Nucleophilic substitution reactions at the Si-Cl bonds of the dichloro(methyl)silyl ligand in five- and six-coordinate complexes of ruthenium(II) and osmium(II)

Article abstract of DOI:10.1016/j.jorganchem.2004.04.039

Treatment of either RuHCl(CO)(PPh₃)₃ or MPhCl(CO) (PPh₃)₂ with HSiMeCl₂ produces the five-coordinate dichloro(methyl)silyl complexes, M(SiMeCl₂) Cl(CO)(PPh₃)₂ (1a, M = Ru; 1b, M = Os). 1a and 1b react readily with hydroxide ions and with ethanol to give M(SiMe[OH]₂)Cl(CO)(PPh₃)₂ (2a, M = Ru; 2b, M = Os) and M(SiMe[OEt]₂)Cl(CO)(PPh₃) ₂ (3a, M = Ru; 3b, M = Os, respectively. 3b adds CO to form the six-coordinate complex, Os(SiMe[OEt]₂)Cl(CO)₂ (PPh₃)₂ (4b) and crystal structure determinations of 3b and 4b reveal very different Os-Si distances in the five-coordinate complex (2.3196(11) ?) and in the six-coordinate complex (2.4901(8) ?). Reaction between 1a and 1b and 8-aminoquinoline results in displacement of a triphenylphosphine ligand and formation of the six-coordinate chelate complexes M(SiMeCl ₂)Cl(CO)(PPh₃)(K²(N,N)-NC₉ H₆NH₂-8) (5a), M = Ru; 5b, M = Os), respectively. Crystal structure determination of 5a reveals that the amino function of the chelating chelating 8-aminoquinoline ligand is located adjacent to the reactive Si-Cl bonds of the dichloro(methyl)silyl ligand but no reaction between these functions is observed. However, 5a and 5b react readily with ethanol to give ultimately M(SiMe[OEt]₂)Cl(CO) (PPh₃)(K²(N,N-NC₉H₆ NH₂-8) (6a, M = Ru; 6b, M = Os). In the case of ruthenium only, the intermediate ethanolysis product Ru(SiMeCl[OEt])Cl(CO) (PPh₃)(K²(N,N-NC₉H₆ NH₂-8) (6c) was also isolated. The crystal structure of 6c was determined. Reaction between 1b 2-aminopyridine results in condensation between the Si-Cl bonds and the N-H bonds with formation of a novel tridentate "NSiN" ligand in the complex Os(K³(Si,N,N)-SiMe[NH(2-C₅H₄N)] ₂)Cl(CO)(PPh₃) (7b). Crystal structure determination of 7b shows that the "NSiN" ligand coordinates to osmium with a "facial" arrangement and with chloride trans to the silyl ligand.

Full text of DOI:10.1016/j.jorganchem.2004.04.039

Journal of Organometallic Chemistry 689 (2004) 2511–2522
www.elsevier.com/locate/jorganchem
Nucleophilic substitution reactions at the Si–Cl bonds of the
dichloro(methyl)silyl ligand in five- and six-coordinate complexes
of ruthenium(II) and osmium(II)
*
Wai-Him Kwok, Guo-Liang Lu, Clifton E.F. Rickard, Warren R. Roper ,
*
L. James Wright
Department of Chemistry, The University of Auckland, Private Bag 92019, Auckland, New Zealand
Received 4 March 2004; accepted 15 April 2004
Abstract
Treatment of either RuHCl(CO)(PPh3)3 or MPhCl(CO)(PPh3)2 with HSiMeCl2 produces the five-coordinate dichloro(methyl)si-
lyl complexes, M(SiMeCl2)Cl(CO)(PPh3)2 (1a, M=Ru; 1b, M=Os). 1a and 1b react readily with hydroxide ions and with ethanol to
give M(SiMe[OH]2)Cl(CO)(PPh3)2 (2a, M=Ru; 2b, M=Os) and M(SiMe[OEt]2)Cl(CO)(PPh3)2 (3a, M=Ru; 3b, M=Os), respec-
tively. 3b adds CO to form the six-coordinate complex, Os(SiMe[OEt]2)Cl(CO)2(PPh3)2 (4b) and crystal structure determinations
˚
of 3b and 4b reveal very different Os–Si distances in the five-coordinate complex (2.3196(11) A) and in the six-coordinate complex
˚
(2.4901(8) A). Reaction between 1a and 1b and 8-aminoquinoline results in displacement of a triphenylphosphine ligand and for-
mation of the six-coordinate chelate complexes M(SiMeCl2)Cl(CO)(PPh3)(j2(N,N)-NC9H6NH2-8) (5a, M=Ru; 5b, M=Os), respec-
tively. Crystal structure determination of 5a reveals that the amino function of the chelating 8-aminoquinoline ligand is located
adjacent to the reactive Si–Cl bonds of the dichloro(methyl)silyl ligand but no reaction between these functions is observed. How-
ever, 5a and 5b react readily with ethanol to give ultimately M(SiMe[OEt]2)Cl(CO)(PPh3)(j2(N,N-NC9H6NH2-8) (6a, M=Ru; 6b,
M=Os). In the case of ruthenium only, the intermediate ethanolysis product Ru(SiMeCl[OEt])Cl(CO)(PPh3)(j2(N,N-NC9H6NH2-
8) (6c) was also isolated. The crystal structure of 6c was determined. Reaction between 1b and excess 2-aminopyridine results in
condensation between the Si–Cl bonds and the N–H bonds with formation of a novel tridentate ‘‘NSiN’’ ligand in the complex
Os(j3(Si,N,N)-SiMe[NH(2-C5H4N)]2)Cl(CO)(PPh3) (7b). Crystal structure determination of 7b shows that the ‘‘NSiN’’ ligand co-
ordinates to osmium with a ‘‘facial’’ arrangement and with chloride trans to the silyl ligand.
ꢀ 2004 Elsevier B.V. All rights reserved.
Keywords: Silyl complex; Osmium; Ruthenium; X-ray crystal structure; Tridentate ligand
1. Introduction
compounds of the type, LnM–SiR3 ꢀ nXn, where X can
be H [1], R [2], OH [3,4], OR [5], SR [6], NR2 [7], and
F [8,2]. Furthermore, several complexes containing the
dimethylamino-bridged bis(silylene) ligand system, have
been prepared directly from reaction between HSi-
Me2NMe2 and chlorodimethylsilyl complexes of ruthe-
nium(II) and osmium(II) in complex reactions in
which one step may involve a nucleophilic substitution
at silicon [9]. The reactivity of the Si–Cl bonds in all
chlorosilyl ligands is variable and in some cases the
Si–Cl bonds are quite unreactive towards hydrolysis.
Metal complexes with chloro-substituted silyl ligands,
LnM–SiR3 ꢀ nCln (n=1–3), have proved to be useful sub-
strates, through nucleophilic substitution reactions, for
the syntheses of silyl complexes with interesting functio-
nalisation at silicon. Examples include the syntheses of
*
Corresponding authors. Tel.: +64-9-373-7999x8320; fax: +64-9-
373-7422.
E-mail address: w.roper@auckland.ac.nz (W.R. Roper).
0022-328X/$ - see front matter ꢀ 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2004.04.039

2512
W.-H. Kwok et al. / Journal of Organometallic Chemistry 689 (2004) 2511–2522
An instance is provided by the ready hydrolysis
of CpFe(CO)2SiR2Cl whereas the corresponding
ruthenium derivative, CpRu(CO)2SiR2Cl, is inert to hy-
drolysis [10]. Two CpFe(CO)2 fragments attached to the
one silicon atom in [CpFe(CO)2]2SiCl2 renders the Si–Cl
bonds unreactive to Cl/OH exchange [11]. Additionally,
the number of halide substituents on the silyl ligand af-
fects the reactivity, e.g., when one of the chlorides in
[CpFe(CO)2]2SiCl2 is replaced by hydride to give
[CpFe(CO)2]2SiHCl the remaining Si–Cl bond is readily
hydrolysed. Interestingly, structural data suggests that
both the Ru–Si and Si–Cl distances in Cp(PR3)2RuSiX3
increase when chloride is replaced by either methyl or
phenyl [12]. The increased Si–Cl distances have been at-
tributed to d(Ru)–r*(Si–Cl) p-back-bonding interac-
tions and this may partly explain the increased Si–Cl
bond reactivity. To contribute to further understanding
of the reactivity of chloro-substituted silyl ligands we
have developed convenient routes to dichloro(methyl)si-
lyl complexes of both ruthenium(II) and osmium(II) and
examined some features of their chemistry.
PPh3
M
HSiMeCl2
Cl
RuHCl(CO)(PPh3)3 or
MPhCl(CO)(PPh3)2
(-H2 or PhH)
OC
SiMeCl2
PPh3
(1a)( M= Ru)
(1b)( M= Os)
OH-
OEt-
PPh3
Cl
M
PPh3
OC
SiMe(OH)2
Cl
M
PPh3
(2a)( M= Ru)
(2b)( M= Os)
OC
SiMe(OEt)2
PPh3
(3a)( M= Ru)
(3b)( M= Os)
CO
(for M= Os)
PPh3
OC
OC
Cl
Os
SiMe(OEt)2
PPh3
(4b)
Scheme 1. Syntheses and reactions of dichloro(methyl)silyl complexes
of ruthenium(II) and osmium(II).
Herein, we report (i) the syntheses of the dichlo-
ro(methyl)silyl complexes, M(SiMeCl2)Cl(CO)(PPh3)2
(1a, M=Ru; 1b, M=Os), (ii) the hydrolysis and ethano-
lysis of the silyl ligands in these complexes, (iii) the car-
bonylation of Os[SiMe(OEt)2]Cl(CO)(PPh3)2 (3b) to
give Os[SiMe(OEt)2]Cl(CO)2(PPh3)2 (4b), (iv) a compar-
ison of the crystal structures of 3b and 4b, (v) the reac-
tion of 1a and 1b with 8-aminoquinoline to give
M(SiMeCl2)Cl(CO)(PPh3)(j2(N,N-NC9H6NH2-8) (5a,
M=Ru (structurally characterized); 5b, M=Os) with
unchanged dichloro(methyl)silyl ligands and triphenyl-
phosphine displacement, and (vi) the reaction of 1b with
2-aminopyridine to give Os(j3(Si,N,N)-SiMe[NH(2-
C5H4N)]2)Cl(CO)(PPh3) (7b) (structurally character-
ized) with formation of a novel ‘‘NSiN’’ tridentate silyl
ligand through reaction at both Si–Cl bonds.
picted in Scheme 1, reaction between MPhCl(CO)(PPh3)2
(or RuHCl(CO)(PPh3)3) and excess H–SiMeCl2, leads
cleanly to M(SiMeCl2)Cl(CO)(PPh3)2 (1a, M=Ru; 1b,
M=Os). The IR spectrum (Nujol mull) of yellow Ru(Si-
MeCl2)Cl(CO)(PPh3)2 has absorptions assigned to
m(CO) at 1953, 1936, 1923 cmꢀ1 and the corresponding
bands for the yellow-orange osmium analogue occur at
1942, 1925, 1911 cmꢀ1 (full spectroscopic data for these
and all other new compounds are in Section 4). Although
these compounds are mono-carbonyl, the multiple carbo-
nyl absorptions observed are attributed to solid-state
splitting. This same phenomenon was also observed for
the hydrolysis products 2a and 2b to be described below.
The other mono-carbonyl compounds described in this
paper all showed the expected single m(CO). Despite the
splitting of these bands for 1a and 1b it is clear that the ab-
sorptions for the osmium compound are lower than those
for the ruthenium compound.
2. Results and discussion
2.1. Syntheses of the dichloro(methyl)silyl complexes,
M(SiMeCl2)Cl(CO)(PPh3)2 (1a, M=Ru; 1b, M=Os)
and subsequent reactions with water and ethanol
Treatment of the dichloro(methyl)silyl complexes, 1a
and 1b, with excess K2CO3 suspended in a THF/H2O mix-
ture leads rapidly to the formation of the yellow dihydrox-
y(methyl)silyl complexes, Ru(SiMe[OH]2)Cl(CO)(PPh3)2
(2a) and Os(SiMe[OH]2)Cl(CO)(PPh3)2 (2b). The IR
spectrum for 2a shows m(CO) at 1926, 1911 cmꢀ1, and
the corresponding absorptions for 2b occur at the lower
values of 1914, 1899 cmꢀ1. As expected, replacement of
Cl on silicon by OH, lowers m(CO) [3]. Significantly,
m(OH) is observed at 3649 cmꢀ1 for 1a and at 3634 cmꢀ1
We have demonstrated that a simple and convenient
route to coordinatively unsaturated silyl complexes of
ruthenium(II) and osmium(II) of general formula
M(SiR3)Cl(CO)(PPh3)2 involves reaction between a
silane, H–SiR3, and MPhCl(CO)(PPh3)2. For M=Ru,
and for certain silanes, an alternative substrate is
RuHCl(CO)(PPh3)3. Successful reactions have been
achieved for SiR3 =SiCl3 [5,3], SiMe3 [5], SiEt3 [5],
SiMe2Cl [13,14], Si(pyrrolyl)3 [15], Si(OEt)3 [16], and
Si(OC2H4)3N [17,18]. We now report that reactions utiliz-
ing H–SiMeCl2 as the silane are equally successful. As de-
1
for 1b and in the H NMR resonances for the silicon-
bound OH groups are observed at d, 2.71 and 2.27 ppm,
respectively.

W.-H. Kwok et al. / Journal of Organometallic Chemistry 689 (2004) 2511–2522
2513
Similarly, treatment of the dichloro(methyl)silyl com-
plexes, 1a and 1b, with ethanol/dichlormethane leads
rapidly to the formation of the yellow diethoxy
(methyl)silyl complexes, Ru(SiMe[OEt]2)Cl(CO)(PPh3)2
(3a) and Os(SiMe[OEt]2)Cl(CO)(PPh3)2 (3b). The IR
spectrum for 3a shows m(CO) at 1918 cmꢀ1 and for 3b
the corresponding band is at 1904 cmꢀ1. The crystal
structure of 3b was determined. Crystal data and refine-
ment details for 3b, and for all other structures reported
in this paper, are given in Table 1. The molecular struc-
ture of 3b is shown in Fig. 1 and selected bond lengths
and angles are given in Table 2. As expected, the geom-
etry about osmium is pyramidal with the silyl ligand in
the apical site. This same geometry has been found for
other five-coordinate silyl complexes of osmium(II)
˚
[2,3,5,16,17]. The Os–Si distance in 3b is 2.3196(11) A,
which is very close to the corresponding values found
˚
for Os[Si(OH)3]Cl(CO)(PPh3)2 (2.319(2) A) [3] and Os[-
˚
Si(OEt)3]Cl(CO)(PPh3)2 (2.319(2) A) [16]. A comparison
with the Os–Si distance in the six-coordinate dicarbonyl
derivative of 3b will be made in the following section.
Fig. 1. Molecular geometry of Os(SiMe[OEt]2)Cl(CO)(PPh3)2 (3b).
2.2. Carbonylation of Os[SiMe(OEt)2]Cl(CO)(PPh3)2
(3b) to give Os[SiMe(OEt)2]Cl(CO)2(PPh3)2 (4b),
and a comparison of the crystal structures of 3b and 4b
Me(OEt)2]Cl(CO)2(PPh3)2 (4b). The IR spectrum of 4b
has two m(CO) bands at 2018, 1959 cmꢀ1 consistent with
a cis arrangement of the two CO ligands. The 13C NMR
spectrum, which is also consistent with this arrange-
ment, shows two down-field signals for the different
As shown in Scheme 1, 3b reacts with CO to form the
colourless, six-coordinate dicarbonyl complex, Os[Si-
Table 1
Data collection and processing parameters for 3b, 4b, 5a, 6c, and 7b
3b
4b
5aÆ1/2(C6 H6)
6c
7b
Formula
C42H43ClO3OsP2Si C43H43ClO4OsP2Si C32H29Cl3N2OPRuSi C31H29Cl2N2O2PRuSi C30H28ClN4OOsPSi
745.27
Molecular weight
Crystal system
Space group
911.44
Triclinic
939.45
Triclinic
724.05
Triclinic
692.59
Monoclinic
P21/n
Monoclinic
P21/n
ꢀ
ꢀ
ꢀ
P1
P1
P1
˚
a (A)
10.3486(1)
12.0345(1)
17.3899(1)
72.621(1)
89.010(1)
72.624(1)
1966.38(3)
2
10.5619(2)
12.6233(2)
15.9928(2)
73.358(1)
89.529(1)
83.332(1)
2028.42(6)
2
10.7815(2)
10.9433(2)
15.3693(3)
99.920(1)
99.910(1)
109.72(1)
1628.79(5)
2
9.6362(1)
16.2133(2)
20.6404(3)
90.0
11.8140(1)
16.1187(1)
17.2170(1)
90.0
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
103.221(1)
90.0
102.075(1)
90.0
3
˚
V (A )
3139.27(7)
4
1.465
3205.9(3)
4
1.544
Z
D(calc) (gcmꢀ3
F(000)
)
1.539
912
3.46
1.817
1114
3.37
1.476
734
0.84
1408
0.79
1548
4.26
l (mmꢀ1
Crystal size (mm)
)
0.42·0.35·0.18
1.2–27.2
19,651
0.28·0.08·0.06
1.3–26.3
18,946
0.42·0.22·0.12
1.4–27.1
16,035
0.44·0.14·0.12
1.6–27.1
30,451
0.12·0.12·0.08
1.7–27.1
19,314
2h (min–max) (ꢁ)
Reflections collected
Independent reflections (Rint
A (min–max)
Goodness-of-fit on F2
R (observed data)
)
8519 (0.0218)
0.324–0.575
1.044
8051 (0.0230)
0.452–0.823
1.085
6965 (0.0195)
0.719–0.906
1.065
6773 (0.0493)
0.723–0.911
1.169
6913 (0.0337)
0.634–0.731
1.047
R1 =0.0339
wR2 =0.0857
R1 =0.0352
wR2 =0.0866
1.81–1.22
R1 =0.0236
wR2 =0.0517
R1 =0.0285
wR2 =0.0542
0.87–0.75
R1 =0.0371
wR2 =0.1069
R1 =0.0418
wR2 =0.1128
1.82–0.85
R1 =0.0621
wR2 =0.1506
R1 =0.0712
wR2 =0.1554
1.72–1.35
R1 =0.0312
wR2 =0.0581
R1 =0.0466
wR2 =0.0628
0.78–0.57
R (all data)
ꢀ3
˚
Diff. map (min–max) (eA
)
P
P
R ¼ jjFoj ꢀ jFcjj= jFoj.
P
P
2
2
1=2
wR2 ¼ f½wðF 2o ꢀ F c2Þ ꢁ= ½wðF 2oÞ ꢁg
.

2514
W.-H. Kwok et al. / Journal of Organometallic Chemistry 689 (2004) 2511–2522
Table 2
Table 3
˚
˚
Selected bond lengths (A) and angles (ꢁ) for 3b
Selected bond lengths (A) and angles (ꢁ) for 4b
Bond lengths
Os–C(1)
Os–Si
Bond lengths
Os–C(2)
Os–C(1)
Os–P(2)
Os–P(1)
Os–Cl
1.824(5)
1.887(3)
2.024(4)
2.4084(8)
2.4149(8)
2.4837(8)
2.4901(8)
1.672(2)
1.676(2)
1.892(3)
1.049(4)
1.149(4)
2.3196(11)
2.3617(10)
2.3671(10)
2.4039(11)
1.639(4)
Os–P(1)
Os–P(2)
Os–Cl
Si–O(3)
Si–O(2)
Si–C(6)
O(1)–C(1)
Os–Si
1.651(4)
1.879(5)
1.139(6)
Si–O(3)
Si–O(4)
Si–C(3)
O(1)–C(1)
O(2)–C(2)
Bond angles
C(1)–Os–Si
C(1)–Os–P(1)
Si–Os–P(1)
C(1)–Os–P(2)
Si–Os–P(2)
P(1)–Os–P(2)
C(1)–Os–Cl
Si–Os–Cl
84.87(16)
88.77(14)
98.05(4)
Bond angles
C(2)–Os–C(1)
C(2)–Os–P(2)
C(1)–Os–P(2)
C(2)–Os–P(1)
C(1)–Os–P(1)
P(2)–Os–P(1)
C(2)–Os–Cl
C(1)–Os–Cl
P(2)–Os–Cl
P(1)–Os–Cl
C(2)–Os–Si
C(1)–Os–Si
P(2)–Os–Si
P(1)–Os–Si
Cl–Os–Si
87.69(13)
93.22(9)
87.65(9)
93.09(14)
95.94(4)
165.99(4)
167.38(16)
107.42(4)
86.73(4)
91.11(9)
86.89(9)
172.89(3)
172.22(9)
99.96(10)
85.72(3)
P(1)–Os–Cl
P(2)–Os–Cl
O(3)–Si–O(2)
O(3)–Si–C(6)
O(2)–Si–C(6)
O(3)–Si–Os
O(2)–Si–Os
C(6)–Si–Os
88.52(4)
104.9(2)
107.2(2)
106.9(2)
90.74(3)
79.86(10)
167.38(9)
95.03(3)
111.85(13)
112.29(14)
113.16(18)
91.28(3)
92.54(3)
O(3)–Si–O(4)
O(3)–Si–C(3)
O(4)–Si–C(3)
O(3)–Si–Os
O(4)–Si–Os
C(3)–Si–Os
107.71(13)
105.81(15)
105.59(15)
106.91(9)
108.20(9)
121.94(11)
CO ligands at 177.4 and 180.4 ppm. This geometry is
confirmed by a crystal structure determination. The mo-
lecular structure of 4b is shown in Fig. 2 and selected
bond lengths and angles are given in Table 3. The geom-
etry about osmium is octahedral with mutually trans tri-
phenylphosphine ligands and mutually cis CO ligands.
The most interesting structural parameter is the Os–Si
˚
bond distance which is 2.4901(8) A. This is an increase
˚
of 0.1705 A over the corresponding distance found in
the five-coordinate complex 3b. Almost identical in-
creases were observed for the related pairs of os-
mium(II)-silyl complexes Os[Si(OEt)3]R(CO)(PPh3)2
and Os[Si(OEt)3]R(CO)2(PPh3)2 (an increase of 0.1688
˚
˚
A (for R=Ph), and an increase of 0.1546 A (for R=
o-tolyl)) [16]. All the other Os–ligand bond distances
in 4b are also increased with respect to the values found
in 3b but the increases are much smaller. It should also
be noted that the CO ligand trans to the silyl ligand is
˚
bound at a distance of 2.024(4) A whereas the other
˚
CO is bound at 1.887(3) A. Clearly, the silyl and CO lig-
ands, when located mutually trans, have a pronounced
bond lengthening effect on each other.
2.3. Reaction of M(SiMeCl2)Cl(CO)(PPh3)2 (1a,
M=Ru; 1b, M=Os) with 8-aminoquinoline to give
M(SiMeCl2)Cl(CO)(PPh3)(j2(N,N)-NC9H6NH2-8)
(5a, M=Ru; 5b, M=Os) and the crystal structure of 5a
In view of the reactivity of 1a and 1b towards the OH
functions in water and ethanol discussed in Section 2.1,
Fig. 2. Molecular geometry of Os(SiMe[OEt]2)Cl(CO)2(PPh3)2 (4b).

W.-H. Kwok et al. / Journal of Organometallic Chemistry 689 (2004) 2511–2522
2515
it was of interest to explore the corresponding reactivity
towards NH functions in appropriate molecules. Our ex-
perience with the nucleophilic substitution reactions of
the BCl2 ligand bound to osmium in Os(BCl2)Cl
(CO)(PPh3)2 showed that more tractable derivatives were
obtained in reactions with molecules which had not only
NH functions but also a separate donor function so that
the resulting amino-boryl ligands became tethered to the
osmium [19–21]. Accordingly, the reactions of 1a and 1b
with 8-aminoquinoline and 2-aminopyridine (discussed
in Section 2.4) were examined. As shown in Scheme 2,
treatment of either 1a or 1b with one equivalent of 8-ami-
noquinoline, even in the presence of excess triethylamine,
gave the coordinatively saturated, orange compounds,
Ru(SiMeCl2)Cl(CO)(PPh3)(j2(N,N)-NC9H6NH2-8) (5a)
or Os(SiMeCl2)Cl(CO)(PPh3)(j2(N,N)-NC9H6NH2-8)
(5b), respectively. Surprisingly, no condensation of the
Si–Cl bonds with the 8-aminoquinoline N–H bonds oc-
curred. Rather, the 8-aminoquinoline coordinated un-
changed as a bidentate ligand through the two nitrogen
atoms with displacement of a triphenylphosphine ligand.
The IR spectra of 5a and 5b show a single m(CO) at 1944
and 1892 cmꢀ1, respectively. The 1H NMR spectra show
two doublet signals for the NH2 protons at 3.99 ppm
(2JHH =12 Hz), 4.44 ppm (2JHH =12 Hz) (5a) and
3.95 ppm (2JHH =11.6 Hz), 4.82 ppm (2JHH =12.4 Hz)
(5b), respectively. This is consistent with there being two
proton environments for the NH2 donor group, as can
be seen in the structure depicted in Scheme 2. This struc-
ture was confirmed by crystal structure analysis of Ru
(SiMeCl2)Cl(CO)(PPh3)(j2(N,N)-NC9H6NH2-8) (5a).
The molecular geometry of 5a is shown in Fig. 3 and
Fig. 3. Molecular geometry of Ru(SiMeCl2)Cl(CO)(PPh3)(j2(N,N)-
NC9H6NH2-8) (5a).
selected bond lengths and angles are given in Table 4.
The geometry about ruthenium is octahedral with the 8-
aminoquinoline coordinated as a bidentate ligand. The
quinoline nitrogen is trans to triphenylphosphine and
the amino nitrogen is trans to carbonyl. It should be noted
that this arrangement leaves the Si–Cl bonds adjacent to
the coordinated NH2 function, yet remarkably, as noted
above no condensation occurs. The Ru–Si distance is
˚
˚
2.3389(8) A while the Ru–Cl distance is 2.5164(7) A indi-
cating the powerful trans influence of the silyl ligand. The
bidentate 8-aminoquinoline is bound with the Ru–
˚
N(quinoline) distance at 2.119(2) A and the Ru–NH2 dis-
˚
tance at 2.193(2) A. The two Si–Cl distances are almost
˚
identical at 2.1210(11) and 2.1247(11) A.
PPh3
M
PPh3
M
N
CO
Cl
CO
NH2
Cl
SiMeCl2
H2N
SiMeCl2
(-PPh3)
Despite the lack of reactivity of the Si–Cl bonds in 5a
and 5b towards the N–H functions in the coordinated 8-
aminoquinoline, both 5a and 5b react readily with ethanol
to give ultimately the diethoxymethylsilyl products, Ru
[SiMe(OEt)2]Cl(CO)(PPh3)(j2(N,N)-NC9H6NH2-8) (6a)
and Os[SiMe(OEt)2]Cl(CO)(PPh3)(j2(N,N)-NC9H6NH2-8)
(6b), respectively (see Scheme 2). The IR spectrum of 6a
shows a single m(CO) at 1907 cmꢀ1 and the corresponding
band for 6b is at 1894 cmꢀ1. The presence of two diaster-
eotopic ethoxy groups, as required by the structure,
is shown by NMR spectroscopy. The 13C NMR spectra
show doublet signals for the carbonyl ligands at
205.8 ppm (2JCP =28.2 Hz) for 6a and at 189.5 ppm
(2JCP =12.1 Hz) for 6b.
PPh3
N
(1a)( M= Ru)
(1b)( M= Os)
(5a)( M= Ru)
(5b)( M= Os)
N
NH2
HOEt
(for M= Os)
PPh3
PPh3
N
Cl
Cl
CO
SiMe(OEt)2
Os
N
M
N
NH
Me
OC
Si
H2N
NH
(7b)
(6a)( M= Ru)
(6b)( M= Os)
During efforts to grow crystals of 5a suitable for X-ray
structure analysis from CH2Cl2/EtOH solution a single
crystal of the product of partial ethanolysis of 5a, i.e.,
Ru[SiMeCl(OEt)]Cl(CO)(PPh3)(j2(N,N)-NC9H6-NH2-8)
Scheme 2. Reactions of dichloro(methyl)silyl complexes of ruthe-
nium(II) and osmium(II) with 8-aminoquinoline and 2-aminopyridine.

2516
W.-H. Kwok et al. / Journal of Organometallic Chemistry 689 (2004) 2511–2522
Table 4
˚
Selected bond lengths (A) and angles (ꢁ) for 5a
Bond lengths
Ru–C(1)
Ru–N(1)
Ru–N(2)
Ru–P
1.841(3)
2.119(2)
2.193(2)
2.3183(7)
2.3389(8)
2.5164(7)
1.857(3)
Ru–Si
Ru–Cl(1)
Si–C(2)
Si–Cl(3)
Si–Cl(2)
O–C(1)
2.1210(11)
2.1247(11)
1.146(4)
Bond angles
C(1)–Ru–N(1)
C(1)–Ru–N(2)
N(1)–Ru–N(2)
C(1)–Ru–P
95.35(11)
173.73(11)
78.43(9)
91.67(9)
N(1)–Ru–P
N(2)–Ru–P
172.56(7)
94.51(7)
88.29(9)
C(1)–Ru–Si
N(1)–Ru–Si
N(2)–Ru–Si
P–Ru–Si
Fig. 4. Molecular geometry of Ru(SiMeCl[OEt])Cl(CO)(PPh3)-
(j2(N,N)-NC9H6NH2-8) (6c).
87.44(7)
92.17(7)
95.26(3)
C(1)–Ru–Cl(1)
N(1)–Ru–Cl(1)
N(2)–Ru–Cl(1)
P–Ru–Cl(1)
Si–Ru–Cl(1)
C(2)–Si–Cl(3)
C(2)–Si–Cl(2)
Cl(3)–Si–Cl(2)
C(2)–Si–Ru
Cl(3)–Si–Ru
Cl(2)–Si–Ru
100.07(9)
83.28(7)
78.59(7)
93.07(3)
Table 5
168.02(3)
100.15(13)
101.10(13)
99.93(5)
˚
Selected bond lengths (A) and angles (ꢁ) for 6c
Bond lengths
Ru–C(1)
Ru–N(1)
Ru–N(2)
Ru–P
1.821(6)
2.132(4)
2.204(5)
2.3195(13)
2.3486(15)
2.5633(13)
1.663(5)
1.837(7)
2.086(2)
1.172(7)
131.31(12)
110.88(4)
109.01(4)
Ru–Si
Ru–Cl(1)
Si–O(2)
Si–C(11)
Si–Cl(2)
O(1)–C(1)
(6c), was inadvertently obtained. A bulk sample of 6c as a
pure compound was not obtained, however, the opportu-
nity to complete the crystal structure was taken. The mo-
lecular geometry of 6c is shown in Fig. 4 and selected bond
lengths and angles are given in Table 5. The arrangement
of the six donor atoms about ruthenium is exactly the
same as for 5a discussed above. The effect of replacing
one chloride on silicon with an ethoxy group is to lengthen
Bond angles
C(1)–Ru–N(1)
C(1)–Ru–N(2)
N(1)–Ru–N(2)
C(1)–Ru–P
95.1(2)
170.8(2)
78.65(18)
92.57(16)
171.23(13)
94.18(12)
86.91(16)
91.41(12)
86.45(13)
93.20(5)
N(1)–Ru–P
N(2)–Ru–P
C(1)–Ru–Si
˚
both the Ru–Si bond (from 2.3389(8) A in 5a to2.3486(15)
˚
˚
A in 6c) and the Ru–Cl bond (from 2.5164(7) A in 5a to
˚
2.5633(13) A in 6c). Clearly the trans influence of the silyl
N(1)–Ru–Si
N(2)–Ru–Si
P–Ru–Si
ligand is strongly increased by this substitution of chloride
by ethoxide. Other molecular parameters for 6c are sub-
stantially unchanged from those for 5a.
C(1)–Ru–Cl(1)
N(1)–Ru–Cl(1)
N(2)–Ru–Cl(1)
P–Ru–Cl(1)
Si–Ru–Cl(1)
O(2)–Si–C(11)
O(2)–Si–Cl(2)
C(11)–Si–Cl(2)
O(2)–Si–Ru
C(11)–Si–Ru
Cl(2)–Si–Ru
C(12)–O(2)–Si
106.00(16)
84.76(12)
80.40(13)
89.09(4)
2.4. Reaction of Os(SiMeCl2)Cl(CO)(PPh3)2 (1b) with
2-aminopyridine to give Os(j3(Si,N,N)-SiMe[NH(2-
C5H4N)]2)Cl(CO)(PPh3) (7b), and the crystal struc-
ture of 7b
166.79(5)
108.6(3)
103.3(2)
100.9(2)
107.49(16)
122.4(2)
Whereas the reaction of 1b with 8-aminoquinoline
described above resulted in coordination of 8-aminoquin-
oline as a bidentate ligand and left the dichloromethylsilyl
112.54(9)
123.6(5)

W.-H. Kwok et al. / Journal of Organometallic Chemistry 689 (2004) 2511–2522
2517
Table 6
ligand unchanged, the reaction of 1b with two equivalents
˚
Selected bond lengths (A) and angles (ꢁ) for 7b
of 2-aminopyridine leads to condensation of the amino
N–H functions with both Si–Cl bonds forming a novel tri-
dentate silyl ligand in the complex Os(j3(Si,N,N)-Si-
Me[NH(2-C5H4N)]2)Cl(CO)(PPh3) (7b) (see Scheme 2).
This marked difference in behaviour between 8-amino-
quinoline and 2-aminopyridine can be attributed to the
formation of favourable five-membered rings in the struc-
ture of 7b (the analogous reaction with 8-aminoquinoline
would produce less-favourable six-membered rings). In a
closely related reaction the chlorodimethylsilyl ligand in
CpFe(CO)2(SiClMe2) has been treated with the sodium
salt of 2-hydroxypyridine to give CpFe (CO)2[SiMe2O
(2-C5H4N)] and this compound in turn when subjected
to photolysis loses CO and forms the bidentate chelate
complex, CpFe(CO)[j2(Si,N)-SiMe2O(2-C5H4N)] [22].
A compound with a tridentate ligand related to the ligand
found in 7b in that it is a ‘‘NSiN’’ donor has been reported
from an oxidative addition reaction utilizing a preformed
bis(8-quinolyl)silane [23]. The IR spectrum of pale yellow
7b has m(CO) at 1900 cmꢀ1. The 1H NMR spectrum of 7b
shows singlet signals for the two different NH groups at
4.95 and 5.18 ppm. In the 13C NMR the carbonyl carbon
resonance is a doublet at 186.8 ppm (2JCP =12.1 Hz). To
confirm the presence of a tridentate ligand and to ascer-
tain the geometry of attachment to osmium the crystal
structure of 7b was determined. The molecular geometry
is shown in Fig. 5 and selected bond lengths and angles
Bond lengths
Os–C(1)
Os–N(1)
Os–N(4)
Os–P
1.829(5)
2.176(4)
2.198(4)
2.3085(12)
2.3121(12)
2.5503(11)
1.767(4)
Os–Si
Os–Cl(1)
Si–N(3)
Si–N(2)
Si–C(2)
O–C(1)
1.777(4)
1.863(5)
1.177(6)
Bond angles
C(1)–Os–N(1)
C(1)–Os–N(4)
N(1)–Os–N(4)
C(1)–Os–P
91.0(2)
169.1(2)
84.0(1)
92.7(2)
N(1)–Os–P
N(4)–Os–P
176.3(1)
92.5(1)
89.2(2)
C(1)–Os–Si
N(1)–Os–Si
N(4)–Os–Si
P–Os–Si
79.8(1)
80.4(1)
101.06(4)
98.7(2)
90.9(1)
C(1)–Os–Cl(1)
N(1)–Os–Cl(1)
N(4)–Os–Cl(1)
P–Os–Cl(1)
Si–Os–Cl(1)
N(3)–Si–N(2)
N(3)–Si–C(2)
N(2)–Si–C(2)
N(3)–Si–Os
N(2)–Si–Os
C(2)–Si–Os
91.1(1)
87.68(4)
168.00(4)
107.8(2)
105.3(2)
103.4(2)
100.7(1)
99.8(1)
˚
are given in Table 6. The Os–Si distance is 2.3121(12) A
which is very short for an octahedral osmium silyl com-
plex and is very close to the Os–Si distance found in the
137.5(2)
˚
five-coordinate complex 3b (2.3196(11) A). The two Os–
˚
N distances are not equal (2.176(4) A for N trans to
PPh3, and 2.198(4) for N trans to CO). The chloride,
which is located trans to the Si donor, is attached at the
˚
very long distance of 2.5503(11) A. The two Si–N distanc-
˚
es (1.767(4) and 1.777(4) A) are at the long end of the
range observed for normal Si–N single bonds (1.70–1.76
˚
A).
3. Conclusions
It has been demonstrated that the dichloro(methyl)si-
lyl ligand in the five-coordinate complexes of ruthenium
and osmium, M(SiCl2Me)Cl(CO)(PPh3)2, readily under-
goes condensation reactions with either the O–H func-
tion in water and ethanol or the N–H function in
2-aminopyridine giving hydroxysilyl, ethoxysilyl, or
2-pyridylaminosilyl complexes, respectively. The last re-
action gives rise to a tridentate ‘‘NSiN’’ ligand indicating
how novel multi-dentate silyl ligands might be assembled
through nucleophilic substitution reactions of the Si–Cl
bonds of chlorosilyl ligands. In contrast to the facility
with which 2-aminopyridine reacts with M(SiCl2Me)Cl
(CO)(PPh3)2, 8-aminoquinoline coordinates unchanged,
Fig. 5. Molecular geometry of Os(j3(Si,N,N)-SiMe[NH(2-C5H4N)]2)-
Cl(CO)(PPh3) (7b).

2518
W.-H. Kwok et al. / Journal of Organometallic Chemistry 689 (2004) 2511–2522
1,3
with triphenylphosphine displacement. This difference in
the reactivity of Si–Cl bonds has been attributed to the
formation of favourable five-membered rings in the reac-
tion with 2-aminopyridine whereas any analogous reac-
tion with 8-aminoquinoline would form six-membered
rings. The structures of key compounds have been deter-
mined by X-ray crystallography confirming that short
M–Si distances depend not only on the presence of elec-
tronegative substituents on Si but also on whether the
metal is five- or six-coordinate and whether the Si is part
of a chelate ring system.
p-C6H5), 131.1 (t0,
J
=45.2 Hz, i-C6H5), 134.6 (t0,
CP
3,5
J
=11.0 Hz, m-C6H5), 198.3 (t, 2JCP =12.6 Hz, CO).
CP
An alternative preparative method for 1a is the fol-
lowing: RuPhCl(CO)(PPh3)2 (0.50 g, 0.65 mmol) was
dried in vacuo in a Schlenk tube, and benzene (25 mL)
was added, and the solvent was degassed. Methyldichlo-
rosilane (0.75 g, 6.5 mmol) was then transferred to the
reaction vessel by ‘‘vacuum freeze trapping’’ and the
tube was sealed. While still under vacuum the mixture
was warmed to room temperature and the red suspen-
sion was then heated (CAUTION: use safety shield)
for 1.5 h in an oil bath maintained at a temperature of
50 ꢁC. After this time a yellow solution was obtained.
The solvent volume was reduced in vacuo and hexane
(15 mL) was added resulting in the formation of pure
1a as bright yellow crystals which were then collected
by filtration (420 mg, 80%).
4. Experimental
4.1. General procedures and instruments
Standard laboratory procedures were followed as
have been described previously [13]. The compounds
RuHCl(CO)(PPh3)3 [24], RuPhCl(CO)(PPh3)2 [25] and
OsPhCl(CO)(PPh3)2 [25], were prepared by literature
methods.
4.3. Preparation of Os(SiMeCl2)Cl(CO)(PPh3)2 (1b)
OsPhCl(CO)(PPh3)2 (0.43 g, 0.51 mmol) was dried in
vacuo in a Schlenk tube, benzene (15 mL) was added and
the solution was degassed. Methyldichlorosilane
(0.587 g, 5.1 mmol) was transferred in a similar manner
to that described in Section 4.2. The evacuated Schlenk
tube was then heated at 70 ꢁC with stirring for 15 min
(CAUTION: safety shield). The solvent volume was re-
duced and hexane (15 mL) was added resulting in the for-
mation of a yellow-orange solid which was then collected
by filtration. Recrystallization of the solid was carried
out in dry benzene and hexane to give pure 1b as yel-
low-orange crystals (421 mg, 93%), m.p. 240 ꢁC (dec.).
Anal. Calc. for C38H33Cl3OOsP2Si: C, 51.15; H, 3.73;
Cl, 11.92. Found: C, 51.29; H, 3.86; Cl, 11.97%. IR
Infrared spectra (4000–400 cmꢀ1) were recorded as
Nujol mulls between KBr plates on a Perkin–Elmer Par-
agon 1000 spectrometer. NMR spectra were obtained on
either a Bruker DRX 400 or Bruker AC 200 at 25 ꢁC.
1
For the Bruker DRX 400, H and 13C NMR spectra
were obtained operating at 400.1 (1H) and 100.6 (13C)
MHz, respectively. For the Bruker AC 200, 1H and
13C NMR spectra were obtained operating at 200.0
(1H) and 50.3 (13C) MHz, respectively. Resonances are
quoted in ppm and 1H NMR spectra referenced to either
tetramethylsilane (0.00 ppm) or the proteo-impurity in
the solvent (7.25 ppm for CHCl3). 13C NMR spectra
were referenced to CDCl3 (77.00 ppm). Elemental anal-
yses were obtained from the Microanalytical Laborato-
ry, University of Otago.
1
(cmꢀ1): 1911, 1925, 1942 m(CO). H NMR (CDCl3, d):
0.69 (s, 3H, SiCH3), 7.36–7.74 (m, 30H, PPh3). 13C
2,4
NMR (CDCl3, d): 17.1 (s, SiCH3), 128.3 (t0,
J
=9.0
CP
1,3
Hz, o-C6H5), 130.6 (s, p-C6H5), 130.8 (t0,
J
=52.2
CP
3,5
J
4.2. Preparation of Ru(SiMeCl2)Cl(CO)(PPh3)2 (1a)
Hz, i-C6H5), 134.8 (t0,
(t, 2JCP =8.6 Hz, CO).
=11.0 Hz, m-C6H5), 181.0
CP
To RuHCl(CO)(PPh3)3 (1.08 g, 1.13 mmol) in dry tol-
uene (20 mL) in a Schlenk tube, was added HSiMeCl2
(2.60 g, 22.6 mmol). The tube was sealed, cooled in liquid
nitrogen and then evacuated. After warming to ambient
temperature, the sealed tube was shielded with a safety
shield (CAUTION: pressure increases as reaction pro-
ceeds) and heated in an oil bath at 60 ꢁC for 1.5 h. Reduc-
tion of the volume of the solution in vacuo followed by
slow addition of dry hexane afforded pure, yellow crys-
tals of Ru(SiMeCl2)Cl(CO)(PPh3)2, (863 mg, 95%),
m.p. 230 ꢁC (dec.). Anal. Calc. for C38H33Cl3OP2SiRu:
C, 56.83; H, 4.14; Cl, 13.24. Found: C, 56.99; H, 4.19;
Cl, 13.52%. IR (cmꢀ1): 1923, 1936, 1953 m(CO). 1H
NMR (CDCl3, d): 0.80 (s, 3H, SiCH3), 7.38–7.65 (m,
4.4. Preparation of Ru(SiMe[OH]2)Cl(CO)(PPh3)2
(2a)
Ru(SiMeCl2)Cl(CO)(PPh3)2 (0.10 g, 0.12 mmol) was
added to a suspension of K2CO3 (0.5 g, excess) in de-
gassed THF (10 mL) and water (1 mL). The mixture
was stirred for 5 min during which time the yellow solu-
tion underwent no visible colour change. The solvent
was evaporated to dryness to give a yellow solid and this
was redissolved in dichloromethane and filtered to re-
move the potassium salts. A yellow solid was obtained
from this solution by reduction of the solvent volume,
followed by the addition of ethanol. Recrystallization
was carried out in dichloromethane/hexane to give pure
2a as a yellow crystalline solid (62 mg, 65%), m.p. 200 ꢁC
30H, PPh3). 13C NMR (CDCl3, d): 19.2 (s, SiCH3),
2,4
J
128.4 (t0 [13],
=9.0 Hz, o-C6H5), 130.5 (s,
CP

W.-H. Kwok et al. / Journal of Organometallic Chemistry 689 (2004) 2511–2522
2519
(dec.). Anal. Calc. for C38H33ClO3P2RuSi: C, 59.57; H,
4.60; Cl, 4.63. Found: C, 59.38; H, 4.22; Cl, 4.87%. IR
(cmꢀ1): 1911, 1926 m(CO); 3649w m(OH). 1H NMR
(CDCl3, d): 0.23 (s, 3H, SiCH3), 2.71 (s, 2H, Si(OH)2),
4.7. Preparation of Os(SiMe[OEt]2)Cl(CO)(PPh3)2
(3b)
Os(SiMeCl2)Cl(CO)(PPh3)2 (0.100 g, 0.11 mmol) was
dissolved in dichloromethane (10 mL), ethanol (2 mL)
was added and the resulting yellow solution was stirred
at room temperature for 5 min. The solvent volume was
then reduced and hexane was added to precipitate a yel-
low solid. This yellow product was recrystallized from
dichloromethane and hexane to yield yellow crystals of
pure 3b (52 mg, 51%). Anal. Calc. for C42H43ClO3OsP2-
Si: C, 55.34; H, 4.75. Found: C, 55.07; H, 4.78%. IR
7.36–7.64 (m, 30H, PPh3). 13C NMR (CDCl3, d): 8.6
2,4
(s, SiCH3), 128.5 (t0,
J
=9.0 Hz, o-C6H5), 130.4 (s,
CP
1,3
p-C6H5), 131.9 (t0,
J
=44.2 Hz, i-C6H5), 134.3 (t0,
CP
3,5
J
=12.0 Hz, m-C6H5), 199.1 (t, 2JCP =13.6 Hz, CO).
CP
4.5. Preparation of Os(SiMe[OH]2)Cl(CO)(PPh3)2
(2b)
1
(cmꢀ1): 1904 m(CO). H NMR (CDCl3,d): 0.05 (s, 3H,
Os(SiMeCl2)Cl(CO)(PPh3)2 (0.080 g, 0.090 mmol)
was added to a suspension of K2CO3 (0.5 g, excess) in
degassed THF (10 mL) and water (1 mL). The mixture
was stirred for 5 min during which time the yellow solu-
tion underwent no visible colour change. The solvent
was evaporated to dryness to give an orange solid and
this was redissolved in dichloromethane and filtered to
remove the potassium salts. An orange solid was ob-
tained from this solution by reduction of the solvent vol-
ume, followed by the addition of ethanol.
Recrystallization was carried out in dichloromethane/
hexane to give pure 2b as an orange crystalline solid
(45 mg, 59%), m.p. 195 ꢁC (dec.). Anal. Calc. for
C38H33ClO3OsP2Si: C, 53.36; H, 4.12. Found: C,
52.96; H, 4.04%. IR (cmꢀ1): 1899, 1914 m(CO); 3634w
3
SiCH3), 0.86 (t, 6H, JHH =7.0 Hz, Si(OCH2CH3)2),
3.36 (q, 4H,3JHH =7.0 Hz, Si(OCH2CH3)2), 7.31–7.71
(m, 30H, PPh3). 13C NMR (CDCl3, d): 3.8 (s, SiCH3),
17.8 (s, Si(OCH2CH3)2), 58.1 (s, Si(OCH2CH3)2), 127.9
2,4
(t0,
(t0,
J
=9.0 Hz, o-C6H5), 130.0 (s, p-C6H5), 132.7
CP
1,3
J
3,5
=50.2 Hz, i-C6H5), 134.8 (t0,
J
=11.0 Hz,
CP
CP
2
m-C6H5), 182.9 (t, JCP =8.6 Hz, CO).
4.8. Preparation of Os(SiMe[OEt]2)Cl(CO)2(PPh3)2
(4b)
Ethanol (2 mL) was added to an orange solution of
Os(SiMeCl2)Cl(CO)(PPh3)2 (207 mg, 0.25 mmol) in di-
chloromethane (20 mL). The solution turned yellow im-
mediately, and it was stirred for 5 min. CO was then
bubbled into the solution until it turned colourless. The
solution was stirred for 5 min more, then concentrated,
and finally hexane was added to give a white solid. This
product was recrystallized from dry benzene and hexane
to give pure 4b as colourless crystals (208 mg, 91%). Anal.
Calc. for C42H43ClO3OsP2Si: C, 55.34; H, 4.75. Found: C,
55.21; H, 4.59%. IR (cmꢀ1): 1959, 2018 m(CO). 1H NMR
(CDCl3, d): 0.01 (s, 3H, SiCH3), 0.88 (t, 6H, 3JHH =6.9 Hz,
Si(OCH2CH3)2), 2.82–2.90 (m, 2H, Si(OCH2CH3)2),
3.24–3.32 (m, 2H, Si(OCH2CH3)2) 7.35–7.91 (m, 30H,
PPh3). 13C NMR (CDCl3, d): ꢀ1.4 (s, SiCH3), 18.0 (s,
1
m(OH). H NMR (CDCl3, d): 0.17 (s, 3H, SiCH3), 2.27
(s, 2H, Si(OH)2), 7.37–7.65 (m, 30H, PPh3). 13C NMR
2,4
(CDCl3, d): 7.8 (s, SiCH3), 128.4 (t0,
J
=9.0 Hz,
CP
1,3
o-C6H5), 130.5 (s, p-C6H5), 131.8 (t0,
J
=50.4 Hz,
CP
3,5
i-C6H5), 134.5 (t0,
2JCP =8.6 Hz, CO).
J
=11.0 Hz, m-C6H5), 182.5 (t,
CP
4.6. Preparation of Ru(SiMe[OEt]2)Cl(CO)(PPh3)2
(3a)
Ru(SiMeCl2)Cl(CO)(PPh3)2 (0.100 g, 0.12 mmol) was
dissolved in dichloromethane (10 mL), ethanol (2 mL)
was added and the resulting solution was stirred at room
temperature for 5 min. The solvent volume was then
reduced and hexane was added to precipitate a yellow sol-
id. The yellow product was recrystallized from dichloro-
methane and hexane to yield yellow crystals of pure 3a
(52 mg, 51%), m.p. 182–184 ꢁC (dec.). Anal. Calc. for
C42H43ClO3P2RuSi: C, 61.34; H, 5.27; Cl, 4.31. Found:
C, 60.94; H, 5.26; Cl, 4.55%. IR (cmꢀ1): 1918 m(CO).
1H NMR (CDCl3, d): 0.19 (s, 3H, SiCH3), 0.87 (t, 6H,
3JHH =7.0 Hz, Si(OCH2CH3)2), 3.38 (q, 4H,3JHH =7.0
Hz, Si(OCH2CH3)2), 7.28–7.70 (m, 30H, PPh3). 13C
Si(OCH2CH3)2), 58.7 (s, Si(OCH2CH3)2), 127.7 (t0,
2,4
J
J
=9.0 Hz, o-C6H5), 129.8 (s, p-C6H5), 134.8 (t0,
CP
CP
1,3
3,5
=53.4 Hz, i-C6H5), 134.2 (t0,
J
=9.0 Hz, m-
CP
2
2
C6H5), 177.4 (t, JCP =6.0 Hz, CO), 180.4 (t, JCP =9.6
Hz, CO).
4.9. Preparation of Ru(SiMeCl2)Cl(CO)(PPh3)-
(j2(N,N)-NC9H6NH2-8) (5a)
Under nitrogen, 8-aminoquinoline (29.5 mg, 0.20
mmol) and NEt3 (27.9 lL) were added to a yellow solu-
tion of Ru(SiMeCl2)Cl(CO)(PPh3)2 (161 mg, 0.20 mmol)
in benzene (20 mL) to produce an orange suspension.
This was stirred for 30 min and the volatiles were then
removed in vacuo, leaving a red residue. This was ex-
tracted by toluene, the orange extract was concentrated,
and hexane then added to give pure 5a as orange crystals
NMR (CDCl3,d): 5.4 (s, SiCH3), 17.8 (s, Si(OCH2CH3)2),
2,4
58.5 (s, Si(OC H2CH3)2), 127.9 (t0,
J
=9.0 Hz,
CP
1,3
J
o-C6H5), 129.9 (s, p-C6H5), 133.0 (t0,
=43.2 Hz,
CP
3,5
i-C6H5), 134.7 (t0,
J
=11.0 Hz, m-C6H5), 199.9 (t,
CP
2JCP =13.6 Hz, CO).

2520
W.-H. Kwok et al. / Journal of Organometallic Chemistry 689 (2004) 2511–2522
1
(107 mg, 78%). Anal. Calc. for C29H26N2Cl3OPRuSi3/
4C7H8: C, 54.55; H, 4.28; N, 3.71. Found: C, 54.46;
H, 4.88; N, 4.11%. IR (cmꢀ1): 1907vs m(CO). H NMR
3
(CD2Cl2, d): 0.15 (s, 3H, SiMe), 0.87 (t, 3H, JHH =7.0
H, 4.25; N, 4.03%. IR (cmꢀ1): 1944 m(CO). H NMR
Hz, OCH2CH3), 1.18 (t, 3H, 3JHH =7.0 Hz, OCH2CH3),
1
2
3.16–3.47 (m, 4H, OCH2CH3), 4.65 (d, 1H, JHH =11.4
(CD2Cl2, d): 0.35 (s, 3H, SiMe), 3.99 (d, 1H,
2
2
Hz, NH2), 4.78 (d, 1H, JHH =11.2 Hz, NH2), 7.26–
2JHH =12.0 Hz, NH2), 4.44 (d, 1H, JHH =12.0 Hz,
NH2), 7.10–7.90 (m, 19H, C9H6N and PPh3), 8.32 (ap-
parent dd, 1H, JHH =1.4, 8.4 Hz, C9H6N), 9.26–9.28
(m, 1H, C9H6N). 13C NMR (CD2Cl2, d): 15.2 (SiMe),
123.3 (C9H6N), 127.7 (C9H6N), 127.8 (C9H6N), 128.8
7.93 (m, 19H, C9H6N and PPh3), 8.28 (apparent dd,
1H, J=1.4, 8.4 Hz, C9H6N), 9.27–9.29 (m, 1H,
C9H6N). 13C NMR (CD2Cl2, d): 0.2 (SiMe), 17.8
(OCH2CH3), 18.1 (OCH2CH3), 58.2 (OCH2CH3), 58.9
(OCH2CH3), 123.1 (C9H6N), 127.5 (C9H6N), 127.5
2
(d, JCP =10.1 Hz, o-C6H5), 129.2 (C9H6N), 130.2
3
(C9H6N), 130.6 (p-C6H5), 134.2 (d, JCP =10.1 Hz, m-
2
(C9H6N), 128.5 (d, JCP =10.1 Hz, o-C6H5), 129.7
(C9H6N), 130.2 (p-C6H5), 130.3 (C9H6N), 134.2 (d,
1
C6H5), 134.7 (d, JCP =48.3 Hz, i-C6H5), 137.6
(C9H6N), 137.9 (C9H6N), 147.2 (C9H6N), 154.5
1
3JCP =10.1 Hz, m-C6H5), 136.7 (d, JCP =47.3 Hz,
2
(C9H6N), 204.5 (d, JCP =17.1 Hz, CO).
i-C6H5), 137.7 (C9H6N), 138.3 (C9H6N), 147.8
(C9H6N), 153.6 (C9H6N), 205.8 (d, 2JCP =28.2 Hz, CO).
4.10. Preparation of Os(SiMeCl2)Cl(CO)(PPh3)-
(j2(N,N)-NC9H6NH2-8) (5b)
4.12. Preparation of Os(SiMe[OEt]2)Cl(CO)(PPh3)-
(j2(N,N)-NC9H6NH2-8) (6b)
Under nitrogen, 8-aminoquinoline (13.4 mg, 0.091
mmol) and NEt3 (12.7 lL) were added to a yellow solu-
tion of Os(SiMeCl2)Cl(CO)(PPh3)2 (76 mg, 0.091 mmol)
in benzene (20 mL) to produce an orange suspension.
This was stirred for 30 min and the volatiles were then
removed in vacuo, leaving a red residue. This was ex-
tracted by toluene, the orange extract was concentrated,
and hexane then added to give pure 5b as orange crystals
(54 mg, 76%). Satisfactory elemental analyses were not
obtained for this compound because of its extreme mois-
ture sensitivity. However, the spectroscopic data for this
compound are very similar to that found for the ruthe-
nium analogue and the bis(ethoxy)-derivative (6b) de-
scribed below was fully characterized. IR (cmꢀ1): 1892
8-Aminoquinoline (38 mg, 0.26 mmol) was added to
an orange solution of Os(SiMeCl2)Cl(CO)(PPh3)2 (107
mg, 0.13 mmol) in benzene (20 mL) to produce an or-
ange suspension. This was stirred for 15 min and then
EtOH (2 mL) was added and the solution stirred for five
more minutes. The volatiles were removed in vacuo, the
residue extracted with benzene and the red extract was
concentrated and hexane then added to give pure 6b
as a yellow solid (74 mg, 72%). Anal. Calc. for
C33H36ClN2O3OsPSi: C, 49.96; H, 4.57; N, 3.53. Found:
C, 49.97; H, 4.69; N, 3.66%. IR (cmꢀ1): 1894vs m(CO).
1H NMR (CD2Cl2, d): ꢀ0.32 (s, 3H, SiMe), 0.34 (t,
3
3
3H, JHH =7.0 Hz, OCH2CH3), 0.75 (t, 3H, JHH =6.8
Hz, OCH2CH3), 2.81–3.33 (m, 4H, OCH2CH3), 3.53
1
m(CO). H NMR (CD2Cl2, d): 0.36 (s, 3H, SiMe), 3.95
2
2
2
(d, 1H, JHH =11.6 Hz, NH2), 4.82 (d, 1H, JHH =12.4
Hz, NH2), 7.23–7.89 (m, 19H, C9H6N and PPh3), 8.35
(apparent dd, 1H, J=1.3, 8.4 Hz, C9H6N), 9.35–9.38
(m, 1H, C9H6N). 13C NMR (CD2Cl2, d): 14.4 (SiMe),
123.9 (C9H6N), 128.0 (C9H6N), 128.2 (C9H6N), 128.9
(d, 1H, JHH =11.2 Hz, NH2), 5.35 (d, 1H,2JHH =11.6
Hz, NH2), 7.22 (apparent d, 1H, J=7.3 Hz, C9H6N),
7.35–7.49 (m, 10H, C9H6N and PPh3), 7.73 (apparent
d, 1H, J=8.2 Hz, C9H6N), 7.83–7.91 (m, 7H, PPh3),
8.29 (apparent dd, 1H, J=1.1, 8.7 Hz, C9H6N), 9.46–
9.48 (m, 1H, C9H6N). 13C NMR (CD2Cl2, d): ꢀ0.4
(SiMe), 18.2 (OCH2CH3), 18.4 (OCH2CH3), 57.5
(OCH2CH3), 58.0 (OCH2CH3), 123.5 (C9H6N), 127.4
2
(d, JCP =10.1 Hz, o-C6H5), 129.5 (C9H6N), 130.6 (p-
3
C6H5), 130.7 (C9H6N), 134.0 (d, JCP =10.1 Hz, m-
1
C6H5), 136.6 (d, JCP =54.3 Hz, i-C6H5), 137.8
(C9H6N), 137.9 (C9H6N), 147.8 (C9H6N), 154.7
2
(C9H6N), 127.6 (C9H6N), 128.2 (d, JCP =10.1 Hz, o-C
6H5), 129.1 (C9H6N), 129.8 (p-C6H5), 130.6 (C9H6N),
2
(C9H6N), 185.4 (d, JCP =11.1 Hz, CO).
3
134.1 (d, JCP =10.1 Hz, m-C6H5), 136.5 (C9H6N),
1
136.6 (d, JCP =53.3 Hz, i-C6H5), 139.6 (C9H6N), 148.4
4.11. Preparation of Ru(SiMe[OEt]2)Cl(CO)(PPh3)-
(j2(N,N)-NC9H6NH2-8) (6a)
(C9H6N), 153.2 (C9H6N), 189.5 (d, 2JCP =12.1 Hz, CO).
EtOH (2 mL) was added to an orange solution of
Ru(SiMeCl2)Cl(CO)(PPh3)(j2(N,N-NC9H6NH2-8) (82
mg, 0.13 mmol) in benzene (20 mL). The reaction mix-
ture was stirred for 30 min and then volatiles were re-
moved in vacuo. The residue was extracted with
CH2Cl2, the orange extract was concentrated and hex-
ane was added to give pure 6a as yellow crystals (55
mg, 65%). Anal. Calc. for C33H36ClN2O3PRuSi1/
3CH2Cl2: C, 54.65; H, 5.04; N, 3.82. Found: C, 54.55;
4.13. Preparation of Os(j3(Si,N,N)-SiMe[NH(2-C5H4-
N)]2)Cl(CO)(PPh3) (7b)
2-Aminopyridine (46.4 mg, 0.24 mmol) in benzene (15
mL) was added slowly to an orange solution of Os(Si-
MeCl2)Cl(CO)(PPh3)2 (103 mg, 0.12 mmol). The orange
mixture turned to a yellow suspension upon stirring. This
was stirred for 4 h and then filtered through Celite. The
pale yellow filtrate was concentrated and hexane was

W.-H. Kwok et al. / Journal of Organometallic Chemistry 689 (2004) 2511–2522
2521
added to give a pale yellow solid. This was recrystallized
from CH2Cl2/hexane to give pure 7b as pale yellow crys-
tals (67 mg, 75%). Anal. Calc. for C30H28N4ClOOsPSi1/
2CH2Cl2: C, 46.50; H, 3.71; N, 7.11. Found: C, 46.85; H,
4.13; N, 7.49%. IR (cmꢀ1): 1900vs m(CO). 1H NMR
(CD2Cl2, d): 0.07 (s, 3H, SiMe), 4.95 (s, 1H, NHpy),
5.18 (s, 1H, NHpy), 5.91 (apparent dt, 1H, J=1.1, 6.6
Hz, C5H4N), 6.30 (apparent d, 1H, J=8.3 Hz, C5H4N),
6.44 (apparent t, 1H, J=6.5 Hz, C5H4N), 6.58 (apparent
d, 1H, J=8.3 Hz, C5H4N), 6.83 (apparent t, 1H, J=8.5
Hz, C5H4N), 7.03–7.07 (m, 1H, C5H4N), 7.17–7.23 (m,
9H, PPh3), 7.54–7.59 (m, 6H, PPh3), 8.51–8.53 (m, 1H,
C5H4N), 9.41–9.43 (m, 1H, C5H4N). 13C NMR (CD2Cl2,
d): ꢀ2.2 (SiMe), 110.2 (C5H4N), 110.5 (C5H4N), 112.5
the Cambridge Crystallographic Data Centre as supple-
mentary publication Nos. 231885-231889 for 3b, 4b, 5a,
6c, and 7b, respectively. Copies of this information can
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).
Acknowledgements
We thank the Marsden Fund administered by the
Royal Society of NZ for supporting this work. We also
thank the Croucher Foundation, Hong Kong, for sup-
port and for granting a Postdoctoral Fellowship to H.-
W.K. We also thank the University of Auckland Re-
search Committee for partial support of this work
through grants-in-aid.
2
(C5H4N), 112.6 (C5H4N), 127.9 (d, JCP =10.1 Hz, o-
3
C6H5), 129.44 (p-C6H5), 134.0 (d, JCP =10.1 Hz, m-
1
C6H5), 136.2 (d, JCP =53.3 Hz, i-C6H5), 138.0
(C5H4N), 138.4 (C5H4N), 148.5 (C5H4N), 149.3
(C5H4N), 164.5 (C5H4N), 165.9 (C5H4N), 186.8 (d,
2JCP =12.1 Hz, CO).
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