Four isomers from the oxidative addition of Me3SnH to Os(CO)2(PPh3)3 and the crystal structure of Os(SnMeI2)I(CO)2(PPh3) 2, in which the pairs of CO and PPh3 ligands are mutually trans

Article abstract of DOI:10.1016/j.jorganchem.2003.11.021

Reaction between Os(CO)₂(PPh₃)₃ and Me₃SnH produces Os(SnMe₃)H(CO)₂ (PPh₃)₂ (1). Multinuclear NMR studies of solutions of 1 reveal the presence of four geometrical isomers, the major one being that with mutually cis triphenylphosphine ligands and mutually trans CO ligands. Os(SnMe₃)H(CO)₂ (PPh₃)₂ undergoes a redistribution reaction, at the trimethylstannyl ligand, when treated with Me₂ SnCl₂ giving Os(SnMe₂Cl)H(CO)₂ (PPh₃)₂ (2). Solutions of 2 again show the presence of four isomers but now the major isomer is that with mutually trans triphenylphosphine ligands and mutually cis CO ligands. The redistribution reaction of 1 with SnI₄ produces Os(SnMeI₂)H(CO)₂(PPh₃)₂ (3) which exists in solution as only one isomer, that with mutually trans triphenylphosphine ligands and mutually trans CO ligands. Treatment of 3 with I₂ cleaves the Os-H bond with retention of geometry giving Os(SnMeI₂)I(CO)₂ (PPh₃)₂ (4). The crystal structure of 4 has been determined. No isomerization of the trans dicarbonyl complex 4 occurs when 4 is heated, instead there is a formal loss of MeSnI and formation of OsI₂ (CO)₂(PPh₃)₂ (5).

Full text of DOI:10.1016/j.jorganchem.2003.11.021

Journal of Organometallic Chemistry 689 (2004) 605–611
www.elsevier.com/locate/jorganchem
Four isomers from the oxidative addition of Me3SnH
to Os(CO)2(PPh3)3 and the crystal structure
of Os(SnMeI2)I(CO)2(PPh3)2, in which the pairs
of CO and PPh3 ligands are mutually trans
*
*
Clifton E.F. Rickard, Warren R. Roper , George R. Whittell, L. James Wright
Department of Chemistry, The University of Auckland, Private Bag 92019, Auckland, New Zealand
Received 26 September 2003; accepted 12 November 2003
Abstract
Reaction between Os(CO)2(PPh3)3 and Me3SnH produces Os(SnMe3)H(CO)2(PPh3)2 (1). Multinuclear NMR studies of
solutions of 1 reveal the presence of four geometrical isomers, the major one being that with mutually cis triphenylphosphine
ligands and mutually trans CO ligands. Os(SnMe3)H(CO)2(PPh3)2 undergoes a redistribution reaction, at the trimethylstannyl
ligand, when treated with Me2SnCl2 giving Os(SnMe2Cl)H(CO)2(PPh3)2 (2). Solutions of 2 again show the presence of four
isomers but now the major isomer is that with mutually trans triphenylphosphine ligands and mutually cis CO ligands. The
redistribution reaction of 1 with SnI4 produces Os(SnMeI2)H(CO)2(PPh3)2 (3) which exists in solution as only one isomer, that
with mutually trans triphenylphosphine ligands and mutually trans CO ligands. Treatment of 3 with I2 cleaves the Os–H bond
with retention of geometry giving Os(SnMeI2)I(CO)2(PPh3)2 (4). The crystal structure of 4 has been determined. No isomer-
ization of the trans dicarbonyl complex 4 occurs when 4 is heated, instead there is a formal loss of ‘‘MeSnI’’ and formation of
OsI2(CO)2(PPh3)2 (5).
Ó 2003 Elsevier B.V. All rights reserved.
Keywords: Stannyl complex; Tin; Osmium; X-ray crystal structure
1. Introduction
Me2)(CO)(PPh3)2 [5] and the iodide substituents on
the stannyl ligand in the latter complex are susceptible
to nucleophilic substitution reactions [6]. A simple and
direct route to trimethylstannyl complexes of osmium
is offered by the oxidative addition of Me3SnH to
Os(CO)2(PPh3)3. Accordingly, in this paper we report:
(i) the synthesis of Os(SnMe3)H(CO)2(PPh3)2 (1) as a
mixture of four isomers, (ii) the synthesis of
Os(SnMe2Cl)H(CO)2(PPh3)2 (2) as a mixture of four
isomers, through a redistribution reaction of 1 with
Me2SnCl2, (iii) the synthesis of Os(SnMeI2)
H(CO)2(PPh3)2 (3) as a single isomer, through a re-
distribution reaction of 1 with SnI4, and (iv) the
synthesis and structure determination of Os(SnMeI2)-
I(CO)2 (PPh3)2 (4), which again is a single isomer with
mutually trans CO ligands and mutually trans PPh3
ligands.
We have demonstrated that Os(CO)2(PPh3)3 is an
excellent substrate for the syntheses of compounds
with Os–E (E ¼ main group element) bonds, through
E–H oxidative addition reactions. Silanes [1,2],
germanes [1], and boranes [3] all readily add. One
stannane, (tolyl)3SnH, has also been added to
Os(CO)2(PPh3)3 [1] and to OsCl(NO)(PPh3)3 [4]. In-
terestingly functionalised stannyl ligands are accessible
through redistribution reactions beginning with the
trimethylstannyl ligand, e.g., Os(SnMe3)(g2-S2CNMe2)-
(CO)(PPh3)2 with SnI4 gives Os(SnMeI2)(g2-S2CN-
* Corresponding authors. Tel.: +64-9-373-7999x8320; fax: +64-9-
373-7422 (W.R. Roper).
E-mail address: w.roper@auckland.ac.nz (W.R. Roper).
0022-328X/$ - see front matter Ó 2003 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2003.11.021

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C.E.F. Rickard et al. / Journal of Organometallic Chemistry 689 (2004) 605–611
2. Results and discussion
CO
PPh3
Os
Ph3P
Ph3P
H
OC
OC
H
Os
2.1. Reaction of Os(CO)2(PPh3)3 with Me3SnH to give
Os(SnMe3)H(CO)2(PPh3)2 (1) as a mixture of four
isomers (1a–d)
SnMe3
SnMe3
CO
(54%)
PPh3
(14%)
(1a)
(1b)
Treatment of Os(CO)2(PPh3)3 with Me3SnH in
benzene under irradiation with a quartz-halogen light
source leads quickly to the colourless complex,
Os(SnMe3)H(CO)2(PPh3)2 (1) in good yield (see Scheme
1). The IR spectrum of a solid sample of 1 shows a single
band at 1913 cmꢀ1 which is assigned to m(CO) (or a
combination of m(CO) and m(Os–H)). However, in di-
chloromethane solution three bands are observed at
2008, 1978, 1926 cmꢀ1 and this spectrum did not change
with time. It is possible that one isomer crystallises
preferentially from an equilibrium mixture of isomers in
solution. These IR data are insufficient to allow unam-
biguous assignment of one or more geometrical isomers.
However, the solution NMR data do allow assignments
to be made. Although more than four isomers are the-
oretically possible for complex 1 the NMR data identi-
fies only four. These are shown in Chart 1. Compounds
of composition, OsX2(CO)2(PPh3)2 usually have a trans
arrangement of the bulky PPh3 ligands. Unexpectedly,
PPh3
PPh3
Ph3P
OC
H
H
CO
Os
Os
SnMe3
OC
SnMe3
CO
(9%)
PPh3
(23%)
(1c)
(1d)
Chart 1. Geometrical isomers of Os(SnMe3)H(CO)2(PPh3)2 (1).
spectrum, 1a shows two doublet signals, one at d, 3.2
ppm and one at d, 7.0 ppm. The 119Sn NMR spectrum
of 1a shows a doublet of doublets at d, )115.4 ppm
through coupling to one trans and one cis PPh3 ligand.
Hetero-nuclear correlation experiments substantiate the
above assignments. In a similar manner, the geometries
of the other three isomers, 1b–d, were assigned, with the
aid of correlation experiments (H–C, H–Sn, and H–P),
and details are in Section 4.
1
the major isomer, 1a (54% from H NMR data), has
mutually cis PPh3 ligands and mutually trans CO li-
2.2. Redistribution of Os(SnMe3)H(CO)2(PPh3)2 (1)
with Me2SnCl2 to give Os(SnMe2Cl)H(CO)2(PPh3)2
(2) as a mixture of four isomers (2a–d)
1
gands. In the H NMR spectrum, 1a shows a high-field
signal at d, )10.54 ppm which is a doublet of doublets
through coupling to both a trans and a cis PPh3 ligand.
In the 13C NMR spectrum, 1a shows a low-field signal at
d, 192.1 ppm for the mutually trans CO ligands, which is
an apparent triplet through coupling to the two mutu-
ally cis, but inequivalent, PPh3 ligands. In the 31P NMR
We have shown that a redistribution reaction of
Os(SnMe3)(g2-S2CNMe2)(CO)(PPh3)2 with SnI4 is an
effective way of introducing iodo-substituents into the
stannyl ligand, giving Os(SnMeI2)(g2-S2CNMe2)
(CO)(PPh3)2 [5]. We now report that treatment of
Os(SnMe3)H(CO)2(PPh3)2 with Me2SnCl2 is equally
effective for the introduction of one chloro-substituent
into the stannyl ligand forming Os(SnMe2Cl)
H(CO)2(PPh3)2 (2) (see Scheme 1). The IR spectrum of a
solid sample of 2 shows a single band at 1938 cmꢀ1
which is assigned to m(CO) (or a combination of m(CO)
and m(Os–H)). However, in dichloromethane solution
CO
CO
Ph3P
Ph3P
H
Me3SnH
PPh3
PPh3
Ph3P
Os
Os
SnMe3
CO
CO
(1)
major isomer (3 others)
Me2SnCl2
SnI4
three bands are observed at 2026, 1989, 1948 cmꢀ1
.
When compared with the corresponding data for com-
pound 1 all these bands are at higher wavenumber val-
ues as would be expected on replacing one methyl group
by a more electron-withdrawing chloro-substituent.
Again these IR data are insufficient to allow unambig-
uous assignment of geometrical isomers, but solution
NMR data allows assignments to be made. The four
identified isomers for complex 2 are shown in Chart 2.
Two isomers are now dominant (2b, 46%; 2c, 40%) and
both are different from the major isomer present for
complex 1 in that the pair of PPh3 ligands are now
mutually trans. The major isomer, 2b (46% from 1H
NMR data), has mutually trans PPh3 ligands and
PPh3
Os
PPh3
OC
OC
H
H
CO
Os
SnMe2Cl
OC
SnMeI2
PPh3
(2)
PPh3
(3)
single isomer
major isomer (3 others)
I2
PPh3
PPh3
I
CO
OC
OC
I
Os
Os
OC
SnMeI2
I
PPh3
(4)
single isomer
PPh3
(5)
Scheme 1. Synthesis and reactions of Os(SnMe3)H(CO)2(PPh3)2 (1).

C.E.F. Rickard et al. / Journal of Organometallic Chemistry 689 (2004) 605–611
607
2.4. Reaction of Os(SnMeI2)H(CO)2(PPh3)2 (3) with
I2 to give Os(SnMeI2)I(CO)2(PPh3)2 (4) and the
crystal structure of 4
CO
Os
PPh3
Os
Ph3P
Ph3P
H
OC
OC
H
SnMe2Cl
SnMe2Cl
CO
(10%)
PPh3
(2b) (46%)
Os(SnMeI2)H(CO)2(PPh3)2 (3) reacts with one
equivalent of I2 to selectively cleave the Os–H bond
rather than the Sn–Me bond to form Os(SnMeI2)
I(CO)2(PPh3)2 (4) (see Scheme 1). This reaction occurs
with retention of geometry as indicated by IR and NMR
data and confirmed by crystal structure determination
(see below). One m(CO) band is observed in the IR
spectrum at 1957 cmꢀ1. In the 13C NMR spectrum, one
triplet signal is observed at d, 183.2 ppm for the equiv-
alent trans CO ligands and in the 31P NMR spectrum a
singlet resonance is observed at d, 5.8 ppm with tin
(2a)
PPh3
Os
PPh3
H
CO
Ph3P
Os
H
OC
SnMe2Cl
OC
SnMe2Cl
PPh3
(40%)
CO
(4%)
(2c)
(2d)
Chart 2. Geometrical isomers of Os(SnMe2Cl)H(CO)2(PPh3)2 (2).
1
satellites (2J
¼ 63:1 Hz) for the equivalent trans
mutually cis CO ligands. In the H NMR spectrum, 2b
117Sn–P
PPh3 ligands. In the 119Sn NMR spectrum, a triplet
shows a high-field signal at d, )7.70 ppm which is a
triplet through coupling to the equivalent trans PPh3
ligands. In the 13C NMR spectrum, 2b shows low-field
triplet signals at d, 180.9 and 186.0 ppm for the two cis
CO ligands. In the 31P NMR spectrum, 2b shows a
singlet resonance at d, 6.1 ppm and in the 119Sn NMR
spectrum, 2b shows a triplet resonance at d, 114.0 ppm
through coupling to two equivalent trans PPh3 ligands.
In a similar manner, the geometries of the other three
isomers, 2a, c, d, were assigned, with the aid of corre-
lation experiments (H–C, H–Sn, and H–P), and details
are in Section 4.
signal is observed at d, )66.0 ppm (2J
¼ 65:7 Hz).
117Sn–P
The molecular geometry of 4 is shown in Fig. 1. Se-
lected bond lengths and angles for 4 are collected in
Table 2. The overall geometry about osmium is octa-
hedral. Os–P and Os–CO distances are unremarkable
and are not discussed further. The Os–I distance at
ꢀ
2.7718(4) A is longer than the mean of reported Os–I
ꢀ
distances (Os–I, mean ¼ 2.705 A, standard devia-
tion ¼ 0.061) [7] indicating the strong trans influence of
the trans stannyl ligand. The Os–Sn distance of
ꢀ
2.6531(4) A is intermediate between the values observed
ꢀ
for the Os–trimethylstannyl distance (2.6616(13) A) in
the complex Os(SnMe3)(g2-S2CNMe2)(CO)(PPh3)2 [6]
2.3. Redistribution of Os(SnMe3)H(CO)2(PPh3)2 (1)
with SnI4 to give Os(SnMeI2)H(CO)2(PPh3)2 (3) as a
single isomer
ꢀ
and the Os–triiodostannyl distance (2.6460(9) A) in the
complex Os(SnI3)(g2-S2CNMe2)(CO)(PPh3)2 [6]. The
ꢀ
observed Sn–I distances of 2.7727(5) and 2.7739(5) A
are close to those observed in Os(SnI3)(g2-S2CNMe2)
Treatment of Os(SnMe3)H(CO)2(PPh3)2 with excess
SnI4 is effective for the introduction of two iodo-
substituents into the stannyl ligand forming Os(SnMeI2)
H(CO)2(PPh3)2 (3) (see Scheme 1). The IR spectrum of a
solid sample of 3 shows a single band at 1964 cmꢀ1
which is assigned to m(CO) (or a combination of m(CO)
and m(Os–H)), higher than the corresponding band for
compounds 1 and 2. The trend is clear, the more methyl
groups on tin that are replaced by halo-substituents, the
higher m(CO) becomes. Unlike compounds 1 and 2,
NMR data for 3 indicates that only one isomer is
present in solution. This isomer has mutually trans PPh3
ligands, mutually trans CO ligands, and the H and
SnMeI2 located trans to one another, as depicted in
Scheme 1. In accordance with this assigned geometry the
1H NMR spectrum shows a triplet signal at d, )10.62
ꢀ
(CO)(PPh3)2 [6] (2.7598(12), 2.7688(11), 2.7602(11) A).
ppm with tin satellites (2J
¼ 233 Hz; 2J
¼
117Sn–H
119Sn–H
244 Hz). In the 13C NMR spectrum one resonance, a
triplet, is observed for the equivalent trans CO ligands at
185.8 ppm. In the 31P NMR spectrum one resonance is
observed at d, 5.9 ppm with tin satellites (2J
¼ 63:8
117Sn–P
Hz). In the 119Sn NMR spectrum a triplet signal is ob-
served at d, 69.6 ppm (2J
¼ 62:7 Hz).
117Sn–P
Fig. 1. Molecular geometry of Os(SnMeI2)I(CO)2(PPh3)2 (4).

608
C.E.F. Rickard et al. / Journal of Organometallic Chemistry 689 (2004) 605–611
The geometrical isomer observed for complex 4, with
(1H), 100.6 (13C), 149.2 (119Sn), and 162.0 (31P) MHz,
respectively. Resonances are quoted in ppm and 1H
NMR spectra referenced to either tetramethylsilane
(0.00 ppm) or the proteo-impurity in the solvent (7.25
ppm for CHCl3). 13C NMR spectra were referenced to
CDCl3 (77.00 ppm), 119Sn NMR spectra to SnMe4 (0.00
ppm), and 31P NMR spectra to 85% orthophosphoric
acid (0.00 ppm) as an external standard. Elemental
analyses were obtained from the Microanalytical Lab-
oratory, University of Otago.
mutually trans CO ligands might be expected to be un-
stable with respect to the isomer with mutually cis CO
ligands. However, heating 4 in toluene under reflux for
16 h did not lead to a rearranged product but instead led
to a formal loss of ‘‘MeSnI’’ and gave OsI2(CO)2(PPh3)2
(5). Complex 5 had mutually trans PPh3 ligands and
mutually cis CO ligands.
3. Conclusions
4.2. Preparation of Os(SnMe3)H(CO)2(PPh3)2 (1)
Oxidative addition of Me3SnH to Os(CO)2(PPh3)2 is a
simple way to introduce the trimethylstannyl ligand to an
osmium(II) complex. Os(SnMe3)H(CO)2(PPh3)2 under-
goes redistribution reactions with either Me2SnCl2
or SnI4 to give Os(SnMe2Cl)H(CO)2(PPh3)2 or Os(Sn-
MeI2)H(CO)2(PPh3)2, respectively. Spectroscopic stud-
ies indicate that in solution Os(SnMe3)H(CO)2(PPh3)2
and Os(SnMe2Cl)H(CO)2(PPh3)2 exist as a mixture of
four isomers whereas Os(SnMeI2)H(CO)2(PPh3)2 exists
as a single isomer. The preferred isomer depends on the
substituents on the stannyl ligand in these compounds:
SnMe3 favours the isomer with mutually cis PPh3 ligands
and mutually trans CO ligands, SnMe2Cl favours the
isomer with mutually trans PPh3 ligands and mutually cis
CO ligands, and SnMeI2 favours exclusively the isomer
with mutually trans PPh3 ligands and mutually trans
CO ligands. The particular isomer distribution for any
given compound is clearly a sensitive balance between
steric and electronic effects, particularly of the stannyl
ligand. It is interesting that the preferred isomer for each
of the three compounds, Os(SnMe3)H(CO)2(PPh3)2,
Os(SnMe2Cl)H(CO)2(PPh3)2, Os(SnMeI2)H(CO)2(PPh3)2,
always has the three largest ligands (two triphenyphos-
phines and the stannyl ligand) arranged meridionally,
although each compound has a different overall geom-
etry. Further rationalisation of the preferred geometries,
especially the frequent observation of isomers with
mutually trans carbonyl ligands, will require detailed
theoretical studies.
Under a nitrogen atmosphere, Me3SnH (0.098 g, 0.592
mmol) was added to
a
yellow suspension of
Os(CO)2(PPh3)3 (0.510 g, 0.494 mmol) in C6H6 (30 mL).
The reaction mixture was then irradiated with a 1000 W
quartz-halogen lamp at room temperature for ca. 30 min,
after which time it had become clear and colourless. The
volume of the solution was reduced, in vacuo, to ca. 5 mL
and ethanol (20 mL) added. Further concentration af-
forded a colourless precipitate from which all solvent was
subsequently removed in vacuo. Recrystallisation from
dichloromethane–ethanol afforeded pure 1 as colourless
crystals (0.443 g, 96%). Anal. Calc. for C41H40O2OsP2Sn:
C, 52.63; H, 4.31. Found: C, 52.62; H, 4.30%. IR (cmꢀ1):
1913 m(CO) and/or m(OsH); 2008, 1978, 1926 (CH2Cl2
solution) m(CO) and/or m(OsH).
The following NMR data are grouped according to
the isomers depicted in Chart 1. The isomer ratios given
in Chart 1 are derived from integral measurements made
1
in the H NMR spectra of the isomer mixture. The 13C
triphenylphosphine resonances could not be assigned to
individual isomers and these data are presented under a
separate heading, only once, along with the data which
could be unambiguously assigned to isomer 1a.
Isomer 1a. 1H NMR (CDCl3, d): )10.54 (dd, 1H, OsH,
2
2
2JPH ¼ 40:0 Hz, JPH ¼ 24:0 Hz, J
¼ 58:0 Hz),
117=119SnH
0.06 (s, 9H, 2J
¼ 42:8 Hz, SnMe3), 6.90–8.00 (m,
117=119SnH
PPh3 all isomers). 13C NMR (CDCl3, d): )6.1 (s,
1J
¼ 116:1 Hz, SnMe3), 192.1 (apparent t,
117=119SnC
2JPC ¼ 8:0 Hz, 2J
¼ 52:3 Hz, CO). The following
117=119SnC
PPh3 resonances are due to all four isomers. 127.9 (ap-
parent d, JPC ¼ 2:0 Hz), 128.0 (apparent d, JPC ¼ 3:0 Hz),
129.4 (apparent d, JPC ¼ 9:1 Hz), 129.9 (s), 130.0 (s), 133.2
4. Experimental
(tÕ [8], JPC ¼ 12:1 Hz), 133.3 (tÕ, JPC ¼ 12:1 Hz), 133.4 (br),
4.1. General procedures and instruments
1;3
134.0 (tÕ, JPC ¼ 6:0 Hz), 136.2 (tÕ,
J
¼ 52:3 Hz, i-
PC
PPh3), 137.1 (tÕ, 1;3JPC ¼ 52:3 Hz, i-PPh3), 137.7 (appar-
Standard laboratory procedures were followed as
have been described previously [8]. The compound
Os(CO)2(PPh3)3 [9] was prepared according to the lit-
erature method.
ent d, JPC ¼ 43:3 Hz), 137.9 (apparent d, JPC ¼ 46:3 Hz).
31P NMR (CDCl3/CH2Cl2, d): 3.2 (d, JPC ¼ 8:8 Hz,
2
2J
2J
¼ 53:5 Hz), 7.0 (d, 2JPC ¼ 8:6 Hz,
¼ 395:2 Hz). 119Sn NMR (CDCl3, d): )115.4
117=119SnP
117=119SnP
Infrared spectra (4000–400 cmꢀ1) were recorded as
Nujol mulls between KBr plates on a Perkin–Elmer
Paragon 1000 spectrometer. NMR spectra were ob-
(dd, 2J
¼ 417:8 Hz, 2J
¼ 59:7 Hz).
119SnP
119SnP
Isomer 1b. 1H NMR (CDCl3, d): )7.77 (t, 1H,
2JPH ¼ 20:0 Hz, 2J
¼ 44:0 Hz, OsH), )0.58 (s,
1
tained on a Bruker DRX 400 at 25 °C. H, 13C, 119Sn,
117=119SnH
2J
¼ 36:8 Hz, SnMe3), 6.90–8.00 (m, PPh3 all
and31P NMR spectra were obtained operating at 400.1
117=119SnH

C.E.F. Rickard et al. / Journal of Organometallic Chemistry 689 (2004) 605–611
609
isomers). 13C NMR (CDCl3, d): )5.0 (s, 1J
¼
under isomer 2a for other unassigned 13C resonances.
117=119SnC
165:5 Hz, SnMe3), 181.3 (t, 2JPC ¼ 9:1 Hz, CO), 189.1 (t,
31P NMR (CDCl3/CH2Cl2, d): 6.1 (s, 2J
¼ 179:3
117SnP
2JPC ¼ 7:0 Hz, CO). See under isomer 1a for other un-
Hz, J
¼ 186:9 Hz). 119Sn NMR (CDCl3, d): 114.0
2
119SnP
assigned 13C resonances. 31P NMR (CDCl3/CH2Cl2, d):
(t, J
¼ 188:0 Hz).
2
119SnP
2
8.8 (s, J
¼ 166:2 Hz). 119Sn NMR (CDCl3, d):
¼ 164:1 Hz).
Isomer 2c. 1H NMR (CDCl3, d): )9.25 (t, 1H,
117=119SnP
2
2
)166.8 (t, J
2JPH ¼ 20:0 Hz, J
¼ 76:0 Hz, OsH), )0.36 (s,
119SnP
117=119SnH
Isomer 1c. 1H NMR (CDCl3, d): )8.31(br t, 1H,
6H, J
¼ 33:2 Hz, SnMe2), 7.25–7.63 (m, PPh3
2
117=119SnH
2JPH ¼ 20:0 Hz, OsH), )0.24 (br s 9H, 2J
¼ 38:0
all isomers). 13C NMR (CDCl3, d): 4.9 (s,
117=119SnH
Hz, SnMe3), 6.90–8.00 (m, PPh3 all isomers). 13C NMR
1J
¼ 170:4 Hz, SnMe2), 188.0 (t, 2JPC ¼ 10:1 Hz,
117=119SnC
1
(CDCl3, d): )8.1 (s, J
¼ 193:8 Hz, SnMe3). See
CO). See under isomer 2a for other unassigned 13C
resonances. 31P NMR (CDCl3/CH2Cl2, d): 7.4 (s,
117=119SnC
under isomer 1a for other unassigned 13C resonances. 31
P
NMR (CDCl3/CH2Cl2, d): 10.2 (s, 2J
¼ 41:6 Hz).
2J
2J
¼ 58:3 Hz). 119Sn NMR (CDCl3, d): 125.7 (t,
117=119SnP
117=119SnP
119Sn NMR (CDCl3, d): )127.2 (t, 2J
¼ 37:3 Hz).
¼ 58:3 Hz).
119SnP
119SnP
Isomer 1d. 1H NMR (CDCl3, d): )7.88 (br apparent t,
1H, 2JPH ¼ 24:0 Hz, OsH), 0.09 (s, SnMe3), 6.90–8.00 (m,
PPh3 all isomers). 13C NMR (CDCl3, d): )5.7 (s, SnMe3).
See under isomer 1a for other unassigned 13C resonances.
31P NMR (CDCl3/CH2Cl2, d): 5.6 (br d, 2JPC ¼ 21:7 Hz),
Isomer 2d. 1H NMR (CDCl3, d): )7.53 (dd, 1H,
2JPH ¼ 20:0 Hz, JPH ¼ 20:0 Hz, OsH), 0.18 (s, 6H,
2
2J
¼ 37:6 Hz, SnMe2), 7.25–7.63 (m, PPh3 all
117=119SnH
isomers). 13C NMR (CDCl3, d): 2.8 (s, SnMe2). See
under isomer 2a for other unassigned 13C resonances.
31P NMR (CDCl3/CH2Cl2, d): 5.0 (br s), 5.7 (br s). 119Sn
9.5 (br d, JPC ¼ 22:4 Hz). 119Sn NMR (CDCl3, d):
2
)127.2 (dd, 2J
¼ 581:9, 2J
¼ 164:1 Hz).
NMR (CDCl3, d): 95.3 (dd, 2J
¼ 808:7 Hz,
119SnP
119SnP
119SnP
2J
¼ 189:5 Hz).
119SnP
4.3. Preparation of Os(SnMe2Cl)H(CO)2(PPh3)2 (2)
A small Schlenk tube was charged with OsH(SnMe3)-
(CO)2(PPh3)2 (0.199 g, 0.213 mmol) and SnMe2Cl2 (0.046
g, 0.213 mmol). CH2Cl2 (5 mL) was added and the re-
sulting clear, colourless solution stirred at room temper-
ature for ca. 16 h. All volatiles were removed in vacuo and
the residual colourless solid was recrystallised from
CH2Cl2/EtOH. This afforded pure 2 as colourless crystals
which were collected by vacuum filtration, washed with
EtOH (3 ꢁ 10 mL) and heptane (10 mL), and dried in
vacuo (yield 0.194 g, 91%). Anal. Calc. for
C40H37ClO2OsP2Sn: C 50.25; H 3.90. Found: C 49.97; H
4.00%. IR (cmꢀ1): 1938 m(CO) and/or m(OsH); 2026, 1989,
1948 (CH2Cl2 solution) m(CO) and/or m(OsH).
4.4. Preparation of Os(SnMeI2)H(CO)2(PPh3)2 (3)
Os(SnMe3)H(CO)2(PPh3)2 (0.352 g, 0.376 mmol)
and SnI4 (1.178 g, 1.881 mmol) were dissolved in di-
chloromethane (20 mL) and the resulting orange sus-
pension stirred at room temperature for ca. 16 h. All
volatiles were removed in vacuo and the residual or-
ange solid recrystallised from dichloromethane–ethanol
to afford pure 3 as a pale yellow microcrystalline solid
(0.392 g, 90%). Anal. Calc. for C39H34I2O2OsP2Sn: C,
40.41; H, 2.96. Found: C, 40.13; H, 2.90%. IR (cmꢀ1):
1964 m(CO). 1H NMR (CDCl3, d): )10.62 (t, 1H,
2JPH ¼ 19:1 Hz, 2J
¼ 233:4 Hz, 2J
¼ 244:1
117SnH
119SnH
Isomer 2a. 1H NMR (CDCl3, d): )10.14 (dd, 1H,
Hz, OsH), 1.09 (s, 3H, 2J
¼ 19:1 Hz, SnMe),
117=119SnH
2
2JPH ¼ 40:0 Hz, JPH ¼ 20:0 Hz, OsH), 0.48 (s, 6H,
7.37 (m, 22H, PPh3), 7.50 (m, 8H, PPh3). 13C NMR
(CDCl3, d): 12.5 (s, SnMe), 128.6 (tÕ,
o-PPh3), 130.8 (s, p-PPh3), 133.6 (tÕ,
2J
¼ 38:8 Hz, SnMe2), 7.25–7.63 (m, PPh3 all
J
J
¼ 10:1 Hz,
2;4
117=119SnH
PC
isomers). 13C NMR (CDCl3, d): 2.8 (s, SnMe2), 188.6 (t,
¼ 11:1 Hz,
3;5
PC
2JPC ¼ 9:1 Hz, CO). The following PPh3 resonances are
m-PPh3), 134.4 (tÕ,
J
¼ 54:3 Hz, i-PPh3), 185.8 (t,
1;3
PC
2;4
due to all four isomers. 128.3 (tÕ,
J
¼ 10:1 Hz,
2JPC ¼ 11:1 Hz, CO). 31P NMR (CDCl3/CH2Cl2, d):
PC
4J
¼ 65:4 Hz, o-PPh3), 129.9 (s), 130.0 (s), 130.4
5.9 (s, 2J
¼ 63:8 Hz). 119Sn NMR (CDCl3, d):
¼ 62:7 Hz).
117=119SnC
117=119SnP
2
(s), 130.4 (s), 132.9 (apparent d, JPC ¼ 11:1 Hz), 133.3
69.6 (t, J
117SnP
3;5
(apparent d, JPC ¼ 11:1 Hz), 133.5 (tÕ,
J
¼ 12:1 Hz,
PC
3;5
m-PPh3), 133.7 (tÕ,
J
¼ 10:1 Hz, m-PPh3), 135.1 (tÕ,
4.5. Preparation of Os(SnMeI2)I(CO)2(PPh3)2 (4)
PC
1;3
1;3
J
¼ 54:3 Hz, i-PPh3), 135.9 (tÕ,
J
¼ 53:3 Hz, i-
PC
PC
PPh3). 31P NMR (CDCl3/CH2Cl2, d): 0.4 (br m). 119Sn
A pale yellow solution of Os(SnMeI2)H(CO)2(PPh3)2
(0.300 g, 0.259 mmol) in dichloromethane (10 mL) was
cooled in an ice-bath and a solution of I2 (0.069 g, 0.272
mmol) in dichloromethane (10 mL) added dropwise
while stirring rapidly. All volatiles were then removed
from the resulting dark orange solution, in vacuo, and
the residual glassy orange solid recrystallised from di-
chloromethane–ethanol to afford pure 4 as a bright
yellow microcrystalline solid (0.292 g, 88%). Anal. Calc.
NMR (CDCl3, d): 106.5 (dd, 2J
¼ 614:7 Hz,
119SnP
2J
¼ 45:1 Hz).
119SnP
Isomer 2b. 1H NMR (CDCl3, d): )7.70 (t, 1H,
2JPH ¼ 16:0 Hz, 2J
¼ 148:0 Hz, 2J
¼ 152:0
117SnH
119SnH
2
Hz, OsH ), 0.25 (s, 6H, J
¼ 31:2 Hz, SnMe2),
117=119SnH
7.25–7.63 (m, PPh3 all isomers). 13C NMR (CDCl3, d):
2.9 (s, 1J
¼ 147:6 Hz, SnMe2), 180.9 (t,
117=119SnC
2JPC ¼ 9:1 Hz, CO), 186.0 (t, JPC ¼ 8:0 Hz, CO). See
2

610
C.E.F. Rickard et al. / Journal of Organometallic Chemistry 689 (2004) 605–611
for C39H33I3O2OsP2Sn: C, 36.45; H, 2.59. Found: C,
36.64; H, 2.37%. IR (cmꢀ1): 1957 m(CO). 1H NMR
4.7. X-ray crystal structure determination for complex 4
2
(CDCl3, d): 1.11 (s, 3H, J
¼ 37:1 Hz, SnMe),
X-ray data collection was by Siemens SMART dif-
fractometer with a CCD area detector using graphite
117=119SnH
7.41 (m, 22H, PPh3), 7.75 (m, 8H, PPh3). 13C NMR
2;4
ꢀ
(CDCl3, d): 13.5 (s, SnMe), 128.4 (tÕ,
o-PPh3), 130.8 (s, p-PPh3), 133.9 (tÕ,
J
¼ 10:1 Hz,
monochromated Mo Ka radiation (k ¼ 0:71073 A). Data
PC
1;3
J
¼ 56:3Hz,
were integrated and corrected for Lorentz and polarisa-
tion effects using SAINT [10]. Semi-empirical absorption
corrections were applied based on equivalent reflections
using SADABS [11]. The structure was solved by Patt-
erson and Fourier methods and refined by full-matrix
least squares using programs SHELXS [11] and
SHELXL [12]. All non-hydrogen atoms were refined
anisotropically. Hydrogen atoms were located geomet-
rically and refined using a riding model. The final electron
density map contained numerous electron density peaks,
three of which could be resolved into a half-weighted
molecule of dichloromethane. The remaining peaks could
not be resolved, sensibly, into molecules and presumably
represent further disordered dichloromethane molecules.
This density was removed using the ÔsqueezeÕ function of
PLATON [13] before the final refinement.
PC
3;5
i-PPh3), 134.6 (tÕ,
J
¼ 10:1 Hz, m-PPh3), 183.2
PC
(t, JPC ¼ 10:1 Hz, CO). 31P NMR (CDCl3/CH2Cl2, d):
2
5.8 (s, 2J
¼ 63:1 Hz). 119Sn NMR (CDCl3, d):
¼ 65:7 Hz).
117=119SnP
2
)66.0 (t, J
119SnP
4.6. Preparation of OsI2(CO)2(PPh3)2 (5)
A stirred, bright yellow suspension of Os(SnMeI2)-
I(CO)2(PPh3)2 (0.081 g, 0.063 mmol) in toluene (10 mL)
was heated under reflux for ca. 16 h, during which time a
slightly cloudy, colourless solution resulted. All volatiles
were then removed in vacuo and the residual colourless
solid recrystallised from dichloromethane–ethanol to
afford pure 5 as a colourless microcrystalline solid (0.054
g, 84%). Anal. Calc. for C38H30I2O2OsP2Sn: C, 44.55; H,
2.95. Found: C,44.31; H,2.67%. IR (cmꢀ1): 2035, 1973
Crystal data and refinement details for both struc-
tures are given in Table 1.
1
m(CO). H NMR (CDCl3, d): 7.38 (m, 22H, PPh3), 7.90
(m, 8H, PPh3). 13C NMR (CDCl3, d): 127.8
(tÕ,2;4JPC ¼ 10:3 Hz, o-PPh3), 130.7 (s, p-PPh3), 132.0 (tÕ,
Table 2
1;3
3;5
J
PC
¼ 54:7 Hz, i-PPh3), 134.9 (tÕ,
J
¼ 9:7 Hz, m-
PC
ꢀ
Selected bond lengths (A) and angles (°) for 4
PPh3), 169.9 (t, JPC ¼ 6:9 Hz, CO). 31P NMR (CDCl3/
2
Os–C(1)
Os–C(2)
Os–P(2)
Os–P(1)
Os–Sn
1.933(6)
1.952(5)
CH2Cl2, d): )28.4 (s).
2.4151(13)
2.4332(13)
2.6531(4)
2.7718(4)
2.294(5)
Table 1
Data collection and processing parameters for 4 ꢂ 0.5CH2Cl2
Os–I(1)
Sn–C(3)
Sn–I(2)
Formula
Molecular weight
Temperature (K)
C39H33I3O2OsP2Snꢂ0.5CH2Cl2
1327.65
150
2.7727(5)
2.7739(5)
1.142(7)
Sn–I(3)
O(1)–C(1)
O(2)–C(2)
ꢀ
Wavelength (A)
0.71073
Monoclinic
P21=n
12.1419(1)
23.4363(3)
16.3552(2)
94.783(1)
4637.85(9)
4
Crystal system
Space group
1.138(7)
ꢀ
a (A)
C(1)–Os–C(2)
C(1)–Os–P(2)
C(2)–Os–P(2)
C(1)–Os–P(1)
C(2)–Os–P(1)
P(2)–Os–P(1)
C(1)–Os–Sn
C(2)–Os–Sn
P(2)–Os–Sn
P(1)–Os–Sn
C(1)–Os–I(1)
C(2)–Os–I(1)
P(2)–Os–I(1)
P(1)–Os–I(1)
Sn–Os–I(1)
172.9(2)
ꢀ
b (A)
91.47(15)
90.17(15)
92.92(15)
86.87(16)
167.74(4)
87.54(15)
85.51(16)
92.03(3)
ꢀ
c (A)
b (°)
V (A )
3
ꢀ
Z
d(calc) (g cmꢀ3
)
1.90
2476
F ð000Þ
l (mmꢀ1
Crystal size (mm)
)
5.43
0.28 ꢁ 0.26 ꢁ 0.26
99.58(3)
2h (minimum and maximum) (°) 1.5 and 27.1
Reflections collected
99.03(15)
88.00(16)
83.36(3)
27,781
9982 [Rint ¼ 0:0281]
0.312 and 0.333
Independent reflections
A (minimum and maximum)
Function minimised
Goodness-of-fit on F 2
R, wR2 (observed data)
R, wR2 (all data)
84.65(3)
P
2
wðFo2 ꢀ Fc2Þ
172.035(13)
126.62(11)
100.18(11)
116.270(16)
93.13(11)
116.646(16)
98.465(15)
176.2(5)
1.089
C(3)–Sn–Os
C(3)–Sn–I(2)
Os–Sn–I(2)
0.0323, 0.0858
0.0360, 0.0885
+2.88 and )1.26
Difference map (minimum
ꢀ3
C(3)–Sn–I(3)
Os–Sn–I(3)
ꢀ
and maximum) (e A
)
P
P
P
2
R ¼ jjFoj ꢀ jFcjj= jFoj
wR2 ¼ f ½wðFo2 ꢀ Fc2Þ ꢃ
I(2)–Sn–I(3)
O(1)–C(1)–Os
O(2)–C(2)–Os
P
2
1=2
=
½wðFo2Þ ꢃg
w ¼ 1:0=½r2ðFo2Þ þ aP2 þ bPꢃ; P ¼ ðFo2 þ 2Fc2Þ=3.
178.2(5)

C.E.F. Rickard et al. / Journal of Organometallic Chemistry 689 (2004) 605–611
611
[2] C.E.F. Rickard, W.R. Roper, S.D. Woodgate, L.J. Wright, J.
Organomet. Chem. 609 (2000) 177.
5. Supplementary material
[3] G.J. Irvine, M.J.G. Lesley, T.B. Marder, N.C. Norman, C.R.
Rice, E.G. Robins, W.R. Roper, G.R. Whittell, L.J. Wright,
Chem. Rev. 98 (1998) 2685.
Crystallographic data (excluding structure factors) for
4 have been deposited with the Cambridge Crystallo-
graphic Data Centre as supplementary publication no.
219511. Copies of this information can be obtained free of
charge from the Director, CCDC, 12 Union Road,
Cambridge, CB2 1EZ, UK (Fax: +44-1223-336-033; e-mail:
deposit@ccdc.cam.ac.uk or http://www.ccdc.cam.ac.uk).
[4] A.M. Clark, C.E.F. Rickard, W.R. Roper, L.J. Wright, J.
Organomet. Chem. 543 (1997) 111.
[5] C.E.F. Rickard, W.R. Roper, T.J. Woodman, L.J Wright, Chem.
Commun. (1999) 837.
[6] A.M. Clark, C.E.F. Rickard, W.R. Roper, T.J. Woodman, L.J.
Wright, Organometallics 19 (2000) 1766.
[7] Cambridge Crystallographic Data Base.
[8] S.M. Maddock, C.E.F. Rickard, W.R. Roper, L.J. Wright,
Organometallics 15 (1996) 1793.
Acknowledgements
[9] T.J. Collins, K.R. Grundy, W.R. Roper, J. Organomet. Chem.
231 (1982) 161.
We thank the Royal Society, London, and the
Marsden Fund, administered by the Royal Society of
New Zealand, for supporting this work and for granting
Post Doctoral Fellowship awards to GRW.
[10] SAINT, Area Detector Integration Software, Siemens Analytical
Instruments Inc., Madison, WI, USA, 1995.
[11] G.M. Sheldrick, SADABS, Program for Semi-empirical Absorp-
€
tion Correction, University of Gottingen, Gottingen, Germany,
€
1997.
[12] G.M. Sheldrick, SHELXL, Program for Crystal Structure
References
€
Refinement, University of Gottingen, Gottingen, Germany,
€
1997.
[13] A.L. Spek, Acta Crystallogr., Sect. A 46 (1990) C34.
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