Synthesis, crystal structure and some reactions of the ruthenacarborane complex [Ru(CO)2(MeCCPh)(η5-7,8-C2B9H11]

Article abstract of DOI:10.1016/S0022-328X(98)00363-5

The alkyne complex [Ru(CO)₂(MeCCPh)(η⁵-7,8-C₂B ₉H₁₁] (3c) has been prepared and its structure determined by X-ray crystallography. The ruthenium is co-ordinated on one side by the nido-7,8-C₂B₉H₁₁ fragment in a pentahapto manner, and on the other by the two CO molecules and the alkyne [Ru-C_av.=2.305, C-C=1.228(3) A. Treatment of 3c with PEt₃ and Ph₂PCH₂PPh₂ in CH₂Cl₂ affords the ylid complexes [Ru{C(Me)=C(Ph)PEt₃}(CO)₂ (η⁵-7,8-C₂B₉H₁₁)] (4b) and [Ru{C(Me)=C(Ph)P(Ph)₂CH₂PPh₂} (CO)₂(η⁵-7,8-C₂B₉H₁₁) ] (4c), respectively. The structure of 4b was established by an X-ray diffraction study which revealed that the PEt₃ molecule was attached to the carbon atom of the CPh group. In contrast, reactions between 3c and the donor molecules AsPh₃, SbPh₃ and Ph₂P(S)CH₂P(S)Ph₂ resulted in displacement of the alkyne and formation of the complexes [Ru(CO)₂(L)(η⁵-7,8-C₂B₉H₁₁)] (5a, L=AsPh₃; 5b, L=SbPh₃; 5c, L=Ph₂P(S)CH₂P(S)Ph₂). Treatment of 4c with the Ru(CO)₂(η⁵-7,8-C₂B₉H₁₁) fragment yielded the diruthenium complex [Ru₂(μ-Ph₂PCH₂PPh₂)(CO)₄ (η⁵-7,8-C₂B₉H₁₁)₂] (6). The structure, based on the linking of two Ru(CO)₂(η⁵-7,8-C₂B₉H₁₁) groups by the ligand Ph₂PCH₂PPh₂, was determined by X-ray crystallography. NMR data for the new complexes are reported.

Full text of DOI:10.1016/S0022-328X(98)00363-5

Journal of Organometallic Chemistry 562 (1998) 17–27
Synthesis, crystal structure and some reactions of the ruthenacarborane
complex [Ru(CO)2(MeCꢀCPh)(p5-7,8-C2B9H11]1,2
John C. Jeffery a, Paul A. Jelliss b, Elefteria Psillakis a, Gillian E.A. Rudd b,
F. Gordon A. Stone b,*
a School of Chemistry, The Uni6ersity of Bristol, Bristol BS8 1TS, UK
b Department of Chemistry, Baylor Uni6ersity, Waco, TX 76798-7348, USA
Received 11 May 1997
Abstract
The alkyne complex [Ru(CO)2(MeCꢀCPh)(p5-7,8-C2B9H11] (3c) has been prepared and its structure determined by X-ray
crystallography. The ruthenium is co-ordinated on one side by the nido-7,8-C2B9H11 fragment in a pentahapto manner, and on
˚
the other by the two CO molecules and the alkyne [Ru–Cav. =2.305, C–C=1.228(3) A. Treatment of 3c with PEt3 and
Ph2PCH2PPh2 in CH2Cl2 affords the ylid complexes [Ru{C(Me)ꢁC(Ph)PEt3}(CO)2(p5-7,8-C2B9H11)] (4b) and [Ru{C(Me)ꢁ
C(Ph)P(Ph)2CH2PPh2}(CO)2(p5-7,8-C2B9H11)] (4c), respectively. The structure of 4b was established by an X-ray diffraction study
which revealed that the PEt3 molecule was attached to the carbon atom of the CPh group. In contrast, reactions between 3c and
the donor molecules AsPh3, SbPh3 and Ph2P(S)CH2P(S)Ph2 resulted in displacement of the alkyne and formation of the complexes
[Ru(CO)2(L)(p5-7,8-C2B9H11)] (5a, L=AsPh3; 5b, L=SbPh3; 5c, L=Ph2P(S)CH2P(S)Ph2). Treatment of 4c with the
Ru(CO)2(p5-7,8-C2B9H11) fragment yielded the diruthenium complex [Ru2(v-Ph2PCH2PPh2)(CO)4(p5-7,8-C2B9H11)2] (6). The
structure, based on the linking of two Ru(CO)2(p5-7,8-C2B9H11) groups by the ligand Ph2PCH2PPh2, was determined by X-ray
crystallography. NMR data for the new complexes are reported. © 1998 Elsevier Science S.A. All rights reserved.
Keywords: Boron; Carborane; Ruthenium; Alkyne
1. Introduction
[NEt4][RuI(CO)2(p5-7,8-C2B9H11)] which reacts with
AgBF4 in THF (tetrahydrofuran) to give [Ru(CO)2
(THF)(p5-7,8-C2B9H11)] (2). Complexes 1 and 2 are
isolobal with the long known and synthetically useful
species [Mn(CO)3(p5-C5H5)] and [Mn(CO)2(THF)(p5-
C5H5)], respectively, and we have been able to employ
them as precursors to a variety of other ruthenacarbo-
rane compounds [1]. Thus the THF molecule in 2 is
readily substituted by MeCꢀCMe or PhCꢀCPh to yield
alkyne complexes [Ru(CO)2(RCꢀCR)(p5-7,8-C2B9H11)]
(3a, R=Me; 3b, R=Ph).
A feature of the chemistry of complexes 3a and
3b, which formally involve RuII centres, is their appar-
ent ready reaction with nucleophiles ([1]b). For
example, 3a with PPh3 gives the ylid complex
[Ru{C(Me)ꢁC(Me)PPh3}(CO)2(p5-7,8-C2B9H11)] (4a).
We have previously reported a high yield synthesis
of the complex [Ru(CO)3(p5-7,8-C2B9H11)] (1) ([1]a).
Treatment of the latter with [NEt4]I affords the salt
* Corresponding author. E-mail: Gordon Stone@baylor.edu
–
1 Dedicated to my (FGAS) student Professor R. Bruce King on the
occasion of his 60th birthday.
2 The ruthenacarboranes described in this article have icosahedral
frameworks with closo-1,2-dicarba-3-ruthenadodecaborane struc-
tures. However, in the formulae we represent the cages as a nido-11-
vertex ligand with numbering as for an icosahedron from which the
twelfth vertex has been removed. This emphasises the pentahapto
ligating character of these groups with the cage acting formally as a
four electron donor to the ruthenium centre and being thus related to
the five-electron donor p5-C5H5.
0022-328X/98/$19.00 © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(98)00363-5

18
J.C. Jeffery et al. / Journal of Organometallic Chemistry 562 (1998) 17–27
Scheme 1.
In this paper we report the synthesis of the alkyne
complex [Ru(CO)2(MeCꢀCPh)(p5-7,8-C2B9H11)] (3c)
and studies of its reactions with some donor molecules.
The object of the study was 2-fold. The presence of the
unsymmetrical alkyne in 3c raises the question as to
which ligated carbon atom is the preferred site of
attachment by a donor molecule in any zwitterionic
product. Secondly, we wished to establish whether a
range of donor molecules would all react to afford ylid
type structures (Scheme 1).
Table 1
Analytical and physical data
Compound
Colour
Yield (%)
wmax(CO)b(cm−1
)
Anal. (%)a
C
H
[Ru(CO)2(MeCꢀCPh)(p5-7,8-C2B9H11)] (3c)
Yellow
Yellow
64
90
91
89
90
60
45d
2070 s, 2024 s
2018 s, 1960 s
2019 s, 1961 s
2052 s, 2004 s
2044 s, 1996 s
2046 s, 1994 s
2050 s, 2002 s
38.2 (38.5)
43.4 (43.6)
58.1 (57.8)
44.7 (44.4)
41.5 (41.1)
49.5 (48.9)c
40.5 (41.1)
4.7 (4.7)
6.9 (6.5)
5.4 (5.2)
4.4 (4.4)
4.1 (4.1)
4.6 (5.1)
4.2 (4.6)
[Ru{C(Me)ꢁC(Ph)PEt3}(CO)2(p5-7,8-C2B9H11)] (4b)
[Ru{C(Me)ꢁC(Ph)P(Ph)2CH2PPh2}(CO)2(p5-7,8-C2B9H11)] (4c) Yellow
[Ru(CO)2(AsPh3)(p5-7,8-C2B9H11)] (5a)
White
Pale yellow
Yellow
[Ru(CO)2(SbPh3)(p5-7,8-C2B9H11)] (5b)
[Ru(CO)2{Ph2P(S)CH2P(S)Ph2}(p5-7,8-C2B9H11)2] (5c)
[Ru2(v-Ph2PCH2PPh2)(CO)4(p5-7,8-C2B9H11)2] (6)
Yellow
a Calculated values are given in parentheses. b Measured in CH2Cl2. All complexes show a broad medium intensity band at ca. 2550 cm−1 due
to cage B–H absorptions. c Crystallised with 0.5 molecule of pentane. d Yield when synthesised from 4c and Ph2PCH2PPh2: 35%.

J.C. Jeffery et al. / Journal of Organometallic Chemistry 562 (1998) 17–27
19

20
J.C. Jeffery et al. / Journal of Organometallic Chemistry 562 (1998) 17–27
Table 3
5
˚
Selected internuclear distances (A) and angles (°) for [Ru(CO)2(MeCꢀCPh)(p -7,8-C2B9H11)] (3c), with estimated standard deviations in
parentheses
˚
Internuclear distances (A)
Ru(1)–C(3)
Ru(1)–C(4)
Ru(1)–C(1)
Ru(1)–C(2)
Ru(1)–B(5)
Ru(1)–B(3)
Ru(1)–B(4)
Ru(1)–C(17)
Ru(1)–C(16)
C(1)–C(2)
1.897(2)
C(1)–B(7)
C(2)–B(8)
C(2)–B(3)
C(2)–B(7)
B(3)–B(9)
B(3)–B(8)
B(3)–B(4)
B(4)–B(10)
B(4)–B(9)
B(4)–B(5)
B(5)–B(10)
B(5)–B(6)
1.730(3)
1.705(3)
1.713(3)
1.736(3)
1.767(3)
1.786(3)
1.839(3)
1.794(3)
1.797(3)
1.823(3)
1.774(3)
1.789(3)
B(6)–B(7)
B(6)–B(10)
B(6)–B(11)
B(7)–B(11)
B(7)–B(8)
B(8)–B(11)
B(8)–B(9)
B(9)–B(11)
B(9)–B(10)
B(10)–B(11)
C(3)–O(3)
C(4)–O(4)
1.759(3)
1.778(3)
1.781(3)
1.767(3)
1.771(3)
1.778(3)
1.784(4)
1.786(3)
1.789(3)
1.785(3)
1.135(3)
1.138(3)
C(15)–C(16)
C(16)–C(17)
C(17)–C(18)
C(18)–C(19)
C(18)–C(23)
C(19)–C(20)
C(20)–C(21)
C(21)–C(22)
C(22)–C(23)
1.475(3)
1.228(3)
1.456(3)
1.397(3)
1.403(3)
1.388(3)
1.382(3)
1.386(3)
1.382(3)
1.899(2)
2.242(2)
2.248(2)
2.262(2)
2.281(2)
2.282(2)
2.302(2)
2.308(2)
1.625(3)
1.707(3)
1.715(3)
C(1)–B(6)
C(1)–B(5)
Internuclear angles (°)
C(3)–Ru(1)–C(4)
C(3)–Ru(1)–C(1)
C(4)–Ru(1)–C(1)
C(3)–Ru(1)–C(2)
C(4)–Ru(1)–C(2)
C(1)–Ru(1)–C(2)
C(3)–Ru(1)–B(5)
C(4)–Ru(1)–B(5)
C(1)–Ru(1)–B(5)
C(2)–Ru(1)–B(5)
C(3)–Ru(1)–B(3)
C(4)–Ru(1)–B(3)
C(17)–C(16)–C(15)
O(4)–C(4)–Ru(1)
88.93(9)
158.14(8)
110.66(8)
117.41(8)
153.10(8)
42.45(7)
134.41(8)
81.84(8)
44.76(8)
75.69(8)
82.82(8)
144.51(9)
161.6(2)
175.9(2)
C(1)–Ru(1)–B(3)
C(2)–Ru(1)–B(3)
B(5)–Ru(1)–B(3)
C(3)–Ru(1)–B(4)
C(4)–Ru(1)–B(4)
C(1)–Ru(1)–B(4)
C(2)–Ru(1)–B(4)
B(5)–Ru(1)–B(4)
B(3)–Ru(1)–B(4)
C(3)–Ru(1)–C(17)
C(4)–Ru(1)–C(17)
C(1)–Ru(1)–C(17)
C(16)–C(17)–C(18)
75.58(8)
44.44(8)
79.70(8)
90.93(8)
98.47(8)
77.04(8)
76.98(8)
47.30(8)
47.53(8)
83.26(8)
102.15(8)
101.20(7)
156.6(2)
C(2)–Ru(1)–C(17)
B(5)–Ru(1)–C(17)
B(3)–Ru(1)–C(17)
B(4)–Ru(1)–C(17)
C(3)–Ru(1)–C(16)
C(4)–Ru(1)–C(16)
C(1)–Ru(1)–C(16)
C(2)–Ru(1)–C(16)
B(5)–Ru(1)–C(16)
B(3)–Ru(1)–C(16)
B(4)–Ru(1)–C(16)
C(17)–Ru(1)–C(16)
O(3)–C(3)–Ru(1)
87.27(8)
142.33(8)
110.99(8)
158.44(8)
106.11(8)
82.00(8)
86.81(7)
94.83(7)
116.47(8)
133.45(8)
162.96(8)
30.90(7)
175.9(2)
2. Results and discussion
by two CO groups in an essentially linear manner
[Ru–C–Oav. =175.9(2) °] and by the MeCꢀCPh
molecule [Ru(1)–C(16)=2.308(2), Ru(1)–C(17)=
The complex 3c was readily obtained by adding the
alkyne MeCꢀCPh to a CH2Cl2 solution of 2 prepared in
situ from [NEt4][RuI(CO)2(p5-7,8-C2B9H11)] and AgBF4
in THF. As previously reported ([1]a), the replacement
of THF solvent by CH2Cl2 in this latter preparation
results in the generation of a mixture in which 2, the
16-electron species [Ru(CO)2(p5-7,8-C2B9H11)] and free
THF are present. The mixture is a ready source of the
Ru(CO)2(p5-7,8-C2B9H11) fragment. Data characterising
3c are given in Tables 1 and 2. A single-crystal X-ray
diffraction study was carried out in order to place the
molecular structures of the alkyne complexes of type 3
on a firm basis and also to use the X-ray generated
atomic co-ordinates for semi-empirical molecular orbital
calculations which will be discussed later. Selected
parameters are listed in Table 3 and the molecule is
shown in Fig. 1.
˚
˚
2.302(2) A]. The C(16)–C(17) separation [1.228(3) A] is
˚
perceptibly shorter than the mean value (1.269 A) found
in alkyne–metal complexes [2]. The ligated alkyne CꢀC–
C bond angles [C(17)–C(16)–C(15)=161.6(2), C(16)–
C(17)–C(18)=156.6(2) °] are, however, comparable
with those found in other transition metal–alkyne com-
plexes [3].
The NMR data (Table 2) for 3c are in accord with the
structure determined by X-ray diffraction. The 1H-NMR
spectrum shows diagnostic peaks of relative intensity 2:3
at l 2.71 and 2.76, respectively, for the cage CH and
alkyne Me groups. The 13C{1H}-NMR spectrum dis-
played a resonance for the cage CH groups at l 54.2 and
peaks for the ligated carbons of the alkyne at l 70.1 and
74.2. The observation of only one signal for the CO
ligands at l 195.4 must be due to rotation of the
p2-MeCꢀCPh group about an axis through the Ru atom
and the mid-point of the CꢀC bond, thus demonstrating
an apparent equivalence of the carbonyls on the NMR
time scale. Treatment of 3c in CH2Cl2 with PEt3 gave the
ylid compound [Ru{C(Me)ꢁC(Ph)PEt3}(CO)2(p5-7,8-
C2B9H11)] (4b) the structure of which was established by
an X-ray diffraction study. The results are given in Table
4 and the molecule is shown in Fig. 2.
The ruthenium atom is pentahapto co-ordinated on
one side by the nido-7,8-C2B9 fragment in the usual
manner. The connectivities between the metal and the
cage atoms [Ru(1)–C(1)=2.242(2), Ru(1)–C(2)=
2.248(2),
Ru(1)–B(3)=2.281(2),
Ru(1)–B(4)=
˚
2.282(2), Ru(1)–B(5)=2.262(2) A] are similar to those
observed in other molecules with the closo-3,1,2-RuC2B9
framework ([1]a,b). On the other side, the metal is ligated

J.C. Jeffery et al. / Journal of Organometallic Chemistry 562 (1998) 17–27
21
Fig. 2. Molecular structure of [Ru{C(Me)ꢁC(Ph)PEt3}(CO)2(p5-7,8-
C2B9H11)] (4b) showing the atom labelling scheme. Hydrogen atoms
are omitted for clarity. Thermal ellipsoids are shown at the 40%
probability level.
Fig. 1. Molecular structure of [Ru(CO)2(MeCꢀCPh)(p5-7,8-C2B9H11)]
(3c) showing the atom labelling scheme. Hydrogen atoms are omitted
for clarity. Thermal ellipsoids are shown at the 40% probability level.
The ruthenium atom is co-ordinated by the nido-
C2B9H11 cage and two CO molecules in the usual
manner. Interest focuses on the attachment of the PEt3
group which has attacked the alkyne in the precursor 3c
in such a manner that in 4b it is bonded to the carbon
atom C(9) carrying the Ph group [P–C(9)=1.820(2)
˚
A]. The Me and Ph groups are transoid to one another
˚
and the C(8)–C(9) separation [1.344(3) A] corresponds
Table 4
5
˚
Selected internuclear distances (A) and angles (°) for [Ru(CO)2{C(Me)ꢁC(Ph)PEt3}(p -7,8-C2B9H11)] (4b), with estimated standard deviations in
parentheses
˚
Internuclear distances (A)
Ru–C(3)
Ru–C(1)
P–C(23)
1.859(2)
Ru–C(4)
Ru–B(3)
P–C(25)
1.870(2)
2.281(3)
1.812(2)
1.694(3)
1.719(3)
1.799(4)
1.778(4)
1.772(4)
1.782(4)
1.144(3)
1.506(3)
Ru–C(8)
Ru–B(5)
P–C(21)
C(1)–B(6)
C(2)–B(7)
B(4)–B(9)
B(5)–B(6)
B(7)–B(8)
B(9)–B(11)
C(4)–O(4)
2.141(2)
2.307(2)
1.815(2)
1.699(3)
1.728(4)
1.783(4)
1.784(4)
1.761(4)
1.773(4)
1.144(3)
Ru–C(2)
Ru–B(4)
P–C(9)
C(1)–B(7)
B(3)–B(9)
B(4)–B(10)
B(6)–B(7)
B(7)–B(11)
B(9)–B(10)
C(8)–C(9)
2.253(2)
2.343(2)
1.820(2)
1.730(3)
1.772(4)
1.786(4)
1.765(4)
1.763(4)
1.777(4)
1.344(3)
2.259(2)
1.811(2)
1.615(3)
1.696(3)
1.797(4)
1.815(3)
1.768(4)
1.768(4)
1.776(4)
1.520(3)
C(1)–C(2)
C(2)–B(8)
B(3)–B(8)
B(4)–B(5)
B(6)–B(11)
B(8)–B(9)
B(10)–B(11)
C(8)–C(10)
C(1)–B(5)
C(2)–B(3)
B(3)–B(4)
B(5)–B(10)
B(6)–B(10)
B(8)–B(11)
C(3)–O(3)
C(9)–C(11)
Internuclear angles (°)
C(3)–Ru–C(4)
C(3)–Ru–C(2)
C(3)–Ru–C(1)
C(2)–Ru–C(1)
C(8)–Ru–B(3)
C(3)–Ru–B(5)
C(2)–Ru–B(5)
C(3)–Ru–B(4)
C(2)–Ru–B(4)
B(5)–Ru–B(4)
C(25)–P–C(21)
C(21)–P–C(9)
C(9)–C(8)–C(10)
C(8)–C(9)–C(11)
88.21(11)
159.15(10)
118.02(9)
41.94(8)
127.58(9)
85.88(10)
74.15(9)
95.33(10)
75.17(9)
45.93(8)
C(3)–Ru–C(8)
C(4)–Ru–C(2)
C(4)–Ru–C(1)
C(3)–Ru–B(3)
C(2)–Ru–B(3)
C(4)–Ru–B(5)
C(1)–Ru–B(5)
C(4)–Ru–B(4)
C(1)–Ru–B(4)
C(23)–P–C(25)
C(23)–P–C(9)
O(3)–C(3)–Ru
C(9)–C(8)–Ru
C(8)–C(9)–P
94.60(9)
111.88(10)
153.75(10)
137.06(10)
44.56(9)
147.90(9)
43.53(8)
103.53(9)
74.70(8)
106.84(11)
114.96(10)
173.5(2)
126.5(2)
121.1(2)
C(4)–Ru–C(8)
C(8)–Ru–C(2)
C(8)–Ru–C(1)
C(4)–Ru–B(3)
C(1)–Ru–B(3)
C(8)–Ru–B(5)
B(3)–Ru–B(5)
C(8)–Ru–B(4)
B(3)–Ru–B(4)
C(23)–P–C(21)
C(25)–P–C(9)
O(4)–C(4)–Ru
C(10)–C(8)–Ru
C(11)–C(9)–P
88.42(9)
91.60(8)
90.32(8)
85.62(10)
74.48(9)
123.48(8)
77.59(9)
164.67(9)
45.75(9)
107.97(11)
108.14(10)
176.8(2)
106.39(12)
112.08(11)
120.2(2)
113.19(14)
113.4(2)
125.4(2)

22
J.C. Jeffery et al. / Journal of Organometallic Chemistry 562 (1998) 17–27
precisely to the mean value found in numerous com-
crystal of 4c clearly revealed that the co-ordinated
phosphorus atom of the Ph2PCH2PPh2 molecule is
bound to the CPh group to give an p1-C(Me)ꢁC
(Ph)P(Ph)2CH2PPh2 ligand with the methyl and phenyl
groups lying transoid to one another as in 4b. Unfortu-
nately the structure analysis could not be completed
due to severe disorder of the free end of the
Ph2PCH2PPh2 molecule. The 31P{1H}-NMR spectrum
of 4c shows two resonances as expected. That at l
−30.4 is diagnostic for the phosphorus nucleus of the
free PPh2 group which is not attached to the ꢁC(Ph)
moiety [5], hence the resonance at l 4.3 must be as-
signed to the ꢁC(Ph)PPh2 nucleus. Careful examination
of the NMR spectra of 4c revealed the absence of any
signals due to the presence of another isomer, as was
observed with 4b.
plexes where a metal carries an p1-C(R1)ꢁC(R2)R3
˚
group [2]. The Ru–C(8) separation [2.141(2) A] may be
compared with the Ru–C(CF3) |-bond distance
[2.082(5) A] in [Ru{|,p2-C(CF3)ꢁC(CF3)C(CF3)ꢁC
˚
(CF3)H}(PPh3)(p5-C5H5)] [4].
The various resonances seen in the NMR spectra of
4b (Table 2) are as expected for the structure estab-
lished by the X-ray diffraction study. It is interesting
that there was no evidence in the spectra for peaks
attributable to an isomer of 4b with the PEt3 moiety
attached to the CMe group, viz. [Ru{C(Ph)ꢁC(Me)
PEt3}(CO)2(p5-7,8-C2B9H11)]. Evidently the formation
of 4b is regiospecific, a feature discussed further below.
The reaction between 3c and Ph2PCH2PPh2 was next
investigated. If these reagents are mixed in 1:1 mol ratio
the product obtained is [Ru{C(Me)ꢁC(Ph)P(Ph)2
CH2PPh2}(CO)2(p5-7,8-C2B9H11)] (4c) characterised by
the data in Tables 1 and 2. Again the structure is one of
the ylid type, formulated with the Ph2PCH2PPh2
molecule bonded through phosphorus to the CPh moi-
ety of the Ru–C(Me)ꢁC(Ph) group. This is in accord
with similarities in the 13C{1H}-NMR spectrum for the
signal for the CMe nucleus in 4c [l 142.0, J(PC)=20
Hz] with that in 4b [l 141.8, J(PC)=17 Hz]. Further-
more, a partial X-ray structure analysis on a single-
Following the successful characterisation of the phos-
phine adducts 4b and 4c, a semi-empirical ZINDO
molecular orbital calculation was carried out on the
alkyne complex 3c to gain further insight into the
nature of these phosphine addition reactions [6]. The
results of this calculation reveal that the LUMO (Fig.
3) in 3c is primarily localised on the alkyne and it is
therefore sensible that nucleophilic addition of phosphi-
nes is experimentally observed to occur at the alkyne
rather than at the metal centre. The ligated carbon
atoms of the alkyne have substantial y* antibonding
character but the LUMO is also delocalised over the
adjacent phenyl substituent and there is a net y bonding
contribution to the alkyne C–Ph bond. As a result the
LUMO tends to be localised in the region of the C–Ph
bond which is consistent with the experimental observa-
tion that nucleophilic addition of phosphines occurs
regiospecifically at the alkyne CPh carbon centre. Simi-
lar calculations were also carried out using both Ex-
tended Hu¨ckel and Iterative Extended Hu¨ckel methods
to test the sensitivity of the results to the computational
method and parameterisation. The computed LUMO
was similar in all cases but there was some variation
in the extent of the metal contribution to the low lying
LUMO orbitals. For this reason we cannot rule out
the possibility that initial attack of phosphine might
occur at the metal followed by regiospecific transfer
to the alkyne CPh carbon centre. However, this mode
of nucleophilic attack would likely yield an alkenyl
ligand with the methyl and phenyl groups lying cisoid
to one another. Previous studies on cationic al-
kyne complexes of the type [PtMe(L)2(RCꢀCR)][PF6]
(L=phosphine or arsine, R=alkyl or aryl) and
[Fe(CO)(L)(MeCꢀCPh)(p5-C5H5)][BF4] [L=PPh3,
P
(OPh)3] have established a trans-attack mechanism for
nucleophiles without prior co-ordination to the metal
centre [7].
Fig. 3. ZINDO calculation of the LUMO of 3c.

J.C. Jeffery et al. / Journal of Organometallic Chemistry 562 (1998) 17–27
23
Table 5
5
˚
Selected internuclear distances (A) and angles (°) for [Ru2(v-Ph2PCH2PPh2)(CO)4(p -7,8-C2B9H11)2] (6), with estimated standard deviations in
parentheses
˚
Internuclear distances (A)
Ru(1)–C(2)
Ru(1)–B(15)
C(1)–O(1)
Ru(2)–C(22)
Ru(2)–B(24)
P(1)–C(41)
P(2)–C(61)
1.880(7)
Ru(1)–C(1)
Ru(1)–B(13)
C(2)–O(2)
Ru(2)–C(21)
Ru(2)–P(2)
P(1)–C(31)
P(2)–C(51)
1.886(7)
2.286(7)
1.141(7)
2.253(6)
2.364(2)
1.821(6)
1.820(6)
Ru(1)–C(11)
Ru(1)–B(14)
Ru(2)–C(3)
Ru(2)–B(23)
C(3)–O(3)
2.234(7)
2.303(7)
1.884(6)
2.283(7)
1.138(7)
1.855(5)
Ru(1)–C(12)
Ru(1)–P(1)
Ru(2)–C(4)
Ru(2)–B(25)
C(4)–O(4)
2.240(6)
2.377(2)
1.889(7)
2.290(7)
1.142(7)
1.859(5)
2.266(8)
1.143(8)
2.245(6)
2.323(7)
1.819(6)
1.818(6)
P(1)–C(5)
C(5)–P(2)
Internuclear angles (°)
C(2)–Ru(1)–C(1)
C(2)–Ru(1)–C(12)
C(2)–Ru(1)–B(15)
C(12)–Ru(1)–B(15)
C(11)–Ru(1)–B(13)
C(2)–Ru(1)–B(14)
C(12)–Ru(1)–B(14)
C(2)–Ru(1)–P(1)
C(12)–Ru(1)–P(1)
B(14)–Ru(1)–P(1)
C(3)–Ru(2)–C(4)
C(3)–Ru(2)–C(21)
C(3)–Ru(2)–B(23)
C(21)–Ru(2)–B(23)
C(22)–Ru(2)–B(25)
C(3)–Ru(2)–B(24)
C(21)–Ru(2)–B(24)
C(3)–Ru(2)–P(2)
C(21)–Ru(2)–P(2)
B(24)–Ru(2)–P(2)
C(41)–P(1)–C(31)
C(41)–P(1)–Ru(1)
P(1)–C(5)–P(2)
89.7(3)
118.1(3)
135.3(3)
75.5(3)
74.7(3)
93.7(3)
75.4(3)
88.4(2)
91.8(2)
166.5(2)
91.5(3)
158.0(2)
83.5(3)
75.5(2)
74.9(2)
94.5(2)
76.2(2)
89.2(2)
96.1(2)
167.6(2)
108.4(3)
114.7(2)
128.6(3)
107.2(2)
111.8(2)
C(2)–Ru(1)–C(11)
C(1)–Ru(1)–C(12)
C(1)–Ru(1)–B(15)
C(2)–Ru(1)–B(13)
C(12)–Ru(1)–B(13)
C(1)–Ru(1)–B(14)
B(15)–Ru(1)–B(14)
C(1)–Ru(1)–P(1)
B(15)–Ru(1)–P(1)
O(1)–C(1)–Ru(1)
C(3)–Ru(2)–C(22)
C(4)–Ru(2)–C(21)
C(4)–Ru(2)–B(23)
C(3)–Ru(2)–B(25)
C(21)–Ru(2)–B(25)
C(4)–Ru(2)–B(24)
B(23)–Ru(2)–B(24)
C(4)–Ru(2)–P(2)
B(23)–Ru(2)–P(2)
O(3)–C(3)–Ru(2)
C(41)–P(1)–C(5)
C(31)–P(1)–Ru(1)
C(61)–P(2)–C(51)
C(61)–P(2)–Ru(2)
159.2(3)
152.1(3)
82.9(3)
84.9(3)
44.0(3)
101.8(3)
46.0(3)
91.5(2)
135.6(2)
177.5(6)
116.3(2)
109.8(2)
147.9(3)
137.7(3)
44.2(2)
102.1(3)
47.2(3)
89.6(2)
121.9(2)
176.8(5)
106.8(2)
109.2(2)
108.4(3)
114.5(2)
C(1)–Ru(1)–C(11)
C(11)–Ru(1)–C(12)
C(11)–Ru(1)–B(15)
C(1)–Ru(1)–B(13)
B(15)–Ru(1)–B(13)
C(11)–Ru(1)–B(14)
B(13)–Ru(1)–B(14)
C(11)–Ru(1)–P(1)
B(13)–Ru(1)–P(1)
O(2)–C(2)–Ru(1)
C(4)–Ru(2)–C(22)
C(22)–Ru(2)–C(21)
C(22)–Ru(2)–B(23)
C(4)–Ru(2)–B(25)
B(23)–Ru(2)–B(25)
C(22)–Ru(2)–B(24)
B(25)–Ru(2)–B(24)
C(22)–Ru(2)–P(2)
B(25)–Ru(2)–P(2)
O(4)–C(4)–Ru(2)
C(31)–P(1)–C(5)
109.7(3)
42.4(3)
44.8(3)
147.0(3)
78.4(3)
75.4(3)
46.4(3)
98.2(2)
120.7(2)
177.9(5)
152.2(2)
42.5(2)
44.6(2)
84.2(3)
78.6(3)
76.5(2)
46.2(2)
91.3(2)
132.7(2)
178.2(5)
108.0(3)
109.6(2)
104.8(2)
109.8(2)
C(5)–P(1)–Ru(1)
C(61)–P(2)–C(5)
C(51)–P(2)–Ru(2)
C(51)–P(2)–C(5)
C(5)–P(2)–Ru(2)
In contrast with the formation of the ylid complexes
4b and 4c, treatment of 3c with the donor molecules
AsPh3 or SbPh3 resulted in displacement of the alkyne
ligand from the latter and formation of the complexes
[Ru(CO)2(L)(p5-7,8-C2B9H11)] (5a, L=AsPh3; 5b, L=
SbPh3). Data characterising these species are given in
Tables and 2. The reaction between 3c and
Ph2P(S)CH2P(S)Ph2 in 1:1 mol ratio followed a similar
path to form [Ru(CO)2{Ph2P(S)CH2P(S)Ph2}(p5-7,8-
C2B9H11)] (5c) rather than an ylid complex. The IR and
1
Fig. 4. Molecular structure of [Ru2(v-Ph2PCH2PPh2)(CO)4(p5-7,8-C2B9H11)2] (6) showing the atom labelling scheme. Hydrogen atoms are omitted
for clarity. Thermal ellipsoids are shown at the 40% probability level.

24
J.C. Jeffery et al. / Journal of Organometallic Chemistry 562 (1998) 17–27
Table 6
Data for X-ray crystal structure analyses
3c
4b
6
Crystal dimensions (mm)
Formula
Mr
0.40×0.64×0.78
C13H19B9O2Ru
405.64
0.50×0.50×0.15
C19H34B9O2PRu
523.79
0.25×0.20×0.05
C35H46B18Cl2O4P2Ru2
1060.28
Crystal colour, shape
Crystal system
Space group
T (K)
Pale yellow
Monoclinic
P21/n
Pale yellow
Monoclinic
P21/c
Pale yellow
Monoclinic
P21/n
173(2)
173(2)
173(2)
Crystal data
˚
a (A)
16.257(4)
6.9867(12)
17.656(3)
116.436(8)
1795.7(6)
4
1.500
8.74
808
11.873(1)
15.106(2)
15.086(3)
110.33(1)
2537.2(7)
4
1.371
6.96
1072
13.670(2)
22.845(2)
15.325(2)
102.55(1)
4671.4(9)
4
1.508
8.67
2120
˚
b (A)
˚
c (A)
i (°)
3
˚
V (A )
Z
Dcalc (g cm−3
)
v(Mo–Kh) (cm−1
F(000) (e)
)
Data frame collection time (s)
10
20
40
2q range (°)
No. of reflections
Measured
Unique
Observed
Reflection limits
h
4.6–50.0
5.0–55.0
5.0–50.0
8159
3146
3144
15523
5799
5799
20768
7851
7851
−19 to 17
−8 to 7
−21 to 16
−9 to 15
−19 to 19
−19 to 15
−15 to 16
−26 to 22
−12 to 17
k
l
Final residuals
Weighting factors
wR2=0.0527a (R1=0.0199)b wR2=0.0648a (R1=0.0276)b wR2=0.0984a (R1=0.0530)b
a=0.0227, b=1.5380a
a=0.0363, b=0.0000a
a=0.0085, b=27.21a
−3
˚
Largest difference peak and hole (e A
Goodness-of-fit
)
0.25/−0.45
1.147
0.52/−0.68
0.976
1.61/−1.60
1.186
a Structure was refined on Fo2 using all data: wR2=[S{w(Fo2−F2c)2}/Sw(Fo2)2]1/2 where w−1=[|2(Fo2)+(aP)2+bP] and P=[max(Fo2, 0)+2F2c]/3.
b The value in parentheses is given for comparison with refinements based on Fo with a typical threshold of Fo\4|(Fo) and R1=SꢀFoꢁ−ꢁFcꢀ/SꢁFoꢁ
and w−1=[|2(Fo)+gF2o].
NMR data for complexes 5a–c are in accord with their
Cs structures (Tables 1 and 2). In particular, the simplic-
ity of the 11B{1H}-NMR spectra of these compounds
(integrated signal ratios: 5a, 1:1:2:2:3; 5b, 1:1:2:2:2:1; 5c,
1:5:1:2) reflects this symmetry.
molecule is shown in Fig. 4.
The two Ru(CO)2(p5-7,8-C2B9H11) fragments are
bridged by the Ph2PCH2PPh2 ligand with the Ru–P
˚
separations (av. 2.371 A) being very similar to those
observed for such distances in other ruthenacarborane
complexes ([1]b), [8]. The four CO molecules are essen-
tially linearly bound to their respective metal centres
[Ru–C–Oav. =177.6 °] and each cage is pentahapto
co-ordinated to its respective ruthenium atom.
Finally, an attempt was made to co-ordinate the
unattached PPh2 group in 4c to the 16-electron fragment
Ru(CO)2(p5-7,8-C2B9H11) by treating the former with a
CH2Cl2 solution obtained by adding AgBF4 to
[NEt4][RuI(CO)2(p5-7,8-C2B9H11)]. The product of this
reaction was, however, the diruthenium complex [Ru2(v-
Ph2PCH2PPh2)(CO)4(p5-7,8-C2B9H11)2] (6), data for
which are given in Tables 1 and 2. Evidently the reaction
proceeds with loss of the MeCꢀCPh group possibly from
an intermediate [Ru2(v-C(Me)ꢁC(Ph)P(Ph)2CH2PPh2)
(CO)4(p5-7,8-C2B9H11)2]. Not surprisingly 6 is readily
synthesised in a more rational manner by treating 2 with
Ph2PCH2PPh2 in a 2:1 mol ratio. The nature of 6 was
firmly established by an X-ray diffraction study. Selected
structural parameters are given in Table 5 and the
The IR spectrum of 6 shows two wmax(CO) bands at
2050 and 2002 cm−1. The NMR spectra reflect its Cs
symmetry in solution with resonances for the cage CH
1
nuclei at l 2.19 in the H-NMR spectrum and at l 47.6
in the 13C{1H}-NMR spectrum (Table 2). The latter
accordingly reveals a single resonance for all four CO
carbon nuclei at l 196.0. The 11B{1H}-NMR spectrum
is also relatively simple with five signals in the ratio
1:1:2:2:3. As far as we are aware 6 is the first molecule
to be described where two metallaborane groups are
bridged by a Ph2PCH2PPh2 ligand.

J.C. Jeffery et al. / Journal of Organometallic Chemistry 562 (1998) 17–27
25
Table 7
described ([1]a). The reagent Ph2P(S)CH2P(S)Ph2 was
prepared according to the literature method [9].
Atomic positional parameters (fractional co-ordinates×104) and
2
3
˚
equivalent isotropic displacement parameters (A ×10 ) for 3c
4.2. Synthesis of [Ru(CO)2(MeCꢀCPh)(p5-7,8-C2B9H11)]
Atom
x
y
z
U(eq)a
The compound [NEt4][RuI(CO)2(p5-7,8-C2B9H11)]
(0.21 g, 0.38 mmol) in THF (15 cm3) was treated with
AgBF4 (0.08 g, 0.41 mmol). After removal of solvent in
vacuo, the residue was taken up in CH2Cl2 (15 cm3),
cooled to ca. −95°C with a toluene–liquid nitrogen
bath and treated with an excess of MeCꢀCPh (0.22 cm3,
1.92 mmol). The reaction mixture was warmed slowly
to room temperature (r.t.). Monitoring of changes in
the IR spectrum in the wmax(CO) region revealed that
the reaction was complete in ca. 60 min. After filtration
through a Celite pad to remove AgI, the yellow filtrate
containing the product was evaporated in vacuo and
the residue obtained crystallised from CH2Cl2–n-pen-
tane (1:2, 5 cm3) to yield pale yellow crystals of
[Ru(CO)2(MeCꢀCPh)(p5-7,8-C2B9H11)] (3c) (0.10 g).
Ru(1)
C(1)
C(2)
B(3)
B(4)
B(5)
B(6)
B(7)
B(8)
4256(1)
2973(1)
3185(1)
3306(2)
3124(2)
2930(2)
1910(2)
2081(2)
2284(2)
2222(2)
1986(2)
1464(2)
5094(1)
5551(1)
4771(1)
5030(1)
5028(2)
5059(1)
5263(1)
5775(1)
5544(2)
6111(2)
6897(2)
7110(2)
6557(1)
5903(1)
4784(3)
3669(3)
5212(3)
7608(3)
7216(3)
5815(3)
3543(4)
3839(4)
6334(4)
7561(3)
5298(4)
6505(3)
6877(2)
7912(3)
9165(2)
4305(3)
4041(3)
3426(3)
2302(3)
2196(3)
1215(3)
316(3)
1806(1)
1826(1)
1123(1)
426(1)
15(1)
19(1)
20(1)
20(1)
20(1)
19(1)
22(1)
24(1)
25(1)
23(1)
22(1)
25(1)
24(1)
35(1)
23(1)
34(1)
30(1)
22(1)
21(1)
21(1)
26(1)
32(1)
33(1)
30(1)
24(1)
755(1)
1684(1)
1375(2)
1039(2)
140(2)
−94(1)
676(1)
B(9)
B(10)
B(11)
C(3)
O(3)
C(4)
O(4)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
276(2)
1362(1)
1050(1)
2603(1)
3062(1)
3803(1)
2988(1)
2442(1)
2101(1)
1239(1)
972(2)
Table 8
Atomic positional parameters (fractional co-ordinates×104) and
2
3
˚
1552(2)
2405(2)
2682(1)
equivalent isotropic displacement parameters (A ×10 ) for 4b
350(3)
1331(3)
Atom
x
y
z
U(eq)a
a
Equivalent isotropic U defined as one-third of the trace of the
orthogonalised Uij tensor.
Ru
P
C(1)
C(2)
B(3)
B(4)
B(5)
B(6)
B(7)
9313(1)
2158(1)
2063(1)
1072(2)
2012(2)
2466(2)
1671(2)
790(2)
1835(1)
3958(1)
2770(2)
3007(2)
2013(2)
1085(2)
1617(2)
2515(2)
3416(2)
2922(2)
1719(2)
1459(2)
2567(2)
855(2)
23(1)
24(1)
27(1)
29(1)
28(1)
26(1)
26(1)
31(1)
34(1)
34(1)
31(1)
30(1)
33(1)
33(1)
50(1)
33(1)
48(1)
25(1)
24(1)
29(1)
25(1)
32(1)
35(1)
36(1)
35(1)
29(1)
35(1)
52(1)
33(1)
39(1)
34(1)
44(1)
13429(1)
9039(2)
8560(2)
7522(2)
7335(2)
8393(2)
7953(2)
8087(2)
7099(2)
6318(2)
6846(2)
6665(2)
9841(2)
10054(2)
9273(2)
9192(2)
11079(2)
12067(2)
11128(2)
12172(2)
12860(2)
13008(2)
12456(2)
11778(2)
11642(2)
13159(2)
12366(3)
14182(2)
14340(2)
14486(2)
15616(2)
3. Conclusion
Further work with complex 3c and analogues thereof
may be warranted in light of the curious ejection of the
alkyne molecule in certain reactions. The chemistry of
this species may be expanded by studying its reactivity
with a range of nucleophilic organic or transition
metal–ligand fragments.
283(2)
1064(2)
1946(2)
1700(2)
666(2)
B(8)
B(9)
B(10)
B(11)
C(3)
O(3)
C(4)
O(4)
C(8)
C(9)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
836(2)
1839(2)
1646(1)
3333(2)
4049(1)
2398(1)
1914(1)
3166(2)
1197(1)
1338(2)
688(2)
−118(2)
−280(2)
364(1)
1926(2)
1142(2)
3114(1)
3379(2)
1206(2)
1162(2)
197(1)
1437(2)
1173(1)
2826(2)
2936(2)
3490(2)
2274(2)
1706(2)
1108(2)
1061(2)
1619(2)
2228(2)
5063(2)
5079(2)
4002(2)
3082(2)
3933(2)
4824(2)
4. Experimental section
4.1. General procedures
All experiments were conducted under an atmosphere
of dry nitrogen or argon using Schlenk-line techniques.
Solvents were freshly distilled under nitrogen from ap-
propriate drying agents before use. Chromatography
columns (ca. 30 cm in length and 3 cm in diameter)
were packed under nitrogen with silica gel (Acros,
60–200 mesh). The NMR spectra were recorded at
ambient temperatures in CD2Cl2, at the following fre-
quencies: H at 360.1, 13C at 90.6, 31P at 145.8 and 11B
at 115.3 MHz. IR spectra were measured with a Bruker
IFS 25 spectrometer. The compound [NEt4]
[RuI(CO)2(p5-7,8-C2B9H11)] was obtained as previously
1
a
Equivalent isotropic U defined as one-third of the trace of the
orthogonalised Uij tensor.

26
J.C. Jeffery et al. / Journal of Organometallic Chemistry 562 (1998) 17–27
4.3. Reactions of [Ru(CO)2(MeCꢀCPh)(p5-7,8-
C2B9H11)]
Table 9
Atomic positional parameters (fractional co-ordinates×104) and
2
3
˚
equivalent isotropic displacement parameters (A ×10 ) for 6
(a) A CH2Cl2 (15 cm3) solution of 3c (0.07 g, 0.17
mmol) was cooled to −95°C and PEt3 (25 ml, 0.17
mmol) added. After warming to r.t., changes in the
yellow mixture were followed by IR spectroscopy in the
wmax (CO) region. The reaction was complete after ca.
60 min. The yellow solution was pumped dry in vacuo
and the residue crystallised from CH2Cl2–n-pentane
Atom
x
y
z
U(eq)a
Ru(1)
C(11)
C(12)
B(13)
B(14)
B(15)
B(16)
B(17)
B(18)
B(19)
B(110)
B(111)
C(1)
11183(1)
11935(6)
11374(5)
11767(6)
12708(5)
12763(6)
13172(8)
12269(8)
12179(6)
13054(6)
13665(6)
13349(6)
11364(5)
11508(4)
10613(4)
10294(4)
7192(1)
5964(4)
5547(4)
5803(6)
6440(6)
6536(5)
5296(5)
4678(5)
4577(5)
5113(5)
5560(6)
4419(6)
7782(4)
8096(4)
8425(5)
9162(4)
9546(1)
8839(4)
8762(4)
8290(5)
7912(5)
8007(4)
8460(4)
9509(4)
10294(4)
10273(5)
9470(5)
8695(5)
8715(5)
8887(4)
7600(1)
7554(4)
8399(5)
8379(6)
7517(6)
6666(5)
6674(5)
6795(4)
6565(4)
6042(5)
5737(5)
5940(4)
6459(4)
9813(11)
10628(2)
9044(3)
−785(1)
7057(1)
7379(6)
6335(6)
5818(5)
6666(6)
7674(5)
7497(6)
6673(8)
5666(6)
5886(6)
7014(6)
6399(6)
8102(5)
8731(4)
6375(4)
5952(3)
8107(1)
8799(4)
7723(4)
7331(5)
8331(5)
9245(5)
9350(5)
8388(5)
7466(5)
7867(5)
9047(5)
8505(5)
7191(4)
6620(3)
8948(4)
9465(3)
7191(1)
6109(4)
5870(4)
5006(4)
4372(4)
4592(4)
5451(4)
8011(4)
8771(4)
9440(4)
9357(4)
8609(5)
7941(4)
7527(4)
7737(1)
8660(4)
9354(4)
22(1)
54(2)
54(2)
42(2)
41(2)
42(2)
59(3)
72(4)
51(2)
41(2)
51(2)
45(2)
34(2)
53(1)
29(1)
44(1)
19(1)
25(1)
25(1)
33(2)
29(2)
28(2)
30(2)
28(2)
32(2)
33(2)
32(2)
33(2)
27(1)
44(1)
32(2)
50(1)
19(1)
20(1)
28(1)
36(2)
38(2)
30(1)
27(1)
21(1)
28(1)
38(2)
37(2)
34(2)
26(1)
20(1)
18(1)
21(1)
29(1)
40(2)
44(2)
41(2)
30(2)
22(1)
28(1)
34(2)
37(2)
35(2)
27(1)
175(9)
95(1)
167(2)
−1650(3)
−1615(3)
−1033(4)
−682(4)
−1083(4)
−1800(4)
−2153(4)
−1760(4)
−1176(4)
−1217(4)
−1867(4)
−325(3)
−41(2)
(1:2,
5
cm3) to afford pale yellow crystals of
[Ru{C(Me)ꢁC(Ph)PEt3}(CO)2(p5-7,8-C2B9H11)]
(0.08 g).
(4b)
(b) In a similar manner, compound 3c (0.06 g, 0.16
mmol) in CH2Cl2 (15 cm3) was treated with
Ph2PCH2PPh2 (0.06 g, 0.16 mmol). Reaction was com-
plete after ca. 45 min. and crystallisation of the yellow
solid obtained from CH2Cl2–n-pentane (1:2, 5 cm3)
yielded pale yellow microcrystals of [ R u { C ( M e ) ꢁ
C ( P h ) P ( P h )2 C H2 P P h2 } ( C O )2 ( p5 - 7 , 8 - C2B9
H11)] (4c) (0.10 g).
(c) Complex 3c (0.06 g, 0.14 mmol) in CH2Cl2 (15
cm3) was treated with AsPh3 (0.05 g, 0.15 mmol) and
the mixture stirred for 45 min, thereby affording, after
removal of solvent in vacuo and crystallisation from
CH2Cl2–n-pentane (1:2, 5 cm3), off-white crystals of
[Ru(CO)2(AsPh3)(p5-7,8-C2B9H11)] (5a) (0.08 g).
(d) The compound [Ru(CO)2(SbPh3)(p5-7,8-C2B9
H11)] (5b) (0.08 g) was similarly obtained as pale yellow
crystals employing 3c (0.06 g, 0.14 mmol) and SbPh3
(0.05 g, 0.14 mmol).
O(1)
C(2)
O(2)
−137(3)
258(2)
Ru(2)
C(21)
C(22)
B(23)
B(24)
B(25)
B(26)
B(27)
B(28)
B(29)
B(210)
B(211)
C(3)
586(1)
326(3)
386(3)
1061(3)
1469(3)
957(3)
766(3)
387(3)
868(3)
1551(3)
1484(3)
1133(3)
877(3)
1063(2)
632(3)
673(2)
O(3)
C(4)
O(4)
P(1)
−1061(1)
−1312(2)
−1900(3)
−2067(3)
−1655(3)
−1070(3)
−896(3)
−1631(2)
−1659(3)
−2066(3)
−2447(3)
−2430(3)
−2026(2)
−417(2)
−374(1)
−868(2)
−912(3)
−1250(3)
−1538(3)
−1487(3)
−1149(3)
−667(2)
−1259(3)
−1481(3)
−1114(3)
−523(3)
−293(3)
2022(7)
C(31)
C(32)
C(33)
C(34)
C(35)
C(36)
C(41)
C(42)
C(43)
C(44)
C(45)
C(46)
C(5)
(e) Compound 3c (0.07 g, 0.17 mmol) in CH2Cl2 (15
cm3) with Ph2P(S)CH2P(S)Ph2 (0.08 g, 0.17 mmol) gave
a yellow solution which, after 45 min, was reduced in
vacuo to ca. 5 cm3. Addition of n-pentane (10 cm3)
followed by cooling to ca. −20°C afforded yellow
crystals
of
[Ru(CO)2{Ph2P(S)CH2P(S)Ph2}(p5-7,8-
C2B9H11)] (5c) (0.08 g).
4.4. Synthesis of [Ru2(v-Ph2PCH2PPh2)(CO)4(p5-7,8-
C2B9H11)2]
P(2)
C(51)
C(52)
C(53)
C(54)
C(55)
C(56)
C(61)
C(62)
C(63)
C(64)
C(65)
C(66)
C(71)
Cl(71)
Cl(72)
(a) A solution of [NEt4][RuI(CO)2(p5-7,8-C2B9H11)]
(0.11 g, 0.20 mmol) in CH2Cl2 (15 cm3) after addition
of AgBF4 (0.04 g, 0.22 mmol) was cooled to −95°C
and compound 4c (0.15 g, 0.19 mmol) was added. The
mixture was slowly warmed to r.t. and after stirring for
30 min, it was filtered through Celite and solvent was
reduced in volume in vacuo to ca. 5 cm3. Addition of
n-pentane (10 cm3) followed by cooling to −20°C gave
yellow crystals of [Ru2(v-Ph2PCH2PPh2)(CO)4(p5-7,8-
C2B9H11)2] (6) (0.07 g) which were washed with n-pen-
tane and dried in vacuo.
10097(4)
10153(5)
9488(5)
8725(4)
6729(4)
6634(4)
5829(4)
5107(5)
5189(4)
6002(4)
7016(8)
7494(2)
7733(4)
1426(2)
2203(2)
(b) To [NEt4][RuI(CO)2(p5-7,8-C2B9H11)] (0.20 g,
0.37 mmol) in CH2Cl2 (15 cm3) was added AgBF4 (0.09
a
Equivalent isotropic U defined as one-third of the trace of the
orthogonalised Uij tensor.

J.C. Jeffery et al. / Journal of Organometallic Chemistry 562 (1998) 17–27
27
parameters for non-hydrogen atoms with equivalent
isotropic thermal parameters (x, y, z, U(eq)) are listed
in Tables 7–9. Atomic co-ordinates, a complete listing
of bond lengths and angles, and the thermal parameters
have been deposited at the Cambridge Crystallographic
Data Centre.
g, 0.46 mmol) and the mixture was cooled to −95°C.
The phosphine Ph2PCH2PPh2 (0.07 g, 0.19 mmol) was
added and the mixture allowed to warm to r.t. and then
stirred for a further 30 min. The suspension was filtered
through Celite and the filtrate reduced in volume in
vacuo to ca. 4 cm3 and chromatographed. Elution with
CH2Cl2–n-pentane (1:1) removed a yellow fraction.
Removal of solvent in vacuo gave yellow crystals of
[Ru2(v-Ph2PCH2PPh2)(CO)4(p5-7,8-C2B9H11)2] (6) (0.16
g) which were washed with n-pentane and dried in
vacuo.
4.6. Molecular orbital calculations
A semi-empirical ZINDO molecular orbital calcula-
tion was carried out using INDO1 parameters with
atomic co-ordinates taken from the X-ray crystal struc-
ture determination on 3c.
4.5. X-ray structural analyses
Crystals of 3c, 4b and 6 were grown by diffusion of
n-pentane into CH2Cl2 solutions of the complexes. The
crystals were mounted on glass fibres and low tempera-
ture data were collected on a Siemens SMART CCD
area-detector three-circle diffractometer using Mo–Kh
Acknowledgements
We thank the Robert A. Welch Foundation for
support (Grant AA-1201).
˚
X-radiation, u=0.71073 A. Crystals of 6 were rela-
tively small and poorly diffracting. In addition, the
asymmetric unit in 6 contains one molecule of CH2Cl2.
For three settings of ƒ, narrow data ‘frames’ were
collected for 0.3° increments in ꢀ. In all cases a total of
1321 frames of data were collected affording rather
more than a hemisphere of data. It was confirmed that
crystal decay had not taken place during the course of
the data collections. The substantial redundancy in data
allows empirical absorption corrections to be applied
using multiple measurements of equivalent reflections.
The data frames were integrated using SAINT [10] and
the structures were solved by conventional direct meth-
ods. The structures were refined by full-matrix least-
squares on all F2 data using Siemens SHELXTL
version 5.03 [10], with anisotropic thermal parameters
for all non-hydrogen atoms. All hydrogen atoms were
included in calculated positions and allowed to ride on
the parent boron or carbon atoms with isotropic ther-
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mal parameters (Uiso=1.2×Uiso
of the parent
equi6.
atom except for Me protons where Uiso=1.5×Uiso
equi6.). All calculations were carried out on Silicon
Graphics Iris, Indigo, or Indy computers. Experimental
data are recorded in Table 6 and final atomic positional
[10] Siemens X-ray Instruments, Madison, WI (1995).
.
.