Some complexes containing Pt-C5-Co3 fragments: Molecular structure of trans-Pt{C≡CC≡C-μ3-C[Co 3(μ-dppm)(CO)6(PPh3)]}2(PPh 3)2 determined using synchrotron r

Article abstract of DOI:10.1016/j.jorganchem.2005.09.051

Reactions of platinum(II) chloro-phosphine complexes with Co ₃(μ₃-CCCCCSiMe₃)(μ-dppm)(CO)₇ in the presence of NaOMe have given the compounds Pt{CCCC-μ ₃-C[Co₃(μ-dppm)(CO)₇]}

Full text of DOI:10.1016/j.jorganchem.2005.09.051

Journal of Organometallic Chemistry 691 (2006) 759–764
www.elsevier.com/locate/jorganchem
Some complexes containing Pt-C5-Co3 fragments: Molecular
structure of trans-Pt{C„CC„C-l3-C[Co3(l-dppm)-
(CO)6(PPh3)]}2(PPh3)2 determined using synchrotron radiation
a,
a
b
Michael I. Bruce *, Natasha N. Zaitseva , Brian W. Skelton
a
Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia
Chemistry M313, University of Western Australia, Crawley, WA 6009, Australia
b
Received 23 August 2005; received in revised form 21 September 2005; accepted 21 September 2005
Available online 28 November 2005
Abstract
Reactions of platinum(II) chloro-phosphine complexes with Co3(l3-CC„CC„CSiMe3)(l-dppm)(CO)7 in the presence of NaOMe
have given the compounds Pt{C„CC„C-l3-C[Co3(l-dppm)(CO)7]}2(dppe) (1), trans-Pt{C„CC„C-l3-C[Co3(l-dppm)(CO)7]}2-
(PEt3)2 (2) and trans-Pt{C„CC„C-l3-C[Co3(l-dppm) (CO)6(PPh3)]}2(PPh3)2 (3), each of which contains two Co3 clusters linked by
C5 chains to the Pt centre. Electrochemical studies (CVs) show the presence of both oxidation and reduction processes, the latter prob-
ably occurring on the CCo3 cores. Ready reductive elimination of {Co3(l-dppm)(CO)7}2(l3:l3-C10) occurs from 1 upon heating. The
X-ray study of 3 was carried out using synchrotron radiation (Advanced Photon Source, Argonne, IL) to confirm its structure.
ꢀ 2005 Elsevier B.V. All rights reserved.
Keywords: Cobalt cluster; Platinum; Poly-yne; X-ray structure; Synchrotron radiation
1. Introduction
tallic systems containing odd-numbered carbon chains [6].
Recently, we were able to prepare compounds which con-
tain two C5 chains linking platinum centres with tricobalt
clusters, and to characterise one of these structurally. This
chemistry is described below.
There is continuing interest in the chemistry and proper-
ties of metal complexes containing carbon chains linking
transition metal centres [1,2]. This arises in part from their
potential as materials with potential for opto-electronic
applications [3] and as models for molecular scale wires
[4], as well as on account of their inherent interest. A con-
siderable amount of work has been reported using plati-
num(II)–phosphine complexes as end groups, which
includes the extensive studies of Gladysz and coworkers
[2b] on ever-longer chains and the construction of
sequences containing two or more platinum centres. While
our own studies of platinum complexes have so far been
limited to the construction of neutral molecular squares
containing C4 chains linking the metal centres [5], we have
recently become interested in the preparation of heterome-
2. Results and discussion
The preparation of platinum(II) alkynyl complexes by
reaction of appropriate 1-alkynes with complexes of the
type PtX2(P)2 [X = halide, cis or trans isomers for monod-
entate P = PR3, (P)2 = bidentate phosphines] in the pres-
ence of sodium methoxide was described many years ago
[7]. More recently, it has become apparent that similar
complexes are directly accessible from the often more sta-
ble trimethylsilyl-substituted alkynes, desilylation occur-
ring in situ [8]. Most recently, the in situ desilylation and
oxidative coupling of the resulting alkynes has been used
to effect the synthesis of several long chain complexes
including {trans-Pt(tol)[P(tol)3]2}2{l-(C„C)14} which
*
Corresponding author. Tel.: +618 8303 5939; fax: +618 8303 4358.
E-mail address: michael.bruce@adelaide.edu.au (M.I. Bruce).
0022-328X/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.09.051

760
M.I. Bruce et al. / Journal of Organometallic Chemistry 691 (2006) 759–764
contains the longest chain linking two metal centres that
has so far been characterised [9].
2152 cmÀ1 and terminal m(CO) bands between 2090 and
1962 cmÀ1 with a pattern characteristic of the substituted
Co3(CO)7 cluster. Resonances characteristic of the dppm
Application of the original methodology to reactions
between PtCl2(PR3)2 [(PR3)2 = dppe, PR3 = PEt3, PPh3]
and two equivalents of Co3(l3-CC„CC„CSiMe3)(l-
dppm)(CO)7 [6b] has resulted in the successful preparation
of the compounds Pt{C„CC„C-l3-C[Co3(l-dppm)-
(CO)7]}2(dppe) (1; Scheme 1), trans-Pt{C„CC„C-
l3-C[Co3(l-dppm)(CO)7]}2(PEt3)2 (2) and trans-Pt-
{C„CC„C-l3-C[Co3(l-dppm)(CO)6(PPh3)]}2(PPh3)2 (3;
Scheme 2), each of which contains two C5 chains linking
the Pt centre with Co3 clusters. The complexes are obtained
in low to moderate yields as red to brown solids which have
been characterised through a combination of elemental
analyses and spectroscopic methods and, in the case of 3,
by an X-ray structural determination.
Complex 1 was obtained in the highest yield (52%), but
on standing or heating in solution (particularly in chlori-
nated solvents), some decomposition resulted with forma-
tion of the C10 derivative {Co3(l-dppm)(CO)7}2(l3:l3-C10),
identified by comparison with an authentic sample [11].
The IR spectrum of 1 contains a weak m(CC) band at
1
and dppe ligands are found in the H and 31P NMR spec-
tra, the latter containing two signals at dP 34.0 (s, dppm)
and 40.86 [triplet with J(PPt) = 2269 Hz, dppe] in a 2/1
ratio. The magnitude of J(PPt) in the latter confirms the
expected cis geometry. In the 13C NMR spectrum, reso-
nances at d 95.30, 97.49 and 103.90 are assigned to atoms
in the C5 chain, the Co3C nucleus being too broadened
by the cobalt quadrupole to be observed, while the PtC res-
onance is probably not found because of coupling to P and
Pt. The Co–CO resonances occur at d 202.56, 210.41 and
224.31. The overall composition is confirmed by ions in
the electrospray mass spectrum (ES MS) at
m/z 2251 [M + Na]+ and 2336 [M + Ag]+, obtained from
solutions containing NaOMe or Ag+, respectively.
Thin red needles of trans-Pt{C„CC„C-l3-C[Co3(l-
dppm)(CO)7]}2(PEt3)2 (2) were obtained similarly from
trans-PtCl2(PEt3)2, but disappointingly were not suitable
for an X-ray study. The IR spectrum contained m(CC) at
2142 and m(CO) between 2079 and 1963 cmÀ1. The 1H
(CO)3
Co
PPh2
+
Ph2P
Pt
Cl
Cl
Me3Si
C
C
C
C
C
Co(CO)2
PPh2
(OC)2Co
PPh2
NaOMe /
MeOH
(CO)3
Co
PPh2
Pt
Ph2P
C
C
C
C
C
Co(CO)2
PPh2
C
(OC)2Co
PPh2
C
C
heat
C
C
{Co3(µ-dppm)(CO)7}2(µ3:µ3-C10
)
(OC)2Co
Ph2P
Co(CO)3
Co(CO)2
PPh2
(1)
Scheme 1.

M.I. Bruce et al. / Journal of Organometallic Chemistry 691 (2006) 759–764
761
(CO)3
PR3
Pt
Co
+
Cl
Cl
Me3Si
C
C
C
C
C
Co(CO)2
PPh2
PR3
(OC)2Co
PPh2
NaOMe /
MeOH
(CO)2L
Co
(CO)2L
Co
PR3
(OC)2Co
Ph2P
C
C
C
C
C
Pt
C
C
C
C
C
Co(CO)2
PPh2
PR3
Co(CO)2
(OC)2Co
PPh2
PPh2
(2) R = Et, L = CO
(3) R = Ph, L = PPh3
Scheme 2.
NMR spectrum contained the expected resonances from
the PEt3 and dppm ligands, with the corresponding 31P sig-
nals at d 12.87 [J(PPt) 2232 Hz] and 34.06, respectively,
confirming the trans geometry about Pt. No 13C NMR
spectrum could be obtained on account of the low solubil-
ity of 2 in suitable solvents.
A 30% yield of 3 was obtained from trans-PtCl2(PPh3)2
as dark brown micro crystals. The IR spectrum contained,
in addition to the m(CC) band at 2146 cmÀ1, m(CO) absorp-
tions between 2082 and 1934 cmÀ1, with a pattern suggest-
ing that the anticipated Co3(CO)7 cluster was no longer
present. There are three 31P resonances at d 18.3
[J(PPt) = 2203 Hz], 33.47 and 48.84 (ratio 1/2/1) which
can be assigned to the Pt-PPh3, dppm and Co–PPh3
ligands, respectively, found by the X-ray structure. Evi-
dently during the reaction, transfer of PPh3 from platinum
to the cobalt cluster has occurred.
values determined earlier for related compounds and merit
no further comment here.
Of most interest in the present context are the carbon
chains. Atoms C(5,10) are l3-bonded to the Co3 cluster
˚
[Co–C 1.876(8)–1.943(7) A] with bond lengths again inde-
pendent of whether the Co atom is attached to dppm or
PPh3 ligands. Along the chain from the Pt centre, the
short–long–short–long bond alternation confirms the pres-
ence of a diyndiyl unit attached to Pt at one end and to the
l3-C atom at the other, the latter separations being 1.42(1),
˚
1.38(1) A. There appears to be little if any electron delocal-
isation along the chain, perhaps not unexpected given the
difficulty of rehybridising the cluster-bonded carbon atoms.
Angles at individual carbon atoms are close to linear, rang-
ing between 172.7(8)ꢁ and 179.5(9)ꢁ.
2.2. Electrochemistry
2.1. Molecular structure of 3
We have recorded cyclic voltammograms (CVs) for the
three complexes described above. For 1, a reversible reduc-
tion wave occurs at À1.17 V and two oxidation waves at
+0.59 and +0.83 V. For 2 and 3, the reduction waves are
found at À1.17 and À1.395 V, respectively, with poorly
resolved irreversible oxidation waves at +0.82 and
+0.68 V. The reduction processes are two-electron events,
while the oxidation events appear to involve 1-e steps. We
assign the reduction events to addition of electrons to the
two CCo3 cores, these being independent of each other, sug-
gesting that there is no electronic interaction between the
two clusters. The oxidation processes probably occur on
the carbon chain or at the Pt centres and, in this connection,
we recall that the HOMOs of the neutral Pt(l-C„CC„
CH)2(dHpe) (dHpe = PH2CH2CH2PH2) are calculated to
be delocalised over the entire Pt(C4H)2 core, so that oxida-
tion processes may affect the entire molecule [5].
The small size of crystals of 3 entailed using synchrotron
radiation to procure a structure. Fig. 1 shows a plot of a
molecule of 3, selected bond distances and angles being
presented in Table 1. The central square-planar Pt atom
is attached to two PPh3 ligands [Pt–P(1,2) 2.290(2),
˚
˚
2.296(2) A] and two C5 chains [Pt–C(1,6) 2.007(8),
2.013(8) A], each pair of ligands being mutually trans
[P(1)–Pt–P(2) 173.22(8), C(1)–Pt–C(6) 179.1(3)ꢁ]. The two
C5 chains are end-capped by Co3(l-dppm)(CO)6(PPh3)
clusters of conventional geometry and dimensions [includ-
ing Co–P(dppm) 2.188–2.203(2), Co–P(PPh3) 2.212(2) and
˚
2.208(2) A] [10]. The Co–Co separations are between
˚
2.449(1) and 2.510(2) A, but show no dependence on the
positions of the tertiary phosphine ligands. Individual
distances and angles show no significant departures from

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M.I. Bruce et al. / Journal of Organometallic Chemistry 691 (2006) 759–764
132
222
221
120
110
CO(132)
CO(112)
133
CO(131)
CO(222)
130
P(22)
212
P(1)
CO(111)
CO(121)
131
CO(221)
6
5
Pt
8
1
9
Co(11)
Co(12)
233
7
3
2
Co(21)
CO(211)
CO(231)
P(11)
01
P(2)
231
210
232
112
230
P(12)
121
CO(212)
CO(232)
220
122
Fig. 1. Plot of a molecule of trans-Pt{C„CC„C-l3-C[Co3(l-dppm)(CO)6(PPh3)]}2(PPh3)2 (3).
Table 1
˚
Selected bond distances (A) and angles (ꢁ) for complex 3
˚
Bond distances (A)
Co(11)–Co(12)
Co(11)–Co(13)
Co(12)–Co(13)
Co(11)–P(11)
Co(12)–P(12)
Co(13)–P(13)
Pt–P(1)
Co(11)–C(5)
Co(12)–C(5)
Co(13)–C(5)
Pt–C(1)
2.497(2)
Co(21)–Co(22)
Co(21)–Co(23)
Co(22)–Co(23)
Co(21)–P(21)
Co(22)–P(22)
Co(23)–P(23)
Pt–P(2)
Co(21)–C(10)
Co(22)–C(10)
Co(23)–C(10)
Pt–C(6)
2.478(2)
2.476(2)
2.510(2)
2.203(2)
2.202(2)
2.208(2)
2.296(2)
1.938(8)
1.904(8)
1.943(7)
2.013(8)
1.20(1)
2.449(1)
2.484(1)
2.188(2)
2.191(2)
2.212(2)
2.290(2)
1.900(8)
1.876(8)
1.919(7)
2.007(8)
1.19(1)
C(1)–C(2)
C(6)–C(7)
C(2)–C(3)
1.37(1)
C(7)–C(8)
1.37(1)
C(3)–C(4)
1.21(1)
C(8)–C(9)
1.22(1)
C(4)–C(5)
1.42(1)
C(9)–C(10)
1.38(1)
Bond angles (ꢁ)
P(1)–Pt–P(2)
P(1)–Pt–C(1)
173.22(8)
91.8(2)
88.2(2)
C(1)–Pt–C(6)
P(2)–Pt–C(1)
P(2)–Pt–C(6)
179.1(3)
87.4(2)
92.8(2)
P(1)–Pt–C(6)
Co(11)–C(5)–C(4)
Co(12)–C(5)–C(4)
Co(13)–C(5)–C(4)
Pt–C(1)–C(2)
C(1)–C(2)–C(3)
C(2)–C(3)–C(4)
C(3)–C(4)–C(5)
127.5(6)
133.7(6)
131.9(6)
177.8(8)
173.5(8)
179.5(9)
177.8(8)
Co(21)–C(10)–C(9)
Co(22)–C(10)–C(9)
Co(23)–C(10)–C(9)
Pt–C(6)–C(7)
C(6)–C(7)–C(8)
C(7)–C(8)–C(9)
C(8)–C(9)–C(10)
126.6(6)
136.3(5)
132.0(6)
176.8(7)
175.6(8)
177.3(8)
172.7(8)
3. Conclusions
cluster acts in part as a PPh3-scavenger, with one CO ligand
on a non-dppm-bridged Co(CO)3 fragment of the cluster
being replaced by this ligand, sourced from the platinum(II)
precursor. Of some interest is the ready reductive elimina-
tion of the C5Co3 fragments from the platinum(II) centre
in 1, followed by their coupling to give the known {Co3(l-
dppm)(CO)7}2(l3:l3-C10) [6a], this reaction no doubt being
facilitated by the mutually cis orientation of these fragments
in 1. Notably, neither 2 nor 3 undergo any similar reaction.
We have made the first examples of complexes containing
odd-numbered carbon chains (C5) linking two different
metal centres. These three complexes contain eleven-atom-
C5-Pt-C5-chains, bent for 1 and approximately linear for 2
and 3. The geometries about platinum reflect those of the
precursor chloro-phosphine-platinum(II) complexes, while
in the reaction which leads to the formation of 3, the cobalt

M.I. Bruce et al. / Journal of Organometallic Chemistry 691 (2006) 759–764
763
4. Experimental
(CO)7}2(dppe) (1) (43.3 mg, 52%), obtained as a brown
solid. Anal. Calc. for C100H68Co6O14P6Pt: C, 53.91; H,
3.08. Found: C, 54.00; H, 3.03%. M, 2228. IR (CH2Cl2,
cmÀ1): m(CC) 2152vw; m(CO) 2090vw, 2054s, 2006vs, 1982
4.1. General
1
All reactions were carried out under dry nitrogen,
although normally no special precautions to exclude air
were taken during subsequent work-up. Common solvents
were dried, distilled under argon and degassed before use.
Separations were carried out by preparative thin-layer
chromatography on glass plates (20 · 20 cm2) coated with
silica gel (Merck, 0.5 mm thick).
(sh), 1962 (sh). H NMR: d 2.62 (m, 4H, CH2), 3.25, 4.44
(2 · m, 2 · 2H, dppm), 6.99–7.93 (m, 60H, Ph). 13C
NMR: d 29.97 (m, dppe), 41.07 [s (br), dppm], 95.30,
97.49, 103.90 (carbon chain), 128.28–136.36 (m, Ph),
202.56, 210.41, 224.31 [3 · s (br), Co–CO]. 31P NMR: d
34.1 [s (br), dppm], 40.86 [t, J(PPt) = 2269 Hz, dppe], ratio
2/1. ES-MS (positive ion, MeOH + NaOMe, m/z): 2251,
[M + Na]+; (CH2Cl2/MeOH + Ag+, m/z): 2336, [M +
Ag]+.
4.2. Instruments
Slow decomposition occurs in solution (especially in
chlorinated solvents) to give as one product {Co3(l-
dppm)(CO)7}2(l3:l3-C10), identified by comparison (IR,
t.l.c.) with an authentic sample [6a].
IR spectra were obtained on a Bruker IFS28 FT-IR
spectrometer. Spectra in CH2Cl2 were obtained using a
0.5 mm path-length solution cell with NaCl windows.
Nujol mull spectra were obtained from samples mounted
between NaCl discs. NMR spectra were recorded on a Var-
ian 2000 instrument (1H at 300.13 MHz, 13C at 75.47 MHz,
31P at 121.503 MHz) with solutions in CDCl3 contained in
5 mm sample tubes. Chemical shifts are given in ppm rela-
tive to internal tetramethylsilane for 1H and 13C NMR
spectra and external H3PO4 for 31P NMR spectra. Electro-
spray mass spectra (ESMS) were obtained from samples
dissolved in MeOH unless otherwise indicated. Solutions
were injected into a Varian Platform II spectrometer via
a 10 ml injection loop. Nitrogen was used as the drying
and nebulising gas. Chemical aids to ionisation were used
[11]. Electrochemical samples (1 mM) were dissolved in
CH2Cl2 containing 0.5 M [NBu4]BF4 as the supporting
electrolyte for the spectro-electrochemical experiments.
Cyclic voltammograms were recorded using a PAR model
263 apparatus, with a saturated calomel electrode, with fer-
rocene as internal calibrant (FeCp2/[FeCp2]+ = +0.46 V).
A 1 mm path-length cell was used with a Pt-mesh working
electrode, Pt wire counter and pseudo-reference electrodes.
Elemental analyses were by CMAS, Belmont, Vic.,
Australia.
4.5. trans-Pt{C„CC„C-l3-C[Co3(l-dppm)(CO)7}2 -
(PEt3)2 (2)
A
solution of Co3(l3-CC„CC„CSiMe3)(l-dppm)-
(CO)7 (50 mg, 0.056 mmol) in thf/MeOH (12 ml, 10/2)
was treated with an excess of NaOMe in MeOH. After
15 min, trans-PtCl2(PEt3)2 (14.6 mg, 0.028 mmol) was
added and the mixture was stirred for 5 h. at r.t. Removal
of solvent, extraction of the residue with CH2Cl2 and sep-
aration by preparative t.l.c. (acetone/hexane 3/7) gave one
major band (Rf 0.56) which contained trans-
Pt{C„CC„C-l3-C[Co3(l-dppm)(CO)7}2(PEt3)2
(2)
(8.6 mg, 15%), obtained as thin red needles. Anal. Calc.
C86H77Co6O14P6Pt: C, 50.00; H, 3.61. Found: C, 49.98;
H, 3.65%. M, 2066. IR (CH2Cl2, cmÀ1): m(CC) 2152vw;
m(CO) 2090vw, 2054s, 2006vs, 1982 (sh), 1962 (sh). 1H
NMR: d 1.25 (m, 18H, PCH2Me), 2.15 (m, 12H, PCH2Me),
3.35, 4.49 (2 · m, 2 · 2H, dppm), 7.10–7.50 (m, 40H, Ph).
31P NMR: d 12.87 [t, J(PPt) 2232, PEt3], 34.06 [s (br),
dppm], ratio 1/2.
4.6. trans-Pt{C„CC„C-l3-C[Co3(l-dppm)(CO)6-
(PPh3)}2(PPh3)2 (3)
4.3. Reagents
PtCl2(dppe) [12], trans-PtCl2(PR3)2 (R = Et, Ph) [13]
and Co3(l3-CC„CC„CSiMe3)(l-dppm)(CO)7 [6b] were
obtained by the cited methods.
A mixture of trans-PtCl2(PPh3)2 (22 mg, 0.028 mmol)
and Co3(l3-CC„CC„CSiMe3)(l-dppm)(CO)7 (50 mg,
0.056 mmol) dissolved in thf/MeOH (22 ml, 10/1) was
treated with NaOMe in MeOH (excess, 1 ml) and left to
stir overnight. Removal of solvent and extraction of the
residue with CH2Cl2 was followed by separation by
preparative t.l.c. (acetone–hexane 3/7). The major
green-brown band (Rf 0.32) afforded dark red microcrys-
tals of trans-Pt{C„CC„C-l3-C[Co3(l-dppm)(CO)6-
(PPh3)}2(PPh3)2 (3) (22.7 mg, 29%) from C6H6/MeOH,
initially identified by an X-ray structural determination.
An analytical sample was obtained from CH2Cl2/MeOH.
Anal. Calc. for C144H104Co6O12P8Pt Æ 2CH2Cl2: C, 58.61;
H, 3.64. Found: C, 58.14; H, 3.64%. M (unsolvated),
2823. IR (CH2Cl2, cmÀ1): m(CC) 2146w; m(CO) 2082w,
4.4. Pt{C„CC„C-l3-C[Co3(l-dppm)(CO)7}2(dppe) (1)
PtCl2(dppe) (25 mg, 0.038 mmol) was dissolved in a mix-
ture of thf and MeOH (13 ml, 10/3) by stirring for 30 min
at 40 ꢁC. Addition of Co3(l3-CC„CC„CSiMe3)(l-
dppm)(CO)7 (67 mg, 0.076 mmol) and NaOMe (excess in
MeOH, 1 ml) was followed by stirring overnight at r.t.
The filtered solution was then evaporated and the residue
extracted into CH2Cl2 and purified by preparative t.l.c.
(acetone/hexane 1/2). The major green-brown band
(Rf 0.16) contained Pt{C„CC„C-l3-C[Co3(l-dppm)-

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M.I. Bruce et al. / Journal of Organometallic Chemistry 691 (2006) 759–764
2056m, 2022s, 1986vs (br), 1968s (br), 1934 (sh). 1H NMR:
UK (Fax: +44 1223 336 033; e-mail: deposit@ccdc.cam.
ac.uk or www: http://www.ccdc.cam.ac.uk).
d 2.90, 3.94 (2 · m, 2 · 2H, dppm), 5.30 [s (br), CH2Cl2],
7.05–7.77 (m, 100H, Ph). 31P NMR:
d 18.30 [t,
J(PPt) = 2203 Hz, Pt-PPh3], 33.37 [s (br), dppm], 48.84 [s
Acknowledgements
(br), Co-PPh3], ratio 1/2/1.
We thank the ARC for support. Use of the ChemMat-
CARS Sector 15 at the Advanced Photon Source was sup-
ported by the Australian Synchrotron Research Program,
which is funded by the Commonwealth of Australia under
the Major National Research Facilities Program. Chem-
MatCARS Sector 15 is also supported by the National Sci-
ence Foundation/Department of Energy under Grant Nos.
CHE9522232 and CHE0087817 and by the Illinois Board
of Higher Education. The Advanced Photon Source is sup-
ported by the US Department of Energy, Basic Energy
Sciences, Office of Science, under Contract No. W-31-
109-Eng-38.
4.7. Structure determination
Full spheres of diffraction data were measured at ca.
103 K using a synchrotron (Sector 15 of the Advanced
Photon Source at the Argonne National Laboratory,
Argonne, IL, USA). 189533 reflections were merged to
25204 unique (Rint 0.085) after ‘‘empirical’’/multiscan
absorption correction (proprietary software) and used in
the full-matrix least-squares refinements on F2. All data
were measured using synchrotron radiation, k =
˚
0.48595 A. Anisotropic displacement parameter forms
were refined for the non-hydrogen atoms. All solvent mol-
ecules were resolved and refined, one only being refined as
a rigid body and with site occupancy set at 0.5 after initial
trial refinement. Conventional residuals are R [I > 2r(I)] =
0.071, Rw(F2) = 0.137 [weights: (r2(F2) + 21F2)À1]. Neutral
atom complex scattering factors were used; computation
used the XTAL 3.7 program system [14]. Pertinent results
are given in Fig. 1 (which shows non-hydrogen atoms with
50% probability amplitude displacement ellipsoids and
References
[1] M.I. Bruce, P.J. Low, Adv. Organomet. Chem. 50 (2004) 179.
[2] (a) R. Dembinski, T. Bartik, B. Bartik, M. Jaeger, J.A. Gladysz, J.
Am. Chem. Soc. 122 (2000) 810;
(b) W. Mohr, J. Stahl, F. Hampel, J.A. Gladysz, Chem. Eur. J. 9
(2003) 3324.
´
[3] J.L. Bredas, R.R. Chance (Eds.), Conjugate Polymeric Materials:
Opportunities in Electronics, Optoelectronics and Molecular Elec-
tronics, Kluwer, Dordrecht, 1990.
[4] (a) F. Paul, C. Lapinte, in: M. Gielen, R. Willem, B. Wrackmeyer
(Eds.), Unusual Structures and Physical Properties in Organometallic
Chemistry, Wiley, New York, 2002, p. 220;
˚
hydrogen atoms with arbitrary radii of 0.1 A) and in
Table 1.
(b) F. Paul, C. Lapinte, Coord. Chem. Rev. 178–180 (1998) 431.
[5] M.I. Bruce, K. Costuas, J.-F. Halet, B.C. Hall, P.J. Low, B.K.
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White, J. Organomet. Chem. 670 (2003) 170;
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4.8. Crystal and refinement data
trans-Pt{C„CC„C-l3-C[Co3(l-dppm)(CO)6(PPh3)]}2-
(PPh3)2 Æ 3.5C6H6„C144H104Co6O12P8Pt Æ 3.5C6H6, Mw =
3096.27. Monoclinic, space group P21/c, a = 17.332(1), b=
3
˚
˚
19.426(2), c = 41.744(3) A, b = 97.409(3), V = 13938 A ,
Z = 4. 2hmax = 34.0ꢁ. Dc = 1.476 g cmÀ3, l = 0.64 mmÀ1
,
Tmin/max = 0.37. Crystal 0.11 · 0.05 · 0.003 mm.
[9] Q. Zheng, J.A. Gladysz, J. Am. Chem. Soc. 127 (2005) 10508.
[10] M.I. Bruce, K.A. Kramarczuk, G.J. Perkins, B.W. Skelton, A.H.
White, N.N. Zaitseva, J. Cluster Sci. 15 (2004) 119.
5. Supplementary material
[11] W. Henderson, J.S. McIndoe, B.K. Nicholson, P.J. Dyson, J. Chem.
Soc., Dalton Trans. (1998) 519.
[12] K. Yasufuku, H. Noda, H. Yamazaki, Inorg. Synth. 26 (1989) 369.
[13] F.R. Hartley, Organomet. Chem. Rev. A 6 (1970) 119.
[14] S.R. Hall, D.J. Du Boulay, R. Olthof-Hazekamp (Eds.), The XTAL 3.7
System, University of Western Australia, Perth, 2000.
Full details of the structure determinations (except
structure factors) have been deposited with the Cambridge
Crystallographic Data Centre as CCDC 280612. Copies of
this information may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge CB2 1EZ,