Syntheses and characterization of nickel(II) and ruthenium(II) complexes with the novel phosphine ligands 1-((diphenylphosphino)methyl)-1-phenyl-1-silacyclopent-3-ene and 1,1-bis((diphenylphosphino)methyl)-1-silacyclopent-3-ene. Crystal structure of CpRuCl[(PPh2CH2)2(SiC4H 6)]

Article abstract of DOI:10.1021/om9709751

The reaction of the lithium salt of chlorodiphenylphosphine with 1-chloro-1-phenylsila-cyclopent-3-ene (1) and 1,1-dichlorosilacyclopent-3-ene (2) gave good yields of 1-((diphenylphosphino)methyl)-1-phenyl-1-silacyclopent-3-ene (L) (3) and 1,1-bis((diphenylphosphino)-methyl)-1-silacyclopent-3-ene (L′) (4). Both molecules were obtained as white solids characterized by NMR. Red and red-violet diamagnetic square-planar complexes trans-NiCl₂L₂ and cis-NiC₂L′ were obtained by reacting NiCl₂·6H₂O with 3 and 4, respectively. Substitution of two PPh₃ in CpRuCl(PPh₃)₂ by 4 gave CpRuCl(L′) (7) in good yield. Orange crystals of 7 contain monomeric pseudooctahedral ruthenium(II) centers surrounded by a Cl atom, a Cp ligand, and the two phosphorus atoms of the 1,1-bis((diphenylphosphino)methyl)-1-silacyclopent-3-ene ligand. The silacyclopentene ring adopts a puckered ground state configuration with a puckering angle of 10°. 7 can be described as a spirannic compound with roughly perpendicular Ru-P(1)-C(10)-Si-C(20)-P(2) and Si-C(6)-C(7)-C(8)-C(9) rings.

Full text of DOI:10.1021/om9709751

Organometallics 1998, 17, 2839-2843
2839
Syn th eses a n d Ch a r a cter iza tion of Nick el(II) a n d
Ru th en iu m (II) Com p lexes w ith th e Novel P h osp h in e
Liga n d s 1-((Dip h en ylp h osp h in o)m eth yl)-
1-p h en yl-1-sila cyclop en t-3-en e a n d
1,1-Bis((d ip h en ylp h osp h in o)m eth yl)-1-sila cyclop en t-3-en e.
Cr ysta l Str u ctu r e of Cp Ru Cl[(P P h 2CH2)2(SiC4H6)]
Pascal Dufour, Vale´rie Capdevielle, Miche`le Dartiguenave,* and
Yves Dartiguenave
Laboratoire de Chimie Inorganique, Universite´ Paul Sabatier, 118 route de Narbonne,
31062 Toulouse, France
Francine Be´langer-Garie´py and Andre´ L. Beauchamp
De´partement de Chimie, Universite´ de Montre´al, C.P. 6128, Succ. Centre-ville,
Montre´al, Que´bec, Canada H3C 3J 7
Received November 7, 1997
The reaction of the lithium salt of chlorodiphenylphosphine with 1-chloro-1-phenylsila-
cyclopent-3-ene (1) and 1,1-dichlorosilacyclopent-3-ene (2) gave good yields of 1-((diphen-
ylphosphino)methyl)-1-phenyl-1-silacyclopent-3-ene (L) (3) and 1,1-bis((diphenylphosphino)-
methyl)-1-silacyclopent-3-ene (L′) (4). Both molecules were obtained as white solids char-
acterized by NMR. Red and red-violet diamagnetic square-planar complexes trans-NiCl2L2
and cis-NiCl2L′ were obtained by reacting NiCl2‚6H2O with 3 and 4, respectively. Substitu-
tion of two PPh3 in CpRuCl(PPh3)2 by 4 gave CpRuCl(L′) (7) in good yield. Orange crystals
of 7 contain monomeric pseudooctahedral ruthenium(II) centers surrounded by a Cl atom,
a Cp ligand, and the two phosphorus atoms of the 1,1-bis((diphenylphosphino)methyl)-1-si-
lacyclopent-3-ene ligand. The silacyclopentene ring adopts a puckered ground state con-
figuration with a puckering angle of 10°. 7 can be described as a spirannic compound with
roughly perpendicular Ru-P(1)-C(10)-Si-C(20)-P(2) and Si-C(6)-C(7)-C(8)-C(9) rings.
Ch a r t 1
In tr od u ction
Complexes containing silacyclopentene ligands Si-
bonded to one or two transition metals, either directly
(A) or through an organic linker (B), are of particular
interest as metal-containing monomeric starting mate-
rials to generate new polymers. Such ligands and
possible coordination modes to metal centers are il-
lustrated in Chart 1.
cobalt complexes, in which the metal is σ-bonded to
silicon (A).2 The second reason is the scarcity of
silacyclopentenes carrying functionalized substituents
that can bind metal centers. A few examples are shown
in Chart 2,3,4 but they have not been coordinated to
transition metals. No molecules bearing a phosphorus
donor in a position â to Si has yet been described.
In the present study, we report the synthesis of two
new silacyclopentenes 3 and 4 containing one and two
Even though organic silacyclopentenes have been
successfully developed as monomeric precursors for
silicon-containing polymers,1 little is known about metal-
containing species. One reason is that there are not
many metal-functionalized silacyclopentenes known and
the examples have been restricted so far to iron and
* Author to whom correspondence should be addressed. Fax: 33 5
61 55 61 18. Telephone: 33 5 61 55 61 21. E-mail: dartigue@iris.ups-
tlse.fr.
(1) (a) Zhang, X.; Zhou, S. Q.; Weber, W. P.; Horvath, R. F.; Chan,
T. H.; Manuel, G.; Macromolecules 1988, 21, 1563. (b) Stonich, D. A.;
Weber, W. P. Polym. Bull. 1991, 25, 629. (c) Anhaus, J . T.; Clegg, W.;
Colligwood, S. P.; Gibson, V. C. J . Chem. Soc. 1991, 1720. (d) Zhou, S.
Q.; Park, Y. T.; Manuel, G.; Weber, W. P. Polym. Bull. 1990, 23, 491.
(e) Zhou, S. Q.; Weber, W. P. Macromolecules 1990, 23, 1915. (f) Liao,
X.; Ko, Y. H.; Manuel, G.; Weber, W. P. Polym. Bull. 1991, 25, 63.
(2) Dufour, P.; Dartiguenave, M.; Dartiguenave, Y.; Simard, M.;
Beauchamp, A. L. J . Organomet. Chem., in press.
(3) (a) Manuel, G.; Mazerolle, P.; Cauquy, G. Synth. React. Inorg.
Met.-Org. Chem. 1974, 4, 143. (b) Ushakov, N. V.; Pritula, N. A. Zh.
Obshch. Khim. 1992, 62, 1318.
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Organomet. Polym. 1995, 5 (1), 61.
S0276-7333(97)00975-8 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 06/05/1998

2840 Organometallics, Vol. 17, No. 13, 1998
Dufour et al.
The 1H, 31P{1H}, and 13C{1H} spectra were recorded on
Bruker WM-200 or WH-80 spectrometers using CDCl3 as
solvent. For 1H and 13C NMR, the chemical shifts were
referenced to the residual solvent signals (CDCl3, δ(1H) )
7.27 ppm and δ (13C) ) 77 ppm), and for 31P NMR, to ex-
ternal H3PO4 85% in D2O (δ ) 0 ppm). UV-visible measure-
ments were carried out using a HP spectrophotometer (10.0
mm cells, CHCl3). The magnetic moments for the nickel(II)
complexes were determined in the solid state by the Faraday
method, using a Cahn microbalance coupled with a Drusch
electromagnet. Measurements were run at room temperature.
HgCo(NCS)4 was used as standard (Xg ) 16.44 10-6 cgs emu).
The experimental values were corrected for the diamagnetism
of the ligands.
Ch a r t 2
phosphine groups, respectively, together with their
reactions with NiCl2‚6H2O and CpRuCl(PPh3)2. These
Microanalyses were performed by the Service Central de
Microanalyse du CNRS, Lyon, and by the Service de Mi-
croanalyse du LCC, Toulouse.
1-((Dip h en ylp h osp h in o)m eth yl)-1-p h en yl-1-sila cyclo-
p en t-3-en e (3). Compound 1 (2.13 g; 6.6 mmol) dissolved in
THF (20 mL) was added to a solution of PPh2CH2Li-TMEDA
(10% excess) in 50 mL of THF at -80 °C and the mixture
stirred for 1 h. The mixture was then allowed to warm up,
and it was kept at room temperature for 12 h. Removal of
THF from the resulting green solution in vacuo gave an oily
product which was recrystallized from ether. Workup and
microdistillation gave an oil. Yield: 2.12 g, 90%. Anal. Calcd
for C23H23PSi: C, 77.06; H, 6.47. Found: C, 76.58; H, 6.55.
1,1-Bis(d ip h en ylp h osp h in o)m eth yl)-1-sila cyclop en t-3-
en e (4). The same procedure applied to 2 (1.22 g, 8 mmol)
gave 4 in 84% yield (3.23 g). Anal. Calcd forC30H30P2Si: C,
74.97; H, 6.29; Found: C, 75.21; H, 6.38.
tr a n s-Dich lor ob is(1-((d ip h en ylp h osp h in o)m et h yl)-1-
p h en yl-1-sila cyclop en t-3-en e)n ick el(II) (5). At room tem-
perature, 353 mg (1.5 mmol) of NiCl2‚6H2O was added to a
solution of 1.06 g (3 mmol) of 3 in 20 mL of ethanol. After 1
h at 20 °C, the solution was filtered and the red solid washed
with diethyl ether and CH2Cl2. Recrystallization from CH2-
Cl2/pentane at -5 °C gave red crystals of 5. Yield: 0.70 g, 55%.
Anal. Calcd for C46H46P2Si2NiCl2: C, 65.26; H, 5.48; P, 7.32;
Si, 6.63; Ni, 6.93. Found: C, 65.25; H, 5.44; P, 7.23; Si, 6.60;
Ni, 6.84. Mp ) 182° dec.
cis-Dich lor o(1,1-bis((d ip h en ylp h osp h in o)m eth yl)-1-si-
la cyclop en t-3-en e)n ick el(II) (6). To a solution of 0.493 g
(2 mmol) of NiCl2‚6H2O in 20 mL of 2-propanol/methanol (5/
2) was added 1.000 g (2.1 mmol) of 4 in 20 mL of 2-propanol.
The solution was refluxed for 3 h. The red precipitate was
filtered off, washed with ether, and dried in vacuo. Recrys-
tallization from CH2Cl2/pentane gave a violet microcrystalline
powder. Yield: 0.79 g, 65%. Anal. Calcd for C30H30P2-
SiNiCl2: C, 59.05; H, 4.96; P, 10.15. Found: C, 59.36; H, 4.86;
P, 10.02. Mp > 200 °C.
Ch lor o(cyclopen tadien yl)(1,1-bis((diph en ylph osph in o)-
m eth yl)-1-sila cyclop en t-3-en e))r u th en iu m (II) (7). A mix-
ture of 1.06 g (1.35 mmol) of CpRuCl(PPh3)2 and 1.25 g (2.6
mmol) of 4 was refluxed in 80 mL of toluene for 3 h.
Evaporation of the solvent in vacuo gave a solid, which was
purified by chromatography on alumina with CH2Cl2 and then
with acetone as eluent. Evaporation of the solvent in vacuo
two metals were chosen because they give stable mon-
omeric phosphine complexes and they can adopt differ-
ent geometries to meet the steric requirement of the
ligands.5 The species were characterized mainly by
NMR spectroscopy. Since no X-ray diffraction work had
yet been done on metal-bonded silacyclopentene, the
crystal structure of the ruthenium complex CpRuCl-
[(PPh2CH2)2(SiC4H6)] was determined.
Exp er im en ta l Section
Solvent distillation and all other manipulations were per-
formed in a dry nitrogen atmosphere using standard Schlenk
techniques. Tetrahydrofuran, toluene, and ether were stirred
with sodium wire and distilled over Na/benzophenone prior
to use. Pentane and hexane were also distilled from Na just
before use. Dichloromethane was dried over P2O5. All solvents
were degassed by three freeze-thaw cycles. 1-Chloro-1-
phenylsilacyclopent-3-ene (1) and 1,1-dichlorosilacyclopent-3-
ene (2) were prepared by literature methods.6 (C6H5)2PCH2Li-
TMEDA (where TMEDA ) tetramethylethylenediamine) was
synthesized as previously described.10 CpRuCl(PPh3)2, pre-
pared as described earlier,17 was recrystallized from ethanol
before use. NiCl2‚6H2O was purchased from Aldrich and used
without purification.
(5) MacAuliffe, C. A.; Levason, W. Phosphine, Arsine and Stibine
Complexes of the Transition Elements. In Studies in Inorganic
Chemistry; Elsevier: Amsterdam, 1979 and references therein. Boere,
R. E.; Montgomery, C. D.; Payne, N. C., Willis, C. J . Inorg. Chem. 1985,
24, 3680. Sembiring, S. B.; Colbran, S. B.; Hanton, L. R. Inorg. Chim.
Acta 1992, 202, 67.
(6) Damrauer, R.; Simon, R.; Laporterie, A.; Manuel, G.; Park, Y.
T.; Weber, W. P. J . Organomet. Chem. 1990, 391, 7.
(7) Gabe, E. J .; Le Page, Y.; Charland, J . P.; Lee, F. L.; White, P. S.
J . Appl. Crystallogr. 1989, 22, 384.
(8) Cromer D. T.; Mann, J . B. Acta Crystallogr. 1968, A24, 321.
Stewart, R. F.; Davidson, E. R.; Simpson, W. T. J . Chem. Phys. 1965,
42, 3175.
(9) Cromer, D. T.; Liberman, D. J . Chem. Phys. 1970, 53, 1891.
(10) Holmes-Smith, R. D.; Osei, R. D.; Strobart, R. S. J . Chem. Soc.,
Perkins Trans. 1 1983, 861.
(14) (a) Ercolani, C.; Quagliano, J . V.; Vallarino, L. M. Inorg. Chim.
Acta 1973, 9, 413. (b) Chow, K. K.; MacAuliffe, C. A. Inorg. Chim. Acta
1974, 10, 197. (c) Que, L., J r.; Pignolet, L. H. Inorg. Chem. 1973, 12,
156. (d) Booth, G.; Chatt, J . J . Chem. Soc. 1965, 3238. (e) Cloyd, J . C.,
J r.; Meek, D. W. Inorg. Chim. Acta 1972, 12, 607. (f) van Hecke, G. R.;
Horrock, W. W., J r. Inorg. Chem. 1966, 5, 1968. (g) Alyea, E.; Ferguson,
G.; Ruhl, B. L.; Shakya, R. Polyhedron 1987, 6, 1223.
(15) (a) Pignolet, L. H.; Horrocks, W. W., J r.; Holm, R. H. J . Am.
Chem. Soc. 1970, 92, 1855. (b) Hayter, R. G.; Humiec, S. Inorg. Chem.
1965, 4, 1701.
(11) Shore, N. E.; Benner, L. S.; LaBelle, B. E. Inorg. Chem. 1981,
20, 3200.
(12) Shore, N. E.; LaBelle, B. E. J . Org. Chem. 1981, 46, 2306.
(13) (a) Laane, J .; Chao, T. H. Spectrochim. Acta 1972, 28A, 2443.
(b) Laane, J . J . Chem. Phys. 1969, 50, 776. (c) Cradock, S.; Ebswoth,
E. A. V.; Hanill, B. A.; Rankin, D. W. H.; Wilson, J . M.; Whiteford, R.
A. J . Mol. Struct. 1979, 57, 123.
(16) Ashby, G. S.; Bruce, M. I.; Tomkins, I. B.; Wallis, R. C. Aust. J .
Chem. 1979, 32, 1003.
(17) (a) Bruce, M. I.; Windsor, N. J . Aust. J . Chem. 1977, 30, 1601.
(b) Bruce, M. I.; Hameister, C.; Swincer, A. G.; Wallis, R. C. Inorg.
Synth. 1982, 21, 78.

Ni(II) and Ru(II) Complexes with Novel Phosphine Ligands
Organometallics, Vol. 17, No. 13, 1998 2841
Ta ble 1. Cr ysta llogr a p h ic Da ta for
Cp Ru Cl[(P P h 2CH2)2(SiC4H6)] (7)
Sch em e 1
formula
mol wt
cryst syst
space group
a, Å
C35H35ClP2RuSi
682.21
monoclinic
P21/c
9.2699(7)
18.2490(13)
18.5500(12)
102.902(6)
3058.8(4)
4
b, Å
c, Å
Ta ble 2. 1H, 31P , a n d 13C NMR Da ta
â, deg
V, Å3
compd
NMR data
Z
d
3a
31P{1H}: -22
calcd, Mg.m-3
1.481
2
1H: 1.9 (2H, d, J HP ) 1 Hz, HA/HB);
radiation (λ, Å)
1.540 56
6.63
210
4
1.5 (2H, d, J HP ) 1 Hz, HC/HD);
µ mm-1
6.0 (2H, s, HE/HF); 7.40 (5H, m, HAr
)
temp, K
13C{1H}: 12.9 (d, J CP ) 30 Hz, C1);
1
no. of measd reflns
no. of indep reflns
no. of reflns with I > 2σ(I)
Ra
21 729
5790
5427
0.025
3
16.6 (d, J CP ) 4.1, C2/C3);
129.5 (C4/C5)
4a
31P{1H}: -22
1H: 1.4 (4H, d, J HP ) 1 Hz, HA/HB);
2
a
Rw
0.035
4
1.1 (4H, d, J HP ) 1 Hz, HC/HD);
a
R ) ∑(||Fo| - |Fc||)/∑(|Fo|), Rw ) [∑[w(|Fo| - |Fc|)2]/∑[w(|Fo|)2]1/2
.
5.7 (2H, s, HE/HF)
13C{1H}: 12.6 (dd, J CP ) 30 Hz,
1
3J CP ) 4.6 Hz, C1); 16.8 (t, J CP
4.1, C2/C3); 130.7 (C4/C5)
31P{1H}: 4.8
)
3
and recrystallization from CH2Cl2/pentane at -20 °C gave
orange crystals of 7 suitable for X-ray work. Yield: 0.53 g,
58%. Anal. Calcd for C35H35P2SiRuCl: C, 61.62; H, 5.17; P,
9.08; Found: C, 61.67; H, 5.14; P, 8.95. Mp > 200 °C.
Cr ysta l Str u ctu r e An a lysis of 7. Orange crystals of 7
were grown from a CH2Cl2/pentane solution at -20 °C. The
X-ray work was carried out on an Enraf-Nonius CAD-4 dif-
fractometer using graphite-monochromatized Cu KR radiation.
The reduced cell deduced from 25 reflections detected on an
oscillation photograph indicated a primitive monoclinic lattice.
The 2/m Laue symmetry was eventually checked from the full
data set, and the space group was unambiguously identified
from the systematic absences. The crystal data and other
relevant information are summarized in Table 1.
5b
1H: 1.47 (4H, q (AB), J HH ) 17 Hz, HC/HD);
1.8 (4H, HA/HB); 5.8 (2H, s, HE/HF);
7.50 (5H, m, HAr)
13C{1H}: 9.4 (C1); 16.2 (C2/C3); 131.3 (C4/C5)
31P{1H}: 17
6b
7a
1H: 0.6 (4H, HC/HD); 1.5 (4H, HA/HB);
5.5 (2H, HE/HF)
13C{1H}: 10.1 (C1); 17.5 (C2/C3); 132.3 (C4/C5)
31P{1H}: 42
1H: 1.54 (2H, q, J HH ) 13.7 Hz, HA/HB);
3
4
0.8, 1.2 (2H, dd, J HH ) 3 Hz, J HH
1.7 Hz, HC/HD); 4.20 (5H, s, Cp);
5.6, 5.7 (2H, m, HE/HF)
)
13C{1H}: 11.5 (t, J CP ) 6.5 Hz, C1);
1
The ω/2θ scan mode was used to collect the intensity data
with a scan range ∆ω of (0.80 + 0.14 tan θ)° and a constant
scan rate of 16.5° min-1. The orientation was monitored every
400 measurements, whereas the intensity was checked every
hour with four standard reflections. Intensity fluctuation
remained within (1.0%. Equivalent reflections were aver-
aged, and corrections for Lorentz and polarization effects were
applied. The data set consisted of 5790 independent reflec-
tions, of which 5427 with I > 2σI were retained for structure
determination. The structure was solved by direct methods
and difference Fourier syntheses using NRCVAX.7 Least-
squares refinement was based on F, and all non-hydrogen
atoms were refined anisotropically. Hydrogen atoms were
initially introduced at idealized positions and then refined
isotropically during the last cycles. The scattering curves were
from standard sources.8 The anomalous dispersion contribu-
tions ∆f ′ and ∆f" for Ru, Si, P, and Cl were from Cromer and
18.3(s), 19.2(t) (3J CP ) 5.2 Hz,
C2/C3); 80 (s, Cp);
4
131.7 (t, J CP ) 5.3 Hz, C4 or C5);
4
132.7 (t, J CP ) 5.5 Hz, C4 or C5)
a
b
CDCl3, room temperature. CD2Cl2, 193 K.
chlorine substitution. Consequently, the chlorosilane
must be added dropwise to the solution containing the
lithium. Methyldiphenylphosphine, which was obtained
as a byproduct, was eliminated by distillation (bp )
120-122 °C/1.5 Torr).12
The structures of 3 and 4 were deduced from the NMR
results (Table 2). The 31P{1H} NMR spectra show
singlets at -22 ppm for both compounds, very close to
that of free PPh2Me (-26 ppm). This indicates that the
substitution of a proton by a silacyclopentene group does
not affect significantly the basicity of the phosphine. The
singlet for 4 showed the equivalence of the two phos-
phorus atoms. The two compounds also gave similar
1H NMR results. In both cases, the presence of equiva-
lent HC and HD protons on the endocyclic methylene
groups confirmed the planarity of the silacyclopentene
Liberman.9 Refinement converged to R ) 0.025 and Rw
)
0.035. The refined parameters are provided in the Supporting
Information.
Resu lts a n d Discu ssion
Syn th esis of th e Liga n d s. Compounds 3 and 4
were prepared following the procedure used to prepare
aliphatic phosphines bearing methylsilane substitu-
ents.10,11 Thus, reacting ((diphenylphosphino)methyl)-
lithium-TMEDA with 1-chloro-1-phenylsilacyclopent-
3-ene (1) and 1,1-dichlorosilacyclopent-3-ene (2) in THF
produced the monodendate phosphine 3 and bidentate
diphosphine 4, respectively, in 85% yield (Scheme 1)
The synthesis of 4 was critically sensitive to the
details of the procedure used. It was crucial to keep
the lithium reactant in excess in order to get complete
ring.13 They appeared as a doublet because of J HP
4
coupling. The exocyclic methylene protons HA and HB
also gave a doublet, due to J HP couplings. The 13C-
2
{1H} spectra of the two ligands were also very similar.
Phosphorus coupling was apparent for the endocyclic
3
C2/C3 atoms (doublet, J CP ) 4.1 Hz). The exocyclic
methylene carbon C1 showed a doublet at 12.9 ppm (1J CP
) 30 Hz) for 3 and a doublet of doublets centered at
12.6 ppm (1J CP ) 30 Hz; J CP ) 4.6 Hz) for 4.
3

2842 Organometallics, Vol. 17, No. 13, 1998
Dufour et al.
Sch em e 2
Sch em e 3
1
Compounds 3 and 4 are functionalized mono- and
diphosphines. Therefore, they should be able to act as
ligands toward transition metals.
observed in the H, 13C, and 31P NMR spectra of 6 and
the fact that square-planar-tetrahedral equilibria in
solution are well documented for nickel(II)-phosphine
complexes.14,15
Syn t h esis a n d Ch a r a ct er iza t ion of t h e Nick el
Com p lexes. The reaction of 2 equiv of 3 and 1 equiv
of 4 with NiCl2‚6H2O, in ethanol for 3 and in methanol/
2-propanol (1/1) for 4, gave the new complexes 5 and 6
in 55 and 65% yield, respectively (Scheme 2). They pre-
cipitated as red and red-violet air-stable powders, re-
spectively. The formula was established from elemental
analysis, and a low-spin Ni(II) square-planar structure
was proposed on the basis of the zero magnetic moment
in the solid state, electronic spectra and NMR data.
Coordination of phosphorus to the metal is reflected
by the low-field shift of the 31P NMR signal. Only one
signal is present at -80 °C, at 4.8 ppm for 5 and 17.0
ppm for 6, the latter being significantly broadened even
at this temperature. The presence of a single 31P signal
for 6 indicates that the ligand is symmetrically bonded
to the metal. The relatively large shift of 6 (∆δ ) 39
ppm) compared to 5 (∆δ ) 27 ppm) could be attributed
to the different configurations of the complexes: cis P-P
in 6 and trans P-P in 5. Such variations are not
uncommon in nickel complexes.5
Ru th en iu m Com p lex 7. The CpRuCl[(PPh2CH2)2-
(SiC4H6)] complex 7 was obtained in refluxing tolu-
ene16 by phosphine substitution, starting from CpRuCl-
(PPh3)2 and 4. Complex 7 was isolated as a pure
orange powder after chromatography on Al2O3
(Scheme 3).
The orange solid was identified as complex 7 by mi-
croanalysis and NMR studies. The equivalence of the
two phosphorus atoms was indicated by the presence
of a single 31P NMR signal at 42 ppm, in the range for
phosphorus atoms bonded to ruthenium.16,17 The 1H
NMR spectrum at 20 °C showed only one broad signal
at 1.54 ppm for the exocyclic methylene protons HA/HB,
which after 31P decoupling became an AB system
(2J HA-HB ) 13.7 Hz), indicating the inequivalence of the
two protons in solution. The doublets of doublets at 0.8
and 1.2 ppm for the inequivalent endocyclic methylene
protons HC and HD were not affected by phosphorus
decoupling, but they both appeared as singlets after
17
irradiation of the ethylenic protons HE and HF (3J HH
)
The 1H NMR spectrum of 5 showed inequivalent
endocyclic methyl protons HC and HD (AB system, 2J HH
) 17 Hz), whereas the exocyclic methylene protons HA
and HB were equivalent and gave a singlet (Table 2).
The signals for 6 were too broad to draw conclusions.
In the 13C spectra, coordination gave rise to only one
small negative shift on C1 (∆δ ) -3.5 ppm for 5 and
-2.7 ppm for 6), due to increased electron density
created on this carbon by the positive charge located
on the nickel atom.
3 Hz; J HH ) 1.7 Hz) at room temperature. The 13C
NMR spectrum shows a triplet at 11.5 ppm, correspond-
ing to the two equivalent C1 atoms coupled with the two
phosphorus atoms (1J PC ) 3J PC ) 6.5 Hz). Phosphorus
coupling is also observed for C3, which appears as a
triplet at 19.2 ppm (J CP ) 5.2 Hz), and for C4 and C5
(triplet at 131.7 ppm (J PC ) 5.2 Hz) for C4 and at 132.7
(J PC ) 5.5 Hz) for C5). Surprisingly, no phosphorus
coupling is observed for C2, which gives only a singlet
at 18.3 ppm.
4
The electronic spectra of 5 and 6 in CH2Cl2 have
profiles similar to those of other Ni(II) complexes. Only
Since no crystallographic results were available for
metal complexes with a silacyclopentene ligand, the
crystal structure of 7 was determined, and it confirmed
the inequivalence of the two halves of the five-mem-
bered ring revealed by NMR. Single crystals were
obtained by recrystallization from a dichloromethane/
pentane mixture at -20 °C. The unit cell contains the
monomeric molecule shown in Figure 1. Selected
intermolecular distances and bond angles are listed in
Table 3.
one broad band is observed at 480 nm (ꢀ ) 400 mol-1
L
cm-1), and it is assigned to the d-d transition 1A1 f
1B2 for the square-planar d8 complex. The spectrum of
6 shows, besides the absorption band at 485 nm (ꢀ )
400 mol-1 L cm-1), an extra, weaker band at 835 nm (ꢀ
) 60 mol-1 L cm-1), which could be attributed to the
3T1 f 3A2 transition in a tetrahedral isomer. In agree-
ment with this interpretation are the signal broadening

Ni(II) and Ru(II) Complexes with Novel Phosphine Ligands
Organometallics, Vol. 17, No. 13, 1998 2843
Ch a r t 3
large steric requirement of PPh3. With the smaller
PMe3 ligand,18the distance is shorter (2.274(6) Å) and
the angle is 94.8(2)°. Reduced steric repulsion in the
complex with a bis(diphenylphosphino)ethane (diphos)
derivative19 results in shorter Ru-P bonds (2.277(2) Å),
whereas the P-Ru-P angle in the five-membered ring
is reduced to 82.9(1)°. In the present case, the Ru-P
bonds (2.2953(5) and 2.2753(5) Å) are comparable with
those of the diphos complex, but the six-membered
chelate ring opens the P-Ru-P angle to 93.41(2)°.
Interestingly, the Ru-P(1)-C(10)-Si-C(20)-P(2) ring
presents a cyclohexane-like chair conformation: P(1),
C(10), C(20), and P(2) are coplanar, and the Si atom lies
0.65 Å above and the Ru atom 1.09 Å below this plane,
which corresponds to dihedral angles of 38.0(1)° and
44.3(1)°, respectively (Chart 3).
The silacyclopentene ring becomes puckered upon
coordination. It adopts an envelope conformation with
a dihedral angle of 10° between the C(6)-C(7)-C(8)-
C(9) and C(6)-Si-C(9) planes. The bond distances and
angles in the ring are not affected,2,20 but appreciable
changes are noted on some of the angles around Si.
Their values still average 110°, but the C(6)-Si-C(9)
angle decreases to 95.0(1)° and the external C(9)-Si-
C(10) angle increases to 119.3(1)° to accommodate the
six-membered chelate ring. Compound 7 can be de-
scribed as a spirannic compound, in which the Ru-
P(1)-C(10)-Si-C(20)-P(2) and Si-C(6)-C(7)-C(8)-
C(9) rings sharing the Si atom make an angle of 87°.
In conclusion, these results demonstrate that, pro-
vided appropriate linkers are devised, functionalized
silacyclopentenes can be used as ligands and stable
metal complexes can be made. Work is in progress to
explore the reactivity of these species as inorganic
monomeric precursors.
F igu r e 1. ORTEP drawing of the CpRuCl[(PPh2CH2)2-
(SiC4H6)] molecule.
Ta ble 3. Selected In ter a tom ic Dista n ces (Å) a n d
Bon d An gles (d eg)
Ru-P(1)
Ru-P(2)
Ru-Cl
2.2953(5)
2.2753(5)
2.4419(5)
2.200(2)
2.224(2)
2.216(2)
2.202(2)
2.201(2)
1.887(2)
1.887(2)
1.877(2)
1.876(2)
1.827(2)
P(1)-C(11)
P(1)-C(11′)
P(2)-C(20)
P(2)-C(21)
P(2)-C(21′)
C(1)-C(2)
C(1)-C(5)
C(2)-C(3)
C(3)-C(4)
C(6)-C(7)
C(7)-C(8)
C(8)-C(9)
1.836(2)
1.848(2)
1.826(2)
1.836(2)
1.835(2)
1.413(4)
1.411(3)
1.403(5)
1.418(5)
1.501(3)
1.317(4)
1.503(4)
Ru-C(1)
Ru-C(2)
Ru-C(3)
Ru-C(4)
Ru-C(5)
Si-C(6)
Si-C(9)
Si-C(10)
Si-C(20)
P(1)-C(10)
P(1)-Ru-P(2)
P(1)-Ru-Cl
93.41(2) Ru-P(2)-C(21)
88.96(2) Ru-P(2)-C(21′)
119.29(7)
109.84(6)
P(2)-Ru-Cl
87.06(2) C(20)-P(2)-C(21) 104.68(10)
C(6)-Si-C(9)
C(6)-Si-C(10)
C(6)-Si-C(20)
C(9)-Si-C(10)
C(9)-Si-C(20)
C(10)-Si-C(20)
Ru-P(1)-C(10)
Ru-P(1)-C(11)
Ru-P(1)-C(11′)
C(10)-P(1)-C(11) 104.0(1)
C(10)-P(1)-C(11′) 101.8(1)
Si-C(10)-P(1)
Ru-P(2)-C(20)
95.0(1)
109.3(1)
109.3(1)
119.1(1)
110.5(1)
112.0(1)
C(20)-P(2)-C(21′) 102.91(9)
C(21)-P(2)-C(21′) 100.39(9)
C(2)-C(1)-C(5)
C(1)-C(2)-C(3)
C(2)-C(3)-C(4)
C(3)-C(4)-C(5)
107.7(2)
107.9(2)
108.4(2)
107.4(2)
108.6(2)
102.4(2)
118.7(2)
119.8(2)
101.8(2)
115.72(7) C(1)-C(5)-C(4)
119.13(7) Si-C(6)-C(7)
113.27(7) C(6)-C(7)-C(8)
C(7)-C(8)-C(9)
Si-C(9)-C(8)
120.5(1)
C(11)-P(1)-C(11′) 100.4(1)
117.29(7) Si-C(20)-P(2)
118.0(1)
Ack n ow led gm en t. We thank the Ministe`re de
l’Education Nationale, de l’Enseignement Supe´rieur et
de la Recherche (France), and the Natural Sciences and
Engineering Research Council (Canada) for financial
support. We would also thank Dr. Boukherroub for his
helpful advice in the ligand syntheses.
The coordination geometry of ruthenium is best de-
scribed as a distorted octahedron, with the η5-Cp ligand
occupying three coordination sites. The remaining
positions are filled with one chlorine atom and the two
phosphorus donors of the chelating ligand. The Cp ring
is planar within 0.008 Å (2.5σ) and symmetrically
bonded to the metal: the Ru-C distances range from
2.200(2) to 2.224(2) Å, whereas the distance to the center
of the ring is 1.854(1) Å. The Ru-Cl bond (2.4419(5)
Å) is typical of such systems. The Ru-P distances and
the P-Ru-P angle show some variation depending on
the type of phosphine. In CpRuCl(PPh3)2,18 the rela-
tively long Ru-P bonds (2.336(1) Å) and the large
P-Ru-P angle (103.99(4)°) can be ascribed to the rather
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
data, atomic coordinates, temperature factors, bond lengths
and angles, refined temperature factors, weighted least-
squares planes, and torsion angles and a stereoview of the unit
cell (14 pages). Ordering information is given on any current
masthead page.
OM9709751
(19) Morandini, F.; Consiglio, G.; Staub, B.; Ciani, G.; Sironi, A. J .
Chem. Soc., Dalton Trans. 1983, 2293.
(18) Bruce, M. I.; Wong, F. S.; Skelton, B. W.; White, A. H. J . Chem.
Soc., Dalton Trans. 1981, 1398.
(20) Ishikawa, M.; Sugisawa, H.; Akitomo, H.; Matsusaki, K. Or-
ganometallics 1986, 5, 2447.