Tricarbonylmanganese(I) derivatives of [Di(pyrazolyl)(2-pyridyl)methyl]aryl scorpionates

Article abstract of DOI:10.1016/j.jorganchem.2004.10.049

The cobalt(II) chloride catalyzed Peterson rearrangement reactions between sulfinyldi-(pyrazolyl) and aryl(pyridyl)methanone derivatives yield di(pyrazolyl)(pyridyl)hetero-scorpionate ligands. Reaction of these ligands with Mn(CO)₅Br in the presence of a silver salt produces the monometallic complexes {[κ³-PhC(pz)₂(2-py)]Mn(CO) ₃}(O₃SCF₃) (1a), {[κ³-PhC(pz) ₂(2-py)]Mn(CO)₃}(PF₆) (1b), {[κ³-PhC(^4-Mepz)₂(2-py)]Mn(CO) ₃}(PF₆) (2), {[κ³-p-BrC₆H ₄C(pz)₂(2-py)]Mn(CO)₃}(PF₆) (3), and the bimetallic complexes [(CO)₃Mn{m-C₆H ₄[C(pz)₂(2-py)]₂}Mn(CO)₃](BF ₄)₂ (5a) and {m-C₆H₄[C(pz) ₂(2-py)Mn(CO)₃]₂}(PF₆)₂ (5b) (pz = pyrazolyl ring, py = pyridyl ring). These octahedral manganese complexes show interesting structural diversity, with the complexes being organized in the solid state into complex supramolecular structures by an array of non-covalent forces.

Full text of DOI:10.1016/j.jorganchem.2004.10.049

Journal of Organometallic Chemistry 690 (2005) 1901–1912
www.elsevier.com/locate/jorganchem
Tricarbonylmanganese(I) derivatives of
[Di(pyrazolyl)(2-pyridyl)methyl]aryl scorpionates
*
Daniel L. Reger , James R. Gardinier, T. Christian Grattan, Mark D. Smith
Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
Received 27 August 2004; accepted 25 October 2004
Available online 29 December 2004
Abstract
The cobalt(II) chloride catalyzed Peterson rearrangement reactions between sulfinyldi-(pyrazolyl) and aryl(pyridyl)methanone
derivatives yield di(pyrazolyl)(pyridyl)hetero-scorpionate ligands. Reaction of these ligands with Mn(CO)5Br in the presence of a
silver salt produces the monometallic complexes {[j3-PhC(pz)2(2-py)]Mn(CO)3}(O3SCF3) (1a), {[j3-PhC(pz)2(2-py)]Mn(CO)3}(PF6)
(1b), {[j3-PhC(4-Mepz)2(2-py)]Mn(CO)3}(PF6) (2), {[j3-p-BrC6H4C(pz)2(2-py)]Mn(CO)3}(PF6) (3), and the bimetallic complexes
[(CO)3Mn{m-C6H4[C(pz)2(2-py)]2}Mn(CO)3](BF4)2 (5a) and {m-C6H4[C(pz)2(2-py)Mn(CO)3]2}(PF6)2 (5b) (pz = pyrazolyl ring,
py = pyridyl ring). These octahedral manganese complexes show interesting structural diversity, with the complexes being organized
in the solid state into complex supramolecular structures by an array of non-covalent forces.
Ó 2004 Elsevier B.V. All rights reserved.
Keywords: Manganese; Supramolecular structures; Tris(scorpionate) ligands
1. Introduction
[6] is responsible for the structural diversity in their me-
tal complexes. In our previous chemistry on multitopic
ligands, we have mainly employed semi-rigid linking
groups, such as in C6H6 ꢁ n[CH2OCH2C(pz)3]n (n = 2,
3, 4, 6) in the formation of discrete coordination com-
plexes and coordination polymers [7]. We have also re-
ported the syntheses of heteroscorpionate ligands
based on di(pyrazolyl)(2-pyridyl)methane units, includ-
ing a fixed geometry ligand, m-C6H4[C(pz)2(2-py)]2
(pz = pyrazolyl ring, py = pyridyl ring) [8]. The silver
derivatives of this potentially bitopic ligand were dis-
crete AgL2 species that had j2-bonding of only one of
the two potentially tridentate [C(pz)2(2-py)] units rather
than coordination polymers or metallacycles as origi-
nally intended and as seen in other linked scorpionate li-
gands. The discrete silver structure was nonetheless
interesting in that it had layered arrays of metal ions
held together via multiple noncovalent interactions
involving the atoms of the ligand framework. The silver
complex of the monotopic ligand PhC(pz)2(2-py) also
shared these structural features [8]. In order to more
There is substantial interest in the planned syntheses
of coordination network solids for use in materials
chemistry and catalysis [1]. An important feature in this
field is the design of specific types of ligands that are
capable of binding to metal centers in a predictable
manner defined in part by the geometry of the ligand.
We have been developing the syntheses of tris(pyraz-
olyl)methane and related ligands [2]. These ligands,
especially those in which we link two or more of the
tris(pyrazolyl)methane units in a single (multitopic) li-
gand, offer substantial structural diversity. The multiple
coordination modes and ability of these ligands to sup-
port important non-covalent interactions such as weak
hydrogen bonds [3], p–p stacking [4], X–Hꢀ ꢀ ꢀp interac-
tions (X = O, N, C) [5], and interhalogen interactions
*
Corresponding author. Tel.: +1 803 777 2587; fax: +1 803 777
9521.
E-mail address: reger@mail.chem.sc.edu (D.L. Reger).
0022-328X/$ - see front matter Ó 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2004.10.049

1902
D.L. Reger et al. / Journal of Organometallic Chemistry 690 (2005) 1901–1912
fully develop the chemistry of these heteroscorpionate li-
gands, we report here their coordination chemistry with
tricarbonylmanganese(I) cations and explore the effects
of substitution along the ligand periphery and of replac-
ing anions on the supramolecular organization of the
solids.
arated aqueous fraction was extracted with four 50 ml
portions of CH2Cl2. The combined organic phases were
dried over MgSO4, filtered and solvent was removed by
rotary evaporation to leave a yellow oil. Chromato-
graphic separation of the product mixture on SiO2 with
50% Et2O/hexanes afforded 0.61 g [27% based on
PhC(O)(2-py)] of L2 as a colorless solid from the second
colorless band (Rf = 0.3 on TLC plate). Mp, 113–115
°C. Anal. Calcd. (Obs.) for L2 Æ 1/2H2O C18H16N5O:
C, 70.98 (70.86) H, 5.96 (5.55); N, 20.69 (20.79). 1H
NMR (400 MHz, CDCl3) 8.71 (d, J = 4 Hz, 1H, H6-
py), 7.71 (ddd, J = 8, 8, 2 Hz, 1H, H4-py), 7.49 (s, 2H,
H3-pz), 7.38–7.34 (m, 3H, Ph and py), 7.31–7.29 m,
3H, Ph and H5-pz), 7.24–7.21 (m, 3H, Ph and py),
2.06 (s, 6H, –CH3). 13C NMR (101.62 MHz, CDCl3)
159.0 (C2-py), 148.8 (C6-py), 141.4 (C3-pz), 139.8
(Cipso-Ph), 137.1 (C4-py), 131.0 (C5-pz), 129.4 (o-Ph)
129.2 (p-Ph), 128.2 (m-Ph), 124.3 (C3-py), 123.6
(C5-py), 116.2 (C4-pz), 86.9 (Ca), 9.2 (CH3). Direct
probe MS m/z (Rel. Int.%) [assgn]: 330(49) [M]+,
248(100) [M–H(4-Me)pz]+.
2. Experimental
2.1. General comments
All manipulations involving air- and moisture-sensi-
tive compounds were carried out either in the drybox
under a purified N2 atmosphere or by using standard
Schlenk techniques. The solvents were commercially
available, purified by conventional means, and distilled
immediately prior to use. Silica gel (230–400 mesh, 40–
63 lm) for chromatographic separations was purchased
from Fisher Scientific. Thionyl chloride, 1-H-pyrazole
(Hpz), 1-H-4-methylpyrazole, (Hpz4Me), 2-benzoylpyri-
dine, AgBF4, AgPF6, and Mn(CO)5Br were purchased
from Aldrich Chemicals. Anhydrous CoCl2 was used
as purchased from Strem Chemicals. The aryl(pyr-
idyl)methanones p-BrC6H4C(O)(2-py), m-[(2-py)C(O)]2-
C6H4 [9], and p-(2-py)2NC6H4C(O)(2-py) [10] were
prepared according to the literature routes. The ligands
L1 [2] and L5 [8] and the manganese complex {[j3-
PhC(pz)2(2-py)]Mn(CO)3}(O3SCF3) (1a) were prepared
as previously described [2]. Robertson Microlit Labora-
tories, Inc. (Madison, NJ) performed all elemental anal-
yses. Samples for melting point determinations were
contained in flame sealed capillaries and the reported
temperatures are uncorrected. The NMR spectra were
recorded by using either a Varian Gemini 300 or a Var-
ian Mercury 400 instrument, as noted within the text.
Chemical shifts were referenced to solvent resonances
at dH 7.27 and dC 77.23 for CDCl3 or at dH 2.05 and
dC 29.15 for acetone-d6. Infrared spectra were recorded
for samples as CH2Cl2 solutions between NaCl plates by
using a Nicolet 5DXB FTIR spectrometer. Mass spec-
trometric measurements recorded in ESI(+/ꢁ) mode
were obtained on a Micromass Q-Tof spectrometer
whereas those performed by using direct probe analyses
were made on a VG 70S instrument.
2.2.2. p-BrC6H4C(pz)2(2-py), p-bromo-a,
a-di(pyrazolyl)-a-(2-pyridyl)toluene (L3)
A mixture of 6.58 mmol SO(pz)2 [from 0.320 g (13.3
mmol) NaH, 0.905 g (13.3 mmol) Hpz, and 0.48 ml (6.58
mmol) SOCl2], 1.71 g (6.52 mmol) p-BrC6H4C(O)(2-py),
and 0.150 g (18 mol%) CoCl2 in 50 ml THF were heated
at reflux for 48 h. After aqueous work-up and extraction
of organics as described for L2 above, chromatographic
separation of the product mixture on SiO2 with 50%
Et2O/hexanes afforded unreacted p-BrC6H4C(O)(2-py)
from the first (photosensitive, turns blue then brown
on exposure to 254 nm light) band (TLC, Rf = 0.75)
and then 1.08 g (45%) of L3 as a colorless solid from
the second colorless band (TLC, Rf = 0.4). Mp, 111–
112 °C. 1H NMR (400 MHz, CDCl3) 8.70 (d, J = 5
Hz, 1H, H6-py), 7.74 (ddd, J = 8, 8, 2 Hz, 1H, H4-py),
7.69 (d, J = 1Hz, 2H, H3-pz), 7.50 (part of AA0BB0,
2H, aryl) 7.48 (d, J = 3 Hz, 2H, H5-pz), 7.33 (ddd,
J = 8, 5, 1 Hz, 1H, H5-py), 7.17 (d, J = 8 Hz, 1H, H3-
py), 7.13 (part of AA0BB0, 2H, aryl), 6.34 (dd, J = 3, 1
Hz, 2H, H4-pz). 13C NMR (101.62 MHz, CDCl3)
158.2 (C2-py), 148.9 (C6-py), 140.9 (C3-pz), 138.7
(Cipso-Ph), 137.1 (C4-py), 132.5 (C5-pz), 131.3, (Ph),
131.2 (Ph), 124.4 (C3-py), 124.0 (Cipso Ph), 123.9 (C5-
py), 106.1 (C4-pz), 86.9 (Ca). Direct Probe MS m/z
(Rel. Int.%) [assgn]: 379 (49) [M]+, 313 (100) [M-pz]+
301 (75) [M–Br]. HRMS Direct probe Calcd. (Obs.)
for C18H14BrN5: 379.0433 (379.0441).
2.2. Ligand syntheses
2.2.1. PhC(4-Mepz)2(2-py), a,a-Bis(4-methyl-1-
pyrazolyl)-a-(2-pyridyl)toluene (L2)
A mixture of 7.5 mmol SO(pz)2 [from 0.35 g (15
mmol) NaH, 1.2 g (15 mmol) Hpz4Me, and 0.55 ml
(7.5 mmol) SOCl2], 1.3 g (6.9 mmol) 2-benzoylpyridine,
and 0.20 g (22 mol% of 1) CoCl2 in 20 ml THF were
heated at reflux for 48 h. The resulting mixture was par-
titioned between 50 ml each CH2Cl2 and water. The sep-
2.2.3. p-[(2-py)2N](C6H4)[C(pz)2(2-py)] (L4)
A mixture of 0.33 g (0.94 mmol) p-(2-py)2NC6H4-
C(O)(2-py) and 1.5 mmol SO(pz)2 [from 0.20 g (2.9
mmol) Hpz, 0.070 g (2.9 mmol) NaH, and 0.11 ml
(0.18 g, 1.5 mmol) SOCl2] in 25 ml THF was heated at

D.L. Reger et al. / Journal of Organometallic Chemistry 690 (2005) 1901–1912
1903
reflux for 3 d. The resulting mixture was partitioned be-
tween 50 ml each CH2Cl2 and water. The separated
aqueous fraction was extracted with four 50 ml portions
of CH2Cl2. The combined organic phases were dried
over MgSO4, filtered, and solvent was removed by ro-
tary evaporation to leave a yellow oily residue. The yel-
low oily residue was adsorbed onto silica gel and loaded
onto a silica gel column. Elution with ethyl acetate affor-
ded unreacted p-(2-py)2NC6H4C(O)(2-py) in the first
pale yellow band (TLC, Rf = 0.5). When the desired
product began eluting (TLC, Rf = 0.3) a gradient of pure
ethyl acetate to 1:1 ethyl acetate/acetone was used to
facilitate the removal of the product from the column.
Evaporation of solvents gave 0.176 g (40%) of L4.
Mp, 176–179 °C. 1H NMR (400 MHz, CDCl3) 8.69
(d, J = 4 Hz, 1H, H6-Cpy), 8.33 (dd, J = 5, 1 Hz, 2 H,
Npy), 7.74 (ddd, J = 8, 8, 2 Hz, 1H, H4-Cpy), 7.69 (d,
J = 1Hz, 2H, H3-pz), 7.58 (ddd, J = 8, 8, 2 Hz, 2H,
H4-Npy), 7.55 (d, J = 2 Hz, 2H, H5-pz), 7.32 (ddd,
J = 8, 5, 1 Hz, 1H, H5-Cpy), 7.24 (d, J = 8 Hz, 1H,
H3-Cpy), 7.22 (part of AA0BB0, 2H, aryl) 7.14 (part of
AA0BB0, 2H, aryl), 7.04 (d, J = 8 Hz, 2H, H3-Npy),
6.97 (ddd, J = 7, 5, 1 Hz, 2H, H5-Npy), 6.34 (dd,
J = 2, 1 Hz, 2H, H4-pz). 13C NMR (101.62 MHz,
CDCl3) 158.7 (C2-Cpy), 158.1 (C2-Npy), 148.9 (C6-
Npy), 148.8 (C6-Cpy), 145.8 (Ci-Ph), 140.8 (C3-pz),
137.9, 137.1 (C4-Cpy), 135.6 (Ci-Ph), 132.6 (C5-pz),
130.8 (Ph), 125.4 (Ph), 124.2 (C3-Cpy), 123.8 (C5-Cpy),
118.9 (C3-Npy), 117.9 (C5-Cpy), 105.8 (C4-pz), 86.9
(Ca). Direct probe MS m/z (Rel. Int.%) [assgn]: 470
(90) [M]+, 43 (100) [M-Hpz]+. HRMS ESI(+) Calcd.
(Obs.) for C28H23N8, [M + H]: 471.2046 (471.2056).
8.26 (m, 3H, aryl and H4-py), 8.04 (d, J = 8 Hz, 1H,
H5-py), 7.95–7.88 (m, 5H, Ph), 7.78 (ps t, 1H, H3-py),
6.70 (s, 2H, H4-pz). 13C NMR (125.8 MHz, acetone-
d6, ꢁ20 °C) 221.0 (CO), 220.1 (CO), 157.3 (C6-py),
156.3 (C2-py), 149.6, 141.9, 137.8, 133.3 (Ph), 133.3,
132.6 (Ph), 129.8, 127.9, 126.8, 109.7 (C4-pz), 83.6 (Ca).
2.3.2. {[j3-PhC(4-Mepz)2(2-py)]Mn(CO)3}(PF6) (2)
A mixture of 0.167 g (0.607 mmol) Mn(CO)5Br, 0.154
g (0.609 mmol) AgPF6 in 10 ml acetone was heated at
reflux in the dark for 1 h. A yellow solution was sepa-
rated from the precipitate of AgBr and was transferred
by cannula filtration to a second solution containing
0.216 g (0.714 mmol) PhC(4Mepz)2(2-py) in 10 ml. The
AgBr was washed with two 5 ml portions of acetone
and these washings were also transferred to the solution
containing the ligand. The resulting yellow-orange solu-
tion was stirred at room temperature 12 h, and then was
heated at reflux for 2 h. Solvent was removed by vacuum
distillation to leave an orange residue. This residue was
washed with two 10 ml portions of diethyl ether and
dried under vacuum to leave 0.335 g (90%) of 2 as a
hygroscopic yellow solid. Mp, 235 °C dec. to green solid
with effervescence. Anal. Calcd. (Obs.) for
C23H21N5F6O4PMn, 2 Æ H2O: C, 43.69 (43.93); H, 3.03
(3.03), N, 11.08 (11.21). For a sample dried in 160 °C
oven for 6 h and sealed while hot, Anal. Calcd. (Obs.)
for C23H19N5F6O3PMn: C, 44.97 (44.27); H, 3.12
1
(3.11), N, 11.40(11.14). IR (cmꢁ1): mco 2047, 1954. H
NMR (400 MHz, acetone-d6, 23 °C) broad resonances
9.46, 8.53, 8.23, 7.89, 7.78, 7.70, 2.06. 13C NMR
(101.62 MHz, acetone-d6, 23 °C) 157.3, 149.7, 141.9,
1
136.1, 133.3, 132.6, 130.7, 127.8, 126.7, 120.2, 8.6. H
2.3. Tricarbonylmanganese complexes
NMR (500 MHz, acetone-d6, 55 °C) 9.43 (1H, H6-py),
8.47 (2H), 8.21 (3H), 7.92 (2H), 7.87 (2H), 7.77 (1H),
7.69 (2H), 2.06 (6H). 13C NMR (101.62 MHz,, ace-
tone-d6, ꢁ20 °C) 221.0 (CO), 220.1 (CO), 157.2 (C6-
py), 156.2 (C2-py), 149.4 (C3-pz), 141.7 (C4-py), 135.9
(Ph), 133.0 (C3-py), 132.4 (Ph), 130.5 (Ph), 129.7 (Ph),
127.6 (C5-py), 126.5 (Ph), 119.9 (C4-pz), 83.2 (Ca), 8.5
(CH3). HRMS-ESI(+) (m/z): [M]+ calcd for
C23H19N5O3Mn, 468.0868; found, 468.0871.
2.3.1. {[j3-PhC(pz)2(2-py)]Mn(CO)3}(PF6) (1b)
Under a nitrogen atmosphere, a mixture of 0.196 g
(0.713 mmol) Mn(CO)5Br, 0.181 g (0.716 mmol) AgPF6
in 10 ml acetone was heated at refluxing the the dark for
1.5 h. A yellow solution was separated from the precip-
itate of AgBr and was transferred by cannula filtration
to a second solution containing 0.216 g (0.714 mmol)
PhC(pz)2(2-py) in 10 ml. The AgBr was washed with
two 5 ml portions of acetone and these washings were
also transferred to the solution containing the ligand.
The resulting red-orange solution was heated at reflux
for 2 h, until gas evolution ceased (monitored with an
external bubbler), and then solvent was removed by vac-
uum distillation to leave a red orange residue. This res-
idue was washed with two 10 ml portions of diethyl
ether and dried under vacuum to leave 0.398 g (95%)
of 1b. Mp, 215 °C dec. to green solid with effervescence.
Anal. Calcd. (Obs.) for C21H15N5F6O3PMn: C, 11.97
(11.60); H, 2.58 (2.90); N, 11.97 (11.60). IR (cmꢁ1): mco
2049, 1956. 1H NMR (500 MHz, acetone-d6, 50 °C)
9.46 (d, J = 5 Hz, 1H, H6-py), 8.67 (s, 2H, H3-pz),
2.3.3. {[j3-p-BrC6H4C(pz)2(2-py)]Mn(CO)3}(PF6)
(3)
A mixture of 0.205 g (0.811 mmol) AgPF6 and 0.223 g
(0.811 mmol) Mn(CO)5Br were heated at reflux in the
dark under nitrogen for 1 h, the yellow solution was
transferred by cannula filtration to a solution containing
0.308 g (0.810 mmol) of p-BrC6H4C(pz)2(2-py), L3. The
acetone insoluble solid of AgBr was washed with 10 ml
acetone and the washings were also transferred to the
solution containing the ligand. The resulting red-orange
solution was heated at reflux for 4 h and then solvent
was removed by vacuum distillation. The residue
was washed with two 10 ml portions of Et2O and the

1904
D.L. Reger et al. / Journal of Organometallic Chemistry 690 (2005) 1901–1912
resulting yellow solid was dried under vacuum to give
0.510 g (90%) of 3 as a diethylether solvate, 3 Æ 1/
2Et2O. Mp, 215 °C dec to green solid, 250 °C black li-
quid. Anal. Calcd. (Obs.) for C23H19BrF6N5O3.5PMn:
C, 39.39 (38.92); H, 2.79 (2.76); N, 9.70 (9.86). IR
the ligand solution. The resulting red-orange solution
was heated at reflux for 4 h and the solvent was removed
by vacuum distillation. The orange solid was washed
with several portions of diethyl ether and was dried
under vacuum to leave 0.13 g (92%) of 5b as a yellow-
orange solid. IR(CH2Cl2) mCO 2048, 1958. 1H NMR
(300 MHz, acetone-d6) all br s: dH 9.46, 9.10, 8.95,
8.76, 8.23, 7.77, 6.75 (H4-pz). HRMS-ESI(+) (m/z):
[M + PF6]+ calcd for C36H24F6N10O6PMn2, 947.0283;
found, 947.0271.
1
(cmꢁ1): mco 2049, 1956. H NMR (400 MHz, acetone-
d6, 23 °C) 9.48 (br s, 1H, H6-py), 8.73 (s, 2H, H3-pz),
8.25 (m, 3H, aryl and H4-py), 8.08 (br m, 3H, H5-py),
7.9 (m, 2H, Ph), 7.80 (br s, 1H, H3-py), 6.73 (br s, 2H,
H4-pz), 3.40 (q, J = 7 Hz, 2H, Et2O-CH2), 1.11 (t,
J = 7 Hz, 3H, Et2O-CH3). 13C NMR (100.6 MHz, ace-
tone-d6, ꢁ20 °C) CO not obs., 157.4 (C6-py), 156.0
(C2-py), 149.7, 142.0, 137.9, 134.6, 133.9, 129.2, 127.9,
2.3.6. Attempted preparation of {m-[(2-py)(pz)2C]-
(C6H4)[C(pz)2(2-py)Mn(CO)3]}(PF6) (5c)
1
127.6, 126.9, 110.0 (C4-pz), 83.6 (Ca). H NMR (500
A mixture of 0.036 g (0.13 mmol) Mn(CO)5Br, 0.033
g (0.13 mmol) AgPF6, and 0.069 g (0.13 mmol) L5 was
reacted under the conditions described above for the
preparation of 5b. In this case, 0.085 g of a light orange
solid was obtained which was identified as a 50% mix-
ture of the desired compound and 5b by elemental anal-
yses and its ESI(+) mass spectrum. Anal. Calcd. (Obs.)
for 50% mixture of 5c and 5b: C, 44.30 (44.28); H,
MHz, acetone-d6, 50 °C) 9.46 (d, J = 5 Hz, 1H, H6-
py), 8.67 (s, 2H, H3-pz), 8.26 (m, 3H, aryl and H4-py),
8.04 (d, J = 8 Hz, 1H, H5-py), 7.95-7.88 (m, 5H, Ph),
7.78 (ps t, 1H, H3-py), 6.70 (s, 2H, H4-pz). 13C NMR
(125.8 MHz, acetone-d6, ꢁ20 °C) 221.0 (CO), 220.0
(CO), 157.3 (C6-py), 155.7 (C2-py), 149.4, 141.8, 137.8,
134.5, 133.6, 129.0, 127.7, 127.4, 126.7, 109.7 (C4-pz),
83.2 (Ca).
1
2.60 (3.03); N, 15.07 (14.78). H NMR (400 MHz, ace-
tone-d6) all br s: dH 9.49 (H6-py), 9.02, 8.75 (sh), 8.73
(H3-pz), 8.55, 8.32, 8.20, 8.12, 7.80 (H3-py), 7.70, 7.60,
7.46, 7.30, 6.76 (H4-pz), 6.52 (H4-pz). HRMS-ESI(+)
(m/z): [(L5)Mn(CO)3]+ calcd for C33H24MnN10O3,
663.1411; found, 663.1413; {[Mn(CO)3]2(l-L5) + PF6}+
calcd for C36H24F6Mn2N10O6P, 947.0283; found,
947.0250.
2.3.4. [(CO)3Mn{m-C6H4[C(pz)2(2-py)]2}-
Mn(CO)3](BF4)2 (5a)
A mixture of 0.074 g (0.27 mmol) Mn(CO)5Br and
0.053 g (0.27 mmol) AgBF4in 20 ml acetone was heated
at reflux 3 h under nitrogen and then the yellow solution
was transferred by cannula filtration (to remove AgBr)
to a nitrogen-purged solution containing 0.071 g (0.14
mmol) m-C6H4[C(pz)2(2-py)]2 in 10 ml acetone. The
AgBr was washed with two 5 ml portions of acetone
to ensure quantitative transfer of manganese reagent
to the acetone solution of the ligand. The resulting yel-
low solution was heated at reflux 14 h, solvent was re-
moved by vacuum distillation, and the resulting yellow
solid was washed with two 10 ml portions of Et2O and
dried under vacuum to leave 0.12 g (89%) of the desired
compound as a hygroscopic yellow solid. Mp, 150–160
°C dec. with effervescence; 210 °C green. Anal Calcd.
(Obs.) for C36H28N10B2F8O8Mn2, 5a Æ 3H2O: C, 41.98
(42.07); H, 2.94 (2.42); 13.60 (13.50). IR (cmꢁ1): mco
2049, 1955. HRMS-ESI(+) (m/z): [M + BF4]+ calcd for
C23H19N5O3Mn, 468.0868; found, 468.0861. Crystals
suitable for single crystal X-ray structural studies were
grown by vapor diffusion of Et2O into a nitromethane
solution of the complex.
2.4. Crystallography
A yellow blocklike crystal of [{PhC(pz)2(2-py)}Mn-
(CO)3](O3SCF3) 1a, a yellow plate of [{PhC(pz2)(2-
py)}Mn(CO)3](PF6) Æ CH2Cl2
1b Æ CH2Cl2,
yellow
blocks of {[PhC(4-Mepz)2(2-py)]Mn(CO)3}(PF6), 2, and
{m-C6H4[C(pz)2(2-py)Mn(CO)3]2}(BF4)2 Æ 2CH3NO2,
5a Æ 2CH3NO2, were each mounted onto the end of thin
glass fibers using inert oil. X-ray intensity data covering
at least >90% of the full sphere of reciprocal space were
measured at 190(1) K for 1a and 1b Æ CH2Cl2, at 100(1)
K for 2, and at 150(1) K for 5a Æ 2CH3NO2 on a Bruker
SMART APEX CCD-based diffractometer system (Mo
˚
Ka radiation, k = 0.71073 A) [11]. The raw data frames
were integrated with SAINT+ [11], which also applied
corrections for Lorentz and polarization effects. The fi-
nal unit cell parameters, see Table 1, for 1a, 1b Æ CH2Cl2,
2, and 5a Æ 2CH3NO2 are based on the least-squares
refinement of 6294, 8578, 6647, and 8893 reflections,
with I > 5(r)I from each respective data set. Analysis
of the data showed negligible crystal decay during data
collection. An empirical absorption correction based
on the multiple measurement of equivalent reflections
was applied to the 1a, 1b Æ CH2Cl2 and 2 data sets with
the program SADABS [11]. No absorption correction
was applied to the 5a Æ 2CH3NO2 data set. The struc-
2.3.5. {m-C6H4[C(pz)2(2-py)Mn(CO)3]2}(PF6)2 (5b)
A mixture of 0.071 g (0.26 mmol) Mn(CO)5Br and
0.066 g (0.27 mmol) AgPF6in 20 ml acetone was heated
at reflux for 2 h, then the canary yellow solution was
transferred by cannula filtration to a solution of 0.068
g (0.13 mmol) L5 in 10 ml acetone. The precipitate of
AgBr from the first flask was washed with two 5 ml por-
tions of diethyl ether and these were also transferred to

D.L. Reger et al. / Journal of Organometallic Chemistry 690 (2005) 1901–1912
1905
Table 1
Experimental and Crystal Data for [{PhC(pz)2(2-py)}Mn(CO)3](O3SCF3) (1a), [{PhC(pz2)(2-py)}Mn(CO)3](PF6) Æ CH2Cl2 (1b Æ CH2Cl2), {[PhC-
(
4-Mepz)2(2-py)]Mn(CO)3}(PF6) (2), and {m-C6H4[C(pz)2(2-py)Mn(CO)3]2}(BF4)2 Æ 2CH3NO2, (5a Æ 2CH3NO2)
Compound 1a
Compound 1b Æ CH2Cl2
Compound 2
Compound 5a Æ 2CH3NO2
Formula
C22H15F3MnN5O6S
589.39
190(1)
C22H17Cl2F6MnN5O3P
670.22
190(1)
C23H19F6MnN5O3P
613.34
100(1)
C38H30B2F8Mn2N12O10
1098.24
150(1)
Molecular weight
Temperature (K)
Crystal system
Space group
Triclinic
P-1
Hexagonal
P63cm
Orthorhombic
P212121
Triclinic
P-1
˚
a (A)
10.1816(6)
12.0181(8)
12.0228(8)
112.5270(10)°
106.8640(10)°
104.7070(10)
1184.41(13)
2
17.8784(9)
17.8784(9)
14.9881(11)
90
10.2687(6)
12.8750(8)
19.3494(12)
90
11.0510(5)
11.5200(5)
19.0625(8)
81.7710(10)
84.8290(10)
69.5560(10)
2248.42(17)
2
˚
b (A)
˚
c (A)
a (°)
b (°C)
c (°)
90
120
90
90
3
˚
V (A )
4148.9(4)
6
1.609
2558.2(3)
4
1.593
Z
qcalc (g/cm3)
1.653
0.720
1.622
0.665
l (mmꢁ1
)
0.803
0.658
h range (°C)
Index range
2.01 to 25.03
ꢁ12 6 h 6 12
ꢁ14 6 k 6 14
ꢁ14 6 l 6 14
9857(4186)
R1 = 0.0598
R1 = 0.0704
wR2 = 0.1655
1.354/ꢁ0.540
2.28 to 26.41
ꢁ22 6 h 6 22
ꢁ22 6 k 6 20
ꢁ18 6 l 6 18
22469(2993)
R1 = 0.0584
R1 = 0.0668
wR2 = 0.1526
0.640/ꢁ0.489
1.90 to 26.39
ꢁ12 6 h 6 12
ꢁ16 6 k 6 16
ꢁ24 6 l 6 22
18798(5234)
R1 = 0.0441
R1 = 0.0488
wR2 = 0.1125
0.818/ꢁ0.342
1.90 to 25.05
ꢁ13 6 h 6 13
ꢁ13 6 k 6 13
ꢁ22 6 l 6 22
18539(7950)
R1 = 0.0464
R1 = 0.0636
wR2 = 0.1165
0.398/ꢁ0.292
Total (Indep.) Rflns
Final R indices [I > 2r(I)]
R indices (all data)
3
Largest differential Peak/hole (e/A )
˚
tures were solved by a combination of direct methods
and difference Fourier syntheses, and refined by full-ma-
trix least-squares against F2, using the SHELXTL soft-
ware package [12]. Except where noted below in the
refinement of 5a Æ 2CH3NO2, all non-hydrogen atoms
were refined with anisotropic displacement parameters.
Hydrogen atoms were placed in geometrically idealized
positions and refined as standard riding atoms. Further
notes regarding the structure solution and refinement for
each compound can be found below.
[{PhC(pz)2(2-py)}Mn(CO)3](SO3CF3), 1a, crystal-
lizes in the triclinic system in the space group P-1. All
atoms reside on positions of general crystallographic
symmetry. Disorder in the PhC(pz)2(2-py) ligand was
observed, in the form of two of the ligating rings appear-
ing to be a mixture of pyrazolyl/pyridyl groups. Initially
the group site occupation factors for the two affected
pyrazolyl/pyridyl groups were allowed to refine, con-
strained to sum to unity; near the end of the refinement
the sofs were fixed at 0.60/0.40 (pyrazolyl/pyridyl, ring 2)
and 0.40/0.60 (pyrazolyl/pyridyl, ring 3). A total of 76
restraints (SHELX FLAT, SADI and SAME) were em-
ployed to assist in the refinement of the disordered
atoms.
the ligand are located in the mirror plane. The mirror
plane bisects the phenyl ring. The remaining pyrazolyl
ring and carbonyl group atoms are located on general
positions. As evident in Fig. 3, the displacement ellip-
soids of pyridyl ring atoms C23 and C24, and of pyraz-
olyl ring atom C12 are slightly inflated compared to
neighboring atoms. This indicates a slight py/pz ring dis-
order analogous to that observed in 1a. However, the
disorder fractions were too small to be modeled success-
fully (ca. <10%). Two independent PFꢁ6 anions are pres-
ent in the asymmetric unit, both of which are disordered
over special positions. The P(1)F6ꢁ anion occupies a po-
sition of local site symmetry C3v. Four independent F
atoms generate a total of 14 F positions around P1.
The site occupation factors for these were allowed to re-
fine freely until reasonable, stable valuꢁes were obtained,
and then they were fixed. The P(2)F6 anion sits on a
threefold axis; the disorder of the F atoms was treated
in a similar fashion as P(1). Near the end of the refine-
ment a slight manual adjustment of the F site occupa-
tion factors was necessary to satisfy charge balance. A
CH2Cl2 molecule of crystallization which is disordered
across a mirror plane is also present in the asymmetric
unit. A total of 17 geometric restraints (SHELX SADI)
were used to assist in modeling the PFꢁ6 and CH2Cl2 dis-
order. At convergence, the absolute structure (Flack)
parameter was ꢁ0.04(4), indicating the correct orienta-
tion of the polar axis and the lack of racemic twinning.
Systematic absences in the intensity data of 2 were
uniquely consistent with the chiral space group
Systematic absences in the intensity data for
1b Æ CH2Cl2, were consistent with the space group
P63cm, clearly showing the presence of a 63 screw axis
and a c-glide plane. The [{PhC(pz2)(2-py)}Mn(CO)3]+
cation is located on a mirror plane. The Mn atom, one
carbonyl group (C41–O41) and the pyridine ring of

1906
D.L. Reger et al. / Journal of Organometallic Chemistry 690 (2005) 1901–1912
P212121. One {[PhC(4-Mepz)2(2-py)]Mn(CO)3]+ and one
PFꢁ6 anion, both well-ordered, are present in the asym-
metric unit. At convergence, the absolute structure
(Flack) parameter was 0.04(2), indicating the correct
absolute structure.
Compound 5a Æ 2CH3NO2 crystallizes in the triclinic
system in the P-1 space group. All atoms reside on posi-
tions of general crystallographic symmetry. One
[(CO)3Mn(l-m-L5)Mn(CO)3]2+ cation, two BF4ꢁ anions
and two nitromethane molecules of crystallization are
present on the asymmetric unit. Extensive disorder of
the {l-m-C6H4[C(pz)2(py)]2} ligand and the BFꢁ4 coun-
terions was encountered; the two included nitromethane
molecules behaved normally. The disorder of the ligand
takes the form of rotation of the [–C(pz)2(2-py)] group
around the methine carbon – (C3/C5) bond and results
in apparent superposition of pyrazolyl/pyridyl rings.
Five of the six rings were affected by the disorder. Dis-
order fractions for each ring were initially refined, but
were subsequently fixed close to the refined values to
provide a more stable refinement. The disorder fractions
were constrained to the composition [(pz)2(2-py)] at each
end. The disorder of both BFꢁ4 anions was modeled
using three orientations. Elongated displacement
parameters for some of the F atoms indicate more orien-
tations are probably present. Similar disorder was
observed in the space group P1. Eventually all non-
hydrogen atoms were refined with anisotropic displace-
ment parameters except for the minor component of
each BFꢁ4 anion (isotropic). A total of 70 restraints were
used to model the disorder.
Fig. 1. Syntheses of heteroscorpionate ligands based on di(pyraz-
olyl)(2-pyridyl)methane units.
could be extended to 4-substituted pyrazoles as in the
case of L2. Longer reaction times were found necessary
to give yields comparable to that of unsubstituted L1.
The use of longer chain alkyls such as in the 4-pentyl
or 4-hexylpyrazolyl derivatives [15] were similarly slug-
gish, and difficulties that were encountered when
attempting to separate the unreacted benzoylpyridine
and other byproducts has thus far prevented the isola-
tion of pure compounds (owing to the similar solubilities
and similar Rfꢁs on both silica and alumina). In the case
of L4, the preparative reaction was seemingly fickle as
yields were diverse and ranged from 4% to 40% indepen-
dent of a constant reaction time of 3 days. Therefore,
different synthetic conditions were explored in an effort
to optimize the yield. Three reactions containing equal
amounts (1 mmol each) of reagents p-(2-py)2NC6H4-
C(O)(2-py), S(O)(pz)2 (prepared and isolated indepen-
dently) and 10 mol% catalyst were performed
simultaneously. A significant amount of product (TLC
monitoring-about 30% relative spot size to the starting
material) was formed when anhydrous CoCl2 was used
as a catalyst and when 3 ml of THF was used as a sol-
vent. Only trace product (<5%) was observed when the
3. Results and discussion
3.1. Syntheses
The cobalt(II) chloride catalyzed Peterson rearrange-
ment reaction between either di(pyrazolyl)carbonyl or
sulfinyldi(pyrazolyl) and either aldehydes or ketones
has proven to be a useful way to prepare di(pyraz-
olyl)alkane or other di(pyrazolyl)heteroscorpionate li-
gands [7a,13, 14]. The aryl(pyridyl)methanone starting
materials of the form (aryl)C(O)(2-py) (left side of Fig.
1) used in this work are accessible from the correspond-
ing aryl cyanides and ꢀ2-Lipyꢁ as has been described else-
where [9]. Our group has also previously reported the
preparation of compounds L1 and L5 by using the Pet-
erson methodology [8].
Generally, this reaction is much more difficult for dia-
rylketones compared to either aldehydes or aliphatic ke-
tones and this difficulty in turn is the reason for the
typically low yields and long reaction times for the
(aryl)C(O)(2-py) systems reported here. In the current
study, it was found that the previously reported Peter-
son rearrangement reaction involving benzolypyridine

D.L. Reger et al. / Journal of Organometallic Chemistry 690 (2005) 1901–1912
1907
reaction was performed neat and no product was
observed when CoCl2 Æ 6H2O was used as a catalyst
and 3 ml of THF was present. We also explored other
routes to these ligands, most notably trying to convert
the phenyl pyridyl diketone to the phenyl pyridyl tetra-
acetal (which would then have been treated with pyraz-
ole in the presence of acid), but the acetalization
reaction proceeds very sluggishly, if at all, depending
on the nature of the catalysts used (many catalysts,
including indium triflate [16] and bismuth triflate [17]
were explored). When it did proceed, the resulting prod-
uct mixture was challenging to separate and very low
yields of the tetraacetal resulted.
Tricarbonylmanganese(I) complexes of monotopic
L1–L3 ligands were prepared in high yield by the reac-
tion between Mn(CO)5Br, a silver salt of a weakly coor-
dinating anion, and then subsequent reaction with the
desired heteroscorpionate, as in Fig. 2.
When similar reactions were performed with a
Mn(CO)5Br/AgBF4 (AgPF6)/L5 ligand ratio of 2:2:1,
the expected homobimetallic complexes 5a and 5b were
obtained in good yield. However, reactions that were
performed with twice the amount of ligand always pro-
duced mixtures of the homobimetallic and the desired
monometallic species as indicated by elemental analyses
1
and by the complex H NMR spectrum. It has not yet
been possible to separate the mixture or to otherwise ob-
tain the pure monometallic manganese compound of L5.
The pure solids are hygroscopic and the monometallic
derivatives are soluble in polar solvents such as acetone
or acetonitrile, exhibit modest solubility in CH2Cl2 but
are only slightly soluble in chloroform and are insoluble
in diethyl ether. The bimetallic compounds are consider-
ably less soluble in acetone than their monometallic
counterparts but they do show good solubility in aceto-
nitrile and nitromethane.
The IR spectra of 1–3, 5a and 5b consist of two bands
centered near 2049 and 1955 cmꢁ1 as expected for fac-
carbonyls. As expected, substitution on the arene ring
has no effect on the carbonyl stretching frequencies and
even the 4-methyl substitution only shifts the frequencies
slightly to lower energy. The room temperature NMR
Fig. 2. Summary of reaction used to prepare tricarbonylmanganese(I) complexes of the heteroscorpionate ligands L1–L3 and L5.

1908
D.L. Reger et al. / Journal of Organometallic Chemistry 690 (2005) 1901–1912
spectra are characterized by broad resonances and the
carbonyl carbon-13 nuclei are not observed. At 55 °C,
the line widths of the proton NMR resonances are greatly
reduced but the resonances for the carbonyls are not ob-
served in the 13C NMR spectra. The carbonyl carbon-13
nuclei can be easily observed at temperatures of ꢁ10 °C
and lower. The temperature dependence of the 1H
NMR spectra can be attributed to the restricted rotation
about the aryl-methine carbon bond that is alleviated at
higher temperatures as the fast exchange region is ap-
proached. This action can be envisioned as one similar
to that observed for the ꢀmolecular turnstileꢁ, [(p-
BrC6H4)5C5]RuTp4Bo where Tp4Bo refers to hydro-
tris(indazolyl)borate [18]. However, in the current system
restricted rotation can be envisioned to arise as a result of
steric interactions involving the atoms of the arene ring
and those at the 5-position of the pyrazolyl rings and at
the 3-position of the pyridine ring. Presumably, the tem-
perature dependence of the 13C NMR spectra can be
attributed to the restricted rotation of the arene ring
(approaching the slow exchange regime) acting in combi-
nation with the reduction of the quadrupolar (55Mn nu-
cleus) component to the 13C relaxation times.
3.2. Solid state structures
The structures and atom labeling schemes of the
cations of 1a, 1b, 2, and 5a are provided in Fig. 3 while
Table 2 summarizes important bond distances and
angles.
Interestingly, the average Mn–C distances, Mn–N,
and C–O bond distances are remarkably constant for
the four compounds, which show that substitution
along the arylC(pz)2(2-py) ligand periphery has little ef-
fect on the electronic environment of the metal complexes.
Thus, the average Mn–N bond distance is 2.04 A for
each of the four structurally characterized derivatives
while the average Mn–C bond distances are 1.82, 1.83,
˚
1.82 and 1.81 A for 1a, 1b, 2, and 5, respectively. These
values are similar to those observed in the structures of
{[HC(3-iPrpz)3]Mn(CO)3}(OSO2CF3) (Mn–N 2.07,
˚
˚
M–C 1.80 A) [2], 1,2,4,5-{[(OC)3Mn(pz)3CCH2OCH2]4-
C6H2}(BF4)4(CH3CN)6(Et2O)2 (Mn–N 2.04, M–C 1.82
˚
A) [7f], p-{[(OC)3Mn(pz)3CCH2OCH2]2C6H4} (OSO2-
˚
CF3)2(THF) (Mn–N 2.04 A, M–C 1.81 A), and m-
{[(OC)3Mn(pz)3CCH2OCH2]2C6H4} (BF4)2 (Mn–N
˚
˚
2.05 and 2.04 A; M–C 1.81 A and 1.80 A) [7f].
˚
˚
Fig. 3. ORTEP diagrams of the cations in [{PhC(pz)2(2-py)}Mn(CO)3](O3SCF3) (1a), [{PhC(pz2)(2-py)}Mn(CO)3](PF6) Æ CH2Cl2 (1b Æ CH2Cl2),
{[PhC(4-Mepz)2(2-py)]Mn(CO)3}(PF6) (2), and {m-C6H4[C(pz)2(2-py)Mn(CO)3]2}(BF4)2 Æ 2CH3NO2, (5a Æ 2CH3NO2). Only the major disorder
components for 1a and 5a Æ 2CH3NO2 are shown. Ellipsoids are drawn at the 50% probability level.

D.L. Reger et al. / Journal of Organometallic Chemistry 690 (2005) 1901–1912
1909
Table 2
˚
Selected bond distances (A) and angles (°) for [{PhC(pz)2(2-py)}Mn(CO)3](O3SCF3) (1a), [{PhC(pz2)(2-py)}Mn(CO)3](PF6) Æ CH2Cl2 (1b Æ CH2Cl2),
{[PhC(4-Mepz)2(2-py)]Mn(CO)3}(PF6) (2), and {m-C6H4[C(pz)2(2-py)Mn(CO)3]2}(BF4)2 Æ 2CH3NO2, (5a Æ 2CH3NO2)
Compound 1a
Compound 1b Æ CH2Cl2
Compound 2
Compound 5a Æ 2CH3NO2
Bond distances
Mn–N(pz)
Mn–N(pz)
Mn–N(py)
Mn–C
2.040(3)
2.007(3)
2.073(3)
1.815(5)
1.821(5)
1.818(4)
1.499(4)
1.506(4)
1.517(5)
1.526(5)
2.054(4)
2.054(4)
2.016(5)
1.820(5)
1.820(5)
1.835(7)
1.507(5)
1.507(5)
1.514(8)
1.527(7)
2.006(3)
2.036(3)
2.089(3)
1.811(4)
1.815(4)
1.822(4)
1.486(4)
1.479(4)
1.531(4)
1.534(4)
1.993(2)
2.062(2)
2.077(2)
1.804(4)
1.815(4)
1.819(3)
1.487(4)
1.493(4)
1.530(4)
1.528(4)
2.000(3)
2.071(3)
2.057(2)
1.811(4)
1.817(4)
1.807(4)
1.489(4)
1.499(4)
1.507(4)
1.534(4)
Mn–C
Mn–C trans py
C(1)–N(pz)
C(1)–N(pz)
C(1)–C(py)
C(1)–C(ipso–Ph)
Bond angles
N(pz)–Mn–N(pz)
N(pz)–Mn–N(py)
N(pz)–Mn–N(py)
C–Mn–C bisect py
C–Mn–C
85.13(12)
84.47(12)
82.82(12)
89.7(2)
84.62(19)
84.15(14)
84.15(14)
90.8(3)
85.71(11)
83.93(10)
83.07(10)
88.95(17)
89.21(16)
89.02(18)
84.36(10)
83.62(9)
84.58(9)
89.83(14)
90.88(15)
89.99(14)
83.77(10)
84.87(10)
83.87(10)
92.21(14)
88.67(15)
90.16(16)
90.80(19)
91.73(19)
89.6(2)
89.6(2)
C–Mn–C
3.3. Supramolecular structures
in the left of Fig. 5). Three sets of CHꢀ ꢀ ꢀO interactions re-
sult in chains that run along the [1 1 1] direction. One in-
volves a hydrogen at the 5-position of the well-ordered
pyrazolyl ring and the oxygen of a triflate counteranion
The crystal packing diagram (Fig. 4) of 1a indicated
that a layered structure is formed in the solid. A cursory
examination of the supramolecular structure was under-
taken in an attempt to verify this hypothesis. Since two of
the three ligating rings (one pyrazolyl and the pyridyl)
were disordered, the separate disorder components were
examined and each gave similar results. The major pyraz-
olyl disorder component acts as an acceptor in a CHꢀ ꢀ ꢀp
interaction with a hydrogen from a well-behaved phenyl
˚
[CH(11)–O(3) 2.29 A, 145.4°] while the other two involve
hydrogens of the disordered pyrazolyl/pyridyl ring sys-
˚
tems [CH(22a)–O(2) 2.31 A, 173.1°; CH(34a)–O(2) 2.30
˚
A 135.4°]. The integrity of the chain remains when the
minor disorder component is examined. The chains are
held together along the a directions into sheets by longer
˚
CHꢀ ꢀ ꢀO interactions between CH(23a) and O(2) (2.55 A,
˚
ring {CH(6)-ring centroid (Ct)[N(21a)] = 2.85 A, C–H–
Ct angle = 140.5°}. This interaction results in the forma-
tion of dimers of cations (three of these dimers are shown
157.3°).
The exquisite three-dimensional supramolecular
structure of 1b (Fig. 6) is organized solely by CHꢀ ꢀ ꢀF
Fig. 4. Crystal packing diagram of 1a emphasizing layered structure of the compound.

1910
D.L. Reger et al. / Journal of Organometallic Chemistry 690 (2005) 1901–1912
Fig. 5. Supramolecular sheet structure of the major disorder component of 1a. Left: chains held together via CH-p (red lines, left) and CH-O
interactions (green lines, left and blue lines, right). Middle: end on view of chain. Right: Stacking of chains along the a directions as a result of CH–O
interactions (blue lines).
Fig. 6. Supramolecular Structure of [{PhC(pz2)(2-py)}Mn(CO)3](PF6) Æ CH2Cl2 (1b Æ CH2Cl2). Left: Hexagonal tube of cations held together by
trifurcated CHꢀ ꢀ ꢀF interactions (green lines) between well-behaved fluorines on disordered PFꢁ6 anions and three pyridiyl ring hydrogens. Center:
Crystal packing with CH2Cl2 molecules (light blue spheres). Right: Top view of two sheets PFꢁ6 organize the cations into a sheet in the ab plane.
˚
interactions that are shorter than the 2.6 A cutoff pro-
posed to be indicative of weak hydrogen bonding [3c].
There are two independent PFꢁ6 sites in the lattice and
each affords connectivity in a different manner. The first
site containing P(1) is rotationally disordered about the
F(11)–P(1)–F(15) axis. The well-ordered fluorines F(11)
and F(15) each participate in trifurcated CHꢀ ꢀ ꢀF inter-
actions with hydrogen atoms at the p- and m-positions,
respectively, of the pyridyl ring on the cations (Fig. 6,
The chiral three-dimensional supramolecular struc-
ture of 2 is organized by CHꢀ ꢀ ꢀp, CHꢀ ꢀ ꢀO, and CHꢀ ꢀ ꢀF
interactions (Table 3). The result of the CHꢀ ꢀ ꢀp and
CHꢀ ꢀ ꢀO interactions is stacked sheets of left-handed
helices where each adjacent sheet is related by the 21
screw axis (Fig. 7). Thus, each sheet is held together
by a set of CHꢀ ꢀ ꢀp interactions between C(5)H(5) of
Table 3
Summary of short CHꢀ ꢀ ꢀF interactions in the structure
˚
left) [CH(24)–F(11) 2.37 A, 137°; CH(23)–F(15) 2.46
˚
A, 139°].
of[PhC(pz4Me)2(2-py)Mn(CO)3](PF6) (2)
This arrangement creates a hexagonal tube of cations
filled with an array of anions directed along c. The tubes
are connected in the ab plane as a result of CHꢀ ꢀ ꢀF inter-
actions involving the o-hydrogen of the phenyl ring H(3)
and F(22) of the second independent PFꢁ6 anion as in
˚
Donorꢀ ꢀ ꢀacceptor
Hꢀ ꢀ ꢀF (A)
C(H)ꢀ ꢀ ꢀF (°)
C(7)H(7)ꢀ ꢀ ꢀF(2)
2.50
2.44
2.47
2.54
2.53
2.49
2.29
134.1
154.0
133.1
120.6
119.3
144.3
146.1
C(13)H(13)ꢀ ꢀ ꢀF(2)
C(23)H(23)ꢀ ꢀ ꢀF(3)
C(24)H(24b)ꢀ ꢀ ꢀF(3)
C(32)H(32)ꢀ ꢀ ꢀF(1)
C(34)H(34)ꢀ ꢀ ꢀF(4)
C(35)H(35)ꢀ ꢀ ꢀF(6)
˚
Fig. 6 (right) [CH(3)–F(22) 2.48 A, 113°]. This structure
is further supported by other short (<2.6 A) CH–F inter-
actions (not shown).
˚

D.L. Reger et al. / Journal of Organometallic Chemistry 690 (2005) 1901–1912
1911
Fig. 7. Supramolecular framework of 2 composed of only CHꢀ ꢀ ꢀp and CHꢀ ꢀ ꢀO interactions (red lines). Top left: Left-handed helix comprised of
CHꢀ ꢀ ꢀp interactions. Middle left: Left-handed helix comprised of CHꢀ ꢀ ꢀp interactions. Bottom left: Left-handed helix comprised of CHꢀ ꢀ ꢀO
interactions. The combination of this CHꢀ ꢀ ꢀO interaction with either of the CHꢀ ꢀ ꢀp interactions above creates sheets in the ab plane. Middle:
Stacking of two sheets of left- and right-handed helices by CHꢀ ꢀ ꢀp interactions (pink lines). Right: View onto top of two sheets. PFꢁ6 anions reside in
channels created by stacking of sheets.
the phenyl ring acting as a hydrogen donor and the cen-
troid (Ct) of the pyrazolyl ring containing N(11) with
lid state by a complex array of non-covalent forces. Par-
ticularly interesting is the three dimensional structure of
{[j3-PhC(pz)2(2-py)]Mn(CO)3}(PF6), organized exclu-
sively by CHꢀ ꢀ ꢀF interactions. In all these complexes,
the [C(pz)2(2-py)]-scorpionate unit shows j3-coordina-
tion, as opposed to the j2-coordination observed in sil-
ver(I) chemistry. We have prepared the first bimetallic
complex of this ligand type, [(CO)3Mn{l-m-
C6H4[C(pz)2(2-py)]2}Mn(CO)3](BF4)2. Unfortunately,
we have been unable to prepare the monometallic ana-
log, {m-C6H4[C(pz)2(2-py)]2}Mn(CO)3](BF4), for use in
the syntheses of heterobimetallic complexes. Clearly,
these ligands and their derivatives are applicable to the
chemistry of many other metal systems.
˚
C(5)H(5)–Ct[N(11)] 2.74 A, 162.3° and by a set of
CHꢀ ꢀ ꢀO interactions involving a 4-methyl hydrogen
C(14)H(14c) and the carbonyl oxygen O(43)
˚
[C(14)H(14c)–O(43), 2.56 A, 153.0°]. The sheets are held
together by another CH Æ Æ Æ p interaction that occurs
between a methyl pyrazolyl hydrogen donor and the
phenyl ring that acts as an acceptor with
˚
C(24)H(24b)–Ct[Ph] of 3.20 A and 102°. These interac-
tions form a porous network of cations as in Fig. 7,
right. The PF6 anions reside in the channels and support
the network of cations in all three dimensions by numer-
˚
ous CHꢀ ꢀ ꢀF interactions that are shorter than the 2.6 A
cutoff proposed to be indicative of weak hydrogen bond-
ing [3c]. Extensive disorder of the ligand and tetrafluoro-
borate anions in 5a prevented
a
comprehensive
5. Supplementary material
examination of its supramolecular structure. An inspec-
tion of the packing arrangement reveals that the cationic
building blocks are arranged into chains along the body
diagonal of the unit cell by intercationic contacts be-
tween the p clouds of the carbonyl groups bonded to
manganese atoms.
Crystallographic data for the structural analysis has
been deposited with the Cambridge crystallographic
Centre, CCDC 247499-247502. Copies of this informa-
tion may be obtained free of charge from the director,
CCDC, 12 Union Road, Cambridge, CB2 1EZ UK
(fax +44-1223-336-033; e-mail deposit@ccdc.cam.ac.uk,
or www: http://www.ccdc.cam.ac.uk).
4. Conclusions
We have shown that the Peterson rearrangement
reaction between either di(pyrazolyl)carbonyl or sul-
finyldi(pyrazolyl) and appropriately substituted ketones
is a useful methodology to prepared ligands containing
the [C(pz)2(2-py)]-scorpionate moiety. The Mn(CO)3
complexes of these ligands show interesting structural
diversity, with the complexes being organized in the so-
Acknowledgement
We thank the National Science Foundation (CHE-
0414239) for support. The Bruker CCD Single Crystal
Diffractometer was purchased using funds provided by
the NSF Instrumentation for Materials Research Pro-
gram through Grant DMR:9975623.

1912
D.L. Reger et al. / Journal of Organometallic Chemistry 690 (2005) 1901–1912
[7] (a) D.L. Reger, K.J. Brown, J.R. Gardinier, M.D. Smith,
Organometallics 22 (2003) 4973;
References
(b) D.L. Reger, J.R. Gardinier, R.F. Semeniuc, M.D. Smith, J.
Chem. Soc., Dalton Trans. (2003) 1712;
[1] (a) O.R. Evans, W. Lin, Acc. Chem. Res. 35 (2002) 511;
(b) D. Braga, J. Chem. Soc., Dalton Trans. 21 (2000) 3705;
(c) S.J. Lee, A. Hu, W. Lin, J. Am. Chem. Soc. 124 (2002) 12948.
[2] D.L. Reger, T.C. Grattan, K.J. Brown, C.A. Little, J.J.S. Lamba,
A.L. Rheingold, R.D. Sommer, J. Organomet. Chem. 607 (2000)
120.
(c) D.L. Reger, T.D. Wright, R.F. Semeniuc, T.C. Grattan,
M.D. Smith, Inorg. Chem. 40 (2001) 6212;
(d) D.L. Reger, R.F. Semeniuc, M.D. Smith, Eur J. Inorg. Chem.
(2002) 543;
(e) D.L. Reger, R.F. Semeniuc, M.D. Smith, J. Chem. Soc.
Dalton Trans. (2002) 476;
[3] (a) Weak hydrogen bonds (X–Hꢀ ꢀ ꢀY) involve less electronegative
atoms; we discuss here only those of the C–Hꢀ ꢀ ꢀY type (Y = O, F).
See for example: M.J. Calhorda, Chem. Commun. (2000) 801;
(b) G.R. Desiraju, Acc. Chem. Res. 29 (1996) 441;
(c) F. Grepioni, G. Cojazzi, S.M. Draper, N. Scully, D. Braga,
Organometallics 17 (1998) 296;
(f) D.L. Reger, R.F. Semeniuc, M.D. Smith, J. Organomet.
Chem. 666 (2003) 87;
(g) D.L. Reger, R.F. Semeniuc, I. Sillaghi-Dumitrescu, M.D.
Smith, Inorg. Chem. 42 (2003) 3751;
(h) D.L. Reger, R.F. Semeniuc, V. Rassolov, M.D. Smith, Inorg.
Chem. 43 (2004) 537.
(d) H.C. Weiss, R. Boese, H.L. Smith, M.M. Haley, Chem.
Commun. (1997) 2403.
[8] D.L. Reger, J.R. Gardinier, M.D. Smith, Polyhedron 23 (2004)
291.
[4] C.J. Janiak, J. Chem. Soc., Dalton Trans. (2000) 3885, and
references therein.
[9] D.L. Reger, J.R. Gardinier, M.D. Smith, P.J. Pellechia, Inorg.
Chem. 42 (2003) 482.
[5] (a) H. Takahashi, S. Tsuboyama, Y. Umezawa, K. Honda, M.
Nishio, Tetrahedron 56 (2000) 6185;
[10] D.L. Reger, J.R. Gardinier, M.D. Smith, Inorg. Chim. Acta 352
(2003) 151.
(b) S. Tsuzuki, K. Honda, T. Uchimaru, M. Mikami, K. Tanabe,
J. Am. Chem. Soc. 122 (2000) 11450;
[11] SMART Version 5.625, SAINT+ Version 6.02a and SADABS.
Bruker Analytical X-ray Systems, Inc., Madison, WI, USA,
1998.
(c) O. Seneque, M. Giorgi, O. Reinaud, Chem. Commun. (2001)
984;
(d) H.C. Weiss, D. Blaser, R. Boese, B.M. Doughan, M.M.
Haley, Chem. Commun. (1997) 1703;
[12] G.M. Sheldrick, SHELXTL, Version 5.1, Bruker Analytical X-ray
Systems, Inc, Madison, WI, USA, 1997.
(e) N.N.L. Madhavi, A.K. Katz, H.L. Carrell, A. Nangia, G.R.
Desiraju, Chem. Commun. (1997) 2249;
[13] D.L. Reger, R.P. Watson, J.R. Gardinier, M.D. Smith, Inorg.
Chem. 43 (2004) 6609.
(f) N.N.L. Madhavi, A.K. Katz, H.L. Carrell, A. Nangia, G.R.
Desiraju, Chem. Commun. (1997) 1953.
´
[14] K.I. The, L.K. Peterson, Can. J. Chem. 51 (1973) 422.
[15] D.L. Reger, J.R. Gardinier, T.C. Grattan, M.R. Smith, M.D.
Smith, New. J. Chem. (2003) 1670.
[6] (a) D.S. Reddy, D.C. Craig, G.R. Desiraju, J. Am. Chem. Soc.
118 (1996) 4090;
[16] S. Muthusamy, S.A. Babu, C. Gunanathan, Tetrahedron 58
(2002) 7897.
(b) J. Kowalik, D. VanDerveer, C. Clower, L.M. Tolbert, Chem.
Commun. (1999) 2007;
[17] N.M. Leonard, M.C. Oswald, D.A. Freiberg, B.A. Nattier, R.C.
Smith, R.S. Mohan, J. Org. Chem. 67 (2002) 5202.
[18] A. Carella, J. Jaud, G. Rapenne, J.-P. Launey, Chem. Commun.
19 (2003) 2434.
(c) M. Freytag, P.G. Jones, B. Ahrens, A.K. Fischer, New J.
Chem. 23 (1999) 1137;
(d) R. Thaimattam, D.S. Reddy, F. Xue, T.C.W. Mak, A.
Nangia, G.R. Desiraju, New J. Chem. (1998) 143.