Synthesis and reactivity studies of cyclopentadienyl bis(triphenylphosphine)osmium(II) complexes. Crystal and molecular structure of [CpOs(PPh3)(phen)]BF4

Article abstract of DOI:10.1016/S0277-5387(03)00132-3

Reaction of [CpOs(PPh₃)₂Br] (1) with acetonitrile ligand or monodentate anions yielded complexes of the type [CpOs(PPh₃)₂(CH₃CN)⁺ (2), [CpOs(PPh₃)₂X], X = CN (3) and N

Full text of DOI:10.1016/S0277-5387(03)00132-3

Polyhedron 22 (2003) 1391ꢂ1395
/
www.elsevier.com/locate/poly
Synthesis and reactivity studies of cyclopentadienyl
bis(triphenylphosphine)osmium(II) complexes. Crystal and molecular
structure of [CpOs(PPh3)(phen)]BF4
R. Lalrempuia a, Patrick J. Carroll a,b, Mohan Rao Kollipara a,*
a Department of Chemistry, North Eastern Hill University, Shillong 793 022, India
b Department of Chemistry, University of Pennsylvania, 3301 Spruce Stree, Philadelphia, PA 19104-6323, USA
Received 6 November 2002; accepted 20 February 2003
Abstract
Reaction of [CpOs(PPh3)2Br] (1) with acetonitrile ligand or monodentate anions yielded complexes of the type
[CpOs(PPh3)2(CH3CN)]ꢀ (2), [CpOs(PPh3)2X], Xꢁ
NH4BF4 yielded the dicationic complex [CpOs(PPh3)2(NO)](BF4)2 (5). Reactions of the complex [CpOs(PPh3)2(CH3CN)]BF4 (2)
/
CN (3) and NCS (4). Treatment of 1 with NaNO2ꢂ/HCl in the presence of
with chelating ligands L2 yielded cationic complexes of the type [CpOs(L2)(PPh3)]BF4, where L2ꢁ2,2?-bipyridine (bipy) (6), 1,10-
/
1
phenanthroline (phen) (7). These compounds were characterized by H NMR, 31P NMR and IR spectral data. The X-ray crystal
structure of the complex [CpOs(PPh3)(phen)]BF4 has been determined.
# 2003 Elsevier Science Ltd. All rights reserved.
Keywords: Cyclopentadienyl; Osmium; Chelating ligands; Bipyridine; Phenanthroline
1. Introduction
two triphenylphosphines by chelating diphos ligands
takes place readily in boiling benzene or toluene,
whereas the same reaction requires boiling decaline for
several hours in case of its osmium analogue [3]. But it
Cyclopentadienyl ruthenium half sandwich complexes
are the most extensively studied class of cyclopentadie-
nyl chemistry among the transition metal complexes.
The spectrum of reactivity and chemical properties to
date for this system is remarkable, especially considering
the limited number of synthetic precursors, viz.
[CpRu(PPh3)2Cl] and [CpRu(CO)2Cl] [1]. Recently,
more convenient routes have been developed by use of
easily exchangeable ligands [2]. However, not much
work has been carried out in the case [CpOs(PPh3)2Br],
which could be due to lower kinetic lability of the
phosphines compared to its ruthenium analogue. For
instance, in the case of ruthenium, the substitution of
was observed that the dissociation of the MꢂX bond
/
takes place readily in polar solvents such as methanol
for both cases [4].
We recently reported the reactions of [(h5-
and
C5Me5)Ru(PPh3)2(CH3CN)]ꢀ
[(h5-C9H7)Ru-
(PPh3)2(CH3CN)]ꢀ with bipy and phen and presented
their results [5]. In this paper, we would like to report a
few substitution reactions at Osꢂ
/
Br and OsꢂP bonds. In
/
methanol, bromide was replaced by other anions to give
neutral complexes of the type [CpOs(PPh3)2X] and in
acetonitrile, the cationic complex [CpOs(PPh3)2-
(NCCH3)]ꢀ was isolated. Reaction of [CpOs(PPh3)2-
(NCCH3)]BF4 with chelating ligands L2 by refluxing in
toluene followed by methanol yielded cationic com-
* Corresponding author. Tel.: ꢀ
2550-486.
E-mail addresses:
kmrao@nehu.ac.in (M.R. Kollipara).
/
91-364-2550-041; fax: ꢀ91-364-
/
plexes [CpOs(L2)(PPh3)]BF4, where L2ꢁbipy and phen.
/
The molecular structure of [CpOs(PPh3)(phen)]BF4 has
been solved by X-ray crystallography.
carrollp@sas.upenn.edu (P.J. Carroll),
0277-5387/03/$ - see front matter # 2003 Elsevier Science Ltd. All rights reserved.
doi:10.1016/S0277-5387(03)00132-3

1392
R. Lalrempuia et al. / Polyhedron 22 (2003) 1391ꢂ1395
/
2. Experimental
2.4. Preparation of [CpOs(PPh3)2(NCS)] (4)
All solvents were dried and distilled by standard
methods. All chemicals were obtained from commercial
sources. Infrared spectra were recorded as KBr pellets
This complex was prepared in a similar manner to
that of complex 3. Here KSCN was used instead of
KCN. The compound is yellow in color.
(CsI for complex 5) using a Perkinꢂ
/
Elmer model-983
Yield: 60 mg, 64%. Anal. Found: C, 59.99; H, 4.16; N,
1.59. Calc. for C42H35NP2SOs: C, 60.20; H, 4.21; N,
1.67%. IR (KBr, nNCS): 2108 (s).
1
spectrophotometer. H NMR spectra were recorded on
a Bruker ACF 300 spectrometer and referenced to
external tetramethylsilane. 31P {1H} NMR chemical
shifts are recorded relative to H3PO4 (85%). Elemental
analyses were performed by the Regional Sophisticated
Instrumentation Centre (RSIC), NEHU, Shillong.
2.5. Preparation of [CpOs(PPh3)2(NO)](BF4)2 (5)
The mixture of [CpOs(PPh3)2Br] (100 mg, 0.116
mmol) and 1 ml HCl was refluxed in EtOH (30 ml)
for 1 h. Then NaNO2 (168 mg, 2.434 mmol) in water (1
ml) was added, the whole mixture turns into a homo-
geneous yellowish clear solution which was filtered while
hot. NH4BF4 (aq) was added to the filtrate which was
then left overnight resulting in the formation of a yellow
precipitate that was collected by centrifuge.
2.1. Preparation of [CpOs(PPh3)2Br] (1)
This compound was prepared by following a litera-
ture procedure [6].
1H NMR (CDCl3, d): 7.25 (m, 30H, Ph), 4.31 (s, 5H,
C5H5). 31P{1H} NMR (CDCl3, d): ꢃ
/
3.85 (s).
Yieldꢁ
/
60 mg, 52.6%. Anal. Found: C, 49.98; H,
3.00; N, 1.45. Calc. for C41H35B2F8NOP2Os: C, 50.07;
1
H, 3.07; N, 1.42%. H NMR (CDCl3, d): 7.51ꢂ
/
7.05 (m,
2.2. Preparation of [CpOs(PPh3)2(CH3CN)]BF4 (2)
30H, Ph), 6.23 (s, 5H, Cp). 31P{1H} NMR (d): ꢃ
(s). IR (CsI): 1845 (s, nNO), 1062 (s, br,nBF).
/2.06
A mixture of [CpOs(PPh3)2Br] (100 mg, 0.116 mmol)
and NH4BF4 (25 mg, 0.24 mmol) was refluxed in
acetonitrile (20 ml) under nitrogen atmosphere. The
insoluble starting material slowly dissolved and the
color changed to very pale yellow solution after 1 h.
The solvent was then evaporated under reduced pres-
sure. The residue was extracted with acetone, filtered
and the volume of the filtrate was reduced. Subsequent
addition of hexane yielded a cream colored product. The
2.6. Preparation of [CpOs(PPh3)(bipy)]BF4 (6)
A mixture of [CpOs(PPh3)2(CH3CN)]BF4 (100 mg,
0.110 mmol) and 2,2?-bipyridine (55 mg, 0.354 mmol)
was refluxed in toluene (30 ml) for 12 h and the solvent
was removed in a rotary evaporator to dryness. Then
methanol (30 ml) was added, the solution turned a deep
red color and was refluxed for 10 h. Methanol was
removed in a rotary evaporator under reduced pressure.
The residue was dissolved in dichloromethane and
loaded onto a silica gel column (hexane) where 20 ml
of dichloromethane was first run to this column. The red
band of the compound was eluted with a mixture of
CH2Cl2 and methanol (3:1). The solution was evapo-
compound recrystallised from dichloromethaneꢂ
/diethy-
lether giving grey needle shaped crystals.
Yield: 86 mg, 82%. Anal. Found: C, 56.88; H, 4.20; N,
1.56. Calc. for C43H38BF4NP2Os: C, 56.89; H, 4.21; N,
1
1.54%. H NMR (CDCl3, d): 7.34ꢂ
/
7.01 (m, 30 H, Ph),
4.66 (s, 5H, Cp), 2.41 (s, 3H, CH3). 31P{1H} NMR (d):
2.11 (s). IR (KBr): 2282 (m, nCN), 1082 (s, br, nBF).
rated to dryness, dissolved in acetone (ꢀ1 ml) and
/
addition of excess hexane precipitated the product as a
dark red crystals.
2.3. Preparation of [CpOs(PPh3)2CN] (3)
Yield: 30 mg, 35.8%. Anal. Found: C, 52.00; H, 3.56;
N, 3.50. Calc. for C33H28BF4N2POs: C, 52.11; H, 3.71;
1
N, 3.68%. H NMR (CDCl3, d): 9.29 (d), 7.87 (d), 7.68
A mixture of [CpOs(PPh3)2Br] (200 mg, 0.233 mmol)
and 600 mg of KCN was refluxed in methanol (20 ml)
for 3 h. A pale yellow solution was evaporated to
dryness under reduced pressure. The residue was ex-
tracted with CH2Cl2 and excess KCN was filtered off.
Addition of excess hexane into the CH2Cl2 solution
yielded the product as a colorless crystalline solid.
Yield: 120 mg, 64%. Anal. Found: C, 62.55; H, 4.36;
N, 1.69. Calc. for C42H35NP2Os: C, 62.59; H, 4.37; N,
1.73%. 1H NMR (CDCl3, d): 7.33 (m, 30H, Ph), 4.46 (s,
5H, Cp). 31P{1H} NMR (CDCl3, d): 2.76 (s).IR (KBr,
nCN): 2063 (s).
(t), 7.40ꢂ
d): 16.65 (s). IR (KBr, nBF): 1089 (s, br). UVꢂ
in CH3CN)ꢁ392 nm.
/
6.70 (m), 4.90 (s, Cp). 31P{1H} NMR (CDCl3,
/Vis (lmax
/
2.7. Preparation of [CpOs(PPh3)(Phen)]BF4 (7)
This compound was prepared in similar manner to the
preparation of 6 except 1,10-phenanthroline was used
instead of 2,2?-bipyridine.
Yield: 36 mg, 41.6%. Anal. Found: C, 53.55; H, 5.56;
N, 3.50. Calc. for C35H28BF4N2POs: C, 53.57; H, 3.59;

R. Lalrempuia et al. / Polyhedron 22 (2003) 1391ꢂ
/
1395
1393
N, 3.57%. 1H NMR (acetone-d6 d): 9.91 (d, 2H), 8.39 (d,
2H) 8.03 (s, 2H) 7.63 (d, 2H), 7.30ꢂ6.92 (m, 17H), 5.21
(s, 5H, Cp). 31P{1H} NMR (d): 22.60 (s). IR (KBr):
1089 (s, br, nBF); UVꢂVis (lmax, in CH3CN)ꢁ375 nm.
Table 1
Summary
of
[CpOs(PPh3)(phen)]BF4
structure
determination
of
compound
/
/
/
Formula
OsC35BH28PN2F4
784.57
Formula weight
Crystal class
Space group
Z
monoclinic
P21/n (no. 14)
4
2.8. Crystallographic analysis
Single crystals suitable for x-ray analysis were grown
by slow diffusion of hexane into acetone solution. X-ray
intensity data were collected on a Rigaku R-AXIS IIc
Unit cell dimensions
˚
a (A)
˚
18.2243(2)
9.49800(10)
19.0352(2)
113.8630(10)
3013.22(6)
43.38
b (A)
˚
c (A)
area detector employing graphite-monochromatic Mo
˚
b (8)
Ka radiation (lꢁ/0.71069 A) at a temperature of 293 K.
3
V (A )
˚
Indexing was performed from a series of 18 oscillation
images with exposures of 100 s per frame. A hemisphere
of data was collected using 68 oscillation angles with
exposures of 100 s per frame and a crystal-to-detector
distance of 82 mm. Oscillation images were processed
using BIOTEX [8], producing a listing of unaveraged F2
and s(F2) values which were then passed to the TEXSAN
[9] program package for further processing and struc-
ture solution on a Silicon Graphics O2 computer. A total
of 22223 reflections were measured over the ranges
m (cmꢃ1
)
Crystal size (mm)
Dcalc (g cmꢃ3
F(000)
0.35ꢄ
/
0.32ꢄ0.10
/
)
1.729
1536
˚
0.71069 A)
Radiation
2u range (8)
hkl collected
Mo Ka (lꢁ
5.02ꢂ54.96
235h 5
l 524
22223
6737 (Rint
6050 (F ꢁ
/
/
ꢃ/
/
/
23; ꢃ
/
105
/
k 5
/
12; ꢃ
/
245
/
/
No. reflections measured
No. unique reflections
No. observed reflections
No. reflections used in re-
finement
ꢁ
/
0.0395)
/
4s)
6737
5.025
/
2u 5
/
54.968,
ꢃ
/
235
/
h 5/23,
ꢃ
/
105
/
k 512,
/
ꢃ
/
245
/
l 524 yielding 6737 unique reflections (Rint
/
ꢁ
/
No. parameters
4s) a
R indices (all data)
398
0.0395). The intensity data were corrected for Lorentz
and polarization effects and for absorption using REQAB
[10] (minimum and maximum transmission 0.655, 1.000)
Table 1.
R indices (F ꢁ
/
R1ꢁ
R1ꢁ
/
0.0488, wR2ꢁ
/
0.1114
/
0.0563, wR2ꢁ
/
0.1166
GOF b
1.134
Final difference peaks (e
ꢃ3
ꢀ
/
1.170, ꢃ1.262
/
˚
A
)
The structure was solved by direct methods (SIR-92
[11]). Refinement was by full-matrix least-squares based
on F2 using SHELXL-93 [12]. All reflections were used
during refinement (F2 values that were experimentally
{a w(Fo2ꢃ
/
Fc2)2/a w(Fo2)2}1/2
the number of re-
.
a
R1ꢁ
/
ajjFojꢃ
GOFꢁ
{a w(Fo2ꢃ
the number of parameters refined.
/
jFcjj/ajFoj, wR2ꢁ
/
b
/
/
Fc2)2/(nꢃp)}1/2, where nꢁ
/
/
flections and pꢁ
/
negative were replaced by F2ꢁ
used was wꢁ
1/[s2(Fo2)ꢀ0.0516P2ꢀ
Pꢁ
(Fo2ꢀ2Fc2)/3. Non-hydrogen atoms were refined
anisotropically and hydrogen atoms were refined using
a ‘riding’ model. Refinement converged to R1ꢁ0.0488
and wR2ꢁ0.1114 for 6050 reflections for which F ꢁ
4s(F) and R1ꢁ0.0563, wR2ꢁ0.1166 and GOFꢁ
/
0). The weighting scheme
9.8409P] where
/
/
/
/
/
/
/
/
/
/
/
1.134 for all 6737 unique, non-zero reflections and 398
variables. The maximum D/s in the final cycle of least
squares was 0.002 and the two most prominent peaks in
the final difference Fourier were ꢀ
/
1.170 and ꢃ
/
1.262 e
ꢃ3
˚
A
.
Fig. 1 is an ORTEP [13] representation of the molecule
with 30% probability thermal ellipsoids displayed.
3. Results and discussion:
Fig. 1. ORTEP drawing of compound 7 with 30% probability thermal
ellipsoids. Hydrogen atoms and BF4 omitted for clarity.
The reaction of the complex [CpOs(PPh3)2Br] with
anions take place by refluxing in methanol yielding
complexes of the type [CpOs(PPh3)2X] via the solvated
compound [CpOs(PPh3)2(MeOH)]ꢀ as shown in
Scheme 1. Complex 2 was obtained by refluxing 1 in
acetonitrile in the presence of NH4BF4.
All these complexes are colorless to pale yellow
colored and soluble in most organic solvents. Complex
2 displays a characteristic IR band at 2282 cmꢃ1 due to

1394
R. Lalrempuia et al. / Polyhedron 22 (2003) 1391ꢂ1395
/
pentadienyl protons at 4.66 ppm while complexes 6 and
7 exhibited the resonance for the same at d 4.91 and 5.21
ppm, respectively. This indicates that there is a sig-
nificant deshielding after substituting CH3CN and one
PPh3 with chelating N,N?-donor heterocyclic ligands.
Scheme 1.
1
The H NMR spectra of these complexes also showed a
multiplet in the range of 7.0ꢂ9.5 ppm due to the phenyl
/
nCN of CH3CN. This compound has been isolated as the
tetraphenylborate salt [3]. The 1H NMR spectrum of the
complex exhibited the resonance of the CH3 protons of
coordinated acetonitrile as a singlet at d 2.41 [lit. d 1.33
(t)]. The IR spectra of complexes 3 and 4 showed strong
bands at 2063 and 2108 cmꢃ1 for nCN and nNCS
respectively [4a].
protons of triphenylphosphine and of the heterocyclic
N,N?-donor ligands. The 31P NMR spectra of the 6 and
7 exhibited a single sharp resonance at 16.65 ppm and
22.60 ppm respectively while the starting complex
[CpOs(PPh3)2CH3CN]BF4 showed the same at 2.11
ppm. These distinct downfield shifts were observed
because of the dissociation of one triphenylphosphine
from the metal centre. The downfield shift of complex 7
is slightly more compared to complex 6 due to steric
bulkiness of the phenanthroline ligand.
The reaction of 1 with NaNO2 and HCl (aq) in
ethanol yielded a yellow compound which was char-
acterized as [CpOs(PPh3)2(NO)](BF4)2 (5). This com-
pound showed a strong nNO band at 1848 cmꢃ1
indicating a linear Osꢂ
NO bond [7]. The 1H NMR
/
spectrum of this complex exhibited a resonance for the
deshielded Cp protons at 6.23 ppm, a very significant
shift compared to the starting complex 1 (4.31 ppm) that
indicates a good p-accepting ability of the nitrosyl
ligand. However, the same reaction conditions in the
case of the ruthenium analogue resulted in the dissocia-
3.1. The structure of [CpOs(PPh3)(phen)]BF4
The structure of complex 7 is shown in Fig. 1. The
bond lengths and bond angles are listed in Table 2. The
osmium atom is bonded to a phenanthroline ligand,
triphenylphosphine ligand and cyclopentadienyl group
through the five-membered ring. The cyclopentadienyl
group is clearly bonded in a pentahapto fashion to the
tion
of
one
triphenylphosphine
forming
1
[CpRu(PPh3)(NO)Cl]BF4 [7]. The integration of the H
NMR spectrum, the absence of band in the range of
metal. Two of the OsꢂC bond lengths, those involving
/
200ꢂ
/
300cmꢃ1 (Osꢂ
Br) in the far IR spectrum and the
/
˚
the C(32) and C(33) are shorter (2.176 and 2.193 A) than
analytical data suggested the compound to be
[CpOs(PPh3)2NO](BF4)2 (5). Moreover, only a slight
shift of phosphorus resonance in the 31P NMR was
observed in comparison to the starting complex. We feel
that there would be significant shift in the position of the
phosphorus peak in the 31P NMR if one triphenylpho-
sphine had been replaced from the metal centre. The
formation of the dication of [CpOs(PPh3)2NO](BF4)2
has been reported previously via a different route [14].
Treatment of [CpOs(PPh3)2Br] (1) with excess of
ligands L2 such as 2,2?-bipyridine or 1,10-phenanthro-
line in methanol, toluene or benzene under refluxing
condition even after 2 days does not give the expected
the other three C(31), C(34) and C(35) carbon atoms
˚
(2.210, 2.215 and 2.211 A). The average OsꢂC bond
/
Table 2
˚
Selected bond lengths (A) and bond angles (8) in the compound
[CpOs(PPh3)(phen)]BF4
Bond lengths
Osꢂ
Osꢂ
Osꢂ
Pꢂ
N1ꢂ
C31ꢂ
C33ꢂ
BꢂF4
Osꢂ
Osꢂ
Osꢂ
Pꢂ
/
N1
2.090(5)
2.193(6)
2.215(6)
1.835(7)
1.373(7)
1.413(11)
1.431(12)
1.352(12)
2.092(5)
2.210(6)
2.318(2)
1.844(7)
N2ꢂ
C31ꢂ
C34ꢂ
BꢂF3
Osꢂ
Osꢂ
Pꢂ
N1ꢂ
N2ꢂ
/
C10
1.345(8)
1.418(11)
1.375(13)
1.371(12)
2.176(6)
2.211(6)
1.831(7)
1.347(8)
1.372(8)
1.409(11)
1.263(12)
1.423(14)
/C33
/
C32
C35
/C34
/
/
C25
/
/C12
/
C32
C35
/C35
/
compounds.
[CpOs(PPh3)2(CH3CN)]BF4 (2) with bipy and phen
yielded cationic complexes of the type
However,
the
reaction
of
/C34
/
C13
/
/C1
/
N2
C31
P
/C11
[CpOs(PPh3)(L2)]BF4, which were isolated as dark red
compounds.
/
C32ꢂ
BꢂF2
BꢂF1
/
C33
/
/
/
C19
/
[CpOs(PPh3)2(CH3CN)]BF4
Bond angles
N1ꢂOsꢂN2
C13ꢂPꢂOs
C1ꢂN1ꢂOs
C19ꢂPꢂOs
F2ꢂBꢂ
F4ꢂBꢂ
N2ꢂ
C25ꢂ
i
and ii
0
/
/
77.2(2)
113.1(2)
128.1(4)
118.7(2)
106.0(10)
109.5(8)
89.02(13)
116.1(2)
C12ꢂ
F2ꢂBꢂ
F4ꢂBꢂ
N1ꢂOsꢂ
C11ꢂN2ꢂ
C10ꢂN2ꢂ
F2ꢂBꢂF3
F3ꢂBꢂF1
/
N1ꢂ
F4
F1
/
Os
115.6(4)
119.3(11)
103.4(10)
88.86(14)
115.5(4)
126.6(5)
111.7(10)
105.8(9)
[CpOs(PPh3)(L2)]BF4
/
/
/
/
/
/
/
/
where iꢁ
/
toluene; iiꢁmethanol; L2ꢁbipy (6) and phen
/
/
/
/
/
/P
(7).
/
/
F1
/
/
Os
A downfield shift of the cyclopentadienyl protons in
comparison to the starting complex was observed in the
1H NMR spectra. The parent complex [CpOs(PPh3)2-
(CH3CN)]BF4, (2) showed the resonance for the cyclo-
/
/
F3
/
/
Os
/Osꢂ
/P
/
/
/
PꢂOs
/
/
/

R. Lalrempuia et al. / Polyhedron 22 (2003) 1391ꢂ
/
1395
1395
˚
distance being 2.201 A, slightly longer than the parent
References
˚
complex [CpOs(PPh3)2Br] (2.177 A) [6].
˚
[1] (a) M.A. Bennett, K. Khan, E. Wenger, in: G. Wilkinson, F.G.A.
Stone, E.W. Abel (Eds.), Comprehensive Organometallic Chem-
istry, Ch. 8, vol. 7, 2nd ed., Elsevier, Oxford, 1995, p. 473;
(b) S.G. Davies, J.P. McNally, A.J. Smallridge, Adv. Organomet.
Chem. 30 (1991) 1;
The Osꢂ
longer than the average Osꢂ
two OsꢂN bonds are almost equal, 2.090 and 2.092 A,
and also are little longer compared to the OsꢂN bond
lengths observed for osmiumꢂphenanthroline com-
plexes which fall within a range of 2.066ꢂ
/
P bond length is 2.318 A which also is slightly
˚
/
P distance (2.293 A) [6]. The
˚
/
/
/
(c) M.I. Bruce, C. Hameister, A.G. Swincer, R.C. Wallis, Inorg.
Synth. 21 (1982) 78.
˚
2.1 A [15].
/
[2] (a) T.P. Gill, K.R. Mann, Organometallics 1 (1982) 485;
(b) B. Steimetz, W.A. Schenk, Organometallics 18 (1999) 943;
(c) E. Ruba, W. Simanko, K. Mauthner, K.M. Soldouzi, C.
Slugovc, K. Mereiter, R. Schmid, K. Kirchner, Organometallics
18 (1999) 3843;
The geometry of complex 7 is octahedral about the
metal center assuming the cyclopentadienyl ligand
occupies three coordinate sites. This is evident by the
near 908 bond angles between N(1)ꢂ
/
OsꢂP (88.868) and
/
(d) C. Slugovc, W. Simanko, K. Mereiter, R. Schmid, K.
Kirchner, L. Xiao, W. Weissensteiner, Organometallics 18
(1999) 3865;
N(2)ꢂOsꢂP (89.028).
/
/
(e) M.O. Albers, D.J. Robinson, A. Shaver, E. Singleton,
Organometallics 5 (1986) 2199;
4. Conclusions
(f) M.O. Albers, D.C. Liles, D.J. Robinson, A. Shaver, E.
Singleton, Organometallics 6 (1987) 2347;
The reactions of [CpOs(PPh3)2Br] with monodentate
anions and neutral ligands were described and they do
not seems to differ much from their ruthenium analo-
gues except in the formation of [CpOs(PPh3)2NO]ꢀ2 (5).
We also observed that the complex [CpOs(PPh3)2-
(CH3CN]ꢀ was a better precursor for the preparation
of [CpOs(PPh3)(L2)]ꢀ compared to [CpOs(PPh3)2Br].
The molecular structure of the complex [CpOs(PPh3)-
(phen)]BF4 was established by single X-ray crystal-
lography.
(g) K. Kirchner, K. Mereiter, A. Umfahrer, R. Schmid, Organo-
metallics 13 (1994) 1886;
(h) T. Daniel, N. Mahr, T. Braun, H. Werner, Organometallics 12
(1993) 1475;
(i) T. Braun, O. Gevert, H. Werner, J. Am. Chem. Soc. 117 (1995)
7291.
[3] G.S. Ashby, M.I. Bruce, I.B. Tomkins, R.C. Wallis, Aust. J.
Chem. 32 (1979) 1003.
[4] (a) T. Wilczewski, M. Bochenska, J.F. Biernat, J. Oganomet.
Chem. 87 (1981) 215;
(b) T. Wilczewski, J. Organomet. Chem. 224 (1982) C1;
(c) T. Blackmore, M.I. Bruce, F.G.A. Stone, J. Chem. Soc. (A)
(1971) 2376.
[5] K. Mohan Rao, E.K. Rymmai, Polyhedron 22 (2003) 307.
[6] M.I. Bruce, P.J. Low, B.W. Skelton, E.R.T. Tiekink, A. Werth,
A.H. White, Aust. J. Chem. 48 (1995) 1887.
5. Supplementary material
[7] F.M. Conroy-Lewis, A.D. Redhouse, S.J. Simpson, J. Organo-
met. Chem. 399 (1990) 307.
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC No. 194247 for complex 7. Copies
of this information may be obtained free of charge from
The Director, CCDC, 12 Union Road, Cambridge, CB2
[8] BIOTEX: A Suite of Programs for the Collection, Reduction and
Interpretation of Imaging Plate Data, Molecular Structure
Corporation, 1995.
[9] TEXSAN: Crystal Structure Analysis Package, Molecular Structure
Corporation, 1985 and 1992.
[10] R.A. Jacobsen, REQAB4: Private communication, 1994.
[11] S.I.R. 92:, A. Altomare, M.C. Burla., M. Camalli, M. Cascarano,
C. Giacovazzo, A. Guagliardi, G. Polidoro, J. Appl. Crystallogr.
27 (1994) 435.
1EZ, UK (fax: ꢀ44-1223-336033; e-mail: deposit@
/
ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).
[12] G.M. Sheldrick, SHELXL-93: Program for the Refinement of
Crystal Structures, University of Gottingen, Germany, 1993.
¨
[13] C.K. Johnson, ORTEP-II: A Fortran Thermal Ellipsoid Plot
Program for Crystal Structure Illustrations, ORNL-5138, 1976.
[14] M.I. Bruce, I.B. Tomkins, F.S. Wong, B.W. Skelton, A.H. White,
J. Chem. Soc., Dalton Trans. (1982) 687.
Acknowledgements
K.M.R. thanks the DST (DST SERC: SP/S1/F-22/
98), New Delhi for financial support. We are very
grateful to one of the referees for his helpful suggestions.
[15] H.A. Goodwin, D.L. Kepert, J.M. Patrick, B.W. Skelton, A.H.
White, Aust. J. Chem. 37 (1984) 1817.