Synthesis and Reactivities of (Arylsulfonyl)amido Complexes of Ruthenium(II)

Full text of DOI:10.1021/ic9513806

Inorg. Chem. 1996, 35, 4801-4803
4801
Preparation. Ru(Et2dtc)(PPh3)2(CO)(NHSO2C6H4CH3-p) (1). To
a solution of Ru(Et2dtc)(PPh3)2(CO)H (0.92 g, 1.17 mmol) in toluene
(20 mL) was added 1 equiv of p-CH3C6H4SO2N3 (0.23 g, 1.17 mmol),
and the mixture was stirred at room temperature overnight. The solvent
was pumped off, and the residue was recrystallized from CH2Cl2/hexane
to give bright yellow crystals (yield 0.89 g, 81%). 1H NMR (CDCl3):
δ 0.44 (t, 3H, CH2CH3), 0.68 (t, 3H, CH2CH3), 2.31 (s, 3H, p-CH3),
2.63 (q, 2H, CH2CH3), 2.90 (q, 2H, CH2CH3), 6.05 (d, 2H, Ph m),
6.85 (d, 2H, Ph-o), 7.26-7.58 (m, 30H, PPh3). 31P NMR (CDCl3): δ
37.7 (s). MS(FAB): m/z 973 (M + 1)+. IR (cm-1): 3369 ν(N-H),
1934 ν(CtO). Anal. Calcd for C49H48N2O3P2S3Ru: C, 60.6; H, 4.9;
N, 2.9. Found: C, 60.3; H, 4.8; N, 2.9.
Ru(Et2dtc)(PPh3)2(CO)(NHSO2C6H4-t-Bu-p) (2). This was pre-
pared as for 1 from Ru(Et2dtc)(PPh3)2(CO)H (0.75 mg, 0.95 mmol)
and p-t-BuC6H4SO2N3 (0.233 mg, 0.94 mmol). The product was
recrystallized from THF as bright yellow crystals (yield 0.66 g, 69%).
1H NMR (CDCl3): δ 0.46 (t, 3H, CH2CH3), 0.68 (t, 3H, CH2CH3), 1.3
(s, 9H, t-Bu), 2.63 (q, 2H, CH2CH3), 2.89 (q, 2H, CH2CH3), 6.74 (d,
2H, Ph m), 7.04 (d, 2H, Ph o), 2.26-7.54 (m, 30H, PPh3). 31P NMR
(CDCl3): δ 37.5 (s). MS(FAB): m/z 1016 (M + 1)+. IR (cm-1), 3306
ν(N-H), 1932 ν(CtO). Anal. Calcd for C52H54N2O3P2S3Ru: C, 61.6;
H, 5.3; N, 2.7. Found: C, 61.5; H, 5.3; N, 2.7.
Ru(Et2dtc)(PPh3)2(CO)(NHSO2C6H2-2,4,6-i-Pr3) (3). This was
prepared as for 1 from Ru(Et2dtc)(PPh3)2(CO)H (0.75g, 0.95 mmol)
and 2,4,6-i-Pr3C6H2SO2N3 (0.29 g, 0.95 mmol). The product was
recrystallized from Et2O at 0 °C as yellow blocks, which were suitable
for a diffraction study (yield 0.51 g, 50%). 1H NMR (CDCl3): δ 0.45
(t, 3H, CH2CH3), 0.71 (t, 3H, CH2CH3), 0.87 (d, 6H, CH(CH3)2), 0.92
(d, 6H, CH(CH3)2), 1.20 (d, 6H, CH(CH3)2), 2.71 (q, 2H, CH2CH3),
2.81 (sept, 1H, CH(CH3)2), 2.93 (q, 2H, CH2CH3), 3.58 (sept, 1H,
CH(CH3)2), 3.74 (sept, 1H, CH(CH3)2), 6.73 (s, 1H, Ph m), 6.95 (s,
1H, Ph m), 7.09-7.64 (m, 30H, PPh3). 31P NMR(CDCl3): δ 38.0 (s).
MS(FAB): m/z 1084 (M + 1)+. IR (cm-1), 3330 ν(N-H), 1938 ν-
(CtO). Anal. Calcd for C57H64N2O3P2S3Ru: C, 58.0; H, 5.4; N, 2.4.
Found: C, 57.0; H, 5.5; N, 2.4.
(CO)(Et2dtc)(PPh3)Ru(µ-Et2dtc)(µ-I)Ru(CO)I(PPh3) (4). To a
solution of 2 (0.3 g, 0.3 mmol) in CH2Cl2 at 0 °C was added a solution
of I2 in CH2Cl2 (0.075 g in 15 mL) dropwise. The resulting red solution
was stirred at room temperature overnight. The solvent was pumped
off in vacuo, and the residue was recrystallized from CH2Cl2/ Et2O to
give red plates (yield 0.13 g, 50%). X-ray-quality crystals were
obtained by recrystallization from a saturated CH2Cl2/hexane solution.
1H NMR (CDCl3): δ 0.86 (t, 3H, CH3CH2), 0.98 (t, 3H, CH3CH2),
1.09 (t, 3H, CH3CH2), 1.23 (t, 3H, CH3CH2), 3.32 (q, 2H, CH3CH2),
3.47 (q, 2H, CH3CH2), 3.74 (q, 2H, CH3CH2), 3.91 (q, 2H, CH3CH2),
7.20-7.64 (m, 30H, PPh3). IR (cm-1): 1940 ν(CtO). Anal. Calcd
for C48H50N2I2O2P2S4Ru2: C, 36.0; H, 3.8; N, 2.1. Found: C, 37.1;
H, 3.8; N, 2.3.
Reaction of 2 with HCl. To a solution of 2 (0.1 g, 0.1 mmol) in
CH2Cl2 (15 mL) was added 1 equiv of HCl (ca. 0.1 mL of a 1 M
solution in ether) at room temperature, and the mixture was stirred for
2 h. The solvent was evaporated to dryness, and the residue was washed
with Et2O. The yellow solid obtained was characterized as Ru(Et2-
dtc)(PPh3)2(CO)Cl. 1H NMR (CDCl3): δ 0.56 (t, 3H, CH2CH3), 0.75
(t, 3H, CH2CH3), 2.69 (q, 2H, CH2CH3), 3.01 (q, 2H, CH2CH3), 7.16-
7.79 (m, 30H, PPh3). IR (cm-1): 1940 ν(CtO). Evaporation of the
Et2O washings afforded a white solid, which was identified as p-t-
BuC6H4SO2NH2 by NMR and IR spectroscopy.
X-ray Analysis. All X-ray data were collected on a Rigaku AFC7R
diffractometer at 295 K using graphite-monochromated Mo KR
radiation. Pertinent crystallogrpahic parameters and refinement data
are listed in Table 1. Intensities of three standard reflections were
monitored showing neither significant decay of crystals nor instrument
instability. Empirical absorption corrections based on ψ scans of several
strong reflection with ø close to 90° were applied for both structures.
All calculations were performed on a Silicon Graphic workstation with
teXsan6 software package. Both structures were solved by direct
methods (SIR88).7 Full-matrix least-squares refinements with aniso-
Synthesis and Reactivities of (Arylsulfonyl)amido
Complexes of Ruthenium(II)
Wa-Hung Leung,*,† Man-Ching Wu,†
Joyce L. C. Chim,† and Wing-Tak Wong‡,§
Departments of Chemistry, The Hong Kong University of
Science and Technology, Clear Water Bay,
Kowloon, Hong Kong, and The University of Hong Kong,
Pokfulam Road, Hong Kong
ReceiVed October 27, 1995
Introduction
Although early transition metal amide complexes are well
documented, mononuclear amido complexes of later transition
metals are rather uncommon.1 Low-valent late transition metals
have a strong tendency to form dimeric and oligomeric amide
complexes in order to avoid the unfavorable pπ(N)-dπ(M)
antibonding interaction. Our interest in (arylsulfonyl)amido
complexes (M-NHSO2Ar) comes from the belief that the
electron-withdrawing sulfonyl group may relieve the pπ(N)-
dπ(M) antibonding interaction by formation of an NdS double
bond. Additionally, tosylamido complexes (M-NHTs, Ts )
tosyl) are potential precursors to tosylimido species (MdNTs)
that are believed to be the active intermediates in metal-catalyzed
olefin azirdination reactions.2 Recently, Templeton and Brookhart
and their co-workers reported that W-H undergoes insertion
reaction with tosyl azide to give W-NHTs, which can be further
oxidized to give WdNTs species.3 This finding prompts us to
study the analogous reaction with Ru(II) hydrides. We here
report the synthesis and molecular structure of tosylamido
complexes of Ru(II).
Experimental Section
All reactions were carried out under nitrogen using standard Schlenck
techniques. Solvents were dried, distilled, and degassed prior to use.
NMR spectra were recorded on a JEOL EX 400 spectrometer.
Chemical shifts (in ppm) were reported referenced to Si(CH3)4 (1H)
and H3PO4(aq) (31P). Infrared spectra were obtained on a Perkin-Elmer
16PC FT-IR spectrophotometer. Mass spectra were recorded on a
Finnagan MAT-95 mass spectrometer. Elemental analyses were
performed by M-H-W Laboratories, Phoenix, AZ.
p-t-BuC6H4SO2Cl and 2,4,6-i-Pr3C6H2SO2Cl were obtained from
Aldrich and used as received. Ru(Et2dtc)(PPh3)2(CO)H (Et2dtc ) N,N′-
diethyldithiocarbamate) was synthesized according to the literature
method.4 ArSO2N3 (Ar ) p-CH3C6H4, p-t-BuC6H4, 2,4,6-i-PrC6H2)
were prepared from ArSO2Cl and NaN3 as described elsewhere.5
* Author to whom correspondence should be addressed.
† The Hong Kong University of Science and Technology.
‡
The University of Hong Kong.
§ Author to whom X-ray crystallographic inquiries should be addressed.
(1) (a) Lappert, M. F.; Power, P. P.; Sanger, A. R.; Srovastava, R. C.
Metal and Metalloid Amides; Wiley: New York, 1980. (b) Bryndza,
H. E.; Tam, W. Chem. ReV. 1988, 88, 1163. (c) Fryzuk, M. D.;
Montgomery, C. D. Coord. Chem. ReV. 1989, 95, 1. (d) Ge, W. Y.;
Peng, F.; Sharp, P. R. J. Am. Chem. Soc. 1990, 112, 2632. (e) Li, W.;
Barnes, C. L.; Sharp, P. R. J. Chem. Soc., Chem. Commun. 1990,
1634. (f) Glueck, D. S.; Winslow, L. J. N.; Bergman, R. G.
Organometallics 1991, 10, 1462. (g) Rahim, M.; Ahmed, K. J.
Organometallics 1994, 13, 1751. (h) VanderLende, D. D.; Abboud,
K. A.; Boncella, J. M. Inorg. Chem. 1995, 34, 5319.
(2) (a) Mahy, J.-P.; Bedi, G.; Battioni, P.; Mansuy, D. J. Chem. Soc.,
Perkin Trans. 2 1988, 1517. (b) Evans, D. A.; Faul, M. M.; Bilodeau,
M. T. J. Am. Chem. Soc. 1994, 116, 2742. (c) Li, Z.; Quan, R. W.;
Jacobsen, E. N. J. Am. Chem. Soc. 1995, 117, 5889.
(3) Pe´rez, P. J.; White, P. S.; Brookhart, M.; Templeton, J. L. Inorg. Chem.
1994, 33, 6050.
(4) Critchlow, P. B.; Robinson, S. D. J. Chem. Soc., Dalton Trans. 1975,
1367.
(5) Regitz, M.; Hocker, J.; Liedhegender, A. Organic Syntheses; Wiley:
New York, 1973; Collect. Vol. V, p 179.
S0020-1669(95)01380-2 CCC: $12.00 © 1996 American Chemical Society

4802 Inorganic Chemistry, Vol. 35, No. 16, 1996
Table 1. Crystallographic Data for 3 and 4‚0.5CH2Cl2
Notes
3
4‚0.5CH2Cl2
empirical formula C57H64N2O3P2S3Ru C48.5H51N2ClI2O2P2S4Ru2
a,Å
b, Å
c, Å
â, deg
V, cm3
Z
13.597(5)
24.348(8)
20.665(5)
108.31(3)
6306(3)
4
10.960(1)
26.355(3)
19.862(2)
103.92(2)
5568.4(9)
4
fw
1084.34
P21/c (No. 14)
0.710 73
22
1.142
4.37
1375.54
P21/n (No. 14)
0.710 73
22
1.641
19.44
space group
λ, Å
T, °C
F, g cm-3
µ, cm-1
Ra
0.075
0.113
0.049
0.064
b
Rw
GOF
1.77
3.10
a R ) ∑|Fo| - |Fc|/ |Fo|. b Rw ) [∑w(|Fo| - |Fc|)2/∑w|Fo|]1/2
.
c GOF
) [∑w(|Fc| - |Fo|)2/(Nobs - Nparam)]1/2
.
Figure 1. Perspective view of 3.
tropic thermal displacement parameters for Ru, S, P, O, N and two
carbon atoms in 3 and Ru, I, S, P, O, N and carbon atoms of Et2dtc
ligands in 4‚0.5CH2Cl2 were carried out. For crystal 3, the refinement
converged to R ) 7.5% and Rw ) 11.3%. For crystal 4.0.5CH2Cl2, a
2-fold positional disorder of one phenyl [C(26)-C(27)-C(28)-C(29)-
C(30), C(50)-C(51)-C(52)-C(53)-C(54)] ring on the triphenylphos-
phine was encountered. Subsequently, the atoms belonging to this ring
were refined with occupancies 0.5. There is a partially disordered
dichloromethane solvent molecule in the crystal lattice. The chlorine
atoms of the solvent molecules were refined with an occupancy factor
0.5, while the carbon was not refined. With this model, the refinement
converged to R ) 4.9% and Rw ) 6.4%. Final difference Fourier maps
revealed no significant features for either structure.
Table 2. Selected Bond Distances (Å) and Angles (deg) for 3
Ru(1)-S(2)
Ru(1)-P(1)
Ru(1)-N(1)
S(1)-N(1)
2.427(4)
2.401(4)
2.21(1)
1.57(1)
Ru(1)-S(3)
Ru(1)-P(2)
Ru(1)-C(1)
O(1)-C(1)
2.417(4)
2.392(4)
1.82(1)
1.15(1)
S(1)-Ru(1)-S(2)
S(2)-Ru(1)-P(2)
S(2)-Ru(1)-C(1)
S(3)-Ru(1)-P(2)
S(3)-Ru(1)-C(1)
P(1)-Ru(1)-N(1)
P(2)-Ru(1)-N(1)
N(1)-Ru(1)-C(1)
Ru(1)-C(1)-O(1)
72.0(1)
89.8(1)
89.1(4)
161.8(1)
86.8(4)
94.8(3)
86.5(3)
179.4(5)
176(1)
S(2)-Ru(1)-P(1)
S(2)-Ru(1)-N(1)
S(3)-Ru(1)-P(1)
S(3)-Ru(1)-N(1)
P(1)-Ru(1)-P(2)
P(1)-Ru(1)-C(1)
P(2)-Ru(1)-C(1)
Ru(1)-N(1)-S(1)
N(1)-S(1)-C(2)
162.4(1)
90.3(3)
90.9(1)
92.9(3)
107.2(1)
85.7(4)
93.6(4)
138.4(6)
107.6(6)
Results and Discussion
a Ru-phenylamide bond (e.g. Ru-N distance in Ru(PMe3)4H-
(NHPh) is 2.160(6) Å10) but also longer than a Ru(II)-amine
bond (e.g. the Ru-N in [(η5-C5H5)Ru(Cy2PCH2CH2PCy2)(C8H17-
NH2)]+ is 2.174(8) Å11). The long Ru-N bond in 3 may
indicate that pπ(N)-dπ(Ru) interaction is not important. Ac-
cordingly, the ν(CtO) for 1-3 (ca. 1932 cm-1) are higher than
those for the amido-carbonyl complex RuH(NHPh)(CO)[P(t-
Bu)2Me]2 (1898 cm-1), in which the Ru-CO back-bonding is
thought to be enhanced by π-donation from the amide.9 It might
also be noted that the N-S distance in 3 of 1.57(1) Å is slightly
shorter than that in Tp′W(CO)2(NHTs)+ (Tp′ ) hydrotris(3,5-
dimethyl-1-pyrazolyl)borate, 1.641(5) Å)3, indicative of double-
bond character of the S-N bond. Therefore the Ru(II)
(arylsulfonyl)amide may be represented by the following
resonance structures:
Reactions of low-valent Ru carbonyls with organic azides,
depending on the experimental conditions, are known to give
the urylene and isocyanate complexes.8 In this work, we found
that the Ru carbonyl hydride Ru(Et2dtc)(PPh3)2(CO)H undergoes
insertion with ArSO2N3 (Ar ) p-CH3C6H4, p-t-BuC6H4, 2,4,6-
i-PrC6H2) to give the corresponding (arylsulfonyl)amido com-
plexes Ru(Et2dtc)(PPh3)2(CO)(NHSO2Ar) in good yields (eq 1).
No isocyanate or urylene complexes were detected.
Ru(Et2dtc)(PPh3)2(CO)H + ArSO2N3 f
Ru(Et2dtc)(PPh3)2(CO)(NHSO2Ar) + N2 (1)
These complexes are air-stable in the solid state and
moderately air-stable in solution. The structure of the ((2,4,6-
triisopropylphenylsulfonyl)amido derivative 3 has been estab-
lished by X-ray crystallography. Figure 1 shows a perspective
view of the molecule; selected bond distances and angles are
given in Table 2. The geometry around Ru is octahedral with
the CO and amido group trans to each other. The trans
disposition of the carbonyl and amide ligands are in agreement
with the bonding picture for Ru(H)(X)[P(t-Bu)2Me]2 (X ) OR,
NHR) suggested by Caulton and co-workers.9 Remarkably, the
Ru-N distance of 2.21(1) Å is significantly longer than that
expected for Ru(II)-N(sp2). In fact it is not only longer than
Treatment of 1-3 with HCl gave the chloro complex Ru-
(Et2dtc)(PPh3)2(CO)Cl and (arylsulfonyl)amides ArSO2NH2 in
good yields. In contrast to the case of other metal amides, no
insertion reactions with CO2 were observed for these complexes.
Reaction of 2 with CO led to the isolation of a yellow solid,
which shows ν(N-H) at 3400 cm-1 and two ν(CtO) bands at
(6) teXsan: Single Crystal Analysis Package, Molecular Structure
Corp.: The Woodlands, TX 77381, 1992.
(7) Burla, M. C.; Camalli, M.; Cascarano, G.; Giacovazzo, C.; Polidori,
G.; Spagna, R.; Viterbo, D. J. Appl. Crystallogr. 1989, 22, 389.
(8) Cenini, S.; Pizzotti, M.; Porta, F.; La Monica, G. J. Organomet. Chem.
1975, 88, 237.
(9) Poulton, J. T.; Folting, K.; Streib, W. E.; Caulton, K. G. Inorg. Chem.
1992, 31, 3190.
(10) (a) Hartwig, J. F.; Andersen, R. A.; Bergman, R. G. Organometallics
1991, 10, 1875. (b) Burn, M. J.; Fickes, M. G.; Hollander, F. J.;
Bergman, R. G. Organometallics 1995, 14, 137.
(11) Joslin, F. L.; Johnson, M. P.; Mague, J. T.; Roundhill, D. M.
Organometallics 1991, 10, 2781.

Notes
Inorganic Chemistry, Vol. 35, No. 16, 1996 4803
n-BuLi to 2 in Et2O at -78 °C resulted in the formation of an
intractable red oil. Treatment of 2 with 1 equiv of I2 in CH2-
Cl2 at 0 °C afforded a red solution from which the crystalline
Ru(II) dimer (CO)(Et2dtc)(PPh3)Ru(µ-Et2dtc)(µ-I)Ru(CO)I-
(PPh3) (4) was isolated. Figure 2 shows a perspective view of
4; selected bond distances and angles are given in Table 3. The
structure of 4 consists of two [Ru(Et2dtc)(PPh3)(CO)I)] units
bridged by a dithiocarbamate sulfur and an iodine. The
unsymmetrically bridging dithiocarbamate can be considered
an η2 ligand of Ru(2) and coordinate to Ru(1) via one of the
two sulfurs. The Ru(2)-S(3) and Ru(1)-S(3) distances are
2.395(4) and 2.448(4) Å, respectively. A similar bridging
coordination mode for dithiocarbamate has been found for the
previously reported cation [Ru2(Et2dtc)5]+.12 The Ru-Ru′
separation is rather long (3.831 Å) indicative of the absence of
direct Ru-Ru′ bond. The Ru(1)-S(2) and Ru(2)-S(4) bonds,
which are trans to CO, are longer than the other Ru-S bonds
due to the trans influence of CO.
Figure 2. Perspective view of 4‚0.5CH2Cl2.
Table 3. Selected Bond Distances (Å) and Angles (deg) for 4‚0.5
CH2Cl2
I(1)-Ru(1)
I(2)-Ru(2)
Ru(1)-S(2)
Ru(1)-P(1)
Ru(2)-S(3)
Ru(2)-P(2)
2.724(2)
2.751(2)
2.486(4)
2.315(1)
2.395(4)
2.307(1)
I(1)-Ru(2)
Ru(1)-S(1)
Ru(1)-S(3)
Ru(1)-C(1)
Ru(2)-S(4)
Ru(2)-C(2)
2.773(1)
2.367(4)
2.448(4)
1.87(2)
2.482(4)
1.85(2)
Ru(1)-I(1)-Ru(2)
I(1)-Ru(1)-S(2)
I(1)-Ru(1)-P(1)
S(1)-Ru(1)-S(2)
S(1)-Ru(1)-P(1)
S(2)-Ru(1)-S(3)
S(2)-Ru(1)-C(1)
S(3)-Ru(1)-C(1)
I(1)-Ru(2)-I(2)
I(1)-Ru(2)-S(4)
I(1)-Ru(2)-C(2)
I(2)-Ru(2)-S(4)
I(2)-Ru(2)-C(2)
S(3)-Ru(2)-P(2)
S(4)-Ru(2)-P(2)
P(2)-Ru(2)-C(2)
88.39(4) I(1)-Ru(1)-S(1)
98.8(1) I(1)-Ru(1)-S(3)
91.58(4) I(1)-Ru(1)-C(1)
168.6(1)
82.41(9)
96.0(5)
89.2(1)
92.6(5)
94.0(1)
169.7(1)
92.8(4)
83.08(9)
176.05(5)
164.9(1)
95.46(4)
71.8(1)
Complex 4 was possibly formed via the coupling of two
coordinately unsaturated [Ru(Et2dtc)(PPh3)(CO)I] intermediates,
the unisolated products of oxidation 2 by I2.13 The fate of the
tosylamide ligand is not clear.
71.9(1)
95.5(1)
78.7(1)
163.6(5)
96.2(4)
S(1)-Ru(1)-S(3)
S(1)-Ru(1)-C(1)
S(2)-Ru(1)-P(1)
S(3)-Ru(1)-P(1)
P(1)-Ru(1)-C(1)
Acknowledgment. We thank The Hong Kong University
of Science and Technology, The University of Hong Kong, and
The Hong Kong Research Grants Council for support.
86.40(4) I(1)-Ru(2)-S(3)
91.3(1)
83.9(4)
97.7(1)
89.5(4)
I(1)-Ru(2)-P(2)
I(2)-Ru(2)-S(3)
I(2)-Ru(2)-P(2)
S(3)-Ru(2)-S(4)
Supporting Information Available: Listings of crystal data (Table
S1 and S6), atomic coordinates and isotropic thermal parameters (Tables
S2 and S7), anisotropic thermal parameters (Tables S3 and S8), and
complete bond distances (Tables S4 and S9) and angles (Tables S5
and S10) (20 pages). Ordering information is given on any current
masthead page.
95.73(9) S(3)-Ru(2)-C(2) 100.1(4)
91.9(1)
92.6(4)
S(4)-Ru(2)-C(2) 171(4)
2000 and 1900 cm-1, suggesting the formation of the dicarbonyl
complex Ru(PPh3)(CO)2(Et2dtc)(NHSO2C6H4-t-Bu-p).
In an attempt to synthesize the first Ru-(arylsulfonyl)imido
complexes, the reactions between the (arylsulfonyl)amide
complexes with bases and oxidants were studied. Addition of
IC9513806
(12) Duffy, D. J.; Pignolet, L. H. Inorg. Chem. 1974, 13, 2051.
(13) The cyclic voltammogram of 2 in CH2Cl2 at a glassy carbon electrode
shows a reversible oxidation couple at ca. 0.21 V vs the ferrocenium-
ferrocene couple.