Platinum metal ditelluroether complexes: Synthesis, spectroscopic and structural studies of [M(L-L)2][PF6]2 [M = Pd or Pt, L-L = RTe(CH2)3TeR (R = Me or Ph) or

Article abstract of DOI:10.1039/a901942a

The reaction of [MCl₂(MeCN)₂] (M = Pd or Pt) with L-L (RTe(CH₂)₃TeR (R = Me or Ph) or C₆H₄(TeMe)₂-o) and TlPF₆ in a 1:2:2 ratio in MeCN gave planar [M(L-L)₂][PF₆]₂ which was confirmed by an X-ray crystallographic study of [Pd{meso-C₆H₄(TeMe)₂-o}₂][PF ₆]₂. The complexes trans-[Ru(L-L)₂X₂] (X = Cl, Br or I) were prepared from [Ru(dmf)₆][CF₃SO₃]₃, L-L and LiX, whilst [Ru(PPh₃)₃Cl₂], L-L and NH₄PF₆ gave /ra/-[Ru(L-L)₂(PPh₃)CI]PF₆. The crystal structure of [Ru{MeTe(CH₂)₃TeMe}₂(PPh ₃)Cl][PF₆] revealed one ditelluroether in the mesa form and the other in the DL, the first time both stereoisomers have been crystallographically identified in the same compound. In contrast in trans-[Ru{PhTe(CH₂)₃TePh}₂Cl₂] both ditelluroethers are meso forms. For Pd, Pt and Ru multinuclear NMR spectroscopy (¹H, ¹²⁵Te-{¹H}, ¹⁹⁵Pt) showed a mixture of stereoisomeric forms in solution, and for the compounds of Pd and Pt pyramidal inversion at Te is fast on the NMR timescales at ambient temperatures. Reaction of RhCl₃·3H₂O, L-L and NH₄PF₆ gave [Rh(L-L)₂Cl₂]PF₆ which appear to be predominantly trans isomers based upon their NMR and UV/vis spectra. Attempts to oxidise the complexes of Pt^II or Ru^II (to Pt^IV or Ru^III) with halogens or electrochemically were unsuccessful, contrasting with the successful oxidation of analogous complexes with dithioether or diselenoether ligands.

Full text of DOI:10.1039/a901942a

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Platinum metal ditelluroether complexes: synthesis, spectroscopic
and structural studies of [M(L–L)2][PF6]2 [M ؍ Pd or Pt,
L–L ؍ RTe(CH2)3TeR (R ؍ Me or Ph) or C6H4(TeMe)2-o],
[Rh(L–L)2Cl2]PF6, [Ru(L–L)2X2] (X ؍ Cl, Br or I) and
[Ru(L–L)2(PPh3)Cl]PF6
William Levason, Simon D. Orchard, Gillian Reid and Vicki-Ann Tolhurst
Department of Chemistry, University of Southampton, Southampton, UK SO17 1BJ
Received 11th March 1999, Accepted 7th May 1999
The reaction of [MCl2(MeCN)2] (M = Pd or Pt) with L–L (RTe(CH2)3TeR (R = Me or Ph) or C6H4(TeMe)2-o)
and TlPF6 in a 1:2:2 ratio in MeCN gave planar [M(L–L)2][PF6]2 which was confirmed by an X-ray crystallographic
study of [Pd{meso-C6H4(TeMe)2-o}2][PF6]2. The complexes trans-[Ru(L–L)2X2] (X = Cl, Br or I) were prepared from
[Ru(dmf)6][CF3SO3]3, L–L and LiX, whilst [Ru(PPh3)3Cl2], L–L and NH4PF6 gave trans-[Ru(L–L)2(PPh3)Cl]PF6.
The crystal structure of [Ru{MeTe(CH2)3TeMe}2(PPh3)Cl][PF6] revealed one ditelluroether in the meso form and
the other in the , the first time both stereoisomers have been crystallographically identified in the same compound.
In contrast in trans-[Ru{PhTe(CH2)3TePh}2Cl2] both ditelluroethers are meso forms. For Pd, Pt and Ru multinuclear
NMR spectroscopy (1H, 125Te-{1H}, 195Pt) showed a mixture of stereoisomeric forms in solution, and for the
compounds of Pd and Pt pyramidal inversion at Te is fast on the NMR timescales at ambient temperatures. Reaction
of RhCl3ؒ3H2O, L–L and NH4PF6 gave [Rh(L–L)2Cl2]PF6 which appear to be predominantly trans isomers based
upon their NMR and UV/vis spectra. Attempts to oxidise the complexes of PtII or RuII (to PtIV or RuIII) with
halogens or electrochemically were unsuccessful, contrasting with the successful oxidation of analogous complexes
with dithioether or diselenoether ligands.
are rather less useful for the bis(ditelluroether) complexes in the
Introduction
present study. The possible combinations of meso or  di-
Chelating ditelluroethers including RTe(CH2)3TeR (R = Me or
telluroethers for planar M(L–L)2 or trans M(L–L)2X2 moieties
Ph) and C6H4(TeMe)2-o (L–L) were first reported about 10
result in five possible isomers (invertomers), containing eight
years ago,1,2 and a range of platinum metal halide complexes
distinct tellurium centres, although all possible isomers need
not be present in significant amounts. For lower symmetry trans
M(L–L)2XY or cis M(L–L)2X2 even more resonances are pre-
with a 1:1 metal:ditelluroether ratio were subsequently charac-
terised, including [M(L–L)X2] (M = Pd or Pt, X = Cl, Br or I),3,4
[Ir(L–L)X4]Ϫ,4 and [{Ir(L–L)Cl3}n].5 Far fewer complexes with
dicted. The isomers interconvert by pyramidal inversion at Te, a
a 2:1 ditelluroether:metal ratio are known, examples being
process whose energy depends upon the metal centre present,
limited to some unstable cobalt() complexes6 and homoleptic
the ligand structure, chelate ring size, and ligands trans to Te.9
compounds of CuI and AgI.7 More recently, ditelluroether
The complexity of the spectra and in some cases the con-
complexes of Group 6 metal carbonyls and Group 7 carbonyl
sequences of the onset of pyramidal inversion means that
halides have been obtained.8 However it remains true that far
assignment of resonances to particular invertomers is not pos-
less is known about tellurium donor ligands than their thio- or
sible, although usually the geometric isomer(s) present can be
seleno-ether analogues. Here we report the synthesis of some
complexes of Pd, Pt, Rh and Ru with a 2:1 ditelluroether:M
ratio, their spectroscopic and structural characterisation, and
an exploration of the redox chemistry of the platinum and
ruthenium complexes. The ligand properties of the ditelluro-
ethers are compared with those of Se, S and Group 15 donor
analogues.
identified. For the planar [M(L–L)2]2ϩ (M = Pd or Pt) the
Te-trans-Te arrangement lowers inversion barriers due to the
high trans influence of tellurium, and at room temperature the
1H NMR spectra of all the complexes show broad features,
sometimes with ill defined splittings, showing that inversion
processes are present. Similarly at 300 K the 125Te-{1H} NMR
spectra show very broad features typical of systems near to
coalescence. On cooling the spectra sharpen and for the plat-
inum complexes individual resonances resolve, but even at 210
K inversion still leads to significant broadening and 195Pt satel-
lites are not resolved. Consistent with this, none of the platinum
complexes exhibited a 195Pt NMR spectrum at ambient temper-
atures, but on cooling a solution of [Pt{C6H4(TeMe)2-o}2]2ϩ to
210 K broad resonances appeared at δ Ϫ4790 and Ϫ4760,
which are entirely reasonable shifts for a PtIITe4 centre. The
Results and discussion
Palladium and platinum
The reaction of [MCl2(MeCN)2] (M = Pd or Pt) with a large
excess of the ditelluroether affords only the [M(L–L)Cl2] com-
plexes.3,4 However, if the halide is removed with TlPF6 the
products are the yellow or orange [M(L–L)2][PF6]2 (L–L =
RTe(CH2)3TeR, R = Me or Ph, or C6H4(TeMe)2-o). Co-
ordinated ditelluroethers exist as two diastereoisomers, meso
(with syn R groups) and  (anti R groups).9 Proton and espe-
cially 125Te-{1H} NMR spectroscopies have proved very useful
in assigning structures to many ditelluroether complexes,3–8 but
structure of [Pd{C6H4(TeMe)2-o}2][PF6]2ؒMeCN reveals
a
square planar cation with the Pd on an inversion centre, co-
ordinated to two meso ditelluroether ligands (Fig. 1, Table 1).
The Te–Pd–Te angles are very close to 90Њ, with Pd–Te
2.5716(4)–2.5789(5) Å, markedly longer than Pd–Te in
J. Chem. Soc., Dalton Trans., 1999, 2071–2076
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Table 1 Selected bond lengths (Å) and angles (Њ) for [Pd{C6H4-
(TeMe)2-o}2][PF6]2ؒMeCN
Table 2 Selected bond lengths (Å) and angles (Њ) for [Ru{MeTe-
(CH2)3TeMe}2(PPh3)Cl]PF6
Te(1)–Pd(1)
Te(1)–C(4)
Te(2)–C(5)
Te(3)–Pd(2)
Te(3)–C(13)
Te(4)–C(10)
2.5716(4)
2.132(8)
2.112(9)
2.5732(5)
2.120(7)
2.118(7)
Te(1)–C(3)
Te(2)–Pd(1)
Te(2)–C(6)
Te(3)–C(12)
Te(4)–Pd(2)
Te(4)–C(11)
2.120(7)
2.5789(5)
2.116(7)
2.112(9)
2.5781(5)
2.136(8)
Te(11)–Ru(1)
Te(11)–C(12)
Te(12)–C(14)
Te(21)–Ru(1)
Te(21)–C(22)
Te(22)–C(24)
Ru(1)–Cl(1)
2.650(1)
2.14(1)
2.18(1)
2.647(1)
2.17(1)
2.12(1)
2.467(4)
Te(11)–C(11)
Te(12)–Ru(1)
Te(12)–C(15)
Te(21)–C(21)
Te(22)–Ru(1)
Te(22)–C(25)
Ru(1)–P(1)
2.13(1)
2.655(1)
2.16(2)
2.16(1)
2.636(1)
2.12(1)
2.304(4)
Pd(1)–Te(1)–C(3)
C(3)–Te(1)–C(4)
Pd(1)–Te(2)–C(6)
Pd(2)–Te(3)–C(12)
C(12)–Te(3)–C(13)
Pd(2)–Te(4)–C(11)
Te(1)–Pd(1)–Te(2)
102.3(2)
93.6(3)
102.4(2)
99.4(3)
92.8(3)
99.7(2)
89.98(1)
Pd(1)–Te(1)–C(4)
Pd(1)–Te(2)–C(5)
C(5)–Te(2)–C(6)
Pd(2)–Te(3)–C(13)
Pd(2)–Te(4)–C(10)
C(10)–Te(4)–C(11)
Te(3)–Pd(2)–Te(4)
98.3(2)
100.5(2)
92.8(3)
103.2(2)
102.7(2)
93.6(3)
Ru(1)–Te(11)–C(11)
C(11)–Te(11)–C(12)
Ru(1)–Te(12)–C(15)
Ru(1)–Te(21)–C(21)
C(21)–Te(21)–C(22)
Ru(1)–Te(22)–C(25)
Te(11)–Ru(1)–Te(12)
Te(11)–Ru(1)–Te(22)
Te(11)–Ru(1)–P(1)
Te(12)–Ru(1)–Te(22)
Te(12)–Ru(1)–P(1)
Te(21)–Ru(1)–Cl(1)
Te(22)–Ru(1)–Cl(1)
Cl(1)–Ru(1)–P(1)
105.2(5)
90.7(6)
108.0(4)
114.3(4)
91.8(6)
109.2(4)
89.00(4)
177.59(5)
89.61(9)
89.96(4)
92.09(9)
78.21(9)
90.35(9)
176.3(1)
Ru(1)–Te(11)–C(12)
Ru(1)–Te(12)–C(14)
C(14)–Te(12)–C(15)
Ru(1)–Te(21)–C(22)
Ru(1)–Te(22)–C(24)
C(24)–Te(22)–C(25)
Te(11)–Ru(1)–Te(21)
Te(11)–Ru(1)–Cl(1)
101.2(3)
107.0(4)
96.2(6)
109.0(4)
106.9(4)
91.6(6)
89.67(1)
92.25(4)
87.47(9)
Te(12)–Ru(1)–Te(21) 168.15(5)
Te(12)–Ru(1)–Cl(1)
Te(21)–Ru(1)–Te(22)
Te(21)–Ru(1)–P(1)
Te(22)–Ru(1)–P(1)
90.09(9)
88.33(4)
99.69(9)
92.60(9)
Fig. 1 View of the structure of one of the two independent [Pd{C6H4-
(TeMe)2-o}2]2ϩ cations with numbering scheme adopted (the other
cation is essentially indistinguishable). Atoms marked * are related by a
centre of inversion at Pd. Ellipsoids are drawn at 40% probability.
[Pd{PhTe(CH2)3TePh}Br2]3 (2.528(1), 2.525(1) Å) and con-
sistent with the relative trans influence Te > Br. Attempts to
oxidise the [Pt(L–L)2]2ϩ to PtIV using Cl2 were unsuccessful,
causing decomposition of the complexes, and treatment of
either the palladium or platinum cations with LiCl in MeCN
resulted in displacement of one ditelluroether and the form-
ation of the corresponding [M(L–L)Cl2].3,4
Ruthenium
Fig. 2 View of the structure of [Ru{MeTe(CH2)3TeMe}2(PPh3)Cl]ϩ
with numbering scheme adopted. Ellipsoids are drawn at 40%
probability.
Direct reaction of the ditelluroethers with RuCl3ؒnH2O proved
generally unsatisfactory, although one example trans-[Ru{C6H4-
(TeMe)2-o}2Cl2] has been obtained by this route.10 Entry into
the ruthenium chemistry was achieved by reaction of the
ligands with [Ru(PPh3)3Cl2] in the presence of NH4PF6, [Ru-
(dmso)4Cl2] or [Ru(dmf)6][CF3SO3]3.11 The first reaction gave
trans-[Ru(L–L)2(PPh3)Cl]PF6 as orange-brown powders, whilst
use of [Ru(dmso)4Cl2] afforded trans-[Ru(L–L)2Cl2]. A more
general route to trans-[Ru(L–L)2X2] (X = Cl, Br or I) was reac-
tion of [Ru(dmf)6][CF3SO3]3 with L–L and LiX in EtOH. The
ruthenium() complexes are air-stable in the solid state; solubil-
ity in organic solvents decreases in the order Cl > Br > I with
the iodides in particular very poorly soluble in chlorocarbons
or MeCN, which limited solution spectroscopic studies.
The structure determination of a yellow crystal of [Ru{Me-
Te(CH2)3TeMe}2(PPh3)Cl]PF6 revealed a trans cation with one
meso and one  form of the ditelluroether (Fig. 2, Table 2), the
first time both forms have been identified crystallographically
in one complex. The d(Ru–P) 2.304(4) Å and d(Ru–Cl) 2.467(4)
Å are similar to those found12 in trans-[Ru{[16]aneSe4}-
(PPh3)Cl]PF6 ([16]aneSe4 = 1,5,9,13-tetraselenacyclohexadec-
ane), 2.307(6), 2.499(5) Å respectively. The d(Ru–Te) lie in
the range 2.636(1)–2.655(1) Å, the first examples of RuII–Te
bond lengths reported. The 31P-{1H} NMR of this complex
shows a strong resonance at δ 51.5 and the corresponding 125Te-
{1H} NMR has four major resonances of similar intensities at
δ 177, 262, 274 and 371 which show doublet splittings of 30–60
2
Hz attributable to J(31P–125Te). Much weaker peaks at 53.1
(31P) and 249 (125Te) are assigned to a second isomer. The spec-
tra are consistent with the form identified in the solid state
being the major invertomer in solution: although there is no
requirement that the form in the crystal should be the major
solution form, studies of several diselenoether systems have
shown this is often true in practice.13 The trans-[Ru{PhTe-
(CH2)3TePh}2(PPh3)Cl]PF6 shows two major 31P NMR reson-
ances of approximately equal intensity (δ 44.8, 46.0) and five
125Te resonances in the range δ 500–550, suggesting two inver-
tomers are present in significant amounts. In the case of trans-
[Ru{C6H4(TeMe)2-o}2(PPh3)Cl]PF6 two 31P resonances (δ 52.0,
44.8) are associated with five 125Te resonances (δ 870–785), one
of which (δ 842) is very much more intense than the rest, sug-
gesting this is an invertomer with both ligands in the meso form.
This complex also decomposes slowly on standing in CH2Cl2
solution in air, developing new 31P resonances at δ 26.0 and 27.2.
This is consistent with the co-ordinated PPh3 being oxidised
to OPPh3, a reaction observed in other ruthenium complexes.14
Cyclic voltammetry revealed that the complexes undergo
irreversible oxidation at ca. 1.2 V in CH2Cl2 solution (vs. Fc–
Fcϩ at 0.49 V), showing that RuIII is not stable when surrounded
by tellurium donors (Te4PCl donor set).
2072
J. Chem. Soc., Dalton Trans., 1999, 2071–2076

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Table 3 Selected bond lengths (Å) and angles (Њ) for [Ru{PhTe-
(CH2)3TePh}2Cl2]
inability to isolate ruthenium() ditelluroether complexes is a
further example of the reduced ability of these ligands to stab-
ilise higher oxidation states of transition metals compared
to their lighter analogues. Phosphorus or arsenic donor
ligands form quite stable ruthenium() complexes as trans-
[Ru(bidentate ligand)2X2]ϩ cations, and most exhibit electro-
chemically reversible RuII–RuIII couples.17
Te(1)–C(11)
Te(1)–Ru(1)
Te(2)–C(3)
Ru(1)–Cl(1)
2.142(5)
2.6247(3)
2.150(6)
Te(1)–C(1)
Te(2)–C(21)
Te(2)–Ru(1)
2.153(6)
2.147(6)
2.6194(3)
2.4389(13)
C(11)–Te(1)–C(1)
C(1)–Te(1)–Ru(1)
C(21)–Te(2)–Ru(1)
Cl(1)–Ru(1)–Te(2)
Te(2)–Ru(1)–Te(1)
89.9(2)
C(11)–Te(1)–Ru(1)
C(21)–Te(2)–C(3)
C(3)–Te(2)–Ru(1)
Cl(1)–Ru(1)–Te(1)
111.38(15)
91.2(2)
104.46(16)
87.71(3)
105.15(17)
110.93(14)
87.62(3)
Rhodium
The reaction of RhCl3ؒ3H2O, L–L and NH4PF6 in EtOH gave
deep orange [Rh(L–L)2Cl2]PF6. The ESϩ mass spectra show ion
multiplets with the correct isotope patterns for [Rh(L–L)2Cl2]ϩ,
and the presence of PF6Ϫ anions is confirmed by the IR spectra
which show the expected bands at ca. 840 (ν(P–F)) and ca. 560
cmϪ1 (δ(PF2)). We have been unable to grow crystals of any of
87.255(11)
Ϫ
Ϫ
these rhodium compounds, either with PF6 or ClO4 anions,
suitable for an X-ray study. The UV/vis spectra each show a
d–d band at ca. 21 000 cmϪ1 which is consistent with trans
geometric isomers (cis isomers have d–d bands at higher energy,
often obscured by charge-transfer transitions).18 The 1H NMR
spectra are complex revealing a number of invertomers are
present. Poor solubility made recording the 125Te-{1H} NMR
spectra difficult, but after very long accumulations the spec-
trum of [Rh{MeTe(CH2)3TeMe}2Cl2]ϩ showed a number of
doublets with δ 250–300 and with the 1J(125Te–103Rh) couplings
of 50–70 Hz. The spectrum of [Rh{PhTe(CH2)3TePh}2Cl2]ϩ
was similar. However, for [Rh{C6H4(TeMe)2-o}2Cl2]ϩ the 125Te-
{1H} NMR spectrum showed, in addition to seven major
doublets, some evidence for a number of weaker features which
may be due to the second geometric isomer (cis). It is notable
that, for dithioether or diselenoether (LЈ–LЈ) ligands, direct
reaction with RhCl3ؒ3H2O leads to mixtures of trans- and cis-
[Rh(LЈ–LЈ)2Cl2]Cl and [{Rh(LЈ–LЈ)Cl3}n]18 and pure trans
isomers were obtained by oxidative addition to rhodium()
analogues.18,19
Fig. 3 View of the structure of [Ru{PhTe(CH2)3TePh}2Cl2] with
numbering scheme adopted. Atoms marked * are related by a centre of
inversion at Ru. Ellipsoids are drawn at 40% probability.
The orange [Ru(L–L)2Cl2] are air-stable solids, moderately
soluble in chlorocarbons and poorly soluble in MeCN. The
crystal structure of triclinic crystals of [Ru{PhTe(CH2)3TePh}2-
Cl2] (Fig. 3, Table 3) revealed a trans geometry with the Ru on
an inversion centre and the ditelluroether ligands have meso
arrangements. The d(Ru–Cl) 2.4389(13) Å is shorter than that
in the chlorophosphine complex (above), consistent with the
expected trans influence order P > Cl, but is similar to those
in other trans Cl–RuII–Cl arrangements in for example
trans-[Ru(PhSeCH2CH2SePh)2Cl2] (2.413(1), 2.444(1) Å)10 or
Experimental
Infrared spectra were measured as CsI discs using a Perkin-
Elmer 983 spectrometer over the range 200–4000 cmϪ1, UV/vis
spectra were recorded in solution using 1 cm path length quartz
cells on a Perkin-Elmer Lambda19 spectrometer. Mass spectra
were run by fast-atom bombardment (FAB) using 3-nitrobenzyl
alcohol as matrix on a VG Analytical 70-250-SE Normal
Geometry Double Focusing Mass Spectrometer or by positive
electrospray (ESϩ) using a VG Biotech Platform. The 1H NMR
spectra were recorded using a Bruker AM300 spectrometer
operating at 300 MHz, 125Te-{1H}, 31P-{1H} and 195Pt NMR
spectra on a Bruker AM360 spectrometer operating at 113.6,
145.8 and 77.4 MHz respectively and referenced to neat Me2Te,
85% H3PO4 and aqueous [PtCl6]2Ϫ. Microanalyses were per-
formed by the microanalytical service of Strathclyde University.
Electrochemical studies used an Eco Chemi PGstat20 with Pt
working and auxiliary electrodes.
trans-[Ru{H C᎐C(PPh ) } Cl ] (2.431(1) Å).15 The d(Ru–Te)
᎐
2
2
2
2
2
(2.6194(3), 2.6247(3) Å) are slightly shorter than in the chloro-
1
phosphine. The H and 125Te-{1H} NMR spectra show that
several diastereoisomers are present in solution, in particular
the latter has a strong resonance at δ 638 due to a high sym-
metry form with all four tellurium sites identical (possibly the
form present in the crystal), and six weaker resonances. The
UV/vis spectra show two bands in the region 18 000–25 000
cmϪ1 as expected for low spin d6 metal centres in local D4h
symmetry.16 The characterisation of [Ru(L–L)2Cl2] (L–L =
C6H4(TeMe)2-o or MeTe(CH2)3TeMe) and the corresponding
bromo- and iodo-complexes was achieved by analysis and ESϩ
mass spectrometry, and their assignment as trans isomers
follows from the similar spectra to those of the dichloro-
compounds. Multinuclear NMR spectroscopy was less success-
ful due to their poor solubility, and convincing 125Te NMR
spectra were not observed from saturated CH2Cl2 solutions of
the bromo- or iodo-complexes after ca. 2 × 106 scans. Cyclic
voltammetry was used to study the oxidation of these com-
Preparations
[Pd{MeTe(CH2)3TeMe}2][PF6]2. The complex [PdCl2-
(MeCN)2] (82 mg, 0.32 mmol) and TlPF6 (226 mg, 0.65 mmol)
were stirred in MeCN (30 cm3) for 30 min under a dinitrogen
atmosphere. The compound MeTe(CH2)3TeMe (221 mg, 0.68
mmol) in MeCN (5 cm3) was then added and the reaction
stirred at room temperature for 18 h to give a yellow solution
and fine white precipitate (TlCl). The solution was filtered to
remove the TlCl, reduced to ca. 2 cm3 in vacuo and diethyl ether
(10 cm3) added to precipitate a yellow solid. Yield: 220 mg, 65%
(Found: C, 11.4; H, 2.3. C10H24F12P2PdTe4 requires C, 11.4; H,
2.3%). 1H NMR (CD3CN): (CH2CH2) δ 2.3 (br) [1H]; (TeCH3)
2.4 (s) [3H]; and (CH2Te) 2.9 (m) [2H]. 125Te-{1H} NMR
(Me2CO–CDCl3, 300 K): δ 198–219 (vbr). IR/cmϪ1: 2957w,
plexes. In CH2Cl2 containing 0.1 mol dmϪ3 NBun BF4 freshly
4
prepared solutions of the dichloro-complexes showed irrevers-
ible or quasi-reversible oxidations at ca. ϩ0.5–0.8 V (vs. Fc–Fcϩ
at 0.49 V), the waves diminishing rapidly on repetitive scans
consistent with deposition of material onto the electrodes.
This behaviour contrasts with [Ru(L–L)2Cl2] (L–L = various
dithioether or diselenoether ligands)10,17 which show reversible
RuII–RuIII couples at less positive potentials, and for which the
ruthenium() complexes can be isolated by halogen oxidation
of the corresponding ruthenium() complex in CH2Cl2. Treat-
ment of CH2Cl2 solutions of [Ru(ditelluroether)2Cl2] with Cl2
gave dark brownish solutions, which rapidly decomposed. Our
J. Chem. Soc., Dalton Trans., 1999, 2071–2076
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2924w, 1425w, 1357s, 1279s, 1212w, 1095m, 987m, 832s, 739w,
709m, 613w and 556s. UV/vis (MeCN)/cmϪ1 (εmol/dm3 molϪ1
cmϪ1): 26 660 (19 800).
[Ru{PhTe(CH2)3TePh}2(PPh3)Cl][PF6]. Yield 89% (Found: C,
39.9; H, 3.4. C48H47Cl2F6P2RuTe4 requires C, 39.8; H, 3.3%). 1H
NMR (CDCl3): δ 7.88–6.25 (Ph) and 2.96–2.23 (CH2). 31P-{1H}
NMR (CDCl3–CH2Cl2): δ 44.8, 46.0 (PPh3) and Ϫ145 (septet,
PF6). 125Te-{1H} NMR (CDCl3–CH2Cl2): δ 500, 508.5, 511.5,
525.5 and 544 (2J(31P–125Te) couplings poorly resolved). ESϩ
(MeCN): m/z = 933, 893 and 852; calc. for [102Ru{Ph130Te-
The following complexes were prepared similarly.
[Pd{PhTe(CH2)3TePh}2][PF6]2. Yield 70% (Found: C, 27.9;
H, 2.3. C30H32F12P2PdTe4 requires C, 27.7; H, 2.5%). 1H NMR
(CD3CN): (CH2CH2) δ 2.6 (br) [1H]; (CH2Te) 3.1 (br) [2H]; and
(TePh) 7.58 (m) [5H]. 125Te-{1H} NMR (Me2CO–CDCl3, 300
K): δ ca. 485, 580 and 605. IR/cmϪ1: 1570w, 1470w, 1432w,
1357s, 1260w, 1210w, 1093s, 1018w, 996m, 840s, 728m, 686m,
615w, 557s and 452w. UV/vis (MeCN)/cmϪ1 (εmol/dm3 molϪ1
cmϪ1): 26 380 (33 300).
(CH2)3130TePh}35Cl(PPh3) ϩ 2MeCN]ϩ 937,
[
102Ru{Ph130Te-
102Ru{Ph-
(CH2)3130TePh}35Cl(PPh3) ϩ MeCN]ϩ 896 and
[
130Te(CH2)3130TePh}35Cl(PPh3)]ϩ 855. IR/cmϪ1: 1576w, 1479m,
1435m, 1358m, 1261w, 1085m, 1018w, 997w, 835s, 732m, 690m,
555m, 530m, 450w, 428w, 280w and 256w. UV/vis (MeCN)/
cmϪ1 (εmol/dm3 molϪ1 cmϪ1): 23 000 (300), 26 200 (1055) and
32 500 (6490).
[Pd{C6H4(TeMe)2-o}2][PF6]2. Yield 80% (Found: C, 17.6; H,
1
1.8. C16H20F12P2PdTe4 requires C, 17.2; H, 1.8%). H NMR
[Ru{C6H4(TeMe)2-o}2(PPh3)Cl][PF6]. Yield 37% (Found: C,
32.0; H, 2.5. C34H35ClF6P2RuTe4 requires C, 32.2; H, 2.8%). 1H
NMR (CDCl3): δ 1.95–2.5 (m, CH3) and 7.3–8.0 (m, C6H4).
31P-{1H} NMR (CDCl3–CH2Cl2): δ 44.8, 52.0 (PPh3) and Ϫ143
(septet, PF6). 125Te-{1H} NMR (CDCl3–CH2Cl2): δ 785, 797,
842 (major), 854 and 870 (2J(31P–125Te) couplings of ca. 30–55
Hz poorly resolved). ESϩ (MeCN): m/z = 1123, 902 and 862;
calc. for [102Ru{C6H4(130TeMe)2-o}235Cl(PPh3)]ϩ 1131, [102Ru-
(CD3CN): (TeCH3) δ 2.6 (s) [3H] and (C6H4) 7.8 (m) [2H]. 125Te-
{1H} (Me2CO–CDCl3, 300 K): δ 770–825 (br). IR/cmϪ1: 1356s,
1093s, 985m, 834s, 756m, 613w and 556m. UV/vis (MeCN)/
cmϪ1 (εmol/dm3 molϪ1 cmϪ1): 26 600 (23 900).
[Pt{MeTe(CH2)3TeMe}2][PF6]2. Yield 80% (Found: C, 11.0;
1
H, 2.0. C10H24F12P2PtTe4 requires C, 10.5; H, 2.1%). H NMR
{C6H4(130TeMe)2}235Cl ϩ MeCN]ϩ 910 and
[
102Ru{C6H4-
(CD3CN): (CH2CH2) δ 2.24 (q) [1H]; (TeCH3) 2.43 (s) [3H];
and (CH2Te) 3.02 (t) [2H]. 125Te-{1H} NMR (Me2CO–CDCl3,
300 K): δ 195, 196, 200, 201 and 202. IR/cmϪ1: 2922w, 2853w,
1357s, 1262vw, 1228w, 1205w, 1092s, 986w, 834s, 613w and
557s. UV/vis (MeCN)/cmϪ1 (εmol/dm3 molϪ1 cmϪ1): 30 770 (sh)
(8300).
(
130TeMe)2}235Cl]ϩ 869. IR/cmϪ1 1478m, 1431m, 1408m,
1356m, 1256w, 1217w, 1087s, 1024w, 998w, 957w, 840s, 747m,
697m, 615w, 557m, 526m, 462w, 428w, 327w, 298w, 216w and
201w.
[Ru{MeTe(CH2)3TeMe}2Cl2]. Method 1. The complex [Ru-
(dmf)6][CF3SO3]3 (151 mg, 0.155 mmol), MeTe(CH2)3TeMe
(100 mg, 0.307 mmol) and LiCl (42 mg, 0.991 mmol) in EtOH
(70 cm3) were refluxed for 4 h. The solvent was removed in vacuo
and CH2Cl2 added (2 cm3). The orange solution was filtered and
Et2O added to precipitate an orange solid. Yield: 40 mg, 32%
(Found: C, 13.9; H, 3.1. C10H24Cl2RuTe4 requires C, 14.5; H,
[Pt{PhTe(CH2)3TePh}2][PF6]2. Yield 76% (Found: C, 26.0;
H, 2.1. C30H32F12P2PtTe4 requires C, 26.0; H, 2.3%). H NMR
1
(CD3CN): (CH2CH2) δ 2.5 (br) [1H]; (CH2Te) 3.0 (br) [1H]; 3.26
(br) [1H]; and (TePh) 7.58 (m) [5H]. 125Te-{1H} NMR (Me2CO–
CDCl3, 300 K): δ 570–580 (br). IR/cmϪ1: 3070w, 1569w, 1471w,
1357m, 1210w, 1093m, 1015w, 996m, 838s, 732m, 689m, 613w,
557s and 453w. UV/vis (MeCN)/cmϪ1 (εmol/dm3 molϪ1 cmϪ1):
29 950 (8400) and 33 330 (16 600).
1
2.9%). H NMR (CDCl3): δ 2.0–3.32 (m). ESϩ (MeCN): m/z =
834, 793 and 754; calc. for [102Ru{Me130Te(CH2)3130TeMe}2-
35Cl ϩ MeCN]ϩ 842, [102Ru{Me130Te(CH2)3130TeMe}235Cl]ϩ 801
and [102Ru{Me130Te(CH2)3130TeMe}2]ϩ 766. IR/cmϪ1: 2918w,
1356s, 1270m, 1227w, 1151m, 1090m, 1028m, 834w, 636m,
516w and 216w. UV/vis (MeCN)/cmϪ1 (εmol/dm3 molϪ1 cmϪ1):
21 000 (180), 24 600 (540) and 38 300 (18 235).
Method 2. The complex [Ru(dmso)4Cl2] (71 mg, 0.129 mmol)
and MeTe(CH2)3TeMe (87 mg, 0.267 mmol) in MeOH were
refluxed for 3 h. The solvent was reduced to ca. 1 cm3 in vacuo
and Et2O added to afford a light orange precipitate. Yield 84
mg, 78%.
[Pt{C6H4(TeMe)2-o}2][PF6]2. Yield 75% (Found: C, 15.9; H,
1
1.6. C16H20F12P2PtTe4 requires C, 15.9; H, 1.7%). H NMR
(CD3CN): (TeCH3) δ 2.6 (m) [3H]; and (C6H4) 7.84 (m) [2H].
125Te-{1H} NMR (MeCN–CD3CN, 300 K): δ 692 and 720 (m).
195Pt-{1H} (Me2CO–CDCl3, 210 K): δ Ϫ4790 and Ϫ4760.
IR/cmϪ1: 1357s, 1261w, 1092s, 987m, 839s, 743m, 613m and
557s. UV/vis (MeCN)/cmϪ1 (εmol/dm3 molϪ1 cmϪ1): 32 800
(14 700).
[Ru{MeTe(CH2)3TeMe}2(PPh3)Cl][PF6].
The
complex
Unless indicated otherwise, the ruthenium complexes below
were made by method 1 using the appropriate LiX.
[RuCl2(PPh3)3] (372 mg, 0.39 mmol) and MeTe(CH2)3TeMe
(274 mg, 0.84 mmol) were refluxed for 3 h under a dinitrogen
atmosphere in EtOH (40 cm3). The orange solution was cooled
to room temperature after which NH4PF6 (221 mg, 1.36 mmol)
was added. A light orange precipitate was formed immediately.
The reaction mixture was refluxed for 10 min. After cooling,
the solution was reduced to ca. 2 cm3 in vacuo and the yellow-
orange precipitate collected. Yield 428 mg, 92% (Found: C,
28.0; H, 3.3. C28H39ClF6P2RuTe4 requires C, 28.1; H, 3.3%). 1H
NMR (CDCl3): δ 1.2–2.6 (CH2 ϩ CH3) and 7.4–7.6 (Ph). 31P-
{1H} NMR (CDCl3–CH2Cl2): δ 51.5 (br, s), 53.1 (PPh3) and
Ϫ143 (septet, PF6). 125Te-{1H} NMR (CDCl3–CH2Cl2): δ 177
(Ϫ), 249 (2J(31P–125Te) = 50), 262 (2J = 30), 274 (2J = 60) and 371
(2J = 55 Hz). ESϩ (MeCN): m/z = 1055, 833 and 792; calc. for
[Ru{MeTe(CH2)3TeMe}2Br2]. Yield 49% (Found: C, 12.7;
1
H, 2.5. C10H24Br2RuTe4 requires C, 13.1; H, 2.6%). H NMR
(CDCl3): δ 1.98–2.93 (CH2, CH3). ESϩ (MeCN): m/z = 878 and
839; calc. for [102Ru{Me130Te(CH2)3130TeMe}279Br ϩ MeCN]ϩ
886 and [102Ru{Me130Te(CH2)3130TeMe}279Br]ϩ 845. IR/cmϪ1
2918w, 1357s, 1272m, 1092s, 1028m, 987w, 834m, 636m,
534w, 248w and 229w. UV/vis (MeCN)/cmϪ1 (εmol/dm3 molϪ1
cmϪ1) 19 200 (570), 24 700 (1575) and 36 250 (1978).
[Ru{MeTe(CH2)3TeMe}2I2]. Yield 16% (Found: C, 11.3; H,
2.5. C10H24I2RuTe4 requires C, 11.9; H, 2.4%). 1H NMR
(CDCl3): δ 2.02–2.32 (CH2, CH3). ESϩ (MeCN): m/z = 1053 and
884; calc. for [102Ru{Me130Te(CH2)3130TeMe}2I ϩ MeCN]ϩ 1061
and [102Ru{Me130Te(CH2)3130TeMe}2I]ϩ 893. IR/cmϪ1: 2918w,
1358s, 1092m, 834m, 614w, 511w and 217w.
[
102Ru{Me130Te(CH2)3130TeMe}235Cl(PPh3)]ϩ 1053, [102Ru{Me-
130Te(CH2)3130TeMe}235Cl ϩ MeCN]ϩ 842 and
[
102Ru{Me-
130Te(CH2)3130TeMe}235Cl]ϩ 801. IR/cmϪ1: 1581w, 1478w,
1430m, 1412m, 1357m, 1274w, 1219w, 1086m, 995w, 960w,
840s, 753w, 704m, 614w, 557s, 516s, 480w, 423w, 279w, 246w
and 204w. UV/vis (MeCN)/cmϪ1 (εmol/dm3 molϪ1 cmϪ1): 25 200
(630) and 37 740 (22 440).
[Ru{PhTe(CH2)3TePh}2Cl2]. From [Ru(dmso)4Cl2] as above
(82%) (Found: C, 33.0; H, 3.0. C30H32Cl2RuTe4 requires C, 33.5;
2074
J. Chem. Soc., Dalton Trans., 1999, 2071–2076

View Article Online
Table 4 Crystallographic data collection and refinement parameters
[Pd{C6H4(TeMe)2-o}2]-
[Ru{PhTe(CH2)3-
TePh}2Cl2]
[Ru{MeTe(CH2)3TeMe}2-
(PPh3)Cl]PF6
[PF6]2ؒMeCN
Formula
M
C18H23F12NPdTe4
1160.11
C30H32Cl2RuTe4
592.22
C28H39ClF6P2RuTe4
1198.48
Crystal system
Space group
Triclinic
P1
Triclinic
P1
Monoclinic
P21/c
¯
¯
a/Å
b/Å
c/Å
α/Њ
8.9645(6)
18.896(2)
8.9325(5)
94.536(6)
95.649(5)
99.533(7)
1478.0(2)
2
10.3523(4)
10.7860(4)
11.1139(5)
114.60(4)
107.14(4)
102.42(4)
993.33(7)
1
9.296(3)
30.811(2)
12.732(3)
β/Њ
105.40(2)
γ/Њ
U/Å3
3515(1)
4
2.264
Z
Dc/g cmϪ3
2.607
2.203
µ(Mo-Kα)/cmϪ1
Absorption correction
(maximum and minimum
transmission factors)
Unique obs. reflections
Obs. reflections with [Io > 2σ(Io)]
No. parameters
R
46.94
—
38.35
0.859, 0.458
39.18
1.000, 0.865
5223
4284
355
0.031
0.035
5594
6316
3723
379
0.045
0.051
206
0.050a
0.118a
RЈ
a R1, wR2 (I > 2σ(I )) 0.076, 0.013 (all data).
1
H, 3.0%). H NMR (CDCl3): δ 1.86–3.75 (12 H, m, CH2) and
6.91–7.92 (10 H, m, C6H5). 125Te-{1H} NMR (CDCl3–CH2Cl2):
δ 545.6, 587.7, 592.6, 606.9, 637.6, 644.5 and 653.4. ESϩ
(MeCN): m/z = 1038; calc. for [102Ru{Ph130Te(CH2)3130TePh}2-
35Cl]ϩ 1049. IR/cmϪ1: 3049w, 2929w, 1572m, 1474m, 1432s,
1413m, 1359s, 1261w, 1195w, 1098m, 1018m, 997m, 875w,
793w, 727s, 690s, 530w, 453m, 305w, 258w and 225w. UV/vis
(MeCN)/cmϪ1 (εmol/dm3 molϪ1 cmϪ1): 20 600 (240) and 24 300
(750).
Me)2}2I ϩ MeCN]ϩ 1002 and [102Ru{C6H4(130TeMe)2}2I]ϩ 961.
IR/cmϪ1: 2929w, 1593s, 1358s, 1076m, 883w, 747w, 598w, 511w
and 254m. UV/vis (diffuse reflectance)/cmϪ1: 20 900, 25 200
and 31 200.
[Rh{MeTe(CH2)3TeMe}2Cl2]PF6. The compounds RhCl3ؒ
3H2O (51 mg, 0.194 mmol) and MeTe(CH2)3TeMe (125 mg,
0.384 mmol) in EtOH (30 ml) were refluxed for 30 min, NH4PF6
(41 mg, 0.252 mmol) was then added and stirred at room tem-
perature for 1 h. The resulting orange precipitate was collected
and washed with diethyl ether. Yield: 76 mg, 41% (Found: C,
12.3; H, 1.7. C10H24Cl2F6PRhTe4 requires C, 12.4; H, 2.5%). 1H
NMR (CD3CN): δ 2.7–2.9 (CH3 ϩ CH2) and 3.0–3.1 (CH2).
125Te-{1H} NMR (CDCl3–CH2Cl2): δ 250.5 (1J(125Te–103Rh) 60),
259.5 (60), 283.4 (50), 292 (70), 300 (Ϫ) and 300.5 (68). ESϩ
(MeCN): m/z = 831; calc. for [Rh{Me130Te(CH2)3130TeMe}2-
35Cl2]ϩ 837. IR/cmϪ1: 1359s, 1262w, 1220w, 1203m, 1090m,
994w, 837s, 745w, 612w, 558m, 331m and 203w. UV/vis
(MeCN)/cmϪ1 (εmol/dm3 molϪ1 cmϪ1): 21 800 (1250).
[Ru{PhTe(CH2)3TePh}2Br2]. Brown powder. Yield: 21%
(Found: C, 31.3; H, 2.9. C30H32Br2RuTe4 requires C, 31.0;
1
H, 2.8%). H NMR (CDCl3): δ 2.65–3.93 (12 H, m, CH2) and
6.91–7.87 (20 H, m, C6H5). ESϩ (MeCN): m/z = 1083; calc. for
[
102Ru{Ph130Te(CH2)3130TePh}279Br]ϩ 1093. IR/cmϪ1: 1473w,
1433m, 1358m, 1198w, 1061m, 998w, 740m, 689m, 671m, 610m,
454m and 223w.
[Ru{C6H4(TeMe)2-o}2Cl2]. Yield 78% (Found: C, 21.2; H, 2.4.
C16H20Cl2RuTe4 requires C, 21.5; H, 2.3%). 1H NMR (CDCl3):
δ 1.20–2.65 (6 H, m, CH3) and 7.38–7.93 (4 H, m, C6H5). 125Te-
{1H} NMR (CDCl3–CH2Cl2): δ 804, 885, 890, 893, 894, 914
and 917. ESϩ (MeCN): m/z = 901 and 859; calc. for [102Ru-
The following complexes were made similarly.
[Rh{PhTe(CH2)3TePh}2Cl2]PF6. Yield 84% (Found: C, 29.7;
H, 1.5. C30H32Cl2F6PRhTe4 requires C, 29.5; H, 2.6%). 1H
NMR ((CD3)2SO): δ 2.9–3.5 (CH2) and 7.1–7.8 (Ph). 125Te-{1H}
NMR (CDCl3–CH2Cl2): δ 481.5 (1J(125Te–103Rh) 75), 492 (72),
534 (70), 540 (Ϫ), 542 (75) and 558 (80). ESϩ (MeCN):
m/z = 1077; calc. for [Rh{Ph130Te(CH2)3130TePh}235Cl2]ϩ 1085.
IR/cmϪ1: 1571w, 1474m, 1434m, 1358m, 1264w, 1206w, 1091m,
1017w, 997m, 837s, 731m, 690m, 654w, 613w, 557m, 451m,
339w, 255w and 226w. UV/vis (MeCN)/cmϪ1 (εmol/dm3 molϪ1
cmϪ1): 21 350 (1700).
{C6H4(130TeMe)2}235Cl ϩ MeCN]ϩ 910 and
[
102Ru{C6H4-
(
130TeMe)2}235Cl]ϩ 869. IR/cmϪ1: 1438w, 1410w, 1358s, 1260w,
1098m, 831w, 803w, 749m, 594s, 248w and 209w. UV/vis
(MeCN)/cmϪ1 (εmol/dm3 molϪ1 cmϪ1): 20 300 (110) and 25 900
(1300).
[Ru{C6H4(TeMe)2-o}2Br2]. Yield 45% (Found: C, 18.9; H, 2.0.
C16H20Br2RuTe4 requires C, 19.5; H, 2.1%). 1H NMR (CDCl3):
δ 2.13–2.97 (6 H, m, CH3) and 7.40–7.97 (4 H, m, C6H5). ESϩ
(MeCN): m/z = 946 and 904; calc. for [102Ru{C6H4(130Te-
Me)2}279Br ϩ MeCN]ϩ 954 and [102Ru{C6H4(130TeMe)2}279Br]ϩ
913. IR/cmϪ1: 2929w, 2852w, 1356s, 1256w, 1089m, 991w,
834w, 746w, 638w and 542w. UV/vis (MeCN)/cmϪ1 (εmol/dm3
molϪ1 cmϪ1): 21 500 (800) and 25 840 (2520).
[Rh{C6H4(TeMe)2-o}2Cl2]PF6. Yield 65% (Found: C, 18.6; H,
1.7. C16H20Cl2F6PRhTe4 requires C, 18.45; H, 1.9%). 1H NMR
((CD3)2SO): δ 2.3–2.7 (Me) and 7.4–7.8 (C6H4). 125Te-{1H}
NMR (CDCl3–CH2Cl2): δ 799 (1J(125Te–103Rh) 90), 814 (Ϫ),
840.3 (70), 840.5 (70), 848.5 (70), 861 (55), 869 (80) and 891.5
(70). ESϩ (MeCN): m/z = 898; calc. for [Rh{C6H4(130TeMe)2}2-
35Cl2]ϩ 905. IR/cmϪ1: 2935w, 1665w, 1355m, 1259w, 1087s,
992sh, 842s, 751m, 561m, 421m, 327w, 303w, 251w and
208m. UV/vis (MeCN)/cmϪ1 (εmol/dm3 molϪ1 cmϪ1): 21 400
(1380).
[Ru{C6H4(TeMe)2-o}2I2]. Yield 32% (Found: C, 13.9; H, 3.1.
1
C16H20I2RuTe4 requires C, 14.5; H, 2.9%). H NMR (CDCl3):
δ 2.31–2.54 (6 H, CH3) and 7.30–7.44 (4 H, m, C6H5). ESϩ
(MeCN): m/z = 998 and 950; calc. for [102Ru{C6H4(130Te-
J. Chem. Soc., Dalton Trans., 1999, 2071–2076
2075

View Article Online
Crystal structures of [Pd{C6H4(TeMe)2-o}2][PF6]2ؒMeCN,
[Ru{PhTe(CH2)3TePh}2Cl2] and [Ru{MeTe(CH2)3TeMe}2-
(PPh3)Cl]PF6
References
1 E. G. Hope, T. Kemmitt and W. Levason, Organometallics, 1988, 7,
78.
2 T. Kemmitt and W. Levason, Organometallics, 1989, 8, 1303.
3 T. Kemmitt, W. Levason and M. Webster, Inorg. Chem., 1989, 28,
692.
4 T. Kemmitt and W. Levason, Inorg. Chem., 1990, 29, 731.
5 R. A. Cipriano, L. R. Hanton, W. Levason, D. Pletcher, N. A.
Powell and M. Webster, J. Chem. Soc., Dalton Trans., 1988, 2483.
6 J. L. Brown, T. Kemmitt and W. Levason, J. Chem. Soc., Dalton
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7 J. R. Black and W. Levason, J. Chem. Soc., Dalton Trans., 1994,
3225; J. R. Black, N. R. Champness, W. Levason and G. Reid,
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the press.
9 E. W. Abel, K. G. Orrell, S. P. Scanlan, D. Stevenson, T. Kemmitt
and W. Levason, J. Chem. Soc., Dalton Trans., 1991, 591; E. W. Abel,
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Merbach and A. Ludi, Inorg. Chem., 1995, 34, 5080.
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13 E. W. Abel, I. Moss, K. G. Orrell, V. Sik, D. Stephenson, P. A. Bates
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17 N. R. Champness, W. Levason, D. Pletcher and M. Webster,
J. Chem. Soc., Dalton Trans., 1992, 3243.
Details of the crystallographic data collection and refinement
parameters are given in Table 4. For [Pd{C6H4(TeMe)2-o}2]-
[PF6]2ؒMeCN and [Ru{MeTe(CH2)3TeMe}2(PPh3)Cl]PF6 data
collection used a Rigaku AFC7S four-circle diffractometer
operating at 150 K and graphite-monochromated Mo-Kα
X-radiation (λ = 0.71073 Å). The data for [Ru{MeTe(CH2)3-
TeMe}2(PPh3)Cl]PF6 were corrected for absorption using
ψ-scans. The structures were solved by heavy atom methods20
and developed by iterative cycles of full-matrix least-squares
refinement21 and Fourier-difference syntheses. All non-H
atoms were refined anisotropically and H atoms were placed in
fixed, calculated positions. The complex [Pd{C6H4(TeMe)2-o}2]-
[PF6]2ؒMeCN shows two independent half-cations with inver-
Ϫ
sion symmetry, two PF6 anions on general positions and two
disordered half MeCN solvent molecules in the asymmetric
unit. The latter are disordered across inversion centres such that
the methyl C atom of one form is superimposed on the cyano C
atom of the other form and vice versa, with the inversion centre
at the midpoint of this C–C vector. The H atoms associated
with the MeCN molecules were not located from the difference
map and therefore were omitted from the final structure factor
calculation.
For [Ru{PhTe(CH2)3TePh}2Cl2] data collection used an
Enraf-Nonius Kappa CCD diffractometer operating at 150 K
and Mo-Kα X-radiation (λ = 0.71073 Å). The data were cor-
rected for absorption using SORTAV.22 The structures were
solved by heavy atom methods20 and refined using SHELXL
97.23 The molecule has crystallographic i symmetry (at Ru). All
non-H atoms were refined anisotropically and H atoms were
placed in fixed, calculated positions.
18 D. J. Gulliver, E. G. Hope, W. Levason, S. G. Murray and G. L.
Marshall, J. Chem. Soc., Dalton Trans., 1985, 1265.
19 R. A. Walton, J. Chem. Soc. A, 1967, 1852; J. Chatt, G. J. Leigh and
A. P. Storace, J. Chem. Soc. A, 1971, 899.
20 PATTY, The DIRDIF Program System, P. T. Beurskens, G.
Admiraal, G. Beurskens, W. P. Bosman, S. Garcia-Granda, R. O.
Gould, J. M. M. Smits and C. Smykalla, Technical Report of the
Crystallography Laboratory, University of Nijmegen, 1992.
21 TEXSAN, Crystal Structure Analysis Package, Molecular Structure
Corporation, Houston, Texas, 1995.
CCDC reference number 186/1454.
See http://www.rsc.org/suppdata/dt/1999/2071/ for crystallo-
graphic files in .cif format.
Acknowledgements
22 R. H. Blessing, Acta Crystallogr., Sect. A, 1995, 51, 33; J. Appl.
We thank EPSRC for support (to V.-A. T. and S. D. O.) and
Johnson Matthey plc for generous loans of platinum metal
salts. We also thank Professor M. B. Hursthouse and Dr S.
Coles for collecting X-ray data for [Ru{PhTe(CH)3TePh}2Cl2].
Crystallogr., 1997, 30, 421.
23 G. M. Sheldrick, SHELXL-97, University of Göttingen, 1997.
Paper 9/01942A
2076
J. Chem. Soc., Dalton Trans., 1999, 2071–2076