Addition of Pt(PBut3) to osmium-tin cluster complexes

Article abstract of DOI:10.1021/ic070261a

The reactions of the osmium-tin cluster complexes Os₃(CO) ₁₂(μ₃-SnPh)Ph, 9, and Os₄(CO) ₁₆(μ₄-Sn), 10, with Pt(PBu^t ₃)₂ have been investigated. Two products, PtOs ₃(CO)₁₂(Ph)(PBu^t₃)(μ₃- SnPh), 11, and Pt₂Os₃(CO)₁₂(μ₂- Ph)(PBu^t₃)₂(μ₃-SnPh), 12, were obtained from the reaction of 9 with Pt(PBu^t₃) ₂. These are mono- and bis-Pt(PBu^t₃) adducts of 9 formed by the addition of a Pt(PBu^t₃) group to the Os-Os bond in 11 and the Os-Os bond and Os-C bond to the σ-bonded phenyl group in 12. A PBu^t₃ derivative of 11, Os ₂(CO)₈(μ₃-SnPh)Os(CO)₃(PBu ^t₃)Ph, 13, was obtained by treating 12 with PBu ^t₃. The reaction of 10 with Pt(PBu^t ₃)₂ provided the bis-Pt(PBu^t₃) adduct Os₄(CO)₁₆[Pt(PBu^t₃)] ₂(μ₄-Sn), 14, that was formed by the addition of a Pt(PBut₃) group across the Os-Os bond of both Os₂(CO) ₈ groups in 10. All four new compounds 11-14 were characterized by single-crystal X-ray diffraction analysis.

Full text of DOI:10.1021/ic070261a

Inorg. Chem. 2007, 46, 4605−4611
Addition of Pt(PBut3) to Osmium
−Tin Cluster Complexes
Richard D. Adams,* Burjor Captain, and Lei Zhu
Department of Chemistry and Biochemistry, UniVersity of South Carolina,
Columbia, South Carolina 29208
Received February 9, 2007
The reactions of the osmium
Pt(PBut3)2 have been investigated. Two products, PtOs3(CO)12(Ph)(PBut3)(
(PBut3)2( 3-SnPh), 12, were obtained from the reaction of 9 with Pt(PBut3)2. These are mono- and bis-Pt(PBut3)
adducts of 9 formed by the addition of a Pt(PBut3) group to the Os
Os bond in 11 and the Os Os bond and Os
bond to the
-bonded phenyl group in 12. A PBut3 derivative of 11, Os2(CO)8( 3-SnPh)Os(CO)3(PBut3)Ph, 13, was
obtained by treating 12 with PBut3. The reaction of 10 with Pt(PBut3)2 provided the bis-Pt(PBut3) adduct
Os4(CO)16[Pt(PBut3)]2( 4-Sn), 14, that was formed by the addition of a Pt(PBut3) group across the Os
Os bond of
14 were characterized by single-crystal X-ray diffraction
−
tin cluster complexes Os3(CO)12
(
µ
3-SnPh)Ph, 9, and Os4(CO)16
(
µ4-Sn), 10, with
µ
3-SnPh), 11, and Pt2Os3(CO)12(µ2-Ph)-
µ
−
−
−C
σ
µ
µ
−
both Os2(CO)8 groups in 10. All four new compounds 11
−
analysis.
Introduction
[Pt(PBut3)]n, 1-3, n ) 1-3.1 Multiple additions of the Pt-
(PBut3) group are frequently observed, as found in the
compounds 2 and 3 and the compounds Ru6(CO)17(µ6-C)-
[Pt(PBut3)]2, 4,2a Pt2Ir4(CO)12(PBut3)2, 5,4 and Rh6(CO)16[Pt-
(PBut3)]4, 66 (see Chart 1).
In recent studies, we have shown that the Pt(PBut3) group
is readily added to the bonds between transition metals in
polynuclear metal carbonyl cluster complexes (eq 1).1-6 An
We have also shown that the Pt(PBut3) group is readily
added to the transition metal-tin and transition metal-
germanium bonds in polynuclear metal carbonyl cluster
complexes that contain phenyltin and phenylgermanium
bonds (eq 2).7 For example, Re2(CO)8(µ-SnPh2)2 adds one
empty orbital on the platinum atom shares the pair of
electrons between the two metal atoms (M) to form a
delocalized three-center two-electron bond. Some examples
of these Pt(PBut3) adducts are the compounds Os3(CO)12-
* To whom correspondence should be addressed. E-mail: Adams@
mail.chem.sc.edu.
(1) Adams, R. D.; Captain, B.; Zhu, L. Organometallics 2006, 45, 430-
436.
(2) (a) Adams, R. D.; Captain, B.; Fu, W.; Hall, M. B.; Manson, J.; Smith,
M. D.; Webster, C. E. J. Am. Chem. Soc. 2004, 126, 5253-5267. (b)
Adams, R. D.; Captain, B.; Fu, W.; Smith, M. D. J. Am. Chem. Soc.
2002, 124, 5628-5629. (c) Adams, R. D.; Captain, B.; Zhu, L. J.
Cluster Sci. 2006, 17, 87-95.
and two Pt(PBut3) groups to form the compounds Re2(CO)8-
(µ-SnPh2)2[Pt(PBut3)]n, 7, and 8, n ) 1,2 (eq 3). Tin has
recently been shown to be a useful modifier of heterogeneous
nanoscale hydrogenation catalysts of the platinum group
metals when placed on mesoporous supports.8-9
(3) (a) Adams, R. D.; Captain, B.; Fu, W.; Pellechia, P. J.; Smith, M. D.
Angew. Chem., Int. Ed. 2002, 41, 1951-1953. (b) Adams, R. D.;
Captain, B.; Fu, W.; Pellechia, P. J.; Smith, M. D. Inorg. Chem. 2003,
42, 2094-2101. (c) Adams, R. D.; Captain, B.; Fu, W.; Pellechia, P.
J.; Zhu, L. Inorg. Chem. 2004, 43, 7243-7249.
(4) Adams, R. D.; Captain, B.; Hall, M. B.; Smith, J. L., Jr.; Webster, C.
E. J. Am. Chem. Soc. 2005, 127, 1007-1014.
We have recently reported the synthesis of the osmium
carbonyl cluster complexes Os3(CO)12(µ3-SnPh)Ph, 9,
(5) Adams, R. D.; Captain, B.; Zhu, L. Organometallics 2006, 25, 2049-
2054.
(6) Adams, R. D.; Captain, B.; Pellechia, P. J.; Smith, J. L. Inorg. Chem.
2004, 43, 2695-2702.
(7) Adams, R. D.; Captain, B.; Herber, R. H.; Johansson, M.; Nowik, I.;
Smith, J. L., Jr.; Smith, M. D. Inorg. Chem. 2005, 44, 6346-6358.
10.1021/ic070261a CCC: $37.00
Published on Web 04/20/2007
© 2007 American Chemical Society
Inorganic Chemistry, Vol. 46, No. 11, 2007 4605

Adams et al.
1
AVATAR 360 FTIR spectrophotometer. H NMR and 31P {1H}
NMR were recorded on a Varian Mercury 400 spectrometer
operating at 400.1 and 161.9 MHz, respectively. 31P {1H} NMR
spectra were externally referenced against 85% o-H3PO4. Electro-
spray mass spectrometric measurements were obtained on a
MicroMass Q-TOF spectrometer. Os3(CO)12(Ph)(µ3-SnPh), 9, and
Os4(CO)16(µ4-Sn), 10, were prepared as previously reported.10 Pt-
(PBut3)2 was purchased from STREM and was used without further
purification. Product separations were performed by TLC in air on
Analtech 0.25 and 0.5 mm silica gel 60 Å F254 glass plates.
Elemental analyses were performed by Desert Analytics, Tuscon,
AZ.
Preparation of PtOs3(CO)12(PBut3)(Ph)(µ3-SnPh) (11) and
Pt2Os3(CO)12(PBut3)2(µ2-Ph)(µ3-SnPh) (12). A 15 mg amount of
9 (0.013 mmol) was dissolved in 15 mL of CH2Cl2 solvent in a 50
mL three-neck flask. A 7.6 mg amount of Pt(PBut3)2 (0.013 mmol)
was added, and the reaction continued at room temperature for 30
min. The solvent was removed in vacuo, and the products were
isolated by TLC by using a 6:1 hexane-methylene chloride solvent
mixture to yield (in order of elution) 8.8 mg of orange 11 (44%
yield) and 2.3 mg of dark orange 12 (9% yield). Spectral data for
11: IR νCO (cm-1 in CH2Cl2) 2123 (m), 2084 (w), 2054 (s), 2007
and Os4(CO)16(µ4-Sn), 10, that contain both Os-Os bonds
and Os-Sn bonds from the thermal transformations of
HOs3(CO)11SnPh3 (eq 4).10
1
(s), 1972 (m), 1838 (m), 1799 (m). H NMR (in CDCl3): δ )
1.49 (d, 27 H, CH3, 3JP-H ) 13 Hz). 31P{1H} NMR (in CDCl3): δ
1
) 124.7 (s, 1 P, JPt-P ) 5005 Hz). Anal. Calcd: C, 27.40; H,
2.35%. Found: C, 27.52; H, 1.73%. Spectral data for 12: IR νCO
(cm-1 in CH2Cl2) 2094 (w), 2075 (w), 2050 (m), 2017 (s), 1997
1
(m), 1966 (m), 1829 (m), 1792 (m). H NMR (in CDCl3): δ )
3
3
1.37 (d, 27 H, CH3, JP-H ) 13 Hz), 1.09 (d, 27 H, CH3, JP-H
)
)
13 Hz). 31P{1H} NMR (in CDCl3): δ ) 125.9 (s, 1 P, JPt-P
1
4995 Hz), 102.7 (s, 1 P, 1JPt-P ) 6630 Hz). Anal. Calcd: C, 29.19;
H, 3.24%. Found: C, 29.97; H, 3.90%.
Improved Yield of 12. A 11 mg amount of Os3(CO)12(Ph)(µ3-
SnPh) (0.0089 mmol) and 21.3 mg of Pt(PBut3)2 (0.356 mmol) were
dissolved in 15 mL of CH2Cl2 solvent in a 50 mL three-neck flask,
and the solution was heated to reflux for 1 h. The solvent was
removed in vacuo. The product was purified by TLC by using a
6:1 hexane-methylene chloride solvent mixture to yield 2.1 mg
of 11 (15% yield) and 7.0 mg of 12 (40% yield).
To try to establish the binding selectivity of the Pt(PBut3)
group for Os-Os or Os-Sn bonds, we have now investigated
the reactions of 9 and 10 with Pt(PBut3)2. The results of this
study are reported here.
Experimental Section
Conversion of 11 to 12. A 8.5 mg amount of 11 (0.0054 mmol)
was dissolved in 15 mL of CH2Cl2 solvent in a 50 mL three-neck
flask, and a 6.5 mg amount of Pt(PBut3)2 (0.011 mmol) was added.
The solution was heated to reflux for 1 h, and the solvent was then
removed in vacuo. The products were separated by TLC by using
General Data. All the reactions were performed under a nitrogen
atmosphere using standard Schlenk techniques. Reagent grade
solvents were dried by the standard procedures and were freshly
distilled prior to use. Infrared spectra were recorded on an
Chart 1
4606 Inorganic Chemistry, Vol. 46, No. 11, 2007

Osmium-Tin Cluster Complexes
a 6:1 hexane-methylene chloride solvent mixture to yield 4.0 mg
of 12 (38% yield).
rameters, and results of the analyses for the compounds are listed
in Tables 1 and 2.
Preparation of PtOs3(CO)11(PBut3)2(Ph)(µ3-SnPh) (13). A 5.0
µL amount (0.0200 mmol) of PBut3 was added to a solution of 7.6
mg of 12 (0.0038 mmol) in 15 mL of CH2Cl2 solvent. The solution
was stirred at room temperature for 15 min, and the solvent was
then removed in vacuo. The products were separated by TLC by
using a 6:1 hexane-methylene chloride solvent mixture to yield
(in order of elution) 1.8 mg of 11 (30% yield) and 1.0 mg of 13
(15% yield). Spectral data for 13: IR νCO (cm-1 in CH2Cl2) 2052
Compound 11 crystallized in the triclinic crystal system. Space
group P1h was assumed and confirmed by the successful solution
and refinement of the structure. There are two independent formula
equivalents of the complex present in the asymmetric unit. All non-
hydrogen atoms were refined with anisotropic displacement pa-
rameters. Hydrogen atoms were placed in geometrically idealized
positions and included as standard riding atoms.
Compound 12 crystallized in the monoclinic crystal system.
There was one significant residual peak near the bridging carbon
atom of the phenyl group. It was approximately 2.9 Å from the Sn
atom and about 2.7 Å from the lone osmium atom. It is believed
that this is an osmium atom from a minor disorder effect produced
by rotating the entire molecule approximately 180° about the Sn-
C(Ph) vector. This disorder would interchange the two Pt(PBut3)
groups and one pair of Os(CO)3 groups almost perfectly. The
residual peak would correspond to the osmium atom of the
unmatched Os(CO)3. The disorder refined best at 8% Os at this
site. At this very low value, the carbonyl ligands on the 8% osmium
atom would not be observed. As a consequence of this disorder,
the carbon atom of the bridging η1-phenyl group which lies in the
vicinity of this disordered osmium atom was refined with an
isotropic thermal parameter only. All other non-hydrogen atoms
were refined with anisotropic thermal parameters. The hydrogen
atoms were placed in geometrically idealized positions and included
as standard riding atoms.
Compound 13 crystallized in the monoclinic crystal system. The
systematic absences in the intensity data were consistent with the
space group P21/c. All non-hydrogen atoms were refined with
anisotropic thermal parameters. Hydrogen atoms were placed in
geometrically idealized positions and included as standard riding
atoms. One molecule of hexane from the crystallization solvent
cocrystallized with the complex and was refined with isotropic
displacement parameters. Geometric restraints were used in model-
ing the hexane molecule which was disordered.
Compound 14 crystallized in the orthorhombic crystal system.
Systematic absences in the intensity data were consistent with either
of the space groups Pnn2 or Pnnm. The structure could only be
solved in the former space group. The molecule sits on a
crystallographic 2-fold symmetry axis. All non-hydrogen atoms
were refined with anisotropic displacement parameters. It cocrys-
tallized with a molecule of CH2Cl2 from the crystallization solvent.
The solvent molecule exhibits a 2-fold disorder of the carbon
atom. This solvent molecule was included in the analysis and
satisfactorily refined with anisotropic thermal parameters with 50%
occupancy of the chlorine atoms. Hydrogen atoms were placed in
geometrically idealized positions and included as standard riding
atoms.
1
(m), 2011 (s), 1978 (m), 1830 (m), 1792 (m). H NMR (in CD2-
Cl2): δ ) 7.65-7.69 and 6.78-7.08 (m, 10 H, Ph), 1.50 (d, 27 H,
CH3, 3JP-H ) 13 Hz), 1.42 (d, broad, 27 H, CH3, 3JP-H ) 12 Hz).
31P{1H} NMR (in CD2Cl2): δ ) 123.2 (s, 1 P, 1JPt-P ) 4957 Hz),
64.2 (s, 1 P). Mass spectrometry: positive ion ESIMS m/z calcd
for [PtOs3SnP2O11C47H64 + H]+, 1753; found 1753. The isotope
distribution pattern is consistent with the presence of one platinum
atom and three osmium atoms.
Preparation of Os4(CO)16[Pt(PBut3)]2(µ4-Sn) (14). An 8.0 mg
amount of 10 (0.0060 mmol) was dissolved in 15 mL of CH2Cl2
solvent in a 50 mL three-neck flask. A 18 mg amount of Pt(PBut3)2
(0.030 mmol) was added, and the solution continued at reflux for
20 min. The solvent was removed in vacuo, and the products were
isolated by TLC by using a 6:1 hexane-methylene chloride solvent
mixture to yield 5.5 mg of an orange 14 (43% yield). Spectral data
for 14: IR νCO (cm-1 in CH2Cl2) 2054 (m), 2013 (s), 1977 (w),
1841 (w), 1804 (w). 1H NMR (in CDCl3): δ ) 1.52 (d, 54H, CH3,
3JP-H ) 13 Hz). 31P{1H} NMR (in CDCl3): δ ) 129.3 (s, 1P,
1JPt-P ) 4999 Hz). Mass spectrometry positive ion ESIMS m/z calcd
for [Pt2Os4SnP2O16C40H54]+, 2123; found 2123. The isotope
distribution pattern is consistent with the presence of two platinum
atoms and four osmium atoms.
Crystallographic Analysis. Orange single crystals of 11 and
13 were directly grown from solution in CH2Cl2-hexane solvent
mixtures by cooling to -25 °C. Orange single crystals of 12 suitable
for diffraction analysis were grown by slow evaporation of
solvent from a benzene-octane solution at 8 °C. Orange single
crystals of 14 suitable for diffraction analysis were grown by slow
evaporation of solvent from a CH2Cl2-hexane solution at 8 °C.
Each data crystal was glued onto the end of a thin glass fiber. X-ray
intensity data were measured by using a Bruker SMART APEX
CCD-based diffractometer using Mo KR radiation (λ ) 0.710 73
Å). The raw data frames were integrated with the SAINT+ program
by using a narrow-frame integration algorithm.11 Corrections
for the Lorentz and polarization effects were also applied by
SAINT. An empirical absorption correction based on the
multiple measurement of equivalent reflections was applied by
using the program SADABS. All structures were solved by a
combination of direct methods and difference Fourier syntheses
and refined by full-matrix least-squares on F2 by using the
SHELXTL software package.12 Crystal data, data collection pa-
Results and Discussion
Two products PtOs3(CO)12(PBut3)(Ph)(µ3-SnPh), 11, and
Pt2Os3(CO)12(PBut3)2(µ2-Ph)(µ3-SnPh), 12, were obtained in
the yields 44 and 9%, respectively, from the reaction of 9
with Pt(PBut3)2 when combined in a 1:1 ratio at room
temperature. When the amount of Pt(PBut3)2 was increased
to 4 times the amount of 9, the yield of 12 was increased to
40% at the expense of 11, yield of 15%.
Compounds 11 and 12 were both characterized by single-
crystal X-ray diffraction analysis. Compound 11 crystallizes
with two independent molecules in the asymmetric crystal
unit. Both molecules are structurally similar. An ORTEP
(8) (a) Hermans, S.; Raja, R.; Thomas, J. M.; Johnson, B. F. G.; Sankar,
G.; Gleeson, D. Angew. Chem., Int. Ed. 2001, 40, 1211. (b) Johnson,
B. F. G.; Raynor, S. A.; Brown, D. B.; Shephard, D. S.; Mashmeyer,
T.; Thomas, J. M.; Hermans, S.; Raja, R.; Sankar, G. J. Mol. Catal.
A: Chem. 2002, 182-183, 89. (c) Hermans, S.; Johnson, B. F. G.
Chem. Commun. 2000, 1955.
(9) Hungria, A. B.; Raja, R.; Adams, R. D.; Captain, B.; Thomas, J. M.;
Midgley, P. A.; Golvenko, V.; Johnson, B. F. G. Angew. Chem., Int.
Ed. 2006, 45, 4782.
(10) Adams, R. D.; Captain, B.; Zhu, L. Organometallics 2006, 25, 4183.
(11) SAINT+, version 6.2a; Bruker Analytical X-ray Systems, Inc.:
Madison, WI, 2001.
(12) Sheldrick, G. M. SHELXTL, version 6.1; Bruker Analytical X-ray
Systems, Inc.: Madison, WI, 1997.
Inorganic Chemistry, Vol. 46, No. 11, 2007 4607

Adams et al.
Table 1. Crystallographic Data for Compounds 11 and 12
11
12
empirical formula
formula weight
crystal system
lattice parameters
a (Å)
PtOs3SnPO12C36H37
1577.01
triclinic
Pt2Os3SnP2O12C54H70
2067.73
monoclinic
17.3194(4)
17.4086(5)
17.6044(5)
61.782(1)
70.331(1)
69.419(1)
4284.1(2)
P1h
9.2366(12)
14.6004(18)
46.617(6)
90
95.151(2)
90
6261.3(14)
P21/n
4
2.194
11.174
294(2)
47.58
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
space group
Z value
4
F
calc (g/cm3)
2.445
12.786
294(2)
55.76
16299
991
µ (Mo KR) (mm-1
temperature (K)
2Θmax (deg)
)
no. observations > 2σ (I)
no. parameters
9094
659
goodness of fit
1.002
1.053
max shift in cycle
0.00
0.02
residuals:a R1; wR2
0.0309; 0.0754
multiscan 1.000/0.587
1.937
0.0579; 0.1226
multiscan 1.000/0.344
3.543
absorption correction, max/min
largest peak in final difference map (e/Å3)
2
a R ) ∑hkl(||Fobs| - |Fcalc||)/∑hkl|Fobs|; Rw ) [∑hklw(|Fobs| - |Fcalc|)2/∑hklwFobs
]
1/2, w ) 1/σ2(Fobs); GOF ) [∑hklw(|Fobs| - |Fcalc|)2/(ndata - nvari)]1/2
.
Table 2. Crystallographic Data for Compounds 13 and 14
13
14
empirical formula
formula weight
crystal system
lattice parameters
a (Å)
PtOs3SnP2O11C47H64‚1.0C6H14
1837.47
monoclinic
Pt2Os4SnP2O16C40H54‚1/2CH2Cl2
2169.90
orthorhombic
17.6264(5)
21.7527(7)
16.0451(5)
90
98.010(1)
90
6092.0(3)
P21/c
4
2.003
9.031
294(2)
56.7
11283
610
1.044
0.003
0.0382; 0.0989
multiscan 1.000/0.595
3.443
12.0546(3)
26.5750(7)
8.9479(2)
90
90
90
2866.40(12)
Pnn2
2
2.514
14.278
294(2)
56.6
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
space group
Z value
F
calc (g/cm3)
µ (Mo KR) (mm-1
temperature (K)
2Θmax (deg)
)
no. observations
no. parameters
goodness of fit
max shift in cycle
6733
311
1.042
0.005
residuals:a R1; wR2
0.0222; 0.0575
multiscan 1.000/0.0.475
2.328
absorption correction, max/min
largest peak in final difference map (e/Å3)
a R ) ∑hkl(||Fobs| - |Fcalc||)/∑hkl|Fobs|; Rw ) [∑hklw(|Fobs| - |Fcalc|)2/∑hklwFobs
]
1/2, w ) 1/σ2(Fobs); GOF ) [∑hklw(|Fobs| - |Fcalc|)2/(ndata - nvari)]1/2
.
2
diagram of the molecular structure of one of the two
molecules of 11 in the asymmetric crystal unit is shown in
Figure 1. Selected bond distances and angles are listed in
Table 3. The molecule is structurally similar to that of 9
except that it contains a Pt(PBut3) group that has been added
across the Os-Os bond that connects the two bonded Os-
(CO)4 groups. The Os-Os bond distance in molecule 1 is
slightly longer, Os(1)-Os(2) ) 3.0139(3) Å, than the Os-
Os bond in 9, Os-Os ) 3.0007(4) Å, but the distance in
molecule 2 is Os(4)-Os(5) ) 2.9910(3) Å, slightly shorter
than that in 9. Accordingly, we think the differences between
the Os-Os bond lengths in 9 and 11 are chemically and
structurally insignificant. The two Pt-Os bond distances in
molecule 1 are significantly different, Pt(1)-Os(2) ) 2.7264-
(3) Å and Pt(1)-Os(1) ) 2.7897(3) Å, but in molecule 2
these two distances are almost the same: Pt(2)-Os(4) )
2.7527(3) Å and Pt(2)-Os(5) ) 2.7644(3) Å. The reason
for this is not clear. It may be due simply to effects of crystal
packing, and thus it would probably not be chemically
significant for the properties of the molecules in solutions.
The long distances are similar to the CO bridged Pt-Os bond
length in 1, Pt(1)-Os(1) ) 2.7929(9).1 CO ligands on the
two platinum bonded osmium atoms have adopted semibridg-
ing coordination to the platinum atom. As in 9, there is a
phenyl group σ-bonded to the third Os(CO)4 group. The
Os-C distance, Os(3)-C(46) ) 2.163(7)Å and Os(6)-C(70)
4608 Inorganic Chemistry, Vol. 46, No. 11, 2007

Osmium-Tin Cluster Complexes
Table 3. Selected Intramolecular Distances and Angles for Compounds 11-13a
(a) Distances
compound 11
compound 12
compound 13
atoms
distance (Å)
atoms
distance (Å)
atoms
distance (Å)
Os(1)-Os(2)
Pt(1)-Os(1)
Pt(1)-Os(2)
Os(1)-Sn(1)
Os(2)-Sn(1)
Os(3)-Sn(1)
Os(3)-C(46)
Pt(1)-P(1)
Os(4)-Os(5)
Pt(2)-Os(4)
Pt(2)-Os(5)
Os(4)-Sn(2)
Os(5)-Sn(2)
Os(6)-Sn(2)
Os(6)-C(70)
Pt(2)-P(2)
3.0139(3)
2.7897(3)
2.7264(3)
2.7021(5)
2.7310(5)
2.7638(5)
2.163(7)
2.3346(16)
2.9910(3)
2.7527(3)
2.7644(3)
2.7220(4)
2.7209(5)
2.7592(5)
2.189(7)
Os(1)-Os(2)
Pt(1)-Os(2)
Pt(1)-Os(1)
Pt(2)-Os(3)
Os(1)-Sn(1)
Os(2)-Sn(1)
Os(3)-Sn(1)
Os(3)-C(46)
Pt(2)-C(46)
Pt(1)-P(1)
2.9844(8)
2.7810(8)
2.7505(8)
2.7445(8)
2.7360(11)
2.7267(11)
2.7058(11)
2.008(18)
2.16(2)
Os(1)-Os(2)
Pt(1)-Os(1)
Pt(1)-Os(2)
Os(1)-Sn(1)
Os(2)-Sn(1)
Os(3)-Sn(1)
Os(3)-C(46)
Pt(1)-P(1)
2.9839(4)
2.7736(3)
2.7372(3)
2.7219(4)
2.7526(5)
2.7354(5)
2.191(7)
2.3468(16)
2.5501(17)
Os(3)-P(2)
2.353(3)
2.268(4)
Pt(2)-P(2)
2.3548(14)
(b) Angles
compound 11
compound 12
compound 13
atoms
angle (deg)
atoms
angle (deg)
atoms
angle (deg)
Os(1)-Sn(1)-Os(3)
Os(2)-Sn(1)-Os(3)
C(46)-Os(3)-Sn(1)
Os(4)-Sn(2)-Os(6)
Os(5)-Sn(2)-Os(6)
C(70)-Os(6)-Sn(2)
130.592(17)
124.941(18)
83.75(17)
127.838(18)
127.569(17)
82.63(17)
Os(1)-Sn(1)-Os(3)
Os(2)-Sn(1)-Os(3)
C(46)-Os(3)-Sn(1)
125.02(4)
134.95(4)
84.2(6)
Os(1)-Sn(1)-Os(3)
Os(2)-Sn(1)-Os(3)
C(46)-Os(3)-Sn(1)
131.906(17)
123.213(17)
78.5(2)
a Estimated standard deviations in the least significant figure are given in parentheses.
) 2.189(7) Å, is similar to that in 9, 2.172(9) Å.10 The Os-
Sn bond distances to Os(1) and Os(2) in molecule 1 are
significantly different, Os(1)-Sn(1) ) 2.7021(5) Å and Os-
(2)-Sn(1) ) 2.7310(5) Å, but in molecule 2, they are
virtually the same length, Os(4)-Sn(2) ) 2.7220(4) and Os-
(5)-Sn(2) ) 2.7209(5), so we think that the difference
observed in molecule 1 is chemically and structurally
insignificant. The Os-Sn distance to the phenyl substituted
osmium atom is the longest of all, Os(3)-Sn(1) ) 2.7638-
(5) Å and Os(6)-Sn(2) ) 2.7592(5), but is similar to that
in 9.10
and Os(2) are also much closer together in length than those
in 11, Os(1)-Sn(1) ) 2.7360(11) Å and Os(2)-Sn(1) )
2.7267(11) Å, but the Os(3)-Sn(1) ) 2.7058(11) Å is
significantly shorter than the others.10
When 12 was treated with PBut3, the platinum phosphine
group that bridges the Os-C (phenyl) bond was removed
and the compounds 11 and 13 were formed in the yields
30% and 15%, respectively. An ORTEP diagram of the
molecular structure of 13 is shown in Figure 3. Selected bond
distances and angles are listed in Table 3. Compound 13 is
structurally similar to 11 but has a PBut3 ligand trans to the
Os-Sn bond in place of one of the CO ligands on the
osmium atom Os(3). The Os-Os bond length in the Os2-
(CO)8 group is similar in length to that in 11, Os(1)-Os(2)
) 2.9839(4) Å. The Pt-Os bonds are unequal, Pt(1)-Os-
(1) ) 2.7736(3) Å and Pt(1)-Os(2) ) 2.7372(3) Å, but as
with 11, we think this is of no chemical significance. The
An ORTEP diagram of the molecular structure of 12 is
shown in Figure 2. Selected bond distances and angles are
listed in Table 3. The molecule is structurally similar to
that of 11, except that there is a second Pt(PBut3) group that
has been added across the Os-C bond to the σ-bonded
phenyl group. As in 11, two of the CO ligands on the osmium
atoms have adopted semibridging coordination to the plati-
num atom Pt(1). The Os-Os bond distance in 12, Os(1)-
Os(2) ) 2.9844(8) Å, is slightly shorter than that in 11
and also shorter than that in 9. The Pt-Os bond dis-
tances are significantly different, but they are much closer
together than they were in 11, Pt(1)-Os(1) ) 2.7505(8) Å
and Pt(1)-Os(2) ) 2.7810(8) Å. Interestingly, the second
platinum atom Pt(2) bridges the Os-C bond to the σ-bonded
phenyl group, Pt(2)-Os(3) ) 2.7445(8) Å and Pt(2)-C(46)
) 2.16(2) Å. The Os-C bond distance to the σ-bonded
phenyl group is slightly shorter than that in 11, Os(3)-C(46)
) 2.008(18) Å. This may be due to the presence of the
bridging platinum atom. The Os-Sn bond distances to Os(1)
Figure 1. An ORTEP diagram of 11 showing 30% probability thermal
ellipsoids.
Inorganic Chemistry, Vol. 46, No. 11, 2007 4609

Adams et al.
Figure 4. An ORTEP diagram of 14 showing 30% probability thermal
ellipsoids. Selected interatomic distances (Å) are Os(1)-Os(2) ) 3.0251-
(3), Pt(1)-Os(1) ) 2.7609(3), Pt(1)-Os(2) ) 2.7557(3), Os(1)-Sn(1) )
2.6824(3), Os(2)-Sn(1) ) 2.6756(4), and Pt(1)-P(1) ) 2.3602(16).
Selected angles (deg) are Os(1)-Sn(1)-Os(2) ) 68.749(7), Os(1)-Sn-
(1)-Os(1′) ) 135.53(3), and Os(1)-Sn(1)-Os(2′) ) 133.53(1).
Figure 2. An ORTEP diagram of 12 showing 30% probability thermal
ellipsoids.
is similar to that of its precursor 10 and contains a spiro-
structure with the Sn atom in the center. A Pt(PBut3)
group was added across each Os-Os bond in 14. The Os-
Os bond distance in 14, Os(1)-Os(2) ) 3.0251(3) Å, is
slightly longer than that in 10, 3.0081(5) and 3.0038(5) Å.
The Pt-Os bond distances, Pt(1)-Os(1) ) 2.7609(3) Å
and Pt(1)-Os(2) ) 2.7557(3) Å, are nearly equal and similar
in length to those in compounds 11-13. As found in
11-13, one CO ligand on each neighboring osmium
atom has formed a bridging interaction to the platinum
atom. The Os-Sn bond distances, Os(1)-Sn(1) ) 2.6824-
(3) Å and Os(2)-Sn(1) ) 2.6756(4) Å, are very similar
to those in 10, 2.6927(7), 2.6883(7), 2.6983(7), and 2.6797-
(7) Å.
Figure 3. An ORTEP diagram of 13 showing 30% probability thermal
ellipsoids.
Os-C distance to the σ-bonded phenyl group, Os(3)-C(46)
) 2.191(7) Å, is slightly longer than that in 11, and the
C-Os-Sn angle is significantly less than 90°, C(46)-Os-
(3)-Sn(1) ) 78.5(2)°, and the P(2)-Os(3)-C(46) angle,
103.4(2)°, is much larger than 90°. This might be due to
steric effects from the neighboring PBut3 ligand. The Os-
Sn distances are similar to those in 11, Os(1)-Sn(1) )
2.7219(4), Os(2)-Sn(1) ) 2.7526(5), and Os(3)-Sn(1) )
2.7354(5).
Compound 10 reacts with Pt(PBut3)2 to form a bis-Pt-
(PBut3) adduct, Os4(CO)16[Pt(PBut3)]2(µ4-Sn), 14, in a
good yield (43%). An ORTEP drawing of the molecular
structure of 14 is shown in Figure 4. Compound 14 lies
on a crystallographic 2-fold axis, so only half of the
molecule is structurally independent. The Os4Sn core of 14
A summary of the products obtained from the reactions
of 9 with Pt(PBut3)2 is shown in Scheme 1. The work
reaffirms the strong affinity of the Pt(PBut3) group for Os-
Os bonds. We have not observed any products with Pt-Sn
interactions. The first Pt(PBut3) addition occurs at the Os-
Os bond of the Os2(CO)8 group to yield 11. Interestingly,
we have observed the addition of a Pt(PBut3) group to an
Os-C bond, in this case to the σ-bonded phenyl group in
12. Pt(PBut3) additions to M-C bonds have not been seen
before and could lead to new chemistry. For example, we
have recently observed the addition of a Pt(PBut3) group to
the Os-H bond of the compound HOs(CO)4(SnPh3) to yield
the adduct PtOs(CO)4(SnPh3)(PBut3)(µ-H), 15.13 It was found
that the Pt(PBut3) group in 15 facilitates the insertion of
phenylacetylene in the Os-H bond. It will be interesting to
Scheme 1
4610 Inorganic Chemistry, Vol. 46, No. 11, 2007

Osmium-Tin Cluster Complexes
see if the addition of Pt(PBut3) groups to M-C bonds will
facilitate the insertion of unsaturated small molecules into
these bonds.
Tin containing cluster complexes are now proving to be
useful precursors to new supported bi- and trimetallic
heterogeneous catalysts.8,9 We are also interested to see how
the addition of Pt(PBut3) groups to polynuclear metal
complexes containing tin can activate them for homogeneous
catalysis.13,14
We have also found that Pt(PBut3) groups can facilitate
the substitution of CO ligands by phosphine ligands.1
This effect appears to be operative in the chemistry of 12
because compound 13, which contains a PBut3 ligand on the
phenyl-substituted carbon atom, was obtained from the
reaction of 12 with PBut3 in the course of the removal of
the Pt(PBut3) group. Interestingly, the Pt(PBut3) group that
bridges the Os-Os bond in 12 was not removed in the
treatment with PBut3.
Acknowledgment. This research was supported by the
Office of Basic Energy Sciences of the U.S. Department of
Energy under Grant No. DE-FG02-00ER14980. This Article
is dedicated to the memory of F. Albert Cotton, a true friend
and leader.
When 10 was treated with Pt(PBut3)2, Pt(PBut3) groups
were added to the Os-Os bond of each Os2(CO)8 group to
yield 14; see eq 5.
Supporting Information Available: CIF files for each of the
structural analyses. This material is available free of charge via
the Internet at http://pubs.acs.org.
(13) Adams, R. D.; Captain, B.; Zhu, L. J. Am. Chem. Soc. 2006, 128,
13672.
(14) Holt, M. S.; Wilson, W. L.; Nelson, J. H. Chem. ReV. 1989, 89, 11.
IC070261A
Inorganic Chemistry, Vol. 46, No. 11, 2007 4611