Phosphine derivatives of the 4-methylquinoline triosmium cluster [(μ-H)Os3(CO)10{μ-1,2-η2-C 9H5(CH3)N}]: Crystal structures of two isomeric compounds.

Article abstract of DOI:10.1016/S0022-328X(98)00762-1

The 4-methylquinoline triosmium cluster [(μ-H)Os₃(CO)₁₀{μ-1,2-η²-C ₉H₅(CH₃)N}] 9 reacts with PPh₃ at 110°C to give the mono and bis-substituted products [(μ-H)Os₃(CO)₉{μ-1,2-η²-C ₉H₅(CH₃)N}(PPh₃)] 10 and [(μ-H)Os₃(CO)₈{μ-1,2-η²-C ₉H₅(CH₃)N}(PPh₃)₂] 11, respectively. Similarly the reaction of 9 with P(OMe)₃ gives [(μ-H)Os₃(CO)₉{μ-1,2-η²-C ₉H₅(CH₃)N}{P(OMe)₃}] 14 and [(μ-H)Os₃(CO)₈{μ-1,2-η²-C ₉H₅(CH₃)N}{P(OMe)₃}₂] 15. Compound 10 exists as a mixture of three isomers in solution with the major (60%) having the PPh₃ ligand on the rear osmium atom and the hydride, which initially bridged the same edge as the 4-methylquinoline ligand, migrating to the carbon bound osmium and the phosphine bearing osmium edge. In contrast compound 14, in which the P(OMe)₃ resides on the unbridged osmium atom and the hydride bridges the same edge as the 4-methylquinoline ligand, exists as two isomers in solution. The structures of 10 and 14 have been ascertained by X-ray crystal structure determination. Compound 11 exists as four isomers in solution and 15 as two isomers.

Full text of DOI:10.1016/S0022-328X(98)00762-1

Journal of Organometallic Chemistry 568 (1998) 133–142
Phosphine derivatives of the 4-methylquinoline triosmium cluster
[(v-H)Os3(CO)10{v-1,2-p2-C9H5(CH3)N}]: crystal structures of two
isomeric compounds [(v-H)Os3(CO)9{v-1,2-p2-C9H5(CH3)N}(PPh3)]
and [(v-H)Os3(CO)9{v-1,2-p2-C9H5(CH3)N}{P(OMe)3}]
Michael B. Hursthouse a,*, Shariff E. Kabir b, K.M. Abdul Malik a, Markus Tesmer b,
Heinrich Vahrenkamp b
a Department of Chemistry, Uni6ersity of Wales Cardiff, P.O. Box 912, Park Place, Cardiff CF1 3TB, Wales, UK
b Institut fu¨r Anorganische und Analytische Chemie, Uni6ersita¨t Freiburg, Albertstr. 21, D-79104 Freiburg, Germany
Received 13 February 1997
Abstract
The 4-methylquinoline triosmium cluster [(v-H)Os3(CO)10{v-1,2-p2-C9H5(CH3)N}] 9 reacts with PPh3 at 110°C to give the
mono and bis-substituted products [(v-H)Os3(CO)9{v-1,2-p2-C9H5(CH3)N}(PPh3)] 10 and [(v-H)Os3(CO)8{v-1,2-p2-
C9H5(CH3)N}(PPh3)2] 11, respectively. Similarly the reaction of
9
with P(OMe)3 gives [(v-H)Os3(CO)9{v-1,2-p2-
C9H5(CH3)N}{P(OMe)3}] 14 and [(v-H)Os3(CO)8{v-1,2-p2-C9H5(CH3)N}{P(OMe)3}2] 15. Compound 10 exists as a mixture of
three isomers in solution with the major (60%) having the PPh3 ligand on the rear osmium atom and the hydride, which initially
bridged the same edge as the 4-methylquinoline ligand, migrating to the carbon bound osmium and the phosphine bearing
osmium edge. In contrast compound 14, in which the P(OMe)3 resides on the unbridged osmium atom and the hydride bridges
the same edge as the 4-methylquinoline ligand, exists as two isomers in solution. The structures of 10 and 14 have been ascertained
by X-ray crystal structure determination. Compound 11 exists as four isomers in solution and 15 as two isomers. © 1998 Elsevier
Science S.A. All rights reserved.
Keywords: Osmium; 4-Methylquinoline; Crystal structure; Carbonyl; Phosphine
1. Introduction
gives the substitution product [(v-H)Os3(CO)9(v-p2-
¸¹¹¹¹¹¹¹º
CꢀNCH2CH2CH2)(PPh3)] 2 (Scheme 1) in which the
phosphine is at osmium atoms bridged by the hydride
and the heterocyclic ligand [1].
The reactivity of trimetallic clusters containing nitro-
gen heterocycles with two-electron ligands such as
phosphines, phosphites and isocyanides has recently
been reported [1–5]. It has been demonstrated that the
structures of the products obtained from such reactions
are sensitive to the structure of the ligand and the
steric bulk of the two electron donor ligands. For
example, the reaction of [(v-H)Os3(CO)10(v-p2-
¸¹¹¹¹¹¹¹º
CꢀNCH2CH2CH2)] 1 with triphenylphosphine at 98°C
* Corresponding author. Fax: +44 1222 874029; e-mail: hurst-
house@cardiff.ac.uk
Scheme 1.
0022-328X/98/$19.00 © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(98)00762-1

134
M.B. Hursthouse et al. / Journal of Organometallic Chemistry 568 (1998) 133–142
2. Results and discussion
The reaction of 9 with PPh3 at 110°C leads to the
isolation of the mono and bis-substituted products [(v-
H)Os3(CO)9{v-1,2-p2-C9H5(CH3)N}(PPh3)] 10 and [(v-
H)Os3(CO)8{v-1,2-p2-C9H5(CH3)N}(PPh3)2] 11 in 30
and 42% yields, respectively. The infrared spectrum of
10 in the carbonyl stretching region is different from
1
Scheme 2.
that of the related compounds 2 and 7. The H-NMR
spectrum of a recrystallized sample of 10 at −40°C
shows three hydride signals, a doublet at l −15.84
(JP–H=14.7 Hz) and two singlets at l −13.75 and
−13.87 with a relative intensity of 3:1:1 (Fig. 1) as well
as three singlets at l 2.56, 2.41 and 2.45 for the methyl
protons in similar integrated intensities indicating the
presence of three isomers in solution.
In
contrast
the
acyclic
compound
[(v-
H)Os3(CO)10(v-p2-CH3CH2CꢀNCH2CH2CH3)] 3 reacts
with PPh3 at 98°C to give the substitution product
[(v-H)Os3(CO)9(v-p2-CH3CH2CꢀNCH2CH2CH3)-
(PPh3)] 4 (Scheme 2) in which the hydride which ini-
tially bridged the same edge as the organic ligand has
migrated [1].
1
The H-NMR data do not allow us to predict struc-
tures for these isomers and so an X-ray structure
determination of the single crystals obtained from this
isomeric mixture was undertaken. The solid state struc-
ture of the single crystals obtained from 10 revealed it
to have structure 10a (Scheme 5) with phosphine substi-
tuted on the unbridged osmium atom and the hydride
bridging this osmium and the osmium atom sigma-
bound to the carbon atom of the quinoline ligand. The
X-ray structure of 10a is shown in Fig. 2 and selected
bond distances and angles are given in Table 1.
It is interesting to note that no such rearrangement is
observed when this compound is reacted with P(OMe)3
and compound 5 (Scheme 3) analogous to 2 is obtained
[1].
On the other hand, the 4-methylthiazolide cluster [(v-
¸¹¹¹¹¹¹¹º
H)Os3(CO)10(v-2,3-p2-CꢀNCMeꢀCHS)] 6 reacts with
PPh3 at 98°C to give mono and bis-substituted com-
The structure contains a scalene triangle of osmium
atoms with three distinctly different osmiumꢁosmium
bond lengths. There are three CO groups bonded to
each osmium, in addition to a hydride and a 4-
methylquinoline ligands bridging different edges of the
¸¹¹¹¹¹¹¹º
pounds [(v-H)Os3(CO)9(v-2,3-p2-CꢀNCMeꢀCHS)(PP-
¸¹¹¹¹¹¹¹º
h3)] 7 and [(v-H)Os3(CO)8(v-2,3-p2-CꢀNCMeꢀCHS)-
(PPh3)2] 8 (Scheme 4), respectively [5].
These studies have demonstrated that in addition to
structural differences, the number of isomers observed
in solution and the barriers to their interconversion are
markedly dependent on the structure of the organic
ligand and the steric bulk of the two electron donors. In
our present work, we have investigated the reactions of
[(v-H)Os3(CO)10{v-1,2-p2-C9H5(CH3)N}] 9 with PPh3
and P(OMe)3. We have obtained distinctly different
products from those reported previously [1–5] and
structurally characterized two new isomeric compounds
[(v-H)Os3(CO)9{v-1,2-p2-C9H5(CH3)N}(PPh3)] 10 and
˚
triangle. The Os(2)ꢁOs(3) bond [3.0442(10) A] spanned
by the hydride ligand is significantly longer than the
other two OsꢁOs bonds [Os(1)ꢁOs(2)=2.7744(9) and
˚
Os(1)ꢁOs(3)=2.8731(9) A]. This is consistent with the
fact that a hydride bridging two metal atoms unaccom-
panied by other bridging groups causes a significant
elongation of the metal-metal bond [6]. A similar
lengthening of the hydride bridging OsꢁOs edge was
observed in the related compound 14 [see later]. The
˚
quinoline bridged Os(1)ꢁOs(2) edge [2.7744(9) A] is
[(v-H)Os3(CO)9{v-1,2-C9H5(CH3)N}{P(OMe)3}]
The results of this study are reported herein.
14.
significantly shorter than the unsupported Os(1)ꢁOs(3)
˚
edge [2.8731(9) A] which is similar to the average
Scheme 3.

M.B. Hursthouse et al. / Journal of Organometallic Chemistry 568 (1998) 133–142
135
Scheme 4.
˚
osmiumꢁosmium bond length of 2.877(3)
A
in
blet at l −15.84 suggests that the hydride is trans to
the phosphine and is consistent with those observed for
related compounds in which the hydrides are trans to
the phosphines and are coordinated to the same metal
atoms [1,2,5], [9]a–c. As the temperature is increased
to +25°C, the singlet resonances at l −13.75 and
[Os3(CO)12] [7]. The triphenylphosphine is substituted at
the rear osmium atom Os(3) and occupies an equatorial
position.
The
metal-phosphine
bond
length,
˚
Os(3)ꢁP(1)=2.353(4) A, is comparable with those of 2
˚
˚
[Os(2)ꢁP=2.371(2) A] [1] and 7 [Os(3)ꢁP=2.376(3) A]
[5]. The 4-methylquinoline ligand bridges the
Os(1)ꢁOs(2) edge through the N(1) and C(10) atoms.
˚
The Os(2)ꢁC(10) bond [2.068(13) A] is significantly
shorter and the Os(1)ꢁN(1) bond [2.184(1) A] is signifi-
˚
cantly longer than the corresponding values found in
other related compounds [1–5]. In the methylquinoline
˚
ring, the N(1)ꢁC(10) bond [1.32(2) A] forming the
bridge between Os(1) and Os(2) is significantly shorter
˚
than the N(1)ꢁC(18) bond [1.41(2) A] but quite close to
˚
the value quoted for CꢀN double bonds [1.25 A] [8];
this indicates that the NꢀC double bond in the quino-
line ligand has been lengthened only slightly by the
bridge formation. This value is intermediate between
those found in the v- and v3-imidoyl clusters [(v-
H)Os3(CO)9(v - p2 - CH3CH2CꢀNCH2CH2CH3)(PPh3)]
2
˚
(1.29 A) and [(v-H)Os3(CO)8(v3-p -CH3CH2CꢀNCH2
˚
CH2CH3)(PPh3)2] (1.37 A) [1]. The Os(1)ꢁN(1)ꢁ
C(10)ꢁOs(2) bridge is nearly perpendicular to the trian-
gle of the osmium atoms with a dihedral angle of
84.0(2)° between the two planes. The bridging hydride
is found to lie very close to the plane of the Os3
triangle. Other parameters related to the 4-
methylquinoline, triphenyl phosphine and carbonyl lig-
ands are as expected for these types of species.
1
By a combination of the variable temperature H-
NMR data and the X-ray determined structure of 10
we can make structural assignment of the three ob-
served isomers (Scheme 5). In the hydride region of the
1H-NMR spectrum the singlet resonances at l −13.75
and −13.87 are due to the two minor radial isomers
10b and 10c while the doublet resonance at l −15.84
can be assigned to the same structure as that found in
the solid state structure 10a with the phosphine on the
rear osmium atom and the hydride ligand migrating to
the carbon bound osmium and the phosphine bearing
osmium edge. The magnitude of the phosphorus-hydro-
gen coupling constant of 14.7 Hz for the hydride dou-
Fig. 1. Variable temperature 1H-NMR spectra of [(v-H)Os3(CO)9{v-
1,2-p2-C9H5(CH3)N}(PPh3)] 10 in the hydride region.

136
M.B. Hursthouse et al. / Journal of Organometallic Chemistry 568 (1998) 133–142
1
The variable temperature H-NMR spectra of 11 are
very similar to those reported [5] for 8 and therefore they
are expected to have similar structures and show similar
coalescence behavior. But this could not be confirmed by
an X-ray structure determination of 11, since our re-
peated efforts to obtain suitable single crystals of this
compound were unsuccessful. However, from the magni-
tude of phosphorus-hydrogen couplings observed for the
hydride resonances of 11 at −40°C, their coalescence
behavior compared with that of 8 [5] along with a
knowledge of the solid state structure of the latter, we
propose the four observed isomers of 11 to possess
structures 11a–d as shown in Scheme 7. We believe that
the major isomer of 11 which exhibits the doublet
hydride resonance at l −13.53 has a structure similar
to that reported for the major isomer of 8 having one
phosphine ligand on the osmium atom bound to the
nitrogen atom of the heterocyclic ring, the second phos-
phine on the rear osmium atom, and the hydride bridg-
ing the same edge as the heterocyclic ligand. The doublet
at l −13.50 which exchanges with the major doublet at
l −13.53 is due to the minor isomer 11b. As reported
for 8 [5], the hydride doublets at l −13.60 and −13.80
which exchange to give a broadened singlet at l −13.70
are due to the isomers 11c and 11d (Scheme 7) differing
by the orientation of the phosphine bonded to the
unbridged osmium atom. Further evidence for the above
assignments comes from the fact that isomers 11a and
11b do not interconvert with 11c and 11d up to +50°C.
The interconversion between isomers 11a or 11b and
isomers 11c or 11d is slow because such an interconver-
sion reaction would require phosphine dissociation
which is a much higher energy process [1,2,5].
Scheme 5.
−13.87 average to a broadened singlet at l −13.81
while the doublet at l −15.84 remains unchanged. The
equivalence of the hydride resonance at l −13.75 and
−13.87 can be explained by a fluxional process whereby
two radial isomers interconvert by the usual trigonal
twist mechanism which is rapid on the NMR time scale
at room temperature. The structures and fluxional be-
havior of the two minor isomers are similar to those
observed for the¸¹PP¹h¹3¹¹a¹dd¹iºtion product of [(v-
H)Os3(CO)9(v3-p2-CꢀNCH2CH2CH2)] 12 which exists
as two isomers in solution (Scheme 6, 13a and 13b). The
structure of 13a was confirmed earlier by a single crystal
X-ray diffraction study [1].
It is of interest to note that in contrast to the two
isomeric PPh3 substituted derivatives 2 and 7 in which
the PPh3 ligand is at one of the two metal atoms bridged
by the hydride and the heterocyclic ligand and which
exist as two isomers in solution, cluster 10 exists as three
isomers (Scheme 5) in solution with the PPh3 substituted
at the rear metal atom.
The reaction of 9 with P(OMe)3 at 110°C in toluene
also yields the mono- and bis-substituted products [(v-
H)Os3(CO)9{v-1,2-p2-C9H5(CH3)N}{P(OMe)3}] 14 and
[(v-H)Os3(CO)8{v-1,2-p2-C9H5(CH3)N}{P(OMe)3}2] 15
in 40 and 46% yields, respectively. Both the compounds
1
were characterized by infrared, H-NMR and elemental
analysis together with X-ray diffraction study for 14.
The infrared spectrum of 14 is similar to that of 10 but
their 1H-NMR spectra in the hydride region are different
1
indicating that they have different structures. The H-
Although 10a has a different structure from those of
2 and 7, compound 11 is structurally similar to that of
8 [5]. The H-NMR spectrum of 11 at −40°C contains
NMR spectrum of 14 at 25°C exhibits a slightly broad-
ened singlet hydride resonance at l −14.12 which is
resolved into two sharp singlets at l −14.11 and
−14.14 with relative intensities 2:1 at −40°C. Two
doublets at l 3.66 and 3.56 in a 2:1 relative ratio are
observed which can be attributed to the methyl protons
of the P(OMe)3 ligand. Two singlets at l 2.44 and 2.46
in a 2:1 ratio due to the methyl protons of 4-methyl
quinoline are also observed. The 31P{1H}-NMR spec-
trum of 14 contains two singlets at l 104.1 and 103.2
with a relative intensity of 2:1. From the above spectro-
scopic data, we suggest that 14 exists as two radial
isomers (14a and 14b) in solution with the trimethyl
1
four doublets at l −13.50 (JP–H=13.5), −13.53 (JP–
H=13.4), −13.60 (JP–H=14.4) and −13.80 (JP–H
=
14.5 Hz) with relative intensities 1:3:1: 0.2 for hydrides
as well as four resonances at l 2.33, 2.28, 2.18 and 1.95
in similar relative integrated intensities for methyl pro-
tons indicating the presence of four isomers in solution.
As the temperature is increased to +25°C the doublet
resonances at l −13.50 and −13.53 average to a
doublet at l −13.51 while the doublets at l −13.60 and
−13.80 average to a broadened singlet at l −13.70.

M.B. Hursthouse et al. / Journal of Organometallic Chemistry 568 (1998) 133–142
137
Fig. 2. Solid state structure of [(v-H)Os3(CO)9{v-1,2-p2-C9H5(CH3)N}(PPh3)] 10 showing the atom labelling scheme. Thermal ellipsoids are drawn
at 50% probability level. The ring hydrogen atoms are omitted for clarity.
phosphite substituted at the rear metal atom. As men-
tioned above for the two minor isomers of 10, these two
isomers interconvert by the usual trigonal twist mecha-
nism on the NMR time scale at room temperature.
The identity of the compound 14 was unambiguosly
determined by a single crystal study. The molecular
structure of this compound is shown in Fig. 3 and
selected bond distances and angles are given in Table 2.
The structure consists of an osmium triangle with
three metal-metal bonds: Os(1)ꢁOs(3)=2.8653(6),
Os(2)ꢁOs(3)=2.8799(7) and Os(1)ꢁOs(2)=2.9282(6)
Os(1)ꢁOs(2) edge through the N(1) and C(13) atoms of
the heterocyclic moiety. The Os(1)ꢁOs(2) edge of the
cluster is also bridged by a hydride ligand on the
opposite side with respect to the organic ligand. The
bridged Os(1)ꢁOs(2) distance is longer than the two
˚
unbridged OsꢁOs edges (by ca. 0.015 A) but the aver-
˚
age value of 2.8726(6) A is not significantly different
˚
from the average value for the OsꢁOs bond [2.877(3) A]
in [Os3(CO)12] [7]. The presence of the bridging hydride
results in an opening of the Os(1)ꢁOs(2)ꢁC(7) and
Os(2)ꢁOs(1)ꢁC(1) angles [115.3(3) and 115.0(3)°, respec-
tively]. The Os(1)ꢁC(13)ꢁN(1)ꢁOs(2) bridge is nearly
perpendicular to the triangle of the osmium atoms with
a dihedral angle of 76.4(2)° between the two planes.
The hydride ligand which bridges the same OsꢁOs edge
as the quinoline ligand does not lie in the Os3 plane as
observed in 10; instead it makes a dihedral angle of 58°
with the latter. The OsꢁNꢁCꢁOs bridge in none of the
compounds 10 or 14 is exactly planar, but somewhat
twisted, as shown by the relevant OsꢁNꢁCꢁOs torsion
angles 5.6(1.1) in 10 and 5.4(9)° in 14. These deviations
from planarity with slight twists may be attributed to
˚
A, one of which is considerably longer than the other
two. As indicated by the spectroscopic data, the
trimethyl phosphite ligand is substituted at the rear
osmium atom Os(3) and occupies an equatorial site.
Os(3) is also coordinated to three terminal carbonyls,
one in an equatorial site and two in axial sites. The
˚
metal-phosphorus bond length, Os(3)ꢁP(1)=2.279(3) A
is somewhat shorter than that in 10, but comparable
with those observed for other phosphite complexes, e.g.
˚
[Os3(CO)10{P(OMe)3}2] (OsꢁPav=2.286 A) [10] and [(v-
˚
H)Os6(CO)20{P(OMe)3}2(v-PH2)] [OsꢁPav=2.276(9) A]
[11]. The 4-methylquinoline ligand bridges the longest

138
M.B. Hursthouse et al. / Journal of Organometallic Chemistry 568 (1998) 133–142
Table 1
˚
Selected bond lengths (A) and angles (°) for [(v-H)Os3(CO)9{v-1,2-
p2-C9H5(CH3)N}(PPh3)] 10
Os(1)ꢁOs(2)
Os(2)ꢁOs(3)
Os(1)ꢁC(2)
Os(1)ꢁN(1)
Os(2)ꢁC(4)
Os(2)ꢁC(10)
Os(3)ꢁC(7)
Os(3)ꢁP(1)
Os(3)ꢁH(23)
2.7744(9)
3.0442(10) Os(1)ꢁC(3)
1.90(2)
2.184(11)
1.95(2)
2.068(13)
1.929(13)
2.353(4)
1.84a
Os(1)ꢁOs(3)
2.8731(9)
1.88(2)
1.91(2)
1.86(2)
1.95(2)
1.88(2)
1.95(2)
1.75a
Os(1)ꢁC(1)
Os(2)ꢁC(5)
Os(2)ꢁC(6)
Os(3)ꢁC(9)
Os(3)ꢁC(8)
Os(2)ꢁH(23)
C(3)ꢁOs(1)–C(2)
C(2)ꢁOs(1)–C(1)
C(2)ꢁOs(1)–N(1)
C(3)ꢁOs(1)–Os(2)
C(1)ꢁOs(1)–Os(2)
C(3)ꢁOs(1)–Os(3)
C(1)ꢁOs(1)–Os(3)
92.8(7)
101.4(7)
91.6(6)
97.3(4)
154.6(5)
85.2(5)
91.7(5)
C(3)ꢁOs(1)ꢁC(1)
C(3)ꢁOs(1)ꢁN(1)
C(1)ꢁOs(1)ꢁN(1)
C(2)ꢁOs(1)ꢁOs(2)
N(1)ꢁOs(1)ꢁOs(2)
C(2)ꢁOs(1)ꢁOs(3)
N(1)ꢁOs(1)ꢁOs(3)
C(5)ꢁOs(2)ꢁC(4)
C(4)ꢁOs(2)ꢁC(6)
C(4)ꢁOs(2)ꢁC(10)
C(5)ꢁOs(2)ꢁOs(1)
C(6)ꢁOs(2)ꢁOs(1)
C(5)ꢁOs(2)ꢁOs(3)
C(6)ꢁOs(2)ꢁOs(3)
Os(1)ꢁOs(2)ꢁOs(3)
C(9)ꢁOs(3)ꢁC(8)
C(9)ꢁOs(3)ꢁP(1)
C(8)ꢁOs(3)ꢁP(1)
C(7)ꢁOs(3)ꢁOs(1)
P(1)ꢁOs(3)ꢁOs(1)
C(7)ꢁOs(3)ꢁOs(2)
P(1)ꢁOs(3)ꢁOs(2)
Os(2)ꢁH(23)ꢁOs(3)
90.7(6)
166.6(5)
100.8(6)
102.2(5)
69.4(3)
166.8(5)
87.6(3)
91.1(6)
96.2(7)
170.2(6)
88.3(5)
162.7(6)
147.1(5)
114.3(5)
58.96(2)
89.6(6)
94.2(5)
93.8(5)
81.3(4)
167.90(8)
94.8(4)
117.25(8)
116a
Os(2)ꢁOs(1)–Os(3) 65.21(3)
C(5)ꢁOs(2)ꢁC(6)
C(5)ꢁOs(2)ꢁC(10)
C(6)ꢁOs(2)ꢁC(10)
C(4)ꢁOs(2)ꢁOs(1)
C(10)ꢁOs(2)ꢁOs(1)
C(4)ꢁOs(2)ꢁOs(3)
C(10)ꢁOs(2)ꢁOs(3)
C(9)ꢁOs(3)ꢁC(7)
C(7)ꢁOs(3)ꢁC(8)
C(7)ꢁOs(3)ꢁP(1)
C(9)ꢁOs(3)ꢁOs(1)
C(8)ꢁOs(3)ꢁOs(1)
C(9)ꢁOs(3)ꢁOs(2)
C(8)ꢁOs(3)ꢁOs(2)
Os(1)ꢁOs(3)ꢁOs(2)
97.9(7)
88.1(6)
93.6(7)
99.9(4)
70.4(4)
91.8(4)
83.7(4)
86.3(6)
174.7(6)
89.9(4)
93.5(5)
95.6(4)
148.6(5)
86.9(4)
55.83(2)
Scheme 7.
isomers of 10 become the major isomers in the case of
14, the major isomer of 10 does not have its counter-
part in detectable amount in the case of 14, illustrating
a The parameters involving the bridging hydride H(23) are only
approximate and should be treated with caution.
the tendency to relieve strain associated with the bridge
formation. The two NꢁC bonds in the methylquinoline
ring show the same trend as observed in 10, i.e. the
˚
bridging NꢁC bond [1.309(12) A] is significantly shorter
˚
than the other NꢁC bond [1.438(12) A], the former
retaining most of its double bond character. In 14, the
OsꢁN and OsꢁC(bridge) bonds [2.141(9) and 2.101(10)
˚
A], respectively, are slightly shorter and longer than the
˚
corresponding values [2.184(11) and 2.068(13) A] in 10.
The remaining molecular dimensions are as expected.
It may be noted here that not only do the minor
Fig. 3. Solid state structure of [(v-H)Os3(CO)9{v-1,2-p2-
C9H5(CH3)N}{P(OMe)3}] 14 showing the atom labelling scheme.
Thermal ellipsoids are drawn at 50% probability level. The ring
hydrogen atoms are omitted for clarity.
Scheme 6.

M.B. Hursthouse et al. / Journal of Organometallic Chemistry 568 (1998) 133–142
139
Table 2
two isomeric bis-phosphite substituted products to
structures 15a and 15b.
The significance of this work is the demonstration
that changes in the structure of the heterocyclic ligands
as well as the steric bulk of the phosphine ligands have
important impact on the structures of the substituted
products and their isomers distribution.
˚
Selected bond lengths (A) and angles (°) for [(v-H)Os3(CO)9{v-1,2-
p2-C9H5(CH3)N}{P(OMe)3}] 14
Os(1)ꢁOs(3)
Os(2)ꢁOs(3)
Os(1)ꢁC(1)
Os(1)ꢁC(13)
Os(2)ꢁC(7)
Os(2)ꢁN(1)
Os(3)ꢁC(4)
Os(3)ꢁP(1)
Os(2)ꢁH(21)
2.8653(6)
2.8799(7)
1.902(12)
2.101(10)
1.887(13)
2.141(9)
1.902(13)
2.279(3)
1.68a
Os(1)ꢁOs(2)
Os(1)ꢁC(2)
Os(1)ꢁC(3)
Os(2)ꢁC(8)
Os(2)ꢁC(9)
Os(3)ꢁC(5)
Os(3)ꢁC(6)
Os(1)ꢁH(21)
2.9282(6)
1.864(12)
1.976(12)
1.880(12)
1.887(13)
1.896(11)
1.922(12)
1.64a
C(2)ꢁOs(1)ꢁC(1)
C(1)ꢁOs(1)ꢁC(3)
C(1)ꢁOs(1)ꢁC(13)
C(2)ꢁOs(1)ꢁOs(3)
C(3)ꢁOs(1)ꢁOs(3)
C(2)ꢁOs(1)ꢁOs(2)
C(3)ꢁOs(1)ꢁOs(2)
Os(3)ꢁOs(1)ꢁOs(2)
C(8)ꢁOs(2)ꢁC(9)
C(8)ꢁOs(2)ꢁN(1)
C(9)ꢁOs(2)ꢁN(1)
C(7)ꢁOs(2)ꢁOs(3)
N(1)ꢁOs(2)ꢁOs(3)
C(7)ꢁOs(2)ꢁOs(1)
N(1)ꢁOs(2)ꢁOs(1)
99.2(5)
94.1(4)
86.7(4)
84.4(3)
90.5(3)
136.3(3)
110.7(3)
59.60(2)
90.3(4)
93.7(4)
175.5(4)
173.0(3)
90.5(2)
115.3(3)
67.7(2)
C(2)ꢁOs(1)ꢁC(3)
C(2)ꢁOs(1)ꢁC(13)
C(3)ꢁOs(1)ꢁC(13)
C(1)ꢁOs(1)ꢁOs(3)
C(13)ꢁOs(1)ꢁOs(3)
C(1)ꢁOs(1)ꢁOs(2)
C(13)ꢁOs(1)ꢁOs(2)
C(8)ꢁOs(2)ꢁC(7)
C(7)ꢁOs(2)ꢁC(9)
C(7)ꢁOs(2)ꢁN(1)
C(8)ꢁOs(2)ꢁOs(3)
C(9)ꢁOs(2)ꢁOs(3)
C(8)ꢁOs(2)ꢁOs(1)
C(9)ꢁOs(2)ꢁOs(1)
Os(3)ꢁOs(2)ꢁOs(1)
92.2(4)
89.6(4)
178.0(4)
174.0(3)
88.6(3)
115.0(3)
67.3(3)
98.4(5)
90.6(5)
90.8(4)
88.3(3)
87.6(4)
140.9(3)
107.8(3)
59.113(14)
C(5)ꢁOs(3)ꢁC(4)
C(4)ꢁOs(3)ꢁC(6)
C(4)ꢁOs(3)ꢁP(1)
C(5)ꢁOs(3)ꢁOs(1)
C(6)ꢁOs(3)ꢁOs(1)
C(5)ꢁOs(3)ꢁOs(2)
C(6)ꢁOs(3)ꢁOs(2)
Os(1)ꢁOs(3)ꢁOs(2)
93.4(5)
93.0(5)
95.5(3)
86.2(3)
88.5(3)
88.0(3)
84.8(3)
61.29(2)
C(5)ꢁOs(3)ꢁC(6)
C(5)ꢁOs(3)ꢁP(1)
C(6)ꢁOs(3)ꢁP(1)
C(4)ꢁOs(3)ꢁOs(1)
P(1)ꢁOs(3)ꢁOs(1)
C(4)ꢁOs(3)ꢁOs(2)
P(1)ꢁOs(3)ꢁOs(2)
Os(1)ꢁH(21)ꢁOs(2)
172.5(5)
90.6(3)
92.6(3)
103.5(3)
160.83(8)
164.6(3)
99.75(8)
124a
a
The parameters involving the bridging hydride H(21) are only
approximate and should be treated with caution.
the sensitivity of isomer distribution to the steric bulk
of the phosphine ligand.
We were unable to obtain X-ray quality crystals of
15; therefore, its structural assignment is based on
spectroscopic data and elemental analysis. The 1H-
NMR spectrum of 15 at −40°C (Fig. 4) shows two
doublets of doublets in an approximate 1:1 ratio at l
−14.38 (J=11.5, 2.2 Hz) and −14.29 (J=11.4, 1.8
Hz) indicating the presence of two isomers in solution
which is in sharp contrast to 11. As the temperature is
increased the hydride resonances are broadened and
averaged to a doublet at l −14.33 (J=11.5 Hz) at
25°C. The hydride signals appear as doublets of dou-
blets because of three-bond phosphorus–hydride cou-
plings. There are numerous examples in the literature
for the observation of small (1–3 Hz) phospho-
rusꢁhydride three bond couplings in metal clusters
[1,12]a, [12]b–c. Based on the crystal structure of 8 and
the solution dynamics of 8 and 11, we can assign these
Fig. 4. Variable temperature 1H-NMR spectra of [(v-H)Os3(CO)8{v-
1,2-p2-C9H5(CH3)N}{P(OMe)3}2] 15 in the hydride region.

140
M.B. Hursthouse et al. / Journal of Organometallic Chemistry 568 (1998) 133–142
3.2. Reaction of 9 with P(OMe)3
3. Experimental
P(OMe)3 (27 ml, 0.226 mmol) was added to a toluene
solution (25 ml) of 9 (0.075 g, 0.075 mmol). The
resulting solution was heated to reflux for 7 h. All the
volatiles were removed in vacuo. Chromatographic sep-
aration of the residue by TLC on silica gel eluting with
hexane/CH2Cl2 (5:1, v/v) resolved three bands. The
faster moving band afforded unreacted 9 (0.005 g) while
the second band gave [(v-H)Os3(CO)9{v-1,2-p2-
C9H5(CH3)N}{P(OMe)3}] 14 (0.033 g, 40%) as yellow
crystals after recrystallization from hexane/CH2Cl2 at
−20°C. (Anal. Found: C, 24.52; H, 1.85; N, 1.35.
C22H18NO12Os3P. Calc.: C, 24.24; H, 1.66; N, 1.29%).
IR(wCO, CH2Cl2): 2080m, 2049vs, 2023s, 1997vs,
Although the reaction products are air stable, all the
reactions were performed under an atmosphere of pre-
purified nitrogen. The solvents were distilled according
to the standard procedure immediately before use. IR
spectra were recorded on a Perkin-Elmer 1420 spec-
trophotometer. 1H-and 31P{1H}-NMR spectra were
recorded on Bruker AC 200 spectrometer. Chemical
shifts for the 31P{1H}-spectra are relative to 85%
H3PO4. Elemental analyses were performed in the mi-
croanalytical laboratory, Institut fu¨r Anorganische und
Analytische Chemie, Universita¨t Freiburg. The starting
cluster 9 was prepared according to the published pro-
cedure ([13]a,b). Triphenylphosphine and trimethyl
phosphite were purchased from Aldrich and used as
received.
1
1975s, 1960sh cm−1. H-NMR (CD2Cl2, −40°C): mix-
ture of two isomers, major isomer, l 7.81 (m, 3H), 7.41
(m, 2H), 3.66 (d, 9H, JP–H=12.1 Hz), 2.44 (s, 3H),
−14.11 (s, 1H); minor isomer, l 7.81 (m, 3H), 7.41 (m,
2H), 3.56 (d, 9H, JP–H=12.4 Hz), 2.34 (s, 3H), −14.14
(s, 1H). 31P{1H}-NMR(CD2Cl2): major isomer, l 104.1
(s), minor isomer, 103.2 (s). The third band yielded
[(v-H)Os3(CO)8{v-1,2-p2-C9H5(CH3)N}{P(OMe)3}2] 15
(0.041 g, 46%) as orange crystals after recrystallization
from hexane/CH2Cl2 at −20°C. Anal. Found: C,
24.45; H, 2.34; N, 1.20. C24H27NO14Os3P2. Calc.: C,
24.30; H, 2.29; N, 1.18%). IR (wCO, CH2Cl2): 2062s,
3.1. Reaction of 9 with PPh3
To a toluene solution (30 ml) of compound 9 (0.105
g, 0.106 mmol) in a flame-dried Schlenk flask was
added PPh3 (0.059 g, 0.225 mmol) and the reaction
mixture was heated to reflux for 8 h. The solvent was
removed in vacuo and the residue was chro-
matographed by TLC plates eluting with hexane/
CH2Cl2 (10:3, v/v) to give three bands. The faster
moving band gave unreacted 9 (0.008 g). The second
band gave [(v-H)Os3(CO)9{v-1,2-p2-C9H5(CH3)N}-
(PPh3)] 10 (0.039 g, 30%) as yellow crystals after recrys-
tallization from hexane/CH2Cl2 at −20°C. (Anal.
Found: C, 36.32; H, 1.99; N, 1.13. C37H24NO9Os3P.
Calc.: C, 36.18; H, 1.97; N, 1.14%). IR(wCO, CH2Cl2):
2081sh, 2077m, 2047vs, 2018vs, 1998vs, 1974m, 1957m,
2025vs, 1996s, 1983vs, 1965sh, 1957s, 1939w cm−1
1H-NMR (CD2Cl2): mixture of two isomers; l 7.74(m,
3H), 7.37(m, 1H), 7.25 (m, 1H), 3.51 (d, 9H, JP–H
;
=
11.6 Hz), 3.42 (d, 9H, JP–H=11.5 Hz), 2.42 (s, 3H),
2.40 (s, 3H), −14.38 (dd, 1H, JP–H=11.5, 2.2 Hz),
−14.29(dd, 1H, JP–H=11.4, 1.8 Hz).
1
1938m cm−1. H-NMR (CD2Cl2, −40°C): mixture of
3.3. X-ray crystallography
three isomers, l 7.77–6.39 (m, 20 H), 2.56 (s, 3H), 2.41
(s, 3H), 2.45 (s, 3H), −13.75 (s, 1H), −13.87 (s, 1H),
−15.84 (d, 1H, JP–H=14.7 Hz). The phenyl protons
resonances of PPh3 and the ring protons resonances of
4-methylquinoline of 10 are overlapped. The third band
afforded [(v-H)Os3(CO)8{v-1,2-p2-C9H5(CH3)N}(PP-
h3)2] 11 (0.065 g, 42%) as orange crystals after recry-
stallization from hexane/CH2Cl2 at −20°C. (Anal.
Found: C, 43.88; H, 2.79; N, 1.00. C54H39NO8Os3P2.
Calc.: C, 44.35; H, 2.69; N, 0.96%). IR(wCO, CH2Cl2):
Crystals of the complexes 10 and 14 were obtained as
described above. All measurements were made using a
Delft Instruments FAST TV area detector diffractome-
ter positioned at the window of a rotating anode (Mo)
generator, in a manner described previously [14]. In
both cases the unit cell parameters were obtained by
least-squares refinement of the diffractometer angles for
250 reflections. The crystallographic data, and the data
collection and refinement details for the compounds are
presented in Table 3.
2058m, 2017vs, 1988s, 1976s, 1947s cm−1 1H-NMR
;
(CD2Cl2, −40°C): l 7.09–7.55 (m, 35H), 2.33 (s, 3H),
2.28 (s, 3H), 2.18 (s, 3H), 1.95 (s, 3H), -13.50 (d,
1H, JP–H=13.5 Hz), −13.53 (d, 1H, JP–H=13.4 Hz),
−13.60 (d, 1H, JP–H=14.4 Hz), −13.80 (d, 1H,
Both data sets were corrected for absorption using
DIFABS [15]. The structures were solved by direct
methods (SHELXS-86) [16], developed via difference
syntheses, and refined on F2 by full-matrix least-squares
(SHELXL-93) [17] using all unique data with intensities
greater than 0. In both cases the non-hydrogen atoms
were anisotropic, and the hydrogen atoms belonging to
the quinoline and phenyl rings included in calculated
JP–H=14.5 Hz). The signals due to the phenyl pro-
tons of the PPh3 ligands and the ring protons of
the 4-methylquinoline for these isomers are over-
lapped.

M.B. Hursthouse et al. / Journal of Organometallic Chemistry 568 (1998) 133–142
141
Table 3
deposited at the Cambridge Crystallographic Data Cen-
tre (CCDC). Any request to the CCDC for this mate-
rial should quote the full literature citation.
Crystal data and details of data collection and structure refinement
for [(v-H)Os3(CO)9{v-1,2-p2-C9H5(CH3)N}(L)] (L=PPh3 10 or
P(OMe)3 14)a
10
14
Table 4
Atomic coordinates (×104) and equivalent isotropic displacement
Empirical formula
Formula weight
Crystal system
Space group
C37H24NO9Os3P
1228.14
Triclinic
C
22H18NO12Os3P
2
3
2
˚
1089.94
Monoclinic
P21/c (no. 14)
14.158(2)
16.649(2)
11.994(2)
90
105.219(8)
90
2728.2(7)
4
parameters (A ×10 ) for [(v-H)Os3(CO)9{v-1,2-p -C9H5(CH3)N}-
(PPh3)] 10
(
P1 (no. 2)
˚
Uaeq
a (A)
9.977(2)
13.359(2)
13.432(2)
81.66(2)
85.41(2)
82.091(11)
1751.3(5)
2
x
y
z
˚
b (A)
˚
c (A)
Os(1)
Os(2)
Os(3)
P(1)
O(1)
O(2)
O(3)
O(4)
O(5)
O(6)
O(7)
O(8)
O(9)
N(1)
C(1)
C(2)
C(3)
C(4)
3880.0(6)
1498.5(6)
3389.1(6)
2563(3)
6244(12)
3960(14)
5761(10)
2582(12)
1083(13)
−1409(12)
2604(11)
4498(11)
6149(10)
2157(12)
5336(18)
3909(17)
5065(15)
2193(15)
1210(17)
−336(22)
2851(13)
4091(14)
5106(15)
1096(15)
−162(14)
−257(15)
898(14)
2306.7(4)
1514.8(4)
2060.1(4)
2088(2)
3510(9)
2202(9)
340(8)
−785(8)
1337(10)
1301(10)
4381(7)
−228(8)
2634(9)
3510(8)
3084(11)
2255(11)
1081(11)
72(13)
1390(12)
1380(14)
3511(10)
617(12)
2386(12)
3079(10)
3741(10)
4781(11)
5216(10)
6282(12)
6667(13)
6045(13)
4963(13)
4564(10)
5448(13)
2695(6)
3738(5)
4234(5)
3686(6)
2642(6)
2147(5)
877(5)
4105.6(4)
3915.2(4)
2081.9(4)
485(3)
3368(9)
6368(9)
4015(8)
4068(10)
6182(9)
3449(10)
1884(8)
2220(9)
22(1)
21(1)
15(1)
14(1)
45(3)
49(3)
35(3)
45(3)
53(3)
50(3)
32(3)
33(3)
42(3)
20(3)
30(4)
32(4)
25(3)
27(4)
34(4)
48(5)
17(3)
25(4)
28(4)
22(3)
19(3)
27(4)
21(3)
41(5)
42(5)
37(4)
38(4)
30(4)
38(4)
19(3)
21(3)
32(4)
29(4)
25(4)
24(3)
16(3)
22(3)
30(4)
32(4)
30(4)
26(4)
16(3)
20(3)
24(3)
19(3)
23(3)
19(3)
h (°)
i (°)
k (°)
3
˚
V (A )
Z
Dcalc. (Mg m−3
)
2.329
10.959
2.654
14.058
Absorption coefficient
(mm−1
F(000)
Crystal size (mm)
)
1136
0.32×0.22×0.07
1984
0.12×0.08×0.06
1.93–24.99
Theta range for data col- 2.03–24.86
lection (°)
hmin, hmmax; kmin, kmax
lmin, lmax
Reflections collected
Independent reflections
Rint
1294(10)
4043(8)
;
−11, 10; −15,
15; −15, 11
7351
4822
0.0955
−15, 9; −19, 19;
−11, 12
8890
3982
0.0772
3641(12)
5526(12)
4092(11)
3985(11)
5310(13)
3596(14)
2005(10)
2202(11)
1560(12)
3885(11)
3651(10)
3573(11)
3795(11)
3759(13)
4042(14)
4301(13)
4321(12)
4084(12)
3260(13)
−476(6)
−784(7)
Absorption correction
factors
0.723–0.998
0.789–1.191
C(5)
C(6)
C(7)
C(8)
Data/restraints/parame-
ters
4822/36/425
3982/18/356
Goodness-of-fit on F2
1.066
0.859
0.0455/0.0661
0.0312/0.0642
C(9)
R1/wR2 (all unique data) 0.0647/0.1418
R1/wR2 [data with I\
2|(I)]
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(111)
C(112)
C(113)
C(114)
C(115)
C(116)
C(121)
C(122)
C(123)
C(124)
C(125)
C(126)
C(131)
C(132)
C(133)
C(134)
C(135)
C(136)
0.0581/0.1397
Largest diff. peak and
2.111 and −2.340 2.117 and −1.253
−3
˚
hole (e A
)
887(19)
2029(19)
3122(19)
3204(19)
2080(18)
−1576(15)
3687(8)
3424(7)
4351(9)
5541(8)
5804(7)
4877(8)
2309(8)
1770(9)
1459(9)
1687(9)
2226(9)
2537(9)
876(6)
a Details in common: Mo–Kh radiation, u=0.71069 A, T=150(2)
K, cell dimensions from 250 reflections, full-matrix least-squares on
F2; R1 and wR2 as defined in [17]; weighting scheme, w=1/[|2(F2o)+
(a*P)2], where P=[max(Fo2)+2F2c)]/3 and a=0.0861 for 10 and
0.0109 for 14.
˚
−1436(7)
−1781(7)
−1474(7)
−822(7)
82(6)
positions (riding model). The bridging hydrides [H(23)
in 10 and H(21) in 14] were located from difference
maps but not refined. Several atoms [C(2), C(5) and
C(15) in 10, and C(3), O(2), O(4), O(5), O(6) and O(8)
in 14] were refined with the restraints ISOR=0.005 and
0.01, respectively, to keep the displacement coefficients
of these atoms ‘approximately isotropic’. Final R-val-
ues are given in Table 3. Sources of scattering factors
are as in [17]. The molecular diagrams were drawn
using SNOOPI [18]. Fractional atomic co-ordinates are
given in Tables 4 and 5.
159(6)
802(5)
525(7)
−741(6)
−924(5)
−207(7)
694(6)
2833(6)
2981(6)
3508(6)
3887(6)
3739(7)
3212(6)
−471(8)
−1190(6)
−914(6)
262(6)
−701(5)
−877(5)
−90(6)
874(6)
405(8)
−874(8)
−1682(6)
−1211(7)
67(8)
1050(5)
a Ueq is defined as one third of the trace of the orthogonalized Uij
tensor.
Full crystallographic details including thermal
parameters and bond lengths and angles have been

142
M.B. Hursthouse et al. / Journal of Organometallic Chemistry 568 (1998) 133–142
Table 5
Alexander von Humboldt Foundation for a fellowship
and Royal Society of Chemistry for partial support.
MBH and KMAM acknowledge the EPSRC for sup-
port of the X-ray facilities at Cardiff.
Atomic coordinates (×104) and equivalent isotropic displacement
2
3
2
˚
parameters (A ×10 ) for [(v-H)Os3(CO)9{v-1,2-p -C9H5(CH3)N}-
{P(OMe)3}] 14
x
y
z
Uaeq
References
Os(1)
Os(2)
Os(3)
P(1)
O(1)
O(2)
O(3)
O(4)
O(5)
O(6)
O(7)
O(8)
O(9)
O(10)
O(11)
O(12)
N(1)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
2119.2(3)
1099.2(2)
−549.6(2)
−221.1(2)
−1490(2)
2383(4)
1944(5)
1791(4)
589(5)
1(4)
−460(4)
−761(5)
−2241(4)
−1120(5)
−2029(4)
−2027(4)
−1592(4)
−78(5)
1899(7)
1616(6)
1497(6)
277(6)
2056.8(4)
1810.3(4)
2029.3(4)
1841(2)
2217(7)
3413(6)
14(1)
14(1)
14(1)
18(1)
38(2)
39(2)
30(2)
39(2)
31(2)
27(2)
31(2)
35(2)
33(2)
24(2)
23(2)
30(2)
16(2)
24(3)
22(3)
23(3)
25(3)
14(2)
17(3)
19(3)
28(3)
22(3)
40(4)
51(4)
40(4)
16(3)
24(3)
23(3)
17(3)
24(3)
22(3)
29(3)
18(3)
17(3)
32(3)
1373.3(3)
3411.0(3)
3952(2)
646(7)
[1] M. Day, D. Espitia, K.I. Hardcastle, S.E. Kabir, E. Rosenberg,
R. Gobetto, L. Milone, D. Osella, Organometallics 10 (1991)
3550.
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house, K.M.A. Malik, N.P.C. Walker, J. Chem. Soc. Dalton
Trans. (1987) 1869. (b) A.J. Deeming, K.I. Hardcastle, S.E.
Kabir, J. Chem. Soc., Dalton Trans. (1988) 827. (c) W.G.
Feighery, R.D. Allendoerfer, J.B. Keister, Organometallics 9
(1990) 2424.
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Skelton, A.H. White, J. Organomet. Chem. 347 (1988) 181.
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Chem. Soc. Dalton Trans. (1996) 755.
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Lewis P.R. Raithby, J. Chem. Soc., Dalton Trans. (1989) 2023.
(b) C. Jangala, E. Rosenberg, D. Shinner, S. Aime, L. Milone, E.
Sappa, Inorg. Chem. 19 (1980) 1571. (c) E.J. Ditzel, B.F.G.
Johnson, J. Lewis, J. Chem. Soc. Dalton Trans. (1987) 1289.
[13] (a) S.E. Kabir, D.S. Kolware, E. Rosenberg, K.I. Hardcastle, W.
Creasswell, J. Grindstaff, Organometallics 14 (1995) 3613. (b) A.
Eisenstadt, C.M. Giandomenico, M.F. Frederick, R.M. Laine,
Organometallics 4 (1985) 2033.
3970(7)
2473(6)
5400(6)
2922(6)
3684(6)
−830(7)
1951(6)
1201(6)
3144(6)
4295(5)
4893(6)
1504(6)
1180(9)
3247(9)
2308(9)
4656(10)
3089(8)
3557(8)
6(10)
1732(9)
1280(8)
3306(9)
5192(10)
4949(10)
1895(8)
2136(9)
2022(8)
1529(8)
1305(8)
823(8)
−202(6)
2385(7)
−591(6)
4638(7)
1348(7)
2726(7)
−636(6)
1045(6)
2960(6)
1376(7)
3505(7)
2135(9)
2906(9)
578(10)
2261(9)
404(9)
3658(11)
1558(9)
2349(10)
282(10)
833(11)
3759(11)
306(11)
3599(9)
4690(9)
5656(10)
5544(9)
6505(10)
6342(10)
5302(10)
4330(9)
4449(9)
6836(9)
−79(6)
−353(6)
−650(6)
−1595(7)
−883(6)
−2882(6)
−1853(7)
−1230(7)
640(6)
1051(7)
715(6)
−44(6)
−448(6)
−1152(6)
−1493(6)
−1159(6)
−426(6)
1125(7)
543(9)
754(8)
1264(8)
2323(9)
a Ueq is defined as one third of the trace of the orthogonalized Uij
tensor.
[14] J.A. Darr, S.R. Drake, M.B. Hursthouse, K.M.A. Malik, Inorg.
Chem. 32 (1993) 5704.
[15] N.P.C. Walker, D. Stuart, Acta Crystallogr. Sect. A 39 (1983)
158; adapted for FAST geometry by A.I. Karaulov, University
of Wales, 1991.
[16] G.M. Sheldrick, Acta Crystallogr. Sect. A 46 (1990) 467.
[17] G.M. Sheldrick, SHELXL93 program for crystal structure refin-
ement, University of Go¨ttingen, 1993.
Acknowledgements
This work was supported by the Fonds der Chemis-
chen Industrie and by the Commission for the Eu-
ropean Communities. SEK gratefully acknowledges the
[18] K. Davies, SNOOPI program for crystal structure drawing,
University of Oxford, 1983.
.