g (0.327 mmol, 96%). mp 240 °C (dec.). IR
(CH2Cl2): ν˜ ) 1659 vs (CO2-), 1565 w (C)N), 1482 m, 1462 vw,
1447 vw, 1434 m, 1420 vw cm-1. IR (KBr): ν˜ ) 1657 vs (CO2-),
1642 vw, 1565 m (C)N), 1483 m, 1461 w, 1446 vw, 1437 w,
1432 w, 1419 vw cm-1. UV/vis (CH2Cl2): λmax/nm (log ε) ) 235.0
(4.33), 268.0 (3.74), 275.0 (3.75), 304.0 (3.76), 362.0 (3.71). FAB-
MS (NBOH-matrix): m/z (%) ) 724 (7) [M+], 647 (7) [M+ - Py],
460 (6) [M+ - PPh3], 363 (6) [M+ - Cl - Py - bdmpza], 217
(100) [M+ - PPh3 - bdmpza]. 1H NMR (CDCl3, 250 MHz): δ )
1.70 (s, 3H, C3′-CH3), 1.91 (s, 3H, C3-CH3), 2.48 (s, 3H, C5′-
CH3), 2.52 (s, 3H, C5-CH3), 5.85 (s, 1H, Hpz), 5.92 (s, 1H, Hpz′),
6.52 (s, 1H, CH), 6.72 (t, 1H, m′-py), 6.87 (t, 1H, m-py), 7.12 (m,
6H, m-PPh3), 7.17 (m, 6H, o-PPh3), 7.23 (m, 3H, p-PPh3), 7.36 (t,
1H, p-py), 8.02 (d 1H, o-py), 8.94 (d, 1H, o′-py) ppm. 13C NMR
(CDCl3, 100.5 MHz): δ ) 11.1 (C5′-CH3), 11.4 (C5-CH3), 12.6
(C3′-CH3), 14.9 (C3-CH3), 69.3 (CH), 108.9 (d, C4′), 109.3 (C4),
122.8, 122.9 (m- and m′-py), 127.4 (m-PPh3), 128.7 (p-PPh3), 134.1
(p-py), 134.1 (o-PPh3), n.d. (i-PPh3), 140.2 (C5′), 141.6 (C5), 154.6
(C3′), 155.2 (o-py), 158.6 (o′-py), 158.8 (C3), 168.1 (CO2-) ppm.
31P NMR (CDCl3, 161.8 MHz): δ ) 49.5 ppm. Anal. Calcd for
C35H35ClN5O2PRu (725.19): C, 57.97; H, 4.86; N, 9.66. Found: C,
57.81; H, 4.99; N, 8.96.
Yield 0.141 g (0.198 mmol, 99%). mp 145 °C (dec). IR (CH2Cl2):
ν˜ ) 2271 w (Ct N), 1663 vs (CO2-), 1648 sh, 1608 m, 1591 sh,
1564 w (C)N), 1484 w, 1464 vw, 1434 m, 1417 vw cm-1. IR
(KBr): ν˜ ) 2263 m (Ct N), 1659 vs (CO2-), 1606 s, 1587 sh,
1564 w (C)N), 1483 w, 1463 vw, 1434 m, 1417 vw cm-1. UV/
vis (CH2Cl2): λmax/nm (log ε) ) 236.0 (4.36), 268.0 (3.91), 275.0
(3.90), 289.0 (3.88). FAB-MS (NBOH-matrix): m/z (%) ) 711 (8)
[M+], 651 (97) [M+ - HO2CMe], 610 (100) [M+ - HO2CMe -
1
MeCN], 565 (46) [M+ - HO2CMe - CO2 - MeCN - H]. H
NMR (CDCl3, 400 MHz): δ ) 1.31 (s, 3H, OAc-CH3), 1.56 (s,
3H, C3-CH3), 2.22 (s, 3H, NC-CH3), 2.43 (s, 3H, C3′-CH3), 2.47
(s, 3H, C5′-CH3), 2.54 (s, 3H, C5-CH3), 5.91 (s, 1H, Hpz), 6.07 (s,
1H, Hpz′), 6.55 (s, 1H, CH), 7.10-7.50 (m, 15H, PPh3) ppm. 13C
NMR (CDCl3, 62.9 MHz): δ ) 4.60 (NC-CH3), 11.0 (C5′-CH3),
11.6 (C5-CH3), 13.3 (C3′-CH3), 14.2 (C3-CH3), 23.8 (OAc-CH3),
4
69.7 (CH), 108.2 (d, C4′, JCP ) 2.9 Hz), 108.4 (C4), 124.7 (CN),
127.5 (d, m-PPh3, 3JCP ) 9.3 Hz), 128.9 (p-PPh3), 134.7 (d, o-PPh3,
2JCP ) 9.7 Hz), n.d. (i-PPh3), 140.5 (C5′), 142.3 (C5), 154.0 (C3′),
157.0 (C3), 166.3 (CO2-), 179.7 (OAc-CO2-) ppm. 31P NMR
(CDCl3, 161.8 MHz):
δ ) 53.4 ppm. Anal. Calcd for
C34H36N5O4PRu × CH2Cl2 (795.67): C, 52.83; H, 4.81; N, 8.80.
Found: C, 52.90; H, 5.03; N, 8.89.
[Ru(bdmpza)(O2CPh)(NCMe)(PPh3)] (5b). Reaction of
[Ru(bdmpza)(O2CPh)(PPh3)] (2b) (0.356 g, 0.487 mmol) in aceto-
nitrile (25 mL) for 4 h according to method A afforded
[Ru(bdmpza)(O2CPh)(NCMe)(PPh3)] (5b) as a yellow microcrys-
talline powder.
Yield 0.372 g (0.481 mmol, 99%). mp 160 °C (dec.). IR
(CH2Cl2): ν˜ ) 2270 w (Ct N), 1663 vs (CO2-), 1645 sh, 1608 m,
1574 m (C)N), 1570 m, 1484 w, 1464 vw, 1434 m, 1419 vw cm-1
.
[Ru(bdmpza)(O2CMe)(PPh3)(py)]
(7a).
Reaction
of
IR (KBr): ν˜ ) 2268 m (Ct N), 1659 vs (CO2-), 1605 s, 1570 s
(C)N), 1484 w, 1465 vw, 1434 m, 1419 vw cm-1. UV/vis
(CH2Cl2): λmax/nm (log ε) ) 238.0 (4.33), 268.0 (3.94), 275.0 (3.93),
296.0 (3.93). FAB-MS (NBOH-matrix): m/z (%) ) 773 (3) [M+],
731 (100) [M+ - MeCN], 651 (29) [M+ - O2CPh], 610 (43) [M+
- O2CPh - MeCN]. Isomer A: 1H NMR (CDCl3, 600 MHz): δ )
1.61 (s, 3H, C3-CH3), 2.23 (s, 3H, NC-CH3), 2.30 (s, 3H, C3′-
CH3), 2.51 (s, 3H, C5′-CH3), 2.57 (s, 3H, C5-CH3), 5.93 (s, 1H,
Hpz), 6.01 (s, 1H, Hpz′), 6.62 (s, 1H, CH), 7.05-7.65 (m, 20H, Ph
and PPh3) ppm. 13C NMR (CDCl3, 150.9 MHz): δ ) 2.23 (NC-
CH3), 11.0 (C5′-CH3), 11.6 (C5-CH3), 13.3 (C3′-CH3), 14.2
(C3-CH3), 69.6 (CH), 108.0 (C4′), 108.4 (C4), 124.7 (CN), 140.2
(C5′), 142.4 (C5), 153.8 (C3′), 157.0 (C3), 166.8 (CO2-), 174.6 (Ph-
CO2-) ppm. 31P NMR (CDCl3, 161.8 MHz): δ ) 53.6 ppm. Isomer
[Ru(bdmpza)(O2CMe)(PPh3)] (2a) (0.278 g, 0.415 mmol) in CH2Cl2
(10 mL) with pyridine (0.336 g, 4.25 mmol) for 3 days according
to method B afforded [Ru(bdmpza)(O2CMe)(PPh3)(py)] (7a) as an
orange microcrystalline powder.
Yield 0.266 g (0.355 mmol, 86%). mp 200 °C (dec.). IR
(CH2Cl2): ν˜ ) 1659 vs (CO2-), 1619 s, 1567 w (C)N), 1482 m,
1464 vw, 1448 w, 1434 m, 1420 vw cm-1. IR (KBr): ν˜ ) 1667 vs
(CO2-), 1631 vs, 1565 w (C)N), 1481 m, 1465 vw, 1444 vw,
1434 w, 1420 vw cm-1. UV/vis (CH2Cl2): λmax/nm (log ε) ) 237.0
(4.32), 268.0 (3.74), 274.0 (3.76), 311.0 (3.84), 368.0 (3.81). FAB-
MS (NBOH-matrix): m/z (%) ) 749 (29) [M+], 689 (88) [M+
O2CMe], 670 (100) [M+ - Py], 611 (41) [M+ - O2CMe - Py],
-
565 (29) [M+ - HO2CMe - CO2 - Py - H], 363 (71) [M+
-
O2CMe - Py - bdmpza]. 1H NMR (CDCl3, 250 MHz): δ ) 1.33
(s, 3H, C3′-CH3), 1.55 (s, 3H, C3-CH3), 1.79 (s, 3H, OAc-CH3),
2.49 (s, 3H, C5′-CH3), 2.52 (s, 3H, C5-CH3), 5.79 (s, 1H, Hpz), 5.85
(s, 1H, Hpz′), 6.53 (s, 1H, CH), 6.82 (m, 2H, m and m′-py),
7.05-7.30 (m, 15H, PPh3), 7.37 (tt, 1H, p-py), 8.05 (d, 1H, o-py),
1
B: H NMR (CDCl3, 600 MHz): δ ) 1.57 (s, 3H, C3-CH3), 1.92
(s, 3H, NC-CH3), 2.25 (s, 3H, C3′-CH3), 2.49 (s, 3H, C5′-CH3), 2.57
(s, 3H, C5-CH3), 5.91 (s, 1H, Hpz), 5.97 (s, 1H, Hpz′), 6.56 (s, 1H,
CH), 7.05-7.65 (m, 20H, Ph and PPh3) ppm. 13C NMR (CDCl3,
150.9 MHz): δ ) 3.56 (NC-CH3), 11.0 (C5′-CH3), 11.5 (C5-CH3),
13.2 (C3′-CH3), 13.9 (C3-CH3), 69.2 (CH), 107.8 (C4′), 108.3 (C4),
124.1 (CN), 140.2 (C5′), 141.5 (C5), 153.9 (C3′), 157.5 (C3), 167.8
(CO2-), 174.9 (Ph-CO2-) ppm. 31P NMR (CDCl3, 161.8 MHz): δ
) 51.9 ppm. 13C NMR (both isomers, CDCl3, 150.9 MHz): δ )
126.2, 126.6, 126.9, 127.4, 127.6, 127.7, 127.9, 128.4, 128.5, 128.6,
128.7, 128.9, 129.0, 131.9, 132.0, 132.1, 133.6, 133.7, 134.0, 134.1,
134.4, 134.8, 135.0, 137.3, 137.7 (Ph and PPh3). Anal. Calcd for
C39H38N5O4PRu (772.80): C, 60.61; H, 4.96; N, 9.06. Found C,
60.27; H, 5.07; N, 8.84.
1
8.90 (d, 1H, o′-py) ppm. H NMR (CDCl3, 400 MHz): δ ) 1.32
(s, 3H, C3′-CH3), 1.59 (s, 3H, C3-CH3), 1.88 (br, 3H, OAc-CH3),
2.52 (s, 3H, C5′-CH3), 2.59 (br, 3H, C5-CH3), 5.77 (s, 1H, Hpz),
5.83 (s, 1H, Hpz′), 6.55 (s, 1H, CH), 6.84 (br, 1H, m′-py), 6.85 (br,
1H, m-py), 7.11 (m, 6H, m-PPh3), 7.17 (m, 6H, o-PPh3), 7.23 (t,
3H, p-PPh3), 7.34 (t, 1H, p-py), 7.97 (br, 1H, o-py), 8.93 (br, 1H,
o′-py) ppm. 13C NMR (CDCl3, 62.9 MHz): δ ) 11.2 (C5′-CH3),
11.5 (C3′-CH3), 11.5 (C5-CH3),14.2 (C3-CH3), 24.8 (OAc-CH3),
4
69.3 (CH), 108.0 (d, C4′, JCP ) 2.8 Hz), 108.1 (C4), 122.6 (m′-
3
py), 123.2 (m-py), 127.4 (d, m-PPh3, JCP ) 8.9 Hz), 128.7 (p-
2
Method B: General Procedure for the Syntheses of Pyri-
dine Complexes. To a solution of the chlorido, carboxylato, or
2-oxocarboxylato complexes 1, 2a, 2b, and 3a-c in dichlo-
PPh3), 133.7 (p-py), 133.9 (d, o-PPh3, JCP ) 9.5 Hz), 135.0 (d,
i-PPh3, 1JCP ) 38.2 Hz), 139.9 (C5′), 141.1 (C5), 153.9 (d, C3′, 3JCP
) 2.8 Hz), 154.6 (o-py), 155.5 (o′-py), 157.7 (C3), 168.4 (CO2-),
9626 Inorganic Chemistry, Vol. 47, No. 20, 2008

Ruthenium Carboxylato and 2-Oxocarboxylato Complexes
178.0 (OAc-CO2-) ppm. 13C NMR (CDCl3, 100.5 MHz): δ ) 11.2
(CH), 108.1, 108.2 (C4 or C4′), 123.0, 123.4 (m- and m′-py), 127.6
(d, m-PPh3, 3JCP ) 9.0 Hz), 128.8 (p-PPh3), 133.9 (d, o-PPh3, 2JCP
) 10.2 Hz), 134.0 (p-py), 134.6 (d, i-PPh3, 1JCP ) 38.9 Hz), 140.1,
141.4 (C5 and C5′), 154.0 (C3 and C3′), 154.4, 155.5 (o and o′-py),
157.7 (C3 and C3′), 168.4 (CO2-), 171.1 (C(O)-CO2-), 197.6 (CdO)
ppm. 31P NMR (CDCl3, 161.8 MHz): δ ) 49.7 ppm. Anal. Calcd
for C38H35N5O5PRu (776.79): C, 58.76; H, 4.93; N, 9.02. Found:
C, 58.42; H, 5.20; N, 8.76.
[Ru(bdmpza)(O2CC(O)Et)(PPh3)(py)] (8b). Reaction of
[Ru(bdmpza)(O2CC(O)Et)(PPh3)] (3b) (0.269 g, 0.378 mmol) in
CH2Cl2 (15 mL) with pyridine (0.302 g, 3.82 mmol) for 3 days
according to method B afforded [Ru(bdmpza)(O2CC(O)Et)-
(PPh3)(py)] (8b) as an orange crystalline powder. Crystals suitable
for X-ray structure determination were obtained from a CH2Cl2
solution layered with n-hexane.
(C5′-CH3), 11.5 (C3′-CH3), 11.5 (C5-CH3), 14.2 (C3-CH3), 24.8
4
(OAc-CH3), 69.2 (CH), 107.9 (d, C4′, JCP ) 2.8 Hz), 108.1 (C4),
3
122.6 (m′-py), 123.2 (m-py), 127.4 (d, m-PPh3, JCP ) 8.8 Hz),
128.7 (p-PPh3), 133.7 (p-py), 133.9 (br, o-PPh3), 134.9 (d, i-PPh3,
3
1JCP ) 38.3 Hz), 139.9 (C5′), 141.1 (C5), 153.9 (d, C3′, JCP ) 2.8
Hz), 154.4 (o-py), 155.4 (o′-py), 157.7 (C3), 168.4 (CO2-), 178.1
(OAc-CO2-) ppm. 31P NMR (CDCl3, 161.8 MHz): δ ) 49.7 ppm.
Anal. Calcd C37H38N5O4PRu (748.78): C, 59.35; H, 5.12; N, 9.35.
Found: C, 59.28; H, 5.22; N, 9.31.
[Ru(bdmpza)(O2CPh)(PPh3)(py)]
(7b).
Reaction
of
[Ru(bdmpza)(O2CPh)(PPh3)] (2b) (0.261 g, 0.357 mmol) in CH2Cl2
(15 mL) with pyridine (0.270 g, 3.41 mmol) for 3 days according
to method B afforded [Ru(bdmpza)(O2CPh)(PPh3)(py)] (7b) as
yellow powder.
Yield 0.265 g (0.327 mmol, 92%). mp 220 °C (dec.). IR
(CH2Cl2): ν˜ ) 1659 vs (CO2-), 1636 w, 1626 w, 1618 w, 1575 m
(C)N), 1568 w, 1482 m, 1464 vw, 1447 w, 1434 w, 1420 vw
cm-1. IR (KBr): ν˜ ) 1662 vs (CO2-), 1641 vs, 1630 vs, 1623 s,
1573 m (C)N), 1561 m, 1483 s, 1465 w, 1450 w, 1444 vw, 1437
vw, 1433 w, 1419 vw cm-1. UV/vis (CH2Cl2): λmax/nm (log ε) )
235.0 (4.35), 268.0 (3.80), 274.0 (3.79), 315.0 (3.88), 361.0 (3.80).
FAB-MS (NBOH-Matrix): m/z (%) ) 810 (9) [M+], 731 (100) [M+
- Py], 690 (31) [M+ - O2Ph], 611 (17) [M+ - O2CPh - Py],
549 (60) [M+ - PPh3], 363 (34) [M+ - O2CPh - Py - bdmpza].
1H NMR (CDCl3, 600 MHz): δ ) 1.16 (s, 3H, C3′-CH3), 1.53 (s,
3H, C3-CH3), 2.52 (s, 3H, C5′-CH3), 2.60 (s, 3H, C5′-CH3), 5.75 (s,
1H, Hpz), 5.80 (s, 1H, Hpz′), 6.59 (s, 1H, CH), 6.91 (br, 2H, m-py),
7.10-7.50 (m, 20H, Ph and PPh3), 7.98 (t, 1H, p-py), 8.05 (br,
1H, o-py), 9.12 (br, 1H, o′-py) ppm. 13C NMR (CDCl3, 150.9 MHz):
δ ) 11.2 (C5-CH3), 11.5 (C3′-CH3), 11.6 (C5′-CH3), 14.4 (C3-CH3),
69.3 (CH), 107.9 (C4′), 108.1 (C4), 122.7, 123.4 (m and m′-py),
127.3 (m-Ph), 127.5 (d, m-PPh3, 3JCP ) 7.8 Hz), 128.7 (o-Ph), 128.8
(p-PPh3), 129.1 (p-Ph), 133.9 (br, p-py and o-PPh3), 135.0 (d,
i-PPh3, 1JCP ) 38.3 Hz), 137.1 (i-Ph), 139.7 (C5′), 140.9 (C5), 153.8
(C3′), 154.8 (o-py), 155.5 (o′-py), 157.6 (C3), 168.5 (CO2-), 171.1
(Ph-CO2-) ppm. 31P NMR (CDCl3, 161.8 MHz): δ ) 50.5 ppm.
For further purification yellow microystals of 7b were obtained from
a CH2Cl2 solution layered with a 1:1 mixture (v/v) of pentane/
Yield 0.209 g (0.264 mmol, 70%). mp 210 °C (dec.). IR
(CH2Cl2): ν˜ ) 1711 w, 1661 vs (CO2-), 1640 s, 1565 w (C)N),
1483 m, 1463 vw, 1448 w, 1434 m, 1420 vw cm-1. IR (KBr): ν˜ )
1709 m, 1664 vs (CO2-), 1639 vs, 1565 m (C)N), 1482 m, 1464
vw, 1448 w, 1437 w, 1433 w, 1420 vw cm-1. UV/vis (CH2Cl2):
λ
max/nm (log ε) ) 236.0 (4.34), 268.0 (3.77), 275.0 (3.79), 307.0
(3.85), 362.0 (3.80). FAB-MS (NBOH-matrix): m/z (%) ) 791 (33)
[M+], 711 (14) [M+ - Py], 689 (100) [M+ - O2CC(O)Et], 611
(43) [M+ - O2CC(O)Et - Py], 529 (14) [M+ - PPh3], 363 (48)
[M+ - O2CC(O)Et - Py - bdmpza]. 1H NMR (CDCl3, 400 MHz):
δ ) 1.02 (t, 3H, CH2-CH3, 3JHH ) 7.3 Hz), 1.26 (s, 3H, C3′-CH3),
1.48 (s, 3H, C3-CH3), 2.48 (s, 3H, C5′-CH3), 2.52 (s, 3H, C5-CH3),
2.58 (q, 2H, CH2-CH3, 3JHH ) 7.3 Hz), 5.80 (s, 1H, Hpz), 5.85 (s,
1H, Hpz′), 6.55 (s, 1H, CH), 6.83 (m, 2H, m- and m′-py), 7.05-7.30
(m, 15H, PPh3), 7.36 (t, 1H, p-py), 8.05 (d, 1H, o-py), 8.96 (d, 1H,
o′-py) ppm. 13C NMR (CDCl3, 100.5 MHz): δ ) 7.45 (CH2-CH3),
11.2 (C5′-CH3), 11.5 (C5-CH3), 11.6 (C3′-CH3), 14.1 (C3-CH3), 32.0
(CH2), 69.2 (CH), 108.0 (d, C4′, 4JCP ) 2.8 Hz), 108.2 (C4), 123.0,
3
123.3 (m- and m′-py), 127.5 (d, m-PPh3, JCP ) 9.0 Hz), 128.8
(p-PPh3), 134.0 (p-py), 133.9 (d, o-PPh3, 2JCP ) 8.8 Hz), 134.6 (d,
i-PPh3, 1JCP ) 39.1 Hz), 140.1 (C5′), 141.4 (C5), 153.9 (d, C3′, 3JCP
) 2.4 Hz), 154.3 (o-py), 155.5 (o′-py), 157.7 (C3), 168.4 (CO2-),
171.6 (C(O)-CO2-), 200.3 (CdO) ppm. 31P NMR (CDCl3, 161.8
MHz): δ ) 49.8 ppm. Anal. Calcd for C39H40N5O5PRu (790.82):
C, 59.23; H, 5.10; N, 8.86. Found: C, 58.62; H, 5.31; N, 8.75.
[Ru(bdmpza)(O2C(CO)Ph)(PPh3)(py)] (8c). Reaction of
[Ru(bdmpza)(O2CC(O)Ph)(PPh3)] (3c) (0.300 g, 0.395 mmol) in
CH2Cl2 (15 mL) with pyridine (0.314 g, 3.97 mmol) for 3 days
according to method B afforded [Ru(bdmpza)(O2CC(O)Ph)-
(PPh3)(py)] (8c) as an orange crystalline powder.
1
diethylether. According to the H NMR spectrum these crystals
contained also 1 equiv CH2Cl2. Anal. Calcd for C42H40N5O4PRu
× CH2Cl2 (895.79): C, 57.66; H, 4.73; N, 7.82. Found: C, 57.88;
H, 4.75; N, 7.91.
[Ru(bdmpza)(O2CC(O)Me)(PPh3)(py)] (8a). Reaction of
[Ru(bdmpza)(O2CC(O)Me)(PPh3)] (3a) (0.267 g, 0.383 mmol) in
CH2Cl2 (15 mL) with pyridine (0.311 g, 3.93 mmol) for 3 days
according to method B afforded [Ru(bdmpza)(O2CC(O)Me)-
(PPh3)(py)] (8a) as an orange crystalline powder.
Yield 0.224 g (0.267 mmol, 68%). mp 205 °C (dec.). IR
(CH2Cl2): ν˜ ) 1662 vs (CO2-), 1634 s, 1597 vw, 1565 w (C)N),
1483 m, 1463 vw, 1448 w, 1434 w, 1421 vw cm-1. IR (KBr): ν˜ )
1665 vs (CO2-), 1640 vs, 1598 vw, 1564 m (C)N), 1482 m, 1464
vw, 1447 w, 1436 vw, 1433 w, 1420 vw cm-1. UV/vis (CH2Cl2):
Yield 0.245 g (0.315 mmol, 82%). mp 175 °C (dec.). IR
(CH2Cl2): ν˜ ) 1707 m, 1662 vs (CO2-), 1640 s, 1565 w (C)N),
1483 m, 1464 vw, 1448 w, 1434 m, 1421 w cm-1. IR (KBr): ν˜ )
1706 m, 1668 vs (CO2-), 1637 s, 1561 m (C)N), 1482 m, 1465
vw, 1446 w, 1436 w, 1420 w cm-1. UV/vis (CH2Cl2): λmax/nm (log
ε) ) 236.0 (4.36), 307.0 (3.86), 361.0 (3.81), 275.0 (3.78). FAB-
λ
max/nm (log ε) ) 236.0 (4.44), 362.0 (3.76). FAB-MS (NBOH-
matrix): m/z (%) ) 839 (26) [M+], 759 (26) [M+ - Py], 690 (54)
[M+ - O2CC(O)Ph], 611 (100) [M+ - O2CC(O)Ph - Py], 567
(43) [M+ - PPh3], 363 (71) [M+ - O2CC(O)Ph - Py - bdmpza].
1H NMR (CDCl3, 400 MHz): δ ) 1.40 (s, 3H, C3′-CH3), 1.63 (s,
3H, C3-CH3), 2.51 (s, 3H, C5′-CH3), 2.55 (s, 3H, C5-CH3), 5.84 (s,
1H, Hpz), 5.90 (s, 1H, Hpz′), 6.57 (s, 1H, CH), 6.82 (m, 1H, m′-py),
6.86 (m, 1H, m-py), 7.04 (m, 6H, m-PPh3), 7.10 (m, 3H, p-PPh3),
7.20 (m, 6H, o-PPh3), 7.34 (m, 2H, m-Ph), 7.37 (m, 1H, p-py),
7.50 (m, 1H, p-Ph), 8.02 (m, 2H, o-Ph), 8.05 (d, 1H, o-py), 8.90
(d, 1H, o′-py) ppm. 13C NMR (CDCl3, 100.5 MHz): δ ) 11.2 (C5′-
CH3), 11.6 (C5-CH3), 12.0 (C3-CH3), 14.6 (C3′-CH3), 69.2 (CH),
108.2 (d, C4′, 4JCP ) 2.7 Hz), 108.3 (C4), 123.0 (m′-py), 123.4 (m-
MS (NBOH-matrix): m/z (%) ) 776 (38) [M+], 689 (50) [M+
-
O2CC(O)Me], 611 (56) [M+ - O2CC(O)Me - Py], 515 (25) [M+
- PPh3], 363 (100) [M+ - O2CC(O)Me - Py - bdmpza]. 1H NMR
(CDCl3, 250 MHz): δ ) 1.26, 1.47 (s, 3H, C3 and C3′-CH3), 2.18
(s, 3H, C(O)-CH3), 2.49, 2.53 (s, 3H, C5 or C5′-CH3), 5.80, 5.85
(s, 1H, Hpz and Hpz′), 6.55 (s, 1H, CH), 6.84 (m, 2H, m- and m′-
py), 7.05-7.30 (m, 15H, PPh3), 7.38 (t, 1H, p-py), 8.05, 8.93 (d,
1H, o- and o′-py) ppm. 13C NMR (CDCl3, 100.5 MHz): δ ) 11.2,
11.5, 11.5, 14.1 (C3, C3′, C5 and C5′-CH3), 26.6 (C(O)-CH3), 69.3
Inorganic Chemistry, Vol. 47, No. 20, 2008 9627

Tampier et al.
3
1
2
py), 127.5 (d, m-PPh3, JCP ) 8.9 Hz), 128.1 (p-Ph), 128.8 (p-
132.6 (d, i-PPh3, JCP ) 46.9 Hz), 133.7 (d, o-PPh3, JCP ) 10.0
Hz), 135.4 (i-Ph), 140.9 (C5′), 141.7 (C5), 154.5 (C3′), 155.4 (C3),
PPh3), 130.0 (o-Ph), 132.7 (i-Ph), 133.9 (d, o-PPh3, 2JCP ) 9.1 Hz),
134.1 (p-py), 134.4 (p-Ph), 134.5 (d, i-PPh3, 1JCP ) 39.1 Hz), 140.2
(C5′), 141.5 (C5), 154.3 (C3′), 154.3 (o-py), 155.6 (o′-py), 157.8
(C3), 168.4 (CO2-), 172.5 (C(O)-CO2-), 190.4 (CdO) ppm. 31P
NMR (CDCl3, 161.8 MHz): δ ) 49.8 ppm. Anal. Calcd for
C43H40N5O5PRu (838.86): C, 61.57; H, 4.81; N, 8.35. Found: C,
61.37; H, 4.89; N, 8.40.
166.3 (CO2-), 172.6 (Ph-CO2-), 204.2 (d, CO, JCP ) 21.2 Hz).
2
31P NMR (CDCl3, 161.8 MHz): δ ) 43.6. Anal. Calcd for
C38H35N4O5PRu (759.76): C, 60.07; H, 4.64; N, 7.37. Found: C,
59.98; H, 4.79; N, 7.32.
[Ru(bdmpza)(O2CMe)(PPh3)(SO2)] (10a). Reaction of
[Ru(bdmpza)(O2CMe)(PPh3)] (2a) (654 mg, 0.977 mmol) in CH2Cl2
(150 mL) with gaseous SO2 for 30 min according to method C
afforded [Ru(bdmpza)(O2CMe)(SO2)(PPh3)] (10a) as a yellow
powder.
Method C: General Procedure for Complex Syntheses with
Gaseous CO, SO2, and NO. A solution of the acetato, benzoato,
or benzoylformato complexes 2a, 2b, or 3c in dichloromethane was
flushed with gaseous CO, SO2, or NO under stirring at ambient
temperature. The progress of the reactions was monitored by IR
spectroscopy. After the reaction was completed, the solvent was
reduced in vacuo, and the product was precipitated with n-pentane.
The precipitate was filtered off and dried in vacuo.
Yield 678 mg (0.924 mmol, 95%). mp 180 °C (dec.). IR
(CH2Cl2): ν˜ ) 1673 vs (CO2-), 1566 w (C)N), 1483 vw, 1465
vw, 1436 m, 1419 vw, 1395 vw, 1350 vw, 1313 vw, 1284 m,
1128 s, 1094 w, 1091 vw cm-1. IR (KBr): ν˜ ) 1672 vs (CO2-),
1566 w (C)N), 1484 vw, 1463 vw, 1437 m, 1420 w, 1374 vw,
1352 vw, 1310 vw, 1282 m, 1128 s, 1093 w, 1089 vw cm-1. UV/
vis (CH2Cl2): λmax (log ε) ) 246.0 (4.26). FAB MS (NBOH): m/z
(%) ) 735 (30) [M+ + H], 670 (100) [M+ - SO2], 611 (92) [M+
- SO2 - O2CMe], 565 (27) [M+ - SO2 - CO2 - HO2CMe -
H], 363 (20) [M+ - bdmpzaH - SO2 - O2CMe]. 1H NMR (CDCl3,
250 MHz): δ ) 1.77, 1.92, 2.12, 2.43, 2.48 (s, 15H, C3,3′,5,5′-CH3,
OAc-CH3), 5.79, 5.92 (s, 2H, Hpz and Hpz′), 6.54 (s, 1H, CH),
7.00-7.65 (m, 15H, PPh3). 13C NMR (CDCl3, 100.5 MHz): δ )
11.5 (C5′-CH3), 11.6 (C5-CH3), 13.7 (C3′-CH3), 14.0 (C3-CH3), 22.8
[Ru(bdmpza)(O2CMe)(CO)(PPh3)] (9a). Reaction of
[Ru(bdmpza)(O2CMe)(PPh3)] (2a) (275 mg, 0.411 mmol) in CH2Cl2
(100 mL) with CO for 2 h according to method C afforded the
product [Ru(bdmpza)(O2CMe)(CO)(PPh3)] (9a) as a yellow powder.
Yield 325 mg (0.400 mmol, 97%). mp 150 °C (dec.). IR
(CH2Cl2): ν˜ ) 1977 vs (CO), 1669 vs (CO2-), 1624 w, 1602 vw,
1564 w (C)N), 1485 vw, 1465 vw, 1437 m, 1419 vw cm-1. IR
(KBr): ν˜ ) 1967 vs (CO), 1672 vs (CO2-), 1620 m, 1600 vw,
1560 m (C)N), 1481 vw, 1462 vw, 1434 m, 1420 vw cm-1. UV/
vis (CH2Cl2): λmax (log ε) ) 245.0 (4.17). FAB MS (NBOH): m/z
(%) ) 698 (34) [M+], 639 (100) [M+ - O2CMe], 565 (12) [M+ -
HO2CMe - CO2 - CO - H], 391 (41) [M+ - bdmpzaH -
(OAc-CH3), 69.3 (CH), 109.3 (C4), 109.7 (d, C4′, JCP ) 2.7 Hz),
4
3
127.9 (d, m-PPh3, JCP ) 7.1 Hz), 129.7 (d, p-PPh3), 134.8 (d,
o-PPh3, 1JCP ) 9.4 Hz), n.d. (i-PPh3), 141.1 (d, C5′ JCP ) 1.3 Hz),
5
,
O2CMe], 363 (35) [M+ - bdmpzaH - O2CMe - CO]. H NMR
1
142.8 (C5), 155.0 (d, C3′, 3JCP ) 2.2 Hz), 156.4 (C3), 167.0 (CO2-),
179.7 (OAc-CO2-). 31P NMR (CDCl3, 161.8 MHz): δ ) 45.4. Anal.
Calcd for C32H33N4O6PRuS (733.74): C, 52.38; H, 4.53; N, 7.64.
Found: C, 52.41; H, 4.70; N, 7.73.
(CD2Cl2, 600 MHz): δ ) 1.55 (s, 3H, OAc-CH3), 1.91 (s, 3H, C3-
CH3), 2.33 (s, 3H, C3′-CH3), 2.46 (s, 3H, C5′-CH3), 2.55 (s, 3H,
C5-CH3), 6.03 (s, 1H, Hpz), 6.04 (s, 1H, Hpz′), 6.57 (s, 1H, CH),
7.32 (vt, 6, m-PPh3), 7.40 (vt, 9, o- and p-PPh3). 13C NMR (CD2Cl2,
150.9 MHz): δ ) 11.3 (C5′-CH3), 11.5 (C5-CH3), 13.7 (C3-CH3),
14.0 (C3′-CH3), 22.9 (OAc-CH3), 69.3 (CH), 108.6 (C4′), 109.3 (C4),
[Ru(bdmpza)(O2CPh)(PPh3)(SO2)] (10b). Reaction of
[Ru(bdmpza)(O2CPh)(PPh3)] (2b) (638 mg, 0.872 mmol) in CH2Cl2
(80 mL) with gaseous SO2 for 2 h according to method C afforded
[Ru(bdmpza)(O2CPh)(SO2)(PPh3)] (10b) as a yellow powder.
Yield 642 mg (0.807 mmol, 92%). mp 180 °C (dec.). IR
(CH2Cl2): ν˜ ) 1673 vs (CO2-), 1567 w (C)N), 1507 w, 1484 vw,
1464 vw, 1435 w, 1420 vw, 1395 m, 1349 vw, 1313 vw, 1286 w,
1129 s, 1094 w, 1090 vw cm-1. IR (KBr): ν˜ ) 1671 vs (CO2-),
1561 w (C)N), 1509 w, 1484 vw, 1461 vw, 1435 w, 1416 vw,
1397 m, 1346 vw, 1283 m, 1125 s, 1093 w cm-1. UV/vis (CH2Cl2):
3
128.4 (d, m-PPh3, JCP ) 9.8 Hz), 130.4 (d, p-PPh3), 133.1 (d,
1
2
i-PPh3, JCP ) 46.4 Hz), 134.0 (d, o-PPh3, JCP ) 9.9 Hz), 142.1
(C5′), 142.9 (C5), 154.6 (C3′), 155.9 (C3), 166.3 (CO2-), 177.3 (OAc-
CO2-), 205.3 (d, CO, JCP ) 19.8 Hz). 31P NMR (CDCl3, 161.8
2
MHz): δ ) 43.3. Anal. Calcd for C33H33N4O5PRu (697.69): C,
56.81; H, 4.77; N, 8.03. Found: C, 57.25; H, 4.86; N, 7.91.
[Ru(bdmpza)(O2CPh)(CO)(PPh3)] (9b). Reaction of
[Ru(bdmpza)(O2CPh)(PPh3)] (2b) (341 mg, 0.466 mmol) in CH2Cl2
(100 mL) with CO for 1 h according to method C afforded
[Ru(bdmpza)(O2CPh)(CO)(PPh3)] (9b) as a yellow powder.
Yield 323 mg (0.425 mmol, 91%). mp 170 °C (dec.). IR
(CH2Cl2): ν˜ ) 1978 vs (CO), 1669 vs (CO2-), 1636 w, 1616 w,
1576 w, 1564 w (C)N), 1485 vw, 1465 vw, 1447 vw, 1436 m,
1419 vw cm-1. IR (KBr): ν˜ ) 1953 vs (CO), 1670 vs (CO2-),
1636 w, 1617 w, 1576 vw, 1565 w (C)N), 1481 vw, 1463 vw,
1446 vw, 1437 m, 1432 m, 1420 vw cm-1. UV/vis (CH2Cl2): λmax
(log ε) ) 246.0 (4.21). FAB MS (NBOH): m/z (%) ) 760 (49)
[M+], 732 (25) [M+ - CO], 638 (100) [M+ - HO2CPh], 565 (11)
[M+ - HO2CPh - CO2 - CO - H], 363 (23) [M+ - bdmpzaH
λ
max/nm (log ε) ) 247.0 (4.39). FAB MS (NBOH): m/z (%) ) 797
(28) [M+ + H], 732 (100) [M+ - SO2], 611 (93) [M+ - SO2 -
O2CPh], 566 (19) [M+ - SO2 - CO2 - HOAc]. 1H NMR (CD2Cl2,
600 MHz): δ ) 1.98 (s, 3H, C3′-CH3), 2.02 (s, 3H, C3-CH3), 2.45
(s, 3H, C5′-CH3), 2.52 (s, 3H, C5-CH3), 5.88 (s, 1H, Hpz), 5.93 (s,
1H, Hpz′), 6.57 (s, 1H, CH), 7.19 (m, 6H, m-PPh3), 7.33 (m, 5H,
p-PPh3, m-Ph), 7.39 (m, 6H, o-PPh3), 7.48 (m, 1H, p-Ph), 7.64 (d,
2H, o-Ph). 13C NMR (CD2Cl2, 150.9 MHz): δ ) 11.5 (C5′-CH3),
11.4 (C6-CH3), 13.4 (C3′-CH3), 14.2 (C3-CH3), 69.4 (CH), 109.4
(C4), 109.6 (C4′), 127.9 (d, 3JCP ) 9.7 Hz, m-PPh3), 128.4 (p-PPh3),
129.8 (broad, i-PPh3), 130.2 (o- and m-Ph), 132.7 (p-Ph), 134.8
(d, o-PPh3, JCP ) 9.2 Hz), 142.0 (d, C5′), 143.6 (C5), 155.2 (d,
2
1
- O2CPh - CO]. H NMR (CDCl3, 400 MHz): δ ) 1.95 (s, 3H,
C3′), 156.6 (C3), 166.8 (CO2-), 175.4 (Ph-CO2-). 31P NMR (CDCl3,
161.8 MHz): δ ) 44.6. Anal. Calcd for C37H35N4O6PRuS (795.82):
C, 55.84; H, 4.43; N, 7.04. Found: C, 55.49; H, 4.49; N, 6.73.
[Ru(bdmpza)(O2CC(O)Ph)(NO)(PPh3)]+ (12). Reaction of
[Ru(bdmpza)(O2CC(O)Ph)(PPh3)] (3c) (828 mg, 1.09 mmol) in
THF (80 mL) with gaseous NO for 1.5 h according to method C
afforded, after precipitation with diethylether, the product
[Ru(bdmpza)(O2CC(O)Ph)(NO)(PPh3)]+ (12) as a pale red solid.
C3-CH3), 2.24 (s, 3H, C3′-CH3), 2.45 (s, 3H, C5′-CH3), 2.56 (s, 3H,
C5-CH3), 5.94 (s, 1H, Hpz′), 6.02 (s, 1H, Hpz), 6.58 (s, 1H, CH),
7.10-7.20 (m, 8H, m-Ph and m-PPh3), 7.23 (d, 1H, p-Ph), 7.29
(vt, 3H, p-PPh3), 7.44 (vt, 6H, o-PPh3), 7.55 (d, 2H, o-Ph). 13C
NMR (CDCl3, 100.5 MHz): δ ) 11.1 (C5′-CH3), 11.3 (C5-CH3),
13.8 (C3′-CH3), 13.9 (C3-CH3), 68.9 (CH), 108.3 (d, C4′, JCP
)
4
2.6 Hz), 108.8 (C4), 127.0 (m-Ph), 128.1 (d, m-PPh3, JCP ) 9.9
3
Hz), 129.2 (o-Ph), 129.4 (p-Ph), 129.8 (d, p-PPh3, 4JCP ) 2.2 Hz),
9628 Inorganic Chemistry, Vol. 47, No. 20, 2008

Ruthenium Carboxylato and 2-Oxocarboxylato Complexes
1
Yield 848 mg. mp 55-60 °C (dec.). IR (CH2Cl2): ν˜ ) 1911 vs
(NO), 1698 s, 1645 m, 1597 vw, 1562 w (C)N), 1483 w, 1463
vw, 1450 vw, 1439 m, 1436 m, 1418 vw cm-1. IR (KBr): ν˜ )
1906 vs (NO), 1688 vs (CO2-), 1662 s (CO2-), 1596 vw, 1561 m
(C)N), 1482 vw, 1465 vw, 1437 m, 1420 vw cm-1. UV/vis
(CH2Cl2): λmax/nm ) 237.0, 268.0. FAB MS (NBOH): m/z (%) )
+ H], 733 (11) [M+ + H - NO], 641 (19) [M+ - O2CPh]. H
NMR (CDCl3, 250 MHz): δ ) 1.99 (s, 3H, C3-CH3), 2.13 (s, 3H,
C3′-CH3), 2.59 (s, 3H, C5′-CH3), 2.70 (s, 3H, C5-CH3), 6.19 (s, 1H,
H
pz′), 6.46 (s, 1H, Hpz), 6.76 (s, 1H, CH), 7.30-7.80 (m, 18H, Ph
and PPh3), 7.85 (d, 2H, o-Ph). 13C NMR (CDCl3, 100 MHz): δ )
11.0 (C5′-CH3), 11.5 (C5-CH3), 13.0 (C3′-CH3), 14.1 (C3-CH3), 68.2
791 (100) [M+], 641 (40) [M+ - O2CC(O)Ph], 363 (17) [M+
-
(CH), 110.2 (d, C4′, JCP ) 3.1 Hz), 111.5 (C4), 125.1 (d, i-PPh3,
4
bdmpza - O2CC(O)Ph - NO]. 1H NMR (CDCl3, 250 MHz): δ )
1JCP ) 54.7 Hz), 128.5 (p-PPh3), 129.5 (d, m-PPh3, JCP ) 11.4
3
1.95, 2.36, 2.57, 2.62 (s, 12H, C3,3′,5,5′-CH3), 6.22, 6.24 (s, 2H,
Hz), 129.7 (o-Ph), 132.2 (i-Ph), 133.0 (m-Ph), 133.5 (d, o-PPh3,
2JCP ) 9.7 Hz), 134.0 (p-Ph), 145.1 (d, C5′, 5JCP ) 2.0 Hz), 146.9
(C5), 154.2 (d, C3′, 3JCP ) 2.0 Hz), 157.6 (C3), 163.6 (CO2-), 172.6
(Ph-CO2-). 31P NMR (CDCl3, 161.8 MHz): δ ) 23.3. Anal. Calcd
for C37H35BF4N5O5PRu (848.56): C, 52.37; H, 4.16; N, 8.25. Found:
C, 51.94; H, 4.28; N, 8.35.
[Ru(bdmpza)(O2CC(O)Me)(NO)(PPh3)]BF4 (14a). Reaction of
[Ru(bdmpza)(O2CC(O)Me)(PPh3)] (3a) (480 mg, 0.688 mmol) with
[NO]BF4 (166 mg, 1.42 mmol) in CH2Cl2 (30 mL) for 1 h at 40
°C afforded according to method D the product [Ru(bdmpza)(O2CC-
(O)Me)(NO)(PPh3)]BF4 (14a) as a pale red powder.
H
pz,pz′), 6.71 (s, 1H, CH), 7.30-7.70 (m, 18H, Ph and PPh3), 7.99
(vt, 2H, o-Ph). 13C NMR (CDCl3, 62.9 MHz): δ ) 11.1, 11.5, 13.9,
14.3 (C3,3′,5,5′-CH3), 68.2 (CH), 110.1 (d, C4 or C4′, 4JCP ) 3.2 Hz),
111.5 (C4 or C4′), 124.8 (d, i-PPh3, JCP ) 54.5 Hz), 128.9, 129.8
1
(d, m-PPh3, 3JCP ) 11.3 Hz), 129.9, 133.1, 133.2, 133.6 (d, o-PPh3,
2JCP ) 9.8 Hz), 134.7, 145.3 (d, C5 or C5′, JCP ) 1.3 Hz), 146.8
5
(C5 or C5′), 154.3 (d, C3 or C3′, JCP ) 2.2 Hz), 158.3 (C3 or C3′),
3
163.0 (CO2-), 169.4 (CO2-), 186.7 (CdO). 31P NMR (CDCl3, 161.8
MHz): δ ) 24.2. Counterion unspecified.
Method D: General Procedure for the Syntheses of NO
Complexes from [NO]BF4. A solution of the carboxylato or
2-oxocarboxylato complexes 2a, 2b, or 3a-c in dichloromethane
was reacted with [NO]BF4. After 0.5 to 1 h the reaction was
completed, the solvent was reduced in vacuo, and the product was
precipitated with diethylether. The precipitate was filtered off and
dried in vacuo.
[Ru(bdmpza)(O2CMe)(NO)(PPh3)]BF4 (13a). Reaction of
[Ru(bdmpza)(O2CMe)(PPh3)] (2a) (533 mg, 0.796 mmol) with
[NO]BF4 (175 mg, 1.50 mmol) in CH2Cl2 (40 mL) at ambient
temperature afforded after 30 min according to method D the
product [Ru(bdmpza)(O2CMe)(NO)(PPh3)]BF4 (13a) as a pale red
powder.
Yield 468 mg (0.575 mmol, 84%). mp 125 °C (dec.). IR
(CH2Cl2): ν˜ ) 1912 vs (NO), 1706 s (CO2-), 1653 m (CO2-),
1560 m (C)N), 1483 w, 1465 w, 1437 m, 1419 vw cm-1. IR (KBr):
ν˜ ) 1904 vs (NO), 1692 vs (CO2-), 1650 m (CO2-), 1562 m
(C)N), 1484 w, 1467 w, 1462 w, 1439 m, 1421 vw, 1416 vw
cm-1. UV/vis (CH2Cl2): λmax/nm (log ε) ) 237.0 (4.36), 276.0
(4.29). FAB MS (NBOH): m/z (%) ) 729 (100) [M+ + H], 641
(52) [M+ - O2CC(O)Me], 363 (21) [M+ - bdmpza - O2CC(O)Me
- NO]. H NMR (CDCl3, 250 MHz): δ ) 2.01 (s, 3H, C3-CH3),
1
2.24 (s, 3H, C3′-CH3), 2.31 (s, 3H, C(O)-CH3), 2.57 (s, 3H, C5′-
CH3), 2.64 (s, 3H, C5-CH3), 6.26 (s, 1H, Hpz′), 6.32 (s, 1H, Hpz),
6.73 (s, 1H, CH), 7.38 (m, 6H, o-PPh3), 7.49 (m, 6H, m-PPh3),
7.64 (m, 3H, p-PPh3). 13C NMR (CDCl3, 100 MHz): δ ) 11.1 (C5′-
CH3), 11.5 (C5-CH3), 13.5 (C3′-CH3), 14.2 (C3-CH3), 27.6 (C(O)-
Yield 593 mg (0.754 mmol, 95%). mp 175 °C (dec.). IR
(CH2Cl2): ν˜ ) 1912 vs (NO), 1698 s (CO2-), 1635 m (CO2-), 1612
vw, 1562 m (C)N), 1483 w, 1465 w, 1439 m, 1415 vw cm-1. IR
(KBr): ν˜ ) 1897 vs (N-O), 1690 vs (CO2-), 1637 m (CO2-), 1612
CH3), 68.1 (CH), 110.3 (d, C4′, JCP ) 3.0 Hz), 111.6 (C4), 124.8
4
1
3
(d, i-PPh3, JCP ) 54.5 Hz), 129.7 (d, m-PPh3, JCP ) 11.4 Hz),
133.2 (p-PPh3), 133.5 (d, o-PPh3, JCP ) 9.8 Hz), 145.4 (d, C5′,
2
vw, 1561 m (C)N), 1483 w, 1462 w, 1438 m, 1420 vw cm-1
.
5JCP ) 1.7 Hz), 147.0 (C5), 154.2 (d, C3′, JCP ) 2.1 Hz), 158.2
3
UV/vis (CH2Cl2): λmax/nm (log ε) ) 237.0 (4.32), 273.0 (4.31).
(C3), 163.3 (CO2-), 168.3 (C(O)-CO2-), 192.9 (CdO). 31P NMR
(CDCl3, 161.8 MHz): δ ) 24.1. Anal. Calcd for C33H33BF4N5O6-
PRu (814.50): C, 48.66; H, 4.08; N, 8.60. Found: C, 48.04; H, 4.20;
N, 8.77.
FAB MS (NBOH): m/z (%) ) 700 (100) [M+], 641 (33) [M+
-
O2CMe]. 1H NMR (CDCl3, 250 MHz): δ ) 1.94 (s, 3H, C3-CH3),
2.07 (s, 3H, OAc-CH3), 2.24 (s, 3H, C3′-CH3), 2.55 (s, 3H, C5′-
CH3), 2.63 (s, 3H, C5-CH3), 6.23 (s, 1H, Hpz′), 6.46 (s, 1H, Hpz),
6.63 (s, 1H, CH), 7.36 (m, 6H, o-PPh3), 7.50 (m, 6H, m-PPh3),
7.63 (m, 3H, p-PPh3). 13C NMR (CDCl3, 62.9 MHz): δ ) 11.0
(C5′-CH3), 11.4 (C5-CH3), 13.2 (C3′-CH3), 14.1 (C3-CH3), 22.1
[Ru(bdmpza)(O2CC(O)Et)(NO)(PPh3)]BF4 (14b). Reaction of
[Ru(bdmpza)(O2CC(O)Et)(PPh3)] (3b) (450 mg, 0.632 mmol) with
[NO]BF4 (151 mg, 1.29 mmol) in CH2Cl2 (50 mL) for 1 h at 40
°C according to method D afforded the product [Ru(bdmpza)(O2-
CC(O)Et)(NO)(PPh3)]BF4 (14b) as a pale red powder.
Yield 500 mg (0.603 mmol, 95%). mp 120 °C (dec.). IR
(CH2Cl2): ν˜ ) 1911 vs (NO), 1670 s (CO2-), 1653 m (CO2-),
1561 m (C)N), 1483 w, 1462 w, 1437 m, 1419 vw cm-1. IR (KBr):
ν˜ ) 1904 vs (NO), 1701 vs (CO2-), 1649 s (CO2-), 1561 m (C)N),
4
(OAc-CH3), 68.2 (CH), 110.1 (d, C4′, JCP ) 2.9 Hz), 111.8 (C4),
1
3
125.0 (d, i-PPh3, JCP ) 54.1 Hz), 129.6 (d, m-PPh3, JCP ) 10.8
2
Hz), 133.1 (p-PPh3), 133.4 (d, o-PPh3, JCP ) 9.8 Hz), 145.0 (d,
C5′, 5JCP ) 1.7 Hz), 146.7 (C5), 154.2 (d, C3′, 3JCP ) 2.0 Hz), 158.2
(C3), 163.3 (CO2-), 176.8 (OAc-CO2-). 31P NMR (CDCl3, 161.8
MHz): δ ) 23.5. Anal. Calcd for C32H33BF4N5O5PRu (786.49): C,
48.87; H, 4.23; N, 8.90. Found: C, 48.45; H, 4.22; N, 8.99.
[Ru(bdmpza)(O2CPh)(NO)(PPh3)]BF4 (13b). Reaction of
[Ru(bdmpza)(O2CPh)(PPh3)] (2b) (355 mg, 0.485 mmol) with
[NO]BF4 (107 mg, 0.916 mmol) in CH2Cl2 (30 mL) for 1 h
according to method D afforded [Ru(bdmpza)(O2CPh)(NO)-
(PPh3)]BF4 (13b) as a pale red powder.
1484 w, 1462 w, 1438 m, 1421 vw cm-1. UV/vis (CH2Cl2): λmax
nm (log ε) ) 237.0 (4.37), 276.0 (4.31). FAB MS (NBOH): m/z
(%) ) 743 (100) [M+ + H], 641 (48) [M+ - O2CC(O)Et], 566
(21) [M+ - O2CC(O)Et - CO2 - NO], 363 (22) [M+ - bdmpza
/
1
- O2CC(O)Et - NO]. H NMR (CDCl3, 400 MHz): δ ) 1.08 (t,
3H, CH2-CH3, 3JHH ) 7.2 Hz), 2.01 (s, 3H, C3-CH3), 2.25 (s, 3H,
C3′-CH3), 2.56 (s, 3H, C5′-CH3), 2.64 (s, 3H, C5-CH3), 2.71 (dq,
1H, CH2, 2JHH ) 19.1 Hz, 3JHH ) 7.2 Hz), 2.76 (dq, 1H, CH2, 2JHH
Yield 390 mg (0.460 mmol, 95%). mp 130 °C (dec). IR (CH2Cl2):
ν˜ ) 1912 vs (NO), 1696 s (CO2-), 1635 w (CO2-), 1616 vw,
3
1561 m (C)N), 1483 w, 1465 w, 1450 vw, 1437 m, 1420 vw cm-1
.
) 19.1 Hz, JHH ) 7.2 Hz), 6.27 (s, 2H, Hpz′), 6.32 (s, 2H, Hpz),
IR (KBr): ν˜ ) 1903 vs (NO), 1692 vs (CO2-), 1632 w (CO2-),
1562 m (C)N), 1483 w, 1467 w, 1463 w, 1450 vw, 1439 m,
1435 m, 1416 vw cm-1. UV/vis (CH2Cl2): λmax/nm (log ε) ) 239.0
(4.45), 273.0 (4.29). FAB MS (NBOH): m/z (%) ) 763 (100) [M+
6.72 (s, 1H, CH), 7.37 (m, 6H, o- or m-PPh3), 7.49 (m, 6H, o- or
m-PPh3), 7.63 (m, 3H, p-PPh3). 13C NMR (CDCl3, 100 MHz): δ )
7.00 (CH2-CH3), 11.1 (C5′-CH3), 11.5 (C5-CH3), 13.6 (C3′-CH3),
14.2 (C3-CH3), 33.6 (C(O)-CH2), 68.1 (CH), 110.2 (d, C4′, 4JCP
)
Inorganic Chemistry, Vol. 47, No. 20, 2008 9629

Tampier et al.
Table 1. Structure Determination Details of Compounds 4, 5a, 7a, and 8b
4
5a
7a
8b
empirical formula
C32H33ClN5O2PRu
× 2CH2Cl2
856.98
P21/a (14), 4
17.715(4)
10.9196(11)
20.288(4)
90
110.040(9)
90
3686.8(11)
2.14-26.98
0.87
C34H36N5O4PRu
× 2CH2Cl2
880.57
C37H38N5O4PRu
C39H40N5O5PRu
× CH2Cl2
875.73
formula weight
space group (No.), Z
748.76
j
j
P1 (2), 2
P21/c (14), 4
11.046(3)
17.400(4)
17.876(4)
90
98.58(2)
90
3397.3(14)
1.64-24.07
0.557
P1 (2), 2
a [Å]
b [Å]
c [Å]
R [°]
ꢀ [°]
γ [°]
V [Å3]
θ [°]
9.792(4)
12.224(5)
16.944(6)
88.22(4)
75.73(7)
85.50(4)
1959.3(13)
1.24-27.49
0.758
10.403(14)
14.176(10)
14.692(19)
87.39(10)
73.93(13)
74.72(9)
2008(4)
2.04-26.98
0.613
1.449
123(2)
µ(Mo KR) [mm-1
]
Dc [g cm-3
T [K]
]
1.544
200(2)
1.493
200(2)
1.464
233(2)
reflections collected
indep. reflections
obs. refl. (>2σ(I))
8269
8001
5962
0.0441, 0.1015
0.0747, 0.1085
9271
8965
6605
0.0713, 0.1937
0.1032, 0.2088
10482
5374
3327
0.0361, 0.0694
0.0933, 0.0782
9208
8732
6925
0.0469, 0.1076
0.0688, 0.1169
b
R1a, wR2 (obs.)
b
R1a, wR2 (overall)
a R1 ) ∑||Fo| - |Fc||/∑|Fo|. b wR2 ) {∑[w(Fo - Fc )2]/∑[w(Fo )2]}1/2
.
2
2
2
3.1 Hz), 111.7 (C4), 124.8 (d, i-PPh3, JCP ) 55.4 Hz), 129.7 (d,
the implemented LACVP* (Hay-Wadt effective core potential
(ECP) basis on heavy atoms, N31G6* for all other atoms) basis
set and with the BP86 density functional. Orbital plots9 were
obtained using Maestro 7.0.113, the graphical interface of Jaguar.
Rotational barriers have been calculated fully relaxed, fixating
one torsion angle around the rotated bond, and optimizing all
remaining degrees of freedom. Torsion angles were modified in
steps of 5° beginning from the structure of minimum energy.
X-ray Structure Determinations. Single crystals of 4, 5a, 7a,
8b, 9b, 10b, and 14a were placed with Paratone-N or glue onto a
glass fiber. A modified Siemens P4-Diffractometer and an Enraf
Nonius CAD4-Mach3 diffractometer were used for data collection
(graphite monochromator, Mo KR radiation, λ ) 0.71073 Å, scan
rate 4-30° min-1). The structures were solved by using either direct
or Patterson methods {Siemens SHELXS-9310} and refined with
full-matrix least-squares against F1 {Siemens SHELXL-9710}. A
weighting scheme was applied in the last steps of the refinement
with w ) 1/[σ2(Fo ) + (aP)2 + bP] and P ) [2Fc2 + Max(Fo ,0)]/
3. The hydrogen atoms were included in calculated positions and
refined in a “riding model”. In the asymmetric units of 8b and 14a
one molecule of dichloromethane was co-crystallized per complex
molecule, and so were two dichloromethane molecules in the
complexes 4, 5a, and 10b. In case of complex 9b two chloroform
molecules were found per asymmetric unit. All cocrystallized
solvent molecules were included into the models and refined
anisotropically. The PPh3 as well as the 2-oxocarboxylato ligand
exhibited a severe disorder in case of 8b. Thus, several restraints
had to be applied, and the structure allows no detailed discussion
of distances and angles. The structure pictures were prepared with
the program Diamond 2.1e.11 All details and parameters of the
measurements are summarized in Tables 1 and 2.
1
m-PPh3, 3JCP ) 11.4 Hz), 133.2 (p-PPh3), 133.5 (d, o-PPh3, 2JCP
)
5
9.8 Hz), 145.3 (d, C5′, JCP ) 2.1 Hz), 147.0 (C5), 154.2 (d, C3′,
3JCP ) 2.1 Hz), 158.2 (C3), 163.4 (CO2-), 168.8 (C(O)-CO2-), 196.0
(CdO). 31P NMR (CDCl3, 161.8 MHz): δ ) 24.0. Anal. Calcd for
C34H35BF4N5O6PRu (828.53): C, 49.29; H, 4.26; N, 8.45. Found:
C, 49.29; H, 4.20; N, 8.30.
[Ru(bdmpza)(O2CC(O)Ph)(NO)(PPh3)]BF4 (14c). Reaction of
[Ru(bdmpza) (O2CC(O)Ph)(PPh3)] (3c) (554 mg, 0.729 mmol) with
[NO]BF4 (163 mg, 1.40 mmol) in CH2Cl2 (40 mL) for 1 h at 40
°C according to method D afforded the product [Ru(bdmpza)(O2CC-
(O)Ph)(NO)(PPh3)]BF4 (14c) as a pale red powder.
Yield 629 mg (0.718 mmol, 98%). mp 135 °C (dec.). IR
(CH2Cl2): ν˜ ) 1911 vs (NO), 1697 s (CO2-), 1647 m (CO2-),
1562 m (C)N), 1483 w, 1462 w, 1450 w, 1437 m, 1418 vw cm-1
.
IR (KBr): ν˜ ) 1906 vs (NO), 1690 vs (CO2-), 1647 m (CO2-),
1595 w, 1561 m (C)N), 1483 w, 1463 w, 1450 vw, 1437 m, 1420
vw cm-1. UV/vis (CH2Cl2): λmax/nm (log ε) ) 238.0 (4.42), 267.0
(4.47). FAB MS (NBOH): m/z (%) ) 791 (100) [M+ + H], 641
(51) [M+ - bF], 566 (21) [M+ - bF - CO2 - NO], 363 (37) [M+
2
2
1
- bdmpza - bF - NO]. H NMR (CDCl3, 250 MHz): δ ) 1.93
(s, 3H, C3-CH3), 2.35 (s, 3H, C3′-CH3), 2.55 (s, 3H, C5′-CH3), 2.62
(s, 3H, C5-CH3), 6.25 (s, 1H, Hpz′), 6.26 (s, 1H, Hpz), 6.70 (s, 1H,
CH), 7.35-7.70 (m, 18H, Ph and PPh3), 7.97 (d, 2H, o-Ph). 13C
NMR (CDCl3, 100 MHz): δ ) 11.1 (C5′-CH3), 11.4 (C5-CH3), 13.9
(C3′-CH3), 14.2 (C3-CH3), 68.1 (CH), 110.1 (d, C4′, 4JCP ) 3.9 Hz),
111.6 (C4), 124.7 (d, i-PPh3, 1JCP ) 54.6 Hz), 128.9 (p-PPh3), 129.8
(d, m-PPh3, 3JCP ) 11.3 Hz), 129.9 (o-Ph), 133.0 (i-Ph), 133.2 (m-
2
Ph), 133.5 (d, o-PPh3, JCP ) 9.8 Hz), 134.7 (p-Ph), 145.6 (C5′),
147.1 (C5), 154.1 (d, C3′, 3JCP ) 2.6 Hz), 158.2 (C3), 163.3 (CO2-),
169.3 (BF-CO2-), 186.7 (CdO). 31P NMR (CDCl3, 161.8 MHz):
δ ) 23.8. For further purification red microystals of 14c were
obtained from a CH2Cl2 solution layered with a 1:1 mixture (v/v)
of pentane/diethylether. According to the 1H NMR spectrum these
crystals contained also half an equivalent CH2Cl2. Anal. Calcd for
Results and Discussion
In a first attempt to exchange one PPh3 for an acetonitrile
ligand, the chlorido complex [Ru(bdmpza)Cl(PPh3)2] (1) was
1
C38H35BF4N5O6PRu × /2CH2Cl2 (919.04): C, 50.32; H, 3.95; N,
(8) Jaguar, version 6.0; Schro¨dinger, LLC: New York, NY, 2005.
(9) Stowasser, R.; Hoffmann, R. J. Am. Chem. Soc. 1999, 121, 3414–
3420.
(10) Sheldrick, G. M.; SHELX-97, Programs for Crystal Structure Analysis;
University of Go¨ttingen, Go¨ttingen, Germany, 1997.
(11) (a) Brandenburg, K.; Berndt, M. Diamond - Visual Crystal Structure
Information System; Crystal Impact GbR: Bonn, Germany, 1999; (b)
for Software Review see Pennington, W. T. J. Appl. Crystallogr. 1999,
32, 1028–1029.
7.62. Found: C, 49.96; H, 3.93; N, 7.97.
Calculations. All density-functional theory (DFT)-calculations
were carried out by using the Jaguar 6.00128 software running on
Linux 2.4.18-14smp on five Athlon MP 2800+ dual-processor
workstations (Beowulf-cluster) parallelized with MPICH 1.2.4.
X-ray structures or MM2 optimized structures were used as starting
geometries. Complete geometry optimizations were carried out on
9630 Inorganic Chemistry, Vol. 47, No. 20, 2008

Ruthenium Carboxylato and 2-Oxocarboxylato Complexes
Table 2. Structure Determination Details of Compounds 9b, 10b, and
14a
9b
10b
14a
empirical formula
formula weight
space group (No.), Z P21/c (14), 4
a [Å]
C38H35N4O5PRu C37H35N4O6PRuS C33H33BF4N5O6PRu
× 2CHCl3
× 2CH2Cl2
965.64
× CH2Cl2
998.48
899.42
j
P21/n (14), 4
10.863(6)
14.380(8)
26.060(13)
90
90.07(5)
90
4074(4)
2.03 - 25.02
0.789
P1 (2), 2
11.809(7)
14.330(2)
26.428(8)
90
102.08(7)
90
4373(3)
2.10 - 27.01
0.809
9.516(4)
11.297(8)
18.399(8)
85.67(5)
86.36(4)
75.70(5)
1909.1(17)
2.11 - 27.00
0.663
b [Å]
c [Å]
R [°]
ꢀ [°]
γ [°]
V [Å3]
θ [°]
µ(Mo KR) [mm-1
]
Dc [g cm-3
T [K]
]
1.517
1.574
1.565
Figure 1. Molecular structure of [Ru(bdmpza)Cl(NCMe)(PPh3)] (4) with
thermal ellipsoids drawn at the 50% probability level. Hydrogen atoms and
solvent molecules are omitted for clarity.
188(2)
188(2)
188(2)
reflections collected 9994
7565
7160
4276
9776
7677
5681
0.0497, 0.1035
0.0819, 0.1197
indep. reflections
9532
7359
obs. refl. (>2σ(I))
b
R1a, wR2 (obs.)
0.0612, 0.1540 0.0628, 0.1127
b
R1a, wR2 (overall) 0.0821, 0.1693 0.1323, 0.1372
a R1 ) ∑||Fo| - |Fc||/∑|Fo|. b wR2 ) {∑[w(Fo2 - Fc )2]/∑[w(Fo )2]}1/2
.
2
2
Scheme 1. Syntheses of Acetonitrile Complexes
Figure 2. Molecular structure of [Ru(bdmpza)(O2CMe)(NCMe)(PPh3)] (5a)
with thermal ellipsoids drawn at the 50% probability level. Hydrogen atoms
and solvent molecules are omitted for clarity.
[Ru(bdmpza)(O2CC(O)Ph)(PPh3)] (3c) with the κ2O1,O2-
coordinated 2-oxocarboxylato ligand exhibits a purple color
due to a MLCT transition.3b Acetonitrile solutions of 3c
changed to yellow upon standing within some days, clearly
indicating a change to κ1O1-coordination and the formation
of [Ru(bdmpza)(O2CC(O)Ph)(NCMe)(PPh3)] (3c ×NCMe).3b
Now, we achieved a controlled synthesis of 3c × NCMe by
reacting [Ru(bdmpza)(O2CC(O)Ph)(PPh3)] (3c) under reflux
with acetonitrile for 2 h. An analogous reaction with the
2-oxocarboxylato complexes [Ru(bdmpza)(O2CC(O)Me)-
(PPh3)] (3a) and [Ru(bdmpza)(O2CC(O)Et)(PPh3)] (3b) was
not successful so far. On the other hand, we reacted the
κ2O1,O1′-carboxylato complexes [Ru(bdmpza)(O2CMe)-
(PPh3)] (2a) and [Ru(bdmpza)(O2CPh)(PPh3)] (2b) with
acetonitrile within 5 h to form the carboxylato complexes
[Ru(bdmpza)(O2CCH3)(NCMe)(PPh3)](5a)and[Ru(bdmpza)-
(O2CPh)(NCMe)(PPh3)] (5b) (Scheme 1).
heated under reflux in acetonitrile. Indeed, one PPh3 ligand
is released and the chiral acetonitrile complex [Ru(bdmpza)
Cl(NCMe)(PPh3)] (4) is formed when the PPh3 is extracted
with n-pentane, although this procedure has to be repeated
several times to obtain a complete conversion (Scheme 1).
The complex 4 exhibits two sets of signals for the
1
pyrazolyl donors in the H and 13C NMR spectra. The
acetonitrile signals have been assigned to 1.88 ppm in the
1H NMR spectrum and to 3.67 and 124.0 ppm in the 13C
NMR spectrum. Only one singlet for a single PPh3 ligand is
found in the 31P NMR spectrum at 48.8 ppm. The IR signal
of the coordinated acetonitrile is observed at 2275 cm-1. The
31P resonance as well as the IR signal of the coordinated
acetonitrile agree well with those reported for the analogous
complex [RuTpCl(NCMe)(PPh3)] (31P: 51.7 ppm; IR: ν˜(CN)
) 2275 cm-1, see Table 3).6
The acetato complex 5a exhibits two sets of signals for
the diastereotopic pyrazolyl groups in the 1H and 13C NMR
1
spectra. One signal at 2.22 ppm in the H NMR spectrum
and two signals at 4.60 and 124.7 ppm in the 13C NMR have
been assigned to the acetonitrile ligand. The 31P NMR singlet
of the PPh3 ligand was observed at 53.4 ppm. X-ray structure
determinations revealed the molecular structures of 4 and
5a which are depicted in Figures 1 and 2. Selected bond
lengths and angles are reported in Table 4. The coordination
geometry of these complexes is approximately octahedral,
and the distances and angles in these two complexes are
As described above, we already observed a hemilabile
coordination of the 2-oxocarboxylato ligands. Usually
(12) Gemel, C.; Trimmel, G.; Slugovc, C.; Kremel, S.; Mereiter, K.;
Schmid, R.; Kirchner, K. Organometallics 1996, 15, 3998–4004.
Inorganic Chemistry, Vol. 47, No. 20, 2008 9631

Tampier et al.
Scheme 2. Syntheses of Pyridine Complexes
relatively uniform. Because of the space groups P21/a and
P1, both enantiomers of the chiral complexes 4 and 5a can
j
be found in the unit cells. The distances and angles agree
well with those of complex 1 which we reported on lately.3a
It is interesting to note that the positions of the chlorido
ligand and also the acetato ligand are trans to a pyrazol donor
of the bdmpza ligand. In contrast, so far most molecular
structures showed a chlorido ligand trans to the carboxylato
donor of the bdmpza ligand.3,4
The complex [Ru(bdmpza)(O2CPh)(NCMe)(PPh3)] (5b)
does form two isomers which show a rather similar pattern
in the NMR spectra. The acetonitrile signals have been
assigned for both isomers (1H NMR: 2.23 and 1.92 ppm;
13C NMR: 2.23, 124.7, and 3.56, 124.1 ppm). The two signals
in the 31P NMR spectrum at 53.6 and 51.9 ppm are due to
the PPh3 ligands of the two isomers. So far, we could not
deduce which of the three possible structural isomers are
preferentially formed, but we assume one isomer might have
a configuration similar to 5a and the other one a configuration
with the benzoato ligand trans to the bdmpza carboxylato
donor.
The CO2 signals in the 13C NMR spectra of the acetato
-
or benzoato ligand in 5a and 5b, respectively, have been
shifted by 9 ppm to higher field compared to 2a and 2b, on
account of the κ1O1-coordination of the acetato and benzoato
ligand. The IR bands assigned to ν˜(Ct N) of the acetonitrile
ligands at 2271 (5a) and 2270 cm-1 (5b) are reasonable
compared to other complexes such as those of the Tp
complex [RuTpCl(NCMe)(PPh3)]6 (see Table 3). In the FAB
massspectramolecularmasspeaksfitto[Ru(bdmpza)(O2CMe)-
(NCMe)(PPh3)] (5a) and [Ru(bdmpza)(O2CPh)(NCMe)-
(PPh3)] (5b), although the 100% peaks are assigned to
[Ru(bdmpza)(O2CMe)(PPh3)] (2a) and [Ru(bdmpza)(O2-
CPh)(PPh3)] (2b).
Cl(PPh3)(py)] (6). All pyridine complexes 6, 7a, 7b, and
1
8a-8c exhibit H and 13C NMR spectra typical for chiral
complexes with two sets of pyrazolyl signals. The PPh3
singlets in the 31P NMR spectra appear around 50 ppm and
are thus shifted by 10 ppm to higher field compared to the
educt complexes. Mass peaks in the FAB mass spectra affirm
the composition of the complexes.
Because of the problems that came about in these reactions
of the acetonitrile sp-N donor with the carboxylato and
2-oxocarboxylato complexes, pyridine has been tested as
sp2-N donor ligand instead. A complete conversion within 3
days could be achieved to give complexes 7 and 8,
respectively, for the carboxylato complexes 2a and 2b as
well as for the 2-oxocarboxylato complexes 3a-3c (Scheme
2) by using 10 equiv of pyridine in dichloromethane.
A similar reaction with [Ru(bdmpza)Cl(PPh3)2] (1) was
also successful and afforded the complex [Ru(bdmpza)-
Table 3. Spectroscopic Data of Various Ruthenium Acetonitrile Complexes
The 13C NMR CO2 signals of the κ1O1-coordinated
-
carboxylato ligands are shifted by 11 ppm to higher field
compared to the κ2-carboxylato complexes (178.0 (7a) and
171.1 ppm (7b)). The ketocarbonyl signals of the 2-oxocar-
boxylato complexes exhibit a similar 15 ppm shift to higher
complex
IR (Ct N) [cm-1
]
1H (MeCN) [ppm]
1.88
13C (MeCN) [ppm]
31P [ppm]
48.8
[Ru(bdmpza)Cl(NCMe)(PPh3)] (4)
2275a
2269b
2271a
2263b
2270a
2268b
2278a
2277b
2278b
2258b
2284c
3.67
124
[Ru(bdmpza)(O2CMe)(NCMe)(PPh3)] (5a)
2.22
4.6
53.4
124.7
2.23; 124.7
3.56; 124.1
3.8
[Ru(bdmpza)(O2CPh)(NCMe)(PPh3)] (5b)
2.23
1.92
1.97
53.6
51.9
49.7
[Ru(bdmpza)(O2CC(O)Ph)(NCMe)(PPh3)] (3c × NCMe)
n.d.
[RuTpCl(NCMe)(PPh3)]6
2.1
1.69
1.86
51.7
77.6
7
[RuTpH(NCMe)(PPh3)]6
[RuTp(dppm)(NCMe)]CF3SO3
12
4.2
126.2
4.9
12
[RuTp(NCMe)(pn)]BPh4
2272c
2.34
69.4
127.4
a CH2Cl2. b KBr. c Diffuse reflectance.
9632 Inorganic Chemistry, Vol. 47, No. 20, 2008

Ruthenium Carboxylato and 2-Oxocarboxylato Complexes
Figure 5. Contour plots (Kohn-Sham orbitals) of (a) the HOMO-2 of
pyridine, (b) the HOMO of pyridine, and (c) the LUMO of pyridine.
(py)()CdC(H)Ph)]OTf (Ru-py
)
2.077(3) Å)14 or
[TpmRu(py)3](PF6)2 (Ru-py ) 2.068(5), 2.090(6), and
2.093(6))Å.15
Although the π-acceptor properties of pyridine are gener-
ally accepted to be moderate,16 the aromatic system of this
ligand allows back-bonding as pointed out by the contour
plots of its highest occupied molecular orbital (HOMO) and
lowest unoccupied molecular orbital (LUMO, Figure 5b and
5c). For a discussion of the almost identical orientation of
the pyridine ligands in 7a and 8b DFT calculations were
performed with the 16 valence electron fragment [Ru-
(bdmpza)(O2CPh)(PPh3)]. Figure 6 shows contour plots of
its LUMO, HOMO, HOMO-1, and HOMO-2.
Figure 3. Molecular structure of [Ru(bdmpza)(O2CMe)(PPh3)(py)] (7a)
with thermal ellipsoids drawn at the 50% probability level. Hydrogen atoms
and solvent molecules are omitted for clarity.
According to these plots, especially the HOMO-2 of the
16 valence electron fragment seems to determine the orienta-
tion of the pyridine ligands in the complexes [Ru(bdmpza)-
(O2CMe)(PPh3)(py)]
(7a)
and
[Ru(bdmpza)(O2-
CC(O)Et)(PPh3)(py)] (8b). The pyridine ligands in 7a and
8b are almost in a plane with O(1)-Ru-OAc-Npy or
O(1)-Ru-O2-oxocarb-Npy respectively (Figure 7a and 7b). This
orientation allows a RudπfNpπ back-donation by interaction
of the pyridine π* orbital with the HOMO-2.
Figure 4. Molecular structure of [Ru(bdmpza)(O2CC(O)Et)(PPh3)(py)] (8b)
with thermal ellipsoids drawn at the 50% probability level. Hydrogen atoms
and solvent molecules are omitted for clarity. PPh3 and O2CC(O)CH2CH3
ligands are disordered. Only one of the two alternative orientations that
have been included into the structure model is shown here for clarity.
Nevertheless, the pyridine ligands in 7a and 8b are slightly
tilted out of the Ocarboxylate-Ru-Npy planes as indicated
field and are assigned to 197.6 (8a), 200.3 (8b), and 190.4
ppm (8c), respectively. These are typical values of nonco-
ordinated keto ligands.3b
by the absolute values of the torsion angles [7a, |∠(OOAc
-
Ru-Npy-Cpy)| ) 22.2(2)°; 8b, |∠(O2-oxocarb-Ru-Npy-
Cpy)| ) 17.9(3)°] (Figure 7). This agrees well with the
calculated (DFT) structure of minimum energy
(|∠(OOAc-Ru-Npy-Cpy)| ) 17.7°) for complex 7a. To
investigate this deviation from the ideal perpendicular
orientation by some 20°, the rotational barrier of the pyridine
ligand in [Ru(bdmpza)(O2CMe)(PPh3)(py)] (7a) has been
calculated in steps of 5° beginning from the minimum energy
structure (Figure 8). A rotation of the pyridine ligand by 20°
causes a rather small increase in energy by 3 to 5 kJ/mol.
Thus, this deviation might be due to crystal-packing effects
or interactions of the pyridine with PPh3 or the pyrazolyl
Me3′. Rather similar findings have been reported recently by
us for a vinylidene ligand instead of pyridine in an analogous
complex [Ru(bdmpza)Cl()C)CHTol)(PPh3)].4
Crystals suitable for a single crystal X-ray structure
determination have been obtained of [Ru(bdmpza)(O2-
CMe)(PPh3)(py)] (7a) and [Ru(bdmpza)(O2CC(O)Et)-
(PPh3)(py)] (8b) (Figure 3 and 4; Table 5). The pyridine and
the PPh3 coordinate trans to the pyrazolyl groups. The acetato
and the 2-oxocarboxylato ligands are trans to the carboxylato
donor of the bdmpza ligand. Because of a disorder of the
PPh3 and the 2-oxocarboxylato ligands in the molecular
structure of 8b, we will focus on the molecular structure of
7a for discussion, although both structures are very similar.
The distances and angles of the [Ru(bdmpza)(PPh3)] frag-
ment are almost identical to those of molecular structures
of 1, 2a × H2O, and 3b.3 The bond lengths of the κ1-acetato
ligand agree well with those of complex 2a × H2O, which
we reported on recently (7a: Ru-O(3) 2.090(3), C(3)-O(3)
1.286(5), C(3)-O(4) 1.221(5); 2a × H2O: Ru-O(3) 2.087(3),
C(3)-O(3) 1.255(6), C(3)-O(4) 1.220(7)).3b
Another text book example for a good σ-donor/π-acceptor
ligand is the carbonyl ligand. In previous studies with
(14) Takahashi, Y.; Akita, M.; Hikichi, S.; Moro-oka, Y. Inorg. Chem.
1998, 37, 3186–3194.
(15) Laurent, F.; Plantalech, E.; Donnadieu, B.; Jime´nez, A.; Herna´ndez,
F.; Mart´ınez-Ripoll, M.; Biner, M.; Llobet, A. Polyhedron 1999, 18,
3321–3331.
(16) (a) Kraihanzel, C. S.; Cotton, F. A. Inorg. Chem. 1963, 2, 533–540.
(b) Graham, W. A. G. Inorg. Chem. 1968, 7, 315–321. (c) Fielder,
S. S.; Osborne, M. C.; Lever, A. B. P.; Pietro, W. J. J. Am. Chem.
Soc. 1995, 117, 6990–6993. (d) Estrin, D. A.; Hamra, O. Y.; Paglieri,
L.; Slep, L. D.; Olabe, J. A. Inorg. Chem. 1996, 35, 6832–6837.
The distance Ru-py in complex [Ru(bdmpza)(O2CMe)-
(PPh3)(py)] (7a) is with 2.080(3) Å identical to that in
[RuTpCl(PPh3)(py)] (2.080(7) Å)13 and agrees also well with
those of cationic Tp and Tpm such as [TpRu(OH2)-
(13) Pavlik, S.; Puchberger, M.; Mereiter, K.; Kirchner, K. Eur. J. Inorg.
Chem. 2006, 4137–4142.
Inorganic Chemistry, Vol. 47, No. 20, 2008 9633

Tampier et al.
Figure 6. Contour plots (frontier Kohn-Sham orbitals) of the [Ru(bdmpza)(κ1-O2CPh)(PPh3)] 16VE fragment (DFT-calculations) with (a) LUMO, (b)
HOMO, (c) HOMO-1, and (d) HOMO-2.
Figure 7. Orientation of the pyridine ligand in (a) [Ru(bdmpza)(O2CMe)(PPh3)(py)] (7a) and (b) in [Ru(bdmpza)(O2CC(O)Et)(PPh3)(py)] (8b).
ruthenium vinylidene complexes [Ru(bdmpza)Cl()C)CHR)-
(PPh3)], as mentioned above, we already obtained a car-
bonyl complex [Ru(bdmpza)Cl(CO)(PPh3)] by a degradation
reaction.4 [Ru(bdmpza)Cl(CO)(PPh3)] can also be obtained
by replacing a PPh3 ligand of [Ru(bdmpza)Cl(PPh3)2] (1)
with CO.4 Therefore, we decided to expose the carboxylato
complexes [Ru(bdmpza)(O2CMe)(PPh3)] (2a) and [Ru-
(bdmpza)(O2CPh)(PPh3)] (2b) to CO. Flushing solutions of
2a and 2b with CO gas resulted within 2 h in a complete
conversion of these complexes to the carbonyl complexes
[Ru(bdmpza)(O2CMe)(CO)(PPh3)] (9a) and [Ru(bdmpza)-
(O2CPh)(CO)(PPh3)] (9b) (Scheme 3).
Mass spectroscopic data with [M+] peaks at m/z 698 (9a)
and 760 (9b) revealed the formation of the carbonyl
9634 Inorganic Chemistry, Vol. 47, No. 20, 2008

Ruthenium Carboxylato and 2-Oxocarboxylato Complexes
ruthenium complexes the bdmpza ligand seems to be less
electron donating compared to Cp*, Cp, and even Tp ligands.
Crystals of [Ru(bdmpza)(O2CPh)(CO)(PPh3)] (9b) suitable
for an X-ray structure determination have been obtained from
a CHCl3 solution. The molecular structure (Figure 9, Table
7) reveals the formation of a carbonyl complex and the κO1-
coordination of the benzoate ligand trans to the bdmpza
carboxylate donor.
The Ru-C(3) and C(3)-O(3) bond distances of the
carbonyl ligand in 9b at 1.870(5) Å and 1.145(6) Å are in
the expected range of other ruthenium carbonyl complexes
(see Table 6).17–20 These Cp and Tp ruthenium carbonyl
complexes show molecular structures with d(Ru-CO) )
1.872(6), d(C-O) ) 1.132(8) Å for [RuCpCl(CO)(PPh3)]
and d(Ru-CO) ) 1.848(6), d(C-O) ) 1.137(8) Å for
[RuTpCl(CO)(PPh3)] (see Table 6). Also, the bond distances
of the previously reported complex [Ru(bdmpza)Cl(CO)(P-
Ph3)] (d(Ru-CO) ) 1.821(5) Å, d(C-O) ) 1.151(6)) are
in this range.4 The angle Ru-C(3)-O(3) is almost linear
(177.0(4)°). The distance d(Ru-N11) ) 2.183(3) Å is
significantly longer compared to d(Ru-N21) ) 2.148(4) Å,
indicating the trans influence of the carbonyl ligand.
Whereas CO is able to replace one O-donor of an
hemilabile chelating κ2O1,O1′-carboxylato ligand, an analo-
gous reaction with κ2O1,O2′-oxocarboxylato complexes has
not been successful so far. Solutions of [Ru(bdmpza)(O2-
CC(O)Me)(PPh3)] (3a) and [Ru(bdmpza)(O2CC(O)Ph)-
(PPh3)] (3c) flushed with CO showed only traces of newly
formed products beside the educts in the NMR spectra. Thus,
2-oxocarboxylato ligands seem to be tighter bound ligands
compared to the carboxylato ligands.
Besides CO, gaseous SO2 can act as a good σ-donor and
π-acceptor ligand too. Various coordination modes to metals
are known for SO2 ligands. A η1-coordination via the sulfur
atom is possible with a planar or a pyramidal geometry. Also
a η2-coordination of SO2 via a sulfur and an oxygen atom
can take place (see Figure 10).24–27
Furthermore, SO2 can be coordinated via the oxygen atom
and might also act as a bridging ligand.25–27 Only a few mainly
cationic ruthenium SO2 complexes such as [RuCp(chir)-
(SO2)]PF6 and [RuCp*(PPh3)2(SO2)]Cl have so far been de-
scribed in the literature.7b,28–30 Thus, we also investigated the
reactivity of carboxylato and 2-oxocarboxylato complexes
toward SO2. Solutions of [Ru(bdmpza)(O2CMe)(PPh3)] (2a) and
[Ru(bdmpza)(O2CPh)(PPh3)] (2c) in CH2Cl2 were flushed with
gaseousSO2for30mintoobtaintheSO2complexes[Ru(bdmpza)-
(O2CMe)(PPh3)(SO2)] (10a) and [Ru(bdmpza)(O2CPh)(PPh3)-
(SO2)] (10b) in high yields (Scheme 3). The IR spectra exhibit
two new bands at 1284 and 1128 cm-1 (for 10a) and 1286 and
1129 cm-1 (for 10b). These have been assigned to the
Figure 8. Rotational barrier of the pyridine ligand in [Ru(bdmpza)-
(O2CMe)(PPh3)(py)] (7a), calculated in 5° steps beginning from the structure
of minimum energy.
complexes. Because of the chiral C1 geometry of the
complexes, again two sets of signals are observed in the 1H
and 13C NMR spectra for the diastereotopic pyrazolyl groups.
The 13C NMR carboxylate signals of the κ1O-coordinated
acetato and benzoato ligands are shifted by 11 ppm to higher
field (177.3 ppm (9a), 172.6 ppm (9b)) compared to the
complexes 2a and 2b with κ2O,O′-coordination. IR bands
at 1669 cm-1 (9a) and 1669 cm-1 (9b) are assigned to the
asymmetric carboxylate vibrations ν˜asym(CO2-) of the bdmpza
ligand. Two additional bands at 1624 cm-1 (9a) and 1636
cm-1 (9b) belong to the carboxylate vibrations ν˜asym(CO2 )
-
of the κ1O-coordinated acetato and benzoato ligands. The
31P NMR singlets of the PPh3 ligands at 43.3 (9a) and 43.6
ppm (9b) are almost identical to the singlet we reported
recently for [Ru(bdmpza)Cl(CO)(PPh3)] (41.7 ppm).4 IR
signals at 1977 (9a) and 1978 (9b) cm-1 (CH2Cl2) and
doublets in the 13C{1H} NMR spectra at 205.3 ppm (2JCP
)
19.8 Hz) and 204.2 ppm (2JCP ) 21.2 Hz) can be assigned
to the carbonyl ligands and agree also well with the data
observed for [Ru(bdmpza)Cl(CO)(PPh3)].4 Several carbonyl
ruthenium complexes bearing Tp (BH(pz)3), Cp (η5-C5H5),
and Cp* (η5-C5Me5) ligands are described in the literature
(see Table 6).17–23
This allows a closer discussion of the electron donating
properties of the bdmpza ligand. The carbonyl vibrations are
observed at higher wavenumbers compared to analogous
Cp*, Cp, and Tp ruthenium complexes such as [RuCp-
Cl(CO)(PPh3)] (1958 cm-1), [RuCp*(O2CMe)(CO)(PPh3)]
(1925 cm-1), or [RuTpCl(CO)(PPh3)] (1965 cm-1) (Table
4). This implies a weaker RudπfCpπ back-donation into the
carbonyl ligand of the bdmpza complexes. Thus, in these
(17) Sun, N.-Y.; Simpson, S. J. J. Organomet. Chem. 1992, 434, 341–
349.
(18) Slugovc, C.; Sapunov, V. N.; Wiede, P.; Mereiter, K.; Schmid, R.;
Kirchner, K. J. Chem. Soc., Dalton Trans. 1997, 4209–4216.
(19) Wilczewski, T.; Dauter, Z. J. Organomet. Chem. 1986, 312, 349–
356.
(20) Cao, M.; Do, L. V.; Hoffman, N. W.; Kwan, M.-L.; Little, J. K.;
McGilvray, J. M.; Morris, C. B.; So¨derberg, B. C.; Wierzbicki, A.;
Cundari, T. R.; Lake, C. H.; Valente, E. J. Organometallics 2001, 20,
2270–2279.
(21) Daniel, T.; Mahr, N.; Braun, T.; Werner, H. Organometallics 1993,
12, 1475–1477.
(22) Conroy-Lewis, F. M.; Simpson, S. J. J. Organomet. Chem. 1987, 322,
221–228.
(23) Werner, H.; Braun, T.; Daniel, T.; Gevert, O.; Schulz, M. J.
Organomet. Chem. 1997, 541, 127–147.
(24) Ryan, R. R.; Kubas, G. J.; Moody, D. C.; Eller, P. G. Struct. Bonding
(Berlin) 1981, 46, 47–100.
(25) Kubas, G. J. Inorg. Chem. 1979, 18, 182–188.
(26) Schenk, W. A. Angew. Chem., Int. Ed. Engl. 1987, 26, 98–109.
(27) Kubas, G. J. Acc. Chem. Res. 1994, 27, 183–190.
(28) Schenk, W. A.; Karl, U.; Horn, M. R. Z. Naturforsch. 1989, 44b, 1513–
1518.
(29) Schenk, W. A.; Karl, U. Z. Naturforsch. 1989, 44b, 988–989.
(30) Schenk, W. A.; Dombrowski, E.; Reuther, I.; Stur, T. Z. Naturforsch.
1992, 47b, 732–740.
Inorganic Chemistry, Vol. 47, No. 20, 2008 9635

Tampier et al.
Scheme 3. Syntheses of Carbonyl and SO2 Complexes
Table 4. Selected Bond Lengths [Å] and Angles [deg] of Complexes 4 and 5a
4
5a
4
5a
Ru-N(11)
Ru-N(21)
Ru-O(1)
Ru-Cl
2.106(3)
2.135(3)
2.098(2)
2.4282(9)
2.069(5)
2.111(5)
2.099(4)
Ru-P
2.3011(10)
1.993(3)
1.138(4)
1.454(5)
2.2969(16)
1.993(5)
1.135(7)
1.455(8)
Ru-N(71)
N(71)-C(71)
C(71)-C(72)
Ru-O(61)
2.075(4)
N(11)-Ru-N(21)
O(1)-Ru-N(11)
O(1)-Ru-N(21)
O(1)-Ru-P
83.20(11)
86.27(10)
87.12(10)
90.30(7)
174.60(8)
91.69(9)
83.30(18)
89.04(16)
85.38(17)
88.68(13)
173.79(12)
95.60(15)
O(1)-Ru-N(71)
P(1)-Ru-Cl
P(1)-Ru-O(61)
N(11)-Ru-Cl
N(11)-Ru-(O61)
Ru-N(71)-C(71)
177.88(11)
86.60(3)
174.48(17)
90.71(13)
171.55(8)
174.7(3)
N(21)-Ru-P
168.03(16)
168.2(5)
P-Ru-N(71)
Table 5. Selected Bond Lengths [Å] and Angles [deg] of the Complexes 7a and 8b
7a
8b
7a
8b
Ru-N(11)
Ru-N(21)
Ru-O(1)
Ru-N(1)
Ru-O(3)
Ru-P
2.138(3)
2.096(3)
2.110(3)
2.080(3)
2.090(3)
2.3051(12)
1.286(5)
1.221(5)
2.115(3)
2.089(4)
2.108(3)
2.095(4)
2.097(3)
2.303(3)
1.278(5)
1.223(5)
N(11)-Ru-N(21)
O(1)-Ru-N(11)
O(1)-Ru-N(21)
O(1)-Ru-O(3)
N(11)-Ru-P
85.71(13)
85.27(11)
87.39(11)
177.31(11)
171.02(9)
172.83(13)
85.71(15)
85.03(13)
87.41(16)
178.27(9)
171.38(8)
173.03(11)
N(21)-Ru-N(1)
C-O(3)
C-O(4)
asymmetric and symmetric SO2 vibrations. Such values are
typical for SO2 complexes with a η1-planar geometry, which
usually reveal two bands in between 1300 to 1225 cm-1 and
1140 to 1060 cm-1.24,25 These vibrations of the bdmpza
ruthenium SO2 complexes are found at smaller wavenumbers
compared to the cyclopentadienyl complex [Ru(Cp)(PPh3)2-
(SO2)]Cl (1294 and 1118 cm-1)28 but at higher wavenumbers
compared to the Cp* ruthenium complex [RuCp*(PPh3)2-
(SO2)]Cl (1277 and 1110 cm-1)28 (see Table 8). The
coordination of the SO2 ligand is also backed by an M+ peak
in the FAB mass spectrum.
The unsymmetrical C1 geometry of both SO2 complexes
10a and 10b is clearly indicated by two sets of signals in
1
the H and 13C NMR spectra, which have been assigned to
the two pyrazolyl donors. The 13C NMR signal of the κ1O-
coordinated carboxylato donor is shifted by 9 ppm to higher
field compared to the κ2O1,O1′-coordinated carboxylato
complexes 2a and 2b. This shift and the 31P NMR signals
of the PPh3 ligand at 45.4 and 44.6 ppm agree well with the
carbonyl complex data discussed above. Similar to the CO
ligand, SO2 is able to replace one O-donor of the hemilabile,
chelating κ2O1,O1′-carboxylato ligand. Again, a similar
reaction of SO2 with the 2-oxocarboxylato complexes [Ru-
(bdmpza)(O2CC(O)CH3)(PPh3)] (3a), [Ru(bdmpza)(O2CC-
(O)CH2CH3)(PPh3)] (3b), and [Ru(bdmpza)(O2CC(O)Ph)-
(PPh3)] (3c) has not been successful so far. An X-ray
structure determination of [Ru(bdmpza)(O2CPh)(PPh3)(SO2)]
(10b) shows a molecular structure with the SO2-ligand trans
to a pyrazolyl donor of the bdmpza ligand (Figure 11, Table
9). This position is also preferred by the other acceptor
ligands, such as CO and pyridine (Figures 3, 4, and 10). The
bond distances from the bdmpza and PPh3 ligands to the
ruthenium and also the angles between the coordinated
Figure 9. Molecular structure of [Ru(bdmpza)(O2CPh)(CO)(PPh3)] (9b)
with thermal ellipsoids drawn at the 50% probability level. Hydrogen atoms
and solvent molecules are omitted for clarity.
(31) Kovalevsky, A. Y.; Bagley, K. A.; Cole, J. M.; Coppens, P. Inorg.
Chem. 2003, 42, 140–147.
9636 Inorganic Chemistry, Vol. 47, No. 20, 2008

Ruthenium Carboxylato and 2-Oxocarboxylato Complexes
Table 6. Spectroscopic and Structure Data of Various Ruthenium Carbonyl Complexes
IR (CO)
[cm-1
d(Ru-CO)/
d(C-O) [Å]
∠(Ru-C-O)
31P
[ppm]
complex
]
[deg]
1977a
[Ru(bdmpza)(O2CMe)(CO)(PPh3)] (9a)
43.3
43.6
41.7
42.4
1967b
1978a
1953b
1.870(5)
1.146(6)
[Ru(bdmpza)(O2CPh)(CO)(PPh3)] (9b)
[Ru(bdmpza)Cl(CO)(PPh3)]4
[RuTpCl(CO)(PPh3)]17,18
177.0(4)
178.0(4)
173.2(5)
176.9(1.2)
178.3(8)
1969a
1965c
1958c
1959a
1.821(5)
1.151(6)
1.848(6)
1.137(8)
[RuCpCl(CO)(PPh3)]19
1.911(20)
1.034(27)
[RuCpCl(CO)(PPh3)]20
48.9
1.872(6)
1.132(8)
[RuCp(O2CMe)(CO)(PPh3)]21
[RuCp*Cl(CO)(PPh3)]22
[RuCp*(O2CMe)(CO)(PPh3)]23
a CH2Cl2. b KBr. c Nujol.
1945b
1918c
1925b
54.3
48.2
53.9
Table 7. Selected Bond Lengths [Å], Angles [deg], and Torsion Angles
[deg] of Complex 9b
Ru-N(11)
Ru-N(21)
Ru-O(1)
Ru-P
Ru-O(3)
Ru-C(3)
2.183(3)
2.148(4)
2.115(3)
2.3293(17) C(2)-O(2)
2.059(3)
1.870(5)
C(3)-O(5)
C(1)-C(2)
C(2)-O(1)
1.145(6)
1.552(6)
1.273(5)
1.233(5)
1.297(5)
1.231(5)
C(31)-O(3)
C(31)-O(4)
N(11)-Ru-N(21)
O(1)-Ru-N(11)
O(1)-Ru-N(21)
Ru-C(3)-O(5)
81.41(14) O(1)-Ru-O(3) 169.37(12)
175.49(10)
85.54(14) N(11)-Ru-C(3) 174.56(18)
177.0(4)
85.89(12) N(21)-Ru-P
O(3)-C(31)-C(32)-C(33) 26.4(6)
ligands are more or less the same compared to the molecular
structures of 2a × H2O and 3c.
The κ1-benzoato bond lengths of 10b [d(C(3)-O(5)) )
1.271(8) Å; d(C(3)-O(6)) ) 1.272(8) Å] are almost equal.
Thus, both oxygen donors seem to share the negative charge
of the benzoato ligand. The phenyl group of the benzoato
ligand in the SO2-complex 10b deviates by -21.1(10)° from
the RCO2-plane. A similar twist by 26.4(6)° is observed for
the carbonyl complex 9b. The η1-bound SO2 is not planar
but distorted with a distance of 0.685(11) Å between
ruthenium and the O(3)-S(1)-O(4) plane. The bond dis-
tances S(1)-O(3) [1.452(5) Å] and S(1)-O(4) [1.456(5) Å]
agree well with those of other ruthenium SO2 complexes such
as [RuCp(chir)SO2]PF6 [1.432(6) and 1.458(6) Å] (see Table
8). The Ru-S(1) distance [2.182(2) Å] is significantly longer
than those found in other ruthenium SO2 complexes like
[RuCp(chir)SO2]PF6 [2.128(2) Å] or trans-[Ru(O2CCF3)-
(NH3)4(SO2)](O2CCF3) [2.0945(5) Å].7b,31
Figure 11. Molecular structure of [Ru(bdmpza)(O2CPh)(PPh3)(SO2)] (10b)
with thermal ellipsoids drawn at the 50% probability level. Hydrogen atoms
and solvent molecules are omitted for clarity.
between the sum of the van der Waals radii (3.25 Å)32 and
a single S-O bond (around 1.6 Å) such as the S-OH bond
in the complex [Ru(SO3H)2(bpy)2] (1.586(5) and
1.612(8)Å).33 This rather short distance indicates an intramo-
lecular Lewis acid-base interaction between the Lewis acid
SO2 and the uncoordinated carboxylate oxygen. Because of
the partial charge at this atom, this oxygen donor should be
a rather good Lewis base.
In η1-planar complexes SO2 usually binds via the sulfur
lone electron pair as a σ-donor to the metal. The LUMO of
SO2 which exhibits a π* antibonding character, allows that
this coordinative bond is enforced via π backdonation by
filled metal d orbitals (Figure 6, Figure 12 and 13).26 A η1-
pyramidal coordination of SO2 ligands is observed for
electron rich complex fragments such as Vaskas SO2 complex
[IrCl(CO)(PPh3)2(SO2)].26 In these η1-pyramidal SO2 com-
plexes the bonding electron pair is formally provided by the
electron-rich transition metal fragment (Figure 12).26
The S(1)-O(6) distance between the SO2 and the benzoato
ligand is surprisingly short [2.022(5) Å]. In fact, it lies in
(32) Weast, R. C. CRC Handbook of Chemistry and Physics; CRC Press,
Boca Raton, 1988; p D-111.
(33) Allen, L. R.; Jeter, D. Y.; Cordes, A. W.; Durham, B. Inorg. Chem.
1988, 27, 3880–3885.
Figure 10. Coordination modes of SO2 in transition metal complexes.23–26
Inorganic Chemistry, Vol. 47, No. 20, 2008 9637

Tampier et al.
Table 8. Spectroscopic and Structural Data Of Cp, Cp*, and bdmpza SO2 Complexes
IR (SO2)
[cm-1
d(Ru-SO2)/
d(S-O) [Å]
∠(Ru-S-O)/
∠(O-S-O) [deg]
31P
[ppm]
complex
]
1284a
1128a
1282b
1128b
1286a
1129a
1283b
1125b
[Ru(bdmpza)(O2CMe)(PPh3)(SO2)] (10a)
45.4
44.6
2.182(2)
1.452(5)
1.456(5)
118.1(2)
124.0(2)
114.2(3)
[Ru(bdmpza)(O2CPh)(PPh3)(SO2)] (10b)
2.128(2)
1.432(6)
1.458(6)
120.9(3)
125.1(3)
113.9(4)
1296c
1118c
69.3
74.2
7b
[RuCp(chir)(SO2)]PF6
1294c
1118c
[RuCp(PPh3)2(SO2)]Cl28
[RuCp*(PPh3)2(SO2)]Cl28
32.6
35.3
1277c
1110c
2.0945(5)
1.444(2)
1.446(2)
1275b
1122b
trans-[Ru(O2CCF3)(NH3)4(SO2)] (O2CCF3)31
a CH2Cl2, b KBr, c Nujol
Table 9. Selected Bond Lengths [Å] and Angles [deg] of Complex 10b
might be partially occupied. This could explain the slight
deviation from the η1-planar geometry, as well as the rather
long Ru-S(1) distance. Until now, in the literature two SO2
complexes with carboxylato ligands have been described:
the mononuclear complex [Ru(O2CCF3)(NH3)4(SO2)](O2-
CCF3), in which SO2 coordinates trans to the carboxylato
ligand, and the dinuclear complex [Mo2(NTo)2(S2P(OEt)2)2(µ-
O2CMe)(µ-SBz)(µ-SO2)], with bridging SO2 and carboxylato
ligands.31,34 Thus, to the best of our knowledge, 10a and
10b are the first examples of intramolecular Lewis acid-base
adducts regarding SO2 complexes.
Ru-N(11)
Ru-N(21)
Ru-O(1)
Ru-P
2.147(6)
2.206(6)
2.092(4)
2.331(2)
2.182(2)
2.073(4)
S-O(3)
1.452(5)
1.456(6)
2.022(5)
1.271(8)
1.272(8)
S-O(4)
S-O(6)
C(3)-O(5)
C(3)-O(6)
Ru-S
Ru-O(5)
Ru-plane (S1-O3-O4) 0.685(11)
N(11)-Ru-N(21) 79.7(2)
Ru-S(1)-O(3)
124.0(2)
118.1(2)
114.2(3)
356.3(7)
O(1)-Ru-N(11)
O(1)-Ru-N(21)
O(1)-Ru-P(1)
P(1)-Ru-S(1)
S(1)-Ru-O(1)
88.82(19) Ru-S(1)-O(4)
86.7(2)
89.25(14)
91.29(7)
O(3)-S(1)-O(4)
Σ
93.90(13) O(5)-C(3)-C(4)-C(9) -21.1(10)
Inspired by the reactivity of the carboxylato complexes
toward CO and also by other ruthenium nitrosyl complexes
described in the literature, such as [RuCpCl(NO)(PPh3)]-
PF6,35 the complex [Ru(bdmpza)(O2CC(O)Ph)(PPh3)] (3c)
was reacted with gaseous nitric oxide (NO). A significant
color change from dark purple to blue was observed. Once
the solvent and the excess of NO were removed in vacuo, a
red product was obtained. The IR spectrum (CH2Cl2) shows
two signals at 1698 and 1645 cm-1 which have been assigned
to asymmetric carboxylate vibrations of the bis(3,5-dimeth-
ylpyrazol-1-yl)acetato and the benzoylformato (BF) ligand.
A vibration at 1911 cm-1 indicates a linear nitrosyl ligand.36
A transition from η1-planar to η1-pyramidal geometry
might be caused if either the σ* orbital of the M-S bond or
the LUMO of SO2 is occupied and both are of similar
energy.26 Obviously, according to the angles around the SO2
ligand [∠Ru-S(1)-O(3) ) 124.0(2)°, ∠Ru-S(1)-O(4) )
118.1(2)°, and ∠O(3)-S(1)-O(4) ) 114.2(3)°], the complex
[Ru(bdmpza)(O2CPh)(PPh3)(SO2)] (10b) is an almost η1-
planar complex in which SO2 acts as σ-donor and π-acceptor.
Because of the Lewis acid-base interaction between the
coordinated SO2 and the carboxylato ligand, indicated by
the short S(1)-O(6) distance [2.022(5) Å], the SO2 LUMO
1
The H and 13C NMR spectra of the diamagnetic complex
Table 10. Selected Bond Lengths [Å], Angles [deg], and Torsion
Angles [deg] of the Complex 14a
show two sets of methyl signals for the pyrazoles (1H: 1.95,
2.36, 2.57, and 2.62 ppm; 13C: 11.1, 11.5, 13.9, and 14.3
ppm) as to be expected for an asymmetric geometry of the
complex. The 13C NMR signal of the benzoylformate keto
group is shifted slightly to higher field (202.8 f 186.7 ppm)
compared to that of the educt complex 3c. This finding is
rather similar to the pyridine complex 8c and consequently
indicates an uncoordinated keto group. 13C NMR signals at
163.0 and 169.4 ppm were assigned to the κ1-coordinated
Ru-N(11)
Ru-N(21)
Ru-O(1)
Ru-P
Ru-O(41)
Ru-N(31)
N(31)-O(31)
2.117(4)
2.130(3)
2.065(3)
C(1)-C(2)
C(2)-O(1)
C(2)-O(2)
1.562(6)
1.308(5)
1.205(6)
1.295(5)
1.215(5)
1.585(7)
1.211(6)
1.470(8)
2.4174(15) C(41)-O(41)
2.028(3)
1.760(4)
1.145(4)
C(41)-O(42)
C(41)-C(42)
C(42)-O(43)
C(42)-C(43)
N(11)-Ru-N(21) 83.12(14) N(11)-Ru-P
O(1)-Ru-N(11) 85.34(14) N(21)-Ru-P
O(1)-Ru-N(21) 86.66(14) N(21)-Ru-N(31)
95.78(11)
175.26(11)
94.34(16)
97.39(16)
93.20(16)
169.39(11)
177.4(4)
(34) Wang, R.; Mashuta, M. S.; Richardson, J. F.; Noble, M. E. Inorg.
Chem. 1996, 35, 3022–3030.
O(1)-Ru-P(1)
88.66(9)
N(31)-Ru-O(41)
N(21)-Ru-O(41) 91.99(14) O(1)-Ru-N(31)
N(11)-Ru-N(31) 177.14(15) O(1)-Ru-O(41)
N(11)-Ru-O(41) 84.05(14) Ru-N(31)-O(31)
(35) Conroy-Lewis, F. M.; Redhouse, A. D.; Simpson, S. J. J. Organomet.
Chem. 1990, 399, 307–315.
(36) Mingos, D. M. P.; Sherman, D. J. AdV. Inorg. Chem. 1989, 34, 293–
O(41)-C(41)-C(42)-O(43) -18.5(7)
377.
9638 Inorganic Chemistry, Vol. 47, No. 20, 2008

Ruthenium Carboxylato and 2-Oxocarboxylato Complexes
Table 11. Spectroscopic and Structural Data of Various Cp, Cp*, Tp, and bdmpza Nitrosyl Complexes
complex
IR (NO) [cm-1
]
d(Ru-NO>)/d(N-O) [Å]
∠(Ru-N-O) [deg]
31P [ppm]
24.2
[Ru(bdmpza)(O2CC(O)Ph)(NO)(PPh3)]+ (12)
1911a
1906b
1912a
1897b
1912a
1903b
1912a
1904b
1911a
1904b
1911a
1906b
1868a
1872b
1862a
1860b
[Ru(bdmpza)(O2CMe)(NO)(PPh3)]BF4 (13a)
[Ru(bdmpza)(O2CPh)(NO)(PPh3)]BF4 (13b)
23.5
23.3
24.1
24
[Ru(bdmpza)(O2CC(O)Me)(NO)
(PPh3)]BF4 (14a)
[Ru(bdmpza)(O2CC(O)Et)(NO)
(PPh3)]BF4 (14b)
1.760(4)
1.145(4)
177.4(4)
[Ru(bdmpza)(O2CC(O)Ph)(NO)
(PPh3)]BF4 (14c)
23.8
[Ru(bdmpza)(Cl)2(NO)]5
[Ru(bdmpza)2(NO)]Cl5
[RuTpCl(CH2C(O)p-CH3C6H4)(NO)]38
1.742(2)
1.128(3)
1.775(5)
1.132(7)
1.748(4)
1.141(5)
178.9(3)
172.2(5)
174.1(4)
35
[RuCpCl(NO)(PPh3)]PF6
1849c
1850b
37.1
66.4
34
[RuCp*(NO)(dppe)](PF6)2
a CH2Cl2. b KBr. c Nujol.
carboxylato groups of the bdmpza and BF ligands. The 31P
NMR singlet signal of the PPh3 ligand can be observed at
23.8 ppm. The product of the reaction can be precipitated
from dichloromethane by adding diethylether. A molecular
mass peak (FAB) at 791 agrees well with a complex cation
[Ru(bdmpza)(O2CC(O)Ph)(NO)(PPh3)]+ and thus with a
coordinated nitrosonium (NO+) ligand. Obviously, reaction
of 3c with a large excess of gaseous NO results in the
formation of a complex cation [Ru(bdmpza)(O2CC(O)Ph)-
(NO)(PPh3)]+ (12) (Scheme 4).
Scheme 4. Synthesis of Nitrosyl Complexes with Gaseous NO
One explanation> for this NO+ formation might be the
presence of NO2 in the reaction mixture, which is almost
impossible to prevent in such reactions. Because NO of low
purity grade has been used in our reaction, the presence of
NO2 traces is very likely here. It is well-known that this might
out completely. Indeed analytical test reactions performed
with 12 indicated traces of NO3- but no NO2-. Unfortunately,
so far we cannot prove the formation of a NO3- counteranion
unequivocally.
37
be a source of NO+ and NO3 . Thus, the counteranion
-
A similar reaction with an excess of NO is also possible
with the acetato complex [Ru(bdmpza)(O2CMe)(PPh3)] (2a),
although no complete conversion could be achieved so far.
Nevertheless, we were able to analyze the reaction product
-
might be nitrate NO3 , although nitrite NO2- cannot be ruled
1
[Ru(bdmpza)(O2CMe)(NO)(PPh3)]+ (11). H NMR signals
at 1.94, 2.07, 2.25, 2.56, and 2.63 ppm have been assigned
to the five methyl groups, and singlets at 6.20, 6.41, and
6.67 ppm belong to the pyrazolyl protons and the CH bridge,
thus indicating again an unsymmetrical complex. Similar to
the benzoylformato complex 12, the NO vibration is observed
at 1911 cm-1 in the IR spectrum. The M+ peak at 700 in the
FAB mass spectrum fits to a [Ru(bdmpza)(O2CMe)(NO)-
(PPh3)]+ cation. Again, the nature of the anion, most likely
Figure 12. SO2 as σ-donor/π-acceptor and as σ-acceptor respectively in
SO2 complexes.23–26
-
nitrate NO3 , stays unresolved so far.
To verify the nitrosyl complex cations [Ru(bdmpza)(O2-
CMe)(NO)(PPh3)]+ (11) and [Ru(bdmpza)(O2CC(O)Ph)(NO)-
(37) Burdinski, D.; Brans, H. J. A.; Decre, M. M. J. J. Am. Chem. Soc.
2005, 127, 10786–10787.
(38) Arikawa, Y.; Nishimura, Y.; Kawano, H.; Onishi, M. Organometallics
2003, 22, 3354–3356.
(39) Mauthner, K.; Mereiter, K.; Schmid, R.; Kirchner, K. Inorg. Chim.
Acta 1995, 236, 95–100.
(40) Nagao, H.; Nishimura, H.; Funato, H.; Ichikawa, Y.; Howell, F. S.;
Mukaida, M.; Kakihana, H. Inorg. Chem. 1989, 28, 3955–3959.
Figure 13. (a) HOMO and LUMO of SO2 according to literature23–26 and
(b) calculated Kohn-Sham orbitals (DFT).
Inorganic Chemistry, Vol. 47, No. 20, 2008 9639

Tampier et al.
Scheme 5. Synthesis of Nitrosyl Complexes with NO[BF4]
Figure 14. Molecular structure of [Ru(bdmpza)(O2CC(O)Me)(NO)(PPh3)]BF4
(14a) with thermal ellipsoids drawn at the 50% probability level. Hydrogen
atoms and solvent molecules are omitted for clarity.
nium nitrosyl complexes bearing Cp or Cp* ligands such as
[CpRuCl(PPh3)(NO)]PF6 (ν˜(NO) ) 1849 cm-1 (Nujol)) and
[Cp*Ru(dppe)(NO)](CF3SO3)2 (ν˜(NO) ) 1850 cm-1 (Nujol))
exhibit NO vibrations at lower wavenumbers (see Table
11).35,39 It is noteworthy that the ν˜(NO) of bis(3,5-dimeth-
ylpyrazol-1-yl)aceto nitrosyl complexes such as [Ru-
(bdmpza)(Cl)2(NO)] (1868 cm-1 (CH2Cl2) and 1872 cm-1
(KBr)) and [Ru(bdmpza)2(NO)]Cl (1862 cm-1 (CH2Cl2) and
1860 cm-1 (KBr)), which have been reported recently by
Cao and Otero, have been observed at much lower wave-
numbers compared to the ν˜(NO) of 13a,b and 14a-c (Table
11).5
Crystals suitable for X-ray structure determination have
been obtained for complex 14a. The molecular structure
of [Ru(bdmpza)(O2CC(O)Me)(NO)(PPh3)]BF4 (14a) (Fig-
ure 14, Table 10) exhibits a complex geometry with the
NO trans to a pyrazolyl donor and a κO1-coordination of
the 2-oxocarboxylato ligand trans to the carboxylate donor
of the bdmpza ligand. The distances and angles of the
[Ru(bdmpza)(PPh3)] fragment agree well with those of
the structures 2a × H2O and 3c.
(PPh3)]+ (12), the carboxylato complexes [Ru(bdmpza)-
(O2CR)(PPh3)] (3a,b) (R ) Me, Ph), as well as the
2-oxocarboxylato complexes [Ru(bdmpza)(O2CC(O)R)-
(PPh3)] (3a-c) (R ) Me, Et, Ph), were reacted with [NO]BF4
to yield the complexes [Ru(bdmpza)(O2CR)(NO)(PPh3)]BF4
(13a,c) (R ) Me, Ph) and [Ru(bdmpza)(O2CC(O)R)-
(NO)(PPh3)]BF4 (14a-c) (R ) Me, Et, Ph) (Scheme 5.).
NMR samples of the complex 11 in combination with 13a
aswellasof12and14cindicatedidenticalcations[Ru(bdmpza)-
(O2CMe)(NO)(PPh3)]+ and [Ru(bdmpza)(O2CC(O)Ph)(NO)-
(PPh3)]+, respectively, according to the spectroscopic data
(1H, 13C, and 31P). The fact that gaseous NO might be used
as NO+ source has been described before.39,40 For example
Kirchner et al. recently reported on a similar transformation
of [Cp*Ru(dppe)]PF6 to [Cp*Ru(dppe)(NO)](PF6)2 by either
gaseous NO or [NO]PF6.39
In general, the yield of these reactions is rather high
(84-98%), and reactions with the carboxylato complexes
are faster compared to with the 2-oxocarboxylato complexes.
The constitution of the nitrosyl complexes 13a,b and 14a-c
is backed by M+ peaks in the FAB mass spectra. The 13C
NMR signals assigned to the keto carbons of the nitrosyl
2-oxocarboxylato complexes 14a-c are shifted to higher field
by 15 ppm compared to the educts 3a-c, thus indicating a
The torsion angle ∠(O(41)-C(41)-C(42)-O(43)) of the
2-oxocarboxylato ligand in 14a (-18.5(7)°) is bigger than
in the benzoylformato complex 3c [-0.3(5)°], but a conjuga-
tion across the π system of the 2-oxocarboxylato ligand
should still be possible. The bond distances of the nitrosyl
ligand are d(Ru-NO) ) 1.760(4) Å and d(N-O) ) 1.145(4)
Å in 14a, and the nitrosyl ligand is close to linear with
∠(Ru-N-O) ) 177.4(4)°. These values agree well with
those of the ruthenium(II) Cp and Tp nitrosyl complexes
(Table 11).
κ1O1-coordination of the 2-oxocarboxylato ligands. The 31
P
NMR signals are observed from 23.3 to 24.2 ppm. This
means a high field shift of almost 25 ppm compared to the
educts. The diamagnetic property observed for the nitrosyl
complexes 11, 12, 13a, 13b, and 14a-c is typical of the
{RuNO}6 type of complexes.41 The NO IR signals [around
1911 cm-1 (CH2Cl2) and 1897 to 1906 cm-1 (KBr)] are lying
in between the vibration of free NO+ (2377 cm-1) and that
of NO or NO- (1860 and 1470 cm-1, respectively),36,42
indicating a nitrosonium NO+ ligand. Other cationic ruthe-
Summary and Prospects
Many preparative and structural studies have demon-
strated the versatility of the complexes [Ru(bdmpza)-
(O2CR)(PPh3)] (2a, 2b) and [Ru(bdmpza)(O2C(CO)R)-
(NO)(PPh3)] (3a-c) as 16 VE fragments with hemilabile
κ2-coordinating carboxylato and 2-oxocarboxylato ligands.
(41) Enemark, J. H.; Feltham, R. D. Coord. Chem. ReV. 1974, 13, 339–
406; Mononitrosyl complexes are described by {RuNO}n, where n is
the number of d electron on ruthenium when the NO is formally bound
as NO+
(42) McCleverty, J. A. Chem. ReV. 2004, 104, 403–418.
9640 Inorganic Chemistry, Vol. 47, No. 20, 2008

Ruthenium Carboxylato and 2-Oxocarboxylato Complexes
Solvent molecules (pyridine, acetonitrile) as well as small
molecules and ions (CO, SO2, NO+) have been coordinated
to a [Ru(bdmpza)(O2CR)(PPh3)] fragment. The chances
of generating otherwise unstable compounds in the
protecting environment of the new transition metal frag-
ments seem quite promising. Future studies will be able
to build on these results and might expand them to an
activation of small molecules. Correlations between
structure and reactivity are beginning to be recognized
with a higher reactivity of the κ2-carboxylato complexes
compared to that of the 2-oxocarboxylato complexes.
Acknowledgment. We gratefully acknowledge financial
support by the Deutsche Forschungsgemeinschaft through
SFB 583 “Redox-active metal complexes” and the Fonds
der Chemie. The authors thank Prof. Dr. H. Fischer for
support and discussion and the Degussa AG for a generous
gift of rutheniumtrichloride hydrate.
Supporting Information Available: Crystallographic informa-
tion files (CIF). This material is available free of charge via the
Internet at http://pubs.acs.org.
IC8000224
Inorganic Chemistry, Vol. 47, No. 20, 2008 9641