The synthesis of new bimetallic complex salts by halide/sulfur chelate cross transfer: X-ray crystal structures of the salts [Ni(S2CNEt2)(dppe)]2[HgBr4], [Pt(S2CNEt2)dppe)]2[CdCl4]

Article abstract of DOI:10.1016/S0277-5387(01)00885-3

The nickel and platinum complexes [MX₂(dppe)] (X = Cl, Br) react with bi- and tri-valent metal diethyldithiocarbamates [M′(S₂CNEt₂)_n] (M′ = Pb, Zn, Cd, Hg, Ni, MoO₂, VO, n = 2; M′ = Co, Fe, Mn, n = 3) to afford salts [M(S₂CNEt₂)(dppe)]₂[M′X₄]; reactions involving [Cu(S₂CNEt₂)₂] and [Ag(S₂CNEt₂)] gave salts of the form [M(S₂CNEt₂)(dppe)][M′X₂] (M′ = Cu, Ag). The complexes cis [RuCl₂(dppm)₂], [CoCl₂(dppe)] and [PdX₂(bipy)] likewise react with the same dithiocarbamates to form salts [Ru(S₂CNEt₂)(dppe)₂]₂ [M′Cl₄] [Co(S₂CNEt₂)₂(dppe)]₂ [M′Cl₄] and [Pd(S₂CNⁿBu₂)(bipy)]₂ [M′X₄], respectively. Sample reactions involving other S-chelate ligands - S₂COEt^-, S₂PPh₂^- and S₂P(OEt)₂^- - appear to follow the same general pattern. However, the O-ethyldithio carbonates (ethylxanthates) are partly converted to the corresponding dithiocarbonates. An anomalous reaction between [CoCl₂(dppe)] and [Zn(S₂CNEt₂)₂] in the presence of (S₂CNEt₂)₂ affords the novel complex [Co(S₂CNEt₂)₂(dppe)]₂[Cl ₃ZnO:(Ph)₂PCH₂CH₂P(Ph) ₂:OZnCl₃]. A selection of these salts have been fully characterised by elemental analysis and spectroscopic techniques, the remainder have been identified by spectroscopic methods alone. X-ray crystal structures are reported for the salts [Ni(S₂CNEt₂)(dppe)]₂ [HgBr₄], [Pt(S₂CNEt₂)(dppe)]₂[CdCl₄], [Co(S₂CNEt₂)₂(dppe)]₂[Cl ₃ZnO:(Ph)₂PCH₂CH₂P(Ph) ₂:OZnCl₃] and [Pd(S₂CNⁿBu₂) (bipy)]₂[CdCl₄].

Full text of DOI:10.1016/S0277-5387(01)00885-3

Polyhedron 20 (2001) 2951–2963
www.elsevier.com/locate/poly
The synthesis of new bimetallic complex salts by halide/sulfur
chelate cross transfer: X-ray crystal structures of the salts
[Ni(S2CNEt2)(dppe)]2[HgBr4], [Pt(S2CNEt2)(dppe)]2[CdCl4],
[Co(S2CNEt2)2(dppe)]2[Cl3ZnO:(Ph)2PCH2CH2P(Ph)2:OZnCl3] and
[Pd(S2CNnBu2)(bipy)]2[CdCl4]
George Exarchos, Stephen D. Robinson *, Jonathan W. Steed
Department of Chemistry, King’s College London, Strand, London, WC2R 2LS, UK
Received 28 February 2001; accepted 4 July 2001
Abstract
The nickel and platinum complexes [MX2(dppe)] (X=Cl, Br) react with bi- and tri-valent metal diethyldithiocarbamates
[M%(S2CNEt2)n] (M%=Pb, Zn, Cd, Hg, Ni, MoO2, VO, n=2; M%=Co, Fe, Mn, n=3) to afford salts [M(S2CNEt2)(dppe)]2[M%X4];
reactions involving [Cu(S2CNEt2)2] and [Ag(S2CNEt2)] gave salts of the form [M(S2CNEt2)(dppe)][M%X2] (M%=Cu, Ag). The
complexes cis [RuCl2(dppm)2], [CoCl2(dppe)] and [PdX2(bipy)] likewise react with the same dithiocarbamates to form salts
[Ru(S2CNEt2)(dppe)2]2[M%Cl4] [Co(S2CNEt2)2(dppe)]2[M%Cl4] and [Pd(S2CNnBu2)(bipy)]2[M%X4], respectively. Sample reactions
involving other S-chelate ligands—S2COEt−, S2PPh2− and S2P(OEt)2− —appear to follow the same general pattern. However,
the O-ethyldithio carbonates (ethylxanthates) are partly converted to the corresponding dithiocarbonates. An anomalous reaction
between [CoCl2(dppe)] and [Zn(S2CNEt2)2] in the presence of (S2CNEt2)2 affords the novel complex
[Co(S2CNEt2)2(dppe)]2[Cl3ZnO:(Ph)2PCH2CH2P(Ph)2:OZnCl3]. A selection of these salts have been fully characterised by elemen-
tal analysis and spectroscopic techniques, the remainder have been identified by spectroscopic methods alone. X-ray crystal
structures are reported for the salts [Ni(S2CNEt2)(dppe)]2 [HgBr4], [Pt(S2CNEt2)(dppe)]2[CdCl4], [Co(S2CNEt2)2(dppe)]2-
[Cl3ZnO:(Ph)2PCH2CH2P(Ph)2:OZnCl3] and [Pd(S2CNnBu2) (bipy)]2[CdCl4]. © 2001 Elsevier Science Ltd. All rights reserved.
Keywords: Bimetallic complex salts; Halide/sulfur chelate cross transfer; Crystal structures
these reactions was the ease with which even soft
metals, notably lead, mercury and silver, readily gave
1. Introduction
up dithiocarbamate ligands to form the halo-metallate
In the course of attempts to synthesise bimetallic
salts of the [Pd(S2CNEt2){Ph2P(CH2)nPPh2}]+ cations
dithiocarbamato complexes we observed facile reactions
in essentially quantitative yield. In this paper we de-
between palladium complexes [PdX2{Ph2P(CH2)nPPh2}]
scribe similar reactions involving the corresponding
(n=1–4) and bi- or tri-valent metal dithiocarbamato
nickel and platinum complexes. [MX2(dppe)], and re-
complexes leading to the formation of salts containing
lated complexes of ruthenium cis-[RuCl2(dppm)2],
cobalt [CoCl2(dppe)] and palladium [PdX2(bipy)]. Fi-
nally, in order to investigate the generality of these
[Pd(S2CNEt2){Ph2P(CH2)nPPh2}]+ cations and a range
of chloro- or bromo-metallate anions [1,2]. A feature of
reactions the dithiocarbamate complex precursors
were replaced by xanthate S2COEt−, dithio-
phosphinate S2PPh2− and dithiophosphate S2P(OEt)2−
* Corresponding author. Fax: +44-207-848-2810.
E-mail address: stephen.robinson@ukgateway.net (S.D. Robinson).
complexes.
0277-5387/01/$ - see front matter © 2001 Elsevier Science Ltd. All rights reserved.
PII: S0277-5387(01)00885-3

2952
G. Exarchos et al. / Polyhedron 20 (2001) 2951–2963
2. Experimental
2.1. General procedures
yellow–ochre powder obtained was filtered off, washed
with diethyl ether and dried in vacuo. Yield 0.262 g,
92%; m.p. 179–181 °C. Anal. Found: C, 48.6; H, 4.3;
N, 1.7. Calc. for C31H34AgCl2NNiP2S2; C, 47.5; H, 4.4;
N, 1.8%. Calc. for C62H68AgCl3N2Ni2P4S4; C, 52.25; H,
4.8; N, 1.85%.
Hydrated cobalt and nickel halides were purchased
from Aldrich and ruthenium, palladium and platinum
halides were obtained from Johnson Matthey. Metal
dithiocarbamates, ethyldithiocarbonates, dithiophos-
phinates and dithiophosphates were prepared by mixing
aqueous solutions of the sodium salts of the sulfur
ligands and the appropriate metal halides, and were
crystallised from dichloromethane. All other reagents
conditions and instrumentation were as described in a
previous paper [1].
2.1.3. (N,N-Diethyldithiocarbamato)[1,2-bis(diphenyl-
phosphino)ethane]nickel(II) tetrachloromanganate(II)·1.0
dichloromethane
Dichloro[1,2-bis(diphenylphosphino)ethane]nickel
(0.211 g, 0.40 mmol) and tris(N,N-diethyldithiocarbam-
ato)manganese (0.100 g, 0.20 mmol) were heated under
reflux in acetonitrile (70 cm3) for 1 h. The solution thus
obtained was filtered and evaporated to dryness under
reduced pressure. The oily residue remaining was dis-
solved in dichloromethane (10 cm3) and the complex
re-precipitated by addition of diethyl ether (75 cm3).
The fine yellow–ochre powder obtained was washed
repeatedly with diethyl ether to remove all the te-
traethylthiuram disulfide by-product, and dried in
vacuo. Yield 0.265 g, 89%; m.p. 127–130 °C. Anal.
Found: C, 50.0; H, 4.7; N, 1.95. Calc. for
C62H68Cl4MnN2Ni2P4S4·1.0CH2Cl2: C, 50.7; H, 4.75;
N, 1.9%.
2.1.1. (N,N-Diethyldithiocarbamato)[1,2-bis(diphenyl-
phosphino)ethane]nickel(II) tetrachlorozincate
Dichloro[1,2-bis(diphenylphosphosphino)ethane]-
nickel (0.211 g, 0.40 mmol) and bis(N,N-diethyldithio-
carbamato)zinc (0.072 g, 0.20 mmol) were heated under
reflux in acetonitrile (60 cm3) for 1 h. The solution
thereby obtained was filtered and evaporated to dryness
under reduced pressure. The oily residue was dissolved
in dichloromethane (10 cm3) and the complex re-precip-
itated by the addition of diethyl ether (75 cm3). The fine
yellow–orange powder obtained was filtered off,
washed with diethyl ether and dried in vacuo. Yield
0.265 g, 93%; m.p. 133–135 °C. Anal. Found: C, 52.05;
H, 4.85; N, 1.85. Calc. for C62H68Cl4N2Ni2P4S4Zn: C,
52.5; H, 4.85; N, 2.0%.
2.1.4. (N,N-Diethyldithiocarbamato)[1,2-bis(diphenyl-
phosphino)ethane]platinum(II) tetrachlorozincate
Dichloro[1,2-bis(diphenylphosphino)ethane]platinum
(0.133 g, 0.20 mmol) and bis(N,N-diethyldithiocarbam-
ato)zinc (0.036 g, 0.10 mmol) were heated under reflux
in acetonitrile (60 cm3) for 1 h. The solution obtained
was filtered and evaporated to dryness under reduced
pressure. The oily residue remaining was dissolved in
dichloromethane (7 cm3) and the complex re-precipi-
tated by addition of diethyl ether (60 cm3). The fine
white powder obtained was filtered off, washed with
diethyl ether and dried in vacuo. Yield 0.151 g, 89%;
m.p. 142–145 °C. Anal. Found: C, 44.15; H, 4.05; N,
1.7. Calc. for C62H68Cl4N2P4Pt2S4Zn: C, 44.05; H, 4.05;
N, 1.65%.
The following complexes were obtained on a similar
scale by the same general method.
(N,N-Diethyldithiocarbamato)[1,2-bis(diphenylphos-
phino)ethane]nickel(II) tetrachlorocadmate 0.5 di-
chloromethane as a fine yellow–orange powder. Yield
93%; m.p. 131–133 °C. Anal. Found: C, 50.15; H, 4.75;
N, 1.80. Calc. for C62H68CdCl4N2Ni2P4S4·0.5CH2Cl2:
C, 49.8; H, 4.6; N, 1.85%.
(N,N-Diethyldithiocarbamato)[1,2-bis(diphenylphos-
phino)ethane]nickel(lI) tetrabromomercurate as a fine
yellow–orange powder. Yield 93%; m.p. 136–138 °C.
Anal. Found: C, 42.8; H, 3.85; N, 1.5. Calc. for
C62H68Br4HgN2Ni2P4S4: C, 43.0; H, 3.95; N, 1.6%.
(N,N-Diethyldithiocarbamato)[1,2-bis(diphenylphos-
phino)ethane]platinum(II) tetrachlorocadmate was sim-
ilarly prepared as a fine white powder. Yield 92%; m.p.
134–136 °C. Anal. Found: C, 42.8; H, 3.9; N, 1.5.
Calc. for C62H68CdCl4N2P4Pt2S4: C, 42.85; H, 3.95; N,
1.6%.
2.1.2. (N,N-Diethyldithiocarbamato)[1,2-bis(diphenyl-
phosphino)ethane]nickel(II) ‘dichloroargentate(I)’
Dichloro[1,2-bis(diphenylphosphino)ethane]nickel
(0.211 g, 0.40 mmol) and (N,N,-diethyldithiocarbam-
ato)silver(I) (0.102 g, 0.40 mmol) were stirred and
heated under reflux in acetonitrile (60 cm3) for 1 h. The
solution obtained was filtered through celite to remove
the fine grey–white precipitate of silver chloride and
then evaporated to dryness under reduced pressure. The
2.1.5. (N,N-Diethyldithiocarbamato)[1,2-bis(diphenyl-
phosphino)ethane]platinum(II) ‘dichloroargentate(I)’
Dichloro[1,2-bis(diphenylphosphino)ethane]platinum
(0.133 g, 0.20 mmol) and (N,N-diethyldithiocarbam-
ato)silver (0.051 g, 0.20 mmol) were heated under reflux
in acetonitrile (60 cm3) for 1 h. The solution obtained
was filtered through celite to remove a fine grey–white
precipitate of silver chloride and evaporated to dryness
oily
residue
remaining
was
dissolved
in
dichloromethane (10 cm3) and the complex re-precipi-
tated by the addition of diethyl ether (75 cm3). The fine

G. Exarchos et al. / Polyhedron 20 (2001) 2951–2963
2953
under reduced pressure. The oily residue thus obtained
2.1.8. (N,N-Diethyldithiocarbamato)di[bis(diphenyl-
phosphino)methane]ruthenium(II) tetrachlorocadmate
was dissolved in dichloromethane (7 cm3) and the com-
plex precipitated by addition of diethyl ether (60 cm3).
The fine white powder obtained was filtered off, washed
with diethyl ether and dried in vacuo. Yield 0.142 g,
91%; m.p. 160–162 °C. Anal. Found: C, 41.15; H, 3.55;
N, 1.55. Calc. for C31H34AgCl2NP2PtS2; C, 40.45; H,
3.7; N, 1.5%. Calc. for C62H68AgCl3N2P4Pt2S4: C,
43.85; H, 4.05; N, 1.65%.
cis-Dichlorodi[bis(diphenylphosphino)methane]ru-
thenium (0.188 g, 0.20 mmol) and bis(N,N-diethyl-
dithiocarbamato)cadmium (0.041 g, 0.10 mmol) were
heated under reflux in acetonitrile (60 cm3) for 3 h. The
solution thus obtained was filtered and evaporated to
dryness under reduced pressure. The oily residue was
dissolved in dichloromethane (10 cm3) and then diluted
with diethyl ether (75 cm3). The resulting precipitate
was filtered off, washed with diethyl ether (3×10 cm3)
and dried in vacuo to yield a yellowish white powder.
Yield 0.213 g, 93%. Crystallisation from chloroform–
toluene gave pale yellow needles. Anal. Found: C,
55.00; H, 4.60; N, 1.20. Calc. for C60H64CdCl4N2P8-
Ru2S4: C, 57.70; H, 4.75; N, 1.20%. Calc. for CHCl3
mono-solvate C, 55.35; H, 4.55; N, 1.15%.
2.1.6. (N,N-Diethyldithiocarbamato)[1,2-bis(diphenyl-
phosphine)ethane]platinum(II) dichlorocuprate(I)·0.5
dichloromethane
Dichloro[1,2-bis(diphenylphosphino)ethane]platinum
(0.133 g, 0.20 mmol) and bis(N,N-diethyldithiocarbam-
ato)copper (0.036 g, 0.10 mmol) were heated under
reflux in acetonitrile for 1 h. The solution was then
filtered and evaporated to dryness under reduced pres-
sure. The oily residue was dissolved in dichloromethane
(7 cm3) and the complex re-precipitated by the addition
of diethyl ether (60 cm3). The fine green powder ob-
tained was filtered off, washed with diethyl ether several
times to remove the tetraethylthiuram disulfide by-
product and dried in vacuo. Yield 0.166 g, 90%; m.p.
163–165 °C. Anal. Found: C, 41.75; H, 4.0; N, 2.05.
Calc. for C31H34Cl2CuNP2PtS2·0.5CH2Cl2: C, 41.2; H,
3.85, N, 1.5%.
A range of tetrachlorometallate salts containing the
same cation were synthesised by similar procedures,
and characterised by spectroscopic methods. Details are
given in Table 2 and in Section 3.
2.1.9. (N,N-Di-n-butyldithiocarbamato)(2,2%-dipyridyl)-
palladium(II) tetrachlorocadmate
Dichloro(2,2%-dipyridyl)palladium (0.133 g, 0.40
mmol) and bis(N,N-di-n-butyldithiocarbam-ato)cadm-
ium (0.104 g, 0.20 mmol) were heated under reflux in
acetonitrile (70 cm3) for 2 h. The solution thus obtained
was filtered hot, evaporated to approximately 25 cm3
under reduced pressure, and then cooled in an ice/water
bath for 30 min. The product which precipitated was
filtered off, washed with ethanol (3×10 cm3) and di-
ethyl ether (3×10 cm3), and then dried in vacuo as
bright yellow feathery plates. Yield 0.213 g, 90%. Anal.
Found: C, 38.30; H, 4.25; N, 6.85. Calc. for
C38H52CdCl4N6Pd2S4: C, 38.65; H, 3.75; N, 7.10%.
A range of tetrahalometallate salts containing the
same cation were synthesised by similar procedures and
characterised by spectroscopic methods. Details are
given in Table 2 and in Section 3.
2.1.7. (N,N-Diethyldithiocarbamato)[1,2-bis(diphenyl-
phosphino)ethane]platinum(II) tetrachloroferrate(II)·1.0
chloroform
Dichloro[1,2-bis(diphenylphosphino)ethane]platinum
(0.133 g, 0.20 mmol) and tris(N,N-diethyldithiocarbam-
ato)iron (0.050 g, 0.10 mmol) were heated under reflux
in acetonitrile (60 cm3) with stirring for 1 h under a
dinitrogen atmosphere. The solution obtained was
filtered and evaporated to dryness under reduced pres-
sure. The residue was dissolved in chloroform (8 cm3)
and the complex re-precipitated by the addition of
diethyl ether (60 cm3). The slightly air-sensitive olive
green powder was filtered off, washed several times
with diethyl ether to remove all traces of tetraethylthi-
uram disulfide byproduct and dried in vacuo. Yield
0.166 g, 92%; m.p. 123–125 °C. Anal. Found: C, 41.9;
H, 3.95; N, 1.75. Calc. for C62H68Cl4FeN2P4Pt2S4·
1.0CHCl3: C, 42.0; H, 3.85; N, 1.55%.
2.1.10. Di(N,N-diethyldithiocarbamato)[1,2-bis(di-
phenylphosphino)ethane]cobalt(III) tetrachlorocadmate
A
solution of bis(N,N-diethyldithiocarbamato)-
cadmium (0.082 g, 0.20 mmol) and tetraethylthiuram
disulfide (0.059 g, 0.20 mmol) in dichloromethane (40
cm3) was added to a solution of dichloro[1,2-bis-
(diphenylphosphino)ethane]cobalt(II) (0.211 g, 0.40
mmol) in dichloromethane (30 cm3). The mixture was
stirred at room temperature for 30 min, filtered and
concentrated under reduced pressure to small volume
(ca. 5 cm3). Diethyl ether (75 cm3) was added to the
concentrate and the precipitate obtained was filtered
off, washed with ethanol (2×10 cm3) and diethylether
(5×10 cm3) then dried in vacuo to yield a fine brick-
red powder. Yield 0.313 g, 89%. Recrystallisation from
In addition to salts described above a further series
of examples were prepared in approximately 85–95%
yields by similar methods, but were not submitted for
elemental analysis. Identification was achieved by spec-
1
troscopic methods (infrared and H and 31P NMR) and
by comparison with the corresponding salts of the
palladium complex cation [Pd(S2CNEt2)(Ph2PCH2-
CH2PPh2)]+. A full listing, together with colour and
selected infrared data, is given in Table 1. Spectroscopic
data are also described in Section 3.

2954
G. Exarchos et al. / Polyhedron 20 (2001) 2951–2963
chloroform solution gave dark red plates. Anal. Found:
C, 46.40; H, 4.65; N, 2.90. Calc. for C72H88CdCl4Co2-
N4P4S8: C, 49.10; H, 5.05; N, 3.20%. Calc. for CHCl3
mono solvate: C, 46.60; H, 4.75; N, 3.0%.
A range of tetrahalometallate salts containing the
same cation were synthesised by similar procedures and
characterised by spectroscopic methods. Details are
given in Table 2 and in Section 3.
2.1.11. Di(N,N-diethyldithiocarbamato)[1,2-bis(di-
phenylphosphino)ethane]cobalt(III) bis-trichloro-
zincate)[v-O,O%-1,2-bis(diphenyl phosphinoyl)ethane]
A solution of bis(N,N-diethyldithiocarbamato)zinc
(0.072 g, 0.02 mmol) and tetraethylthiuram disulfide
(0.059 g, 0.20 mmol) in dichloromethane (40 cm3) was
added to a solution of dichloro[2-bis(diphenylphos-
phino)ethane]cobalt (0.211 g, 0.40 mmol) in di-
Table 1
Colour and metal halide infrared vibrations for halometallate salts of [M(S2CNEt2)(dppe)]+ cations
Anions
M=Ni
M=Pt
Colour
w(MꢀX) (cm−1
)
Colour
w(MꢀX) (cm−1
)
[PbCl4]2−
yellow–orange
yellow–orange
yellow–orange
yellow–orange
brown–green
yellow–ochre
brown–green
brown–green
olive-green
201vw a
278s
247m
white
white
white
white
green
white
pale green
green
olive-green
pale yellow
pale yellow
pale green
white
white
white
white
brown–green
white
205vw a
278s
243m
[ZnCl4]2−
[CdCl4]2−
[HgCl4]2−
[CuCl2]−
221m
222m
409w
411w
[AgCl2]−/Cl−
[NiCl4]2−
295vw a
288m
293vwa
290m
[CoCl4]2−
[FeCl4]2−
296m
285m
282m
325m, 263m
310m, 282m
144vw a
211m
183m
155w
297m
285m
283m
321m, 268m
312m, 281m
146vw a
213m
186m
157w
[MnCl4]2−
[MoO2Cl4]2− b
[VOCl4]2− c
[PbBr4]2−
[ZnBr4]2−
[CdBr4]2−
[HgBr4]2−
[CuBr2]−
yellow–ochre
yellow–orange
pale green
yellow–ochre
yellow–brown
yellow–orange
yellow–orange
brown–green
yellow–ochre
brown–green
brown–green
brown–green
yellow–orange
yellow–orange
pale green
325w
323w
[AgBr2]−/Br−
[NiBr4]2−
247vw a
224w
244vw a
219w
pale green
green
dark olive green
pale yellow
pale yellow
pale green
[CoBr4]2−
[FeBr4]2−
226m
218m
222m
244w, 218w
243w, 217w
227m
218m
222m
243w, 219w
242w, 220w
[MnBr4]2−
[MoO2Br4]2− b
[VOBr4]2−
a Tentative assignments.
b w(MoꢁO) 912 and 877 cm−1 (X=Cl and Br).
c w(VꢁO) 952 cm−1 (X=Cl); 955 cm−1 (X=Br).
Table 2
Infrared data w3(MꢀX) for halometallate anions [MX4]2−
Anion
Cation
A
B
C
D
E
F
[ZnCl4]2−
[CdCl4]2−
[HgCl4]2−
[PdCl4]2−
[FeCl4]2−
[CoCl4]2−
[NiCl4]2−
[ZnBr4]2−
[CdBr4]2−
[HgBr4]2−
[PbBr4]2−
278 (s)
276 (s)
279 (m)
249 (m)
224 (m)
206 (vw)
283 (m)
277 (m)
246 (m)
218 (m)
203 (vw)
276 (m)
244 (m)
220 (m)
206 (vw)
286 (m)
245 (m)
219 (m)
207 (vw)
247 (m)
223 (m)
245 (m)
220 (m)
202 (vw)
291 (m)
287 (m)
220 (m)
183 (m)
155 (w)
147 (vw)
287
288 (m)
222 (m)
186 (m)
157 (w)
151 (vw)
218 (m)
179 (m)
156 (w)
219 (m)
186 (m)
158 (w)
185 (m)
157 (w)
A=[Ru(S2CNEt2)(dppm)2]+
F=[Pd{S2P(OEt)2}(dppe)]+
;
.
B=[Co(S2CNEt2)2(dppe)]+
;
C=[Pd(S2CNnBu2)(bipy)]+
;
D=[Pd(S2COEt)(dppe)]+
;
E=[Pd(S2PPh2)(dppe)]+
;

G. Exarchos et al. / Polyhedron 20 (2001) 2951–2963
2955
chloromethane (30 cm3). The mixture was stirred at
room temperature for 30 min, filtered and concentrated
under reduced pressure to small volume (ca. 5 cm3).
Diethyl ether (75 cm3) was added to the concentrate
and the precipitate obtained was filtered off, washed
with ethanol (2×10 cm3) and diethyl ether (5×10 cm3)
then dried in vacuo to yield a fine bright red powder.
Yield 0.201 g. Recrystallisation from chloroform gave
dark red prisms. Anal. Found: C, 50.3; H, 4.95; N, 2.4.
Calc. for C98H112Cl6Co2N4O2P6S8Zn2: C, 51.6; H, 4.95;
N, 2.45%. Calc. for CHCl3 hemi-solvate: C, 50.8; H,
4.85; N, 2.4%.
gether in dichloromethane (60 cm3) for 1 h. The
solution was then filtered, concentrated to small volume
(ca. 5 cm3) and diluted with diethyl ether. The precipi-
tate which formed was filtered off, washed with diethyl
ether (3×10 cm3) and dried in vacuo for 3 h to leave a
fine yellow powder (yield 0.288 g, 91%); m.p. 144–
146 °C.
A range of tetrahalometallate salts containing the
same cation were synthesised by similar procedures and
characterised by spectroscopic methods. Details are
given in Table 2 and in Section 3.
Attempted synthesis of O-ethyldithiocarbonato-
[1,2-bis(diphenylphosphino)ethane]palladium(II) tetra-
chlorozincate
2.2. Crystallography
X-ray crystal structures have been determined for the
complexes [Ni(S2CNEt2)(dppe)]2[HgBr4] (1), [Pt(S2-
CNEt2)(dppe)]2[CdCl4]·0.5CH2Cl2·H2O (2), [Co(S2-
CNEt2)2(dppe)]2[Cl3ZnO:(Ph)2PCH2CH2P(Ph)2:OZn-
Cl3]·6CHCl3 (3) and [Pd(S2CNnBu2)(bipy)]2[CdCl4]·
2.0MeCN (4). Crystals suitable for X-ray diffraction
study were grown from CH2Cl2–C6H5Me solution ((1)
and (2)), CHCl3 solution (3) and MeCN–C6H5CH3
solution (4). Dark orange needles of 1, colourless
needles of 2, thin yellow plates of 3 and dark red prisms
of 4 were mounted on thin glass fibres using fast setting
resin. A total of 180 oscillation frames of 90 s exposure
time with 1° in q were recorded using a Nonius Kappa
CCD diffractometer, with a detector to crystal distance
of 35 mm. The crystals were indexed from the first 10
frames using the DENZO package [3] and positional data
were refined along with diffractometer constants to give
the final unit cell parameters. Data were corrected for
Lorentz and polarisation effects. The structures were
solved using the direct methods option of SHELXS-86 [4]
and developed via alternating least-squares cycles and
difference Fourier synthesis SHELXL-93 [5] with the aid
Dichloro[1,2-bis(diphenylphosphino)ethane]pallad-
ium (0.230 g, 0.40 mmol) and bis(O-ethyldithiocarbon-
ato)zinc (0.062 g, 0.20 mmol) were stirred with
dichloromethane (60 cm3) for 1 h. The solution thus
obtained was filtered and concentrated under reduced
pressure to small volume (ca. 5 cm3) then diluted with
diethyl ether (75 cm3). The resulting precipitate was
filtered off, washed with diethyl ether (3×10 cm3) and
dried in vacuo to yield a fine yellow powder (yield 0.272
g). Spectroscopic examination revealed that the major
product was the dithiocarbonato complex [Pd(S2CO)-
(dppe)]. Reactions involving a range of these O-
ethyldithiocarbonato complexes also gave mixtures of
O-ethyldithiocarbonato and dithiocarbonato products.
Further details are given in Section 3.
2.1.12. Diphenyldithiophosphinato[1,2-bis(diphenylphos-
phino)ethane]palladium(II) tetrachlorocadmate·1.0
dichloromethane
Dichloro[1,2-bis(diphenylphosphino)ethane]pallad-
ium (0.230 g, 0.40 mmol) and bis(diphenyldithiophos-
phinato)cadmium (0.12 g, 0.20 mmol) were stirred in
dichloromethane (60 cm3) for 1 h. The solution ob-
tained was filtered and concentrated under reduced
pressure to small volume (ca. 5 cm3), then diluted with
diethyl ether (75 cm3). The resulting precipitate was
filtered off, washed with diethyl ether (3×10 cm3) and
dried in vacuo for 3 h to yield a fine yellowish white
powder. Yield 0.33 g, 94%. Anal. Found: C, 50.35; H,
3.80. Calc. for C76H68CdCl4P6Pd2S4·1.0 CH2Cl2:
C,50.05; H, 3.85%.
of the program RES2INS [6]. All non-hydrogen atoms
were modelled anisotropically, while hydrogen atoms
were assigned an isotropic thermal parameter 1.2 times
(1.5 times for CH3 groups) that of the parent atom and
allowed to ride. Crystal data and structure refinement
details for all four complex salts are given in Table 3.
A range of tetrahalometallate salts containing the
same cation was synthesised by similar procedures and
characterised by spectroscopic methods. Details are
given in Table 2 and in Section 3.
3. Results and discussion
3.1. Nickel and platinum dithiocarbamato complexes
The reactions of nickel and platinum complexes
[MX2(dppe)] with metal dithiocarbamato complexes
[M%(S2CNEt2)n] (M%=Co, Fe, Mn, n=3; M%=Pb, Zn,
Cd, Hg, Ni, Cu, MoO2, VO, n=2; M%=Ag, n=1) in
boiling acetonitrile followed a similar pattern to that
2.1.13. Diethyldithiophosphato[1,2-bis(diphenylphos-
phino)ethane]palladium(II) tetrachlorozincate
Dichloro[1,2-bis(diphenylphosphino)ethane]pallad-
ium (0.230 g, 0.40 mmol) and bis(O,O-diethyldithio-
phosphato)zinc (0.086 g, 0.20 mmol) were stirred to-

2956
G. Exarchos et al. / Polyhedron 20 (2001) 2951–2963
Table 3
Crystal data and structure refinement parameters for the complex salts [Ni(S2CNEt2)(dppe)]2[HgBr4] (1), Pt(S2CNEt2)(dppe)]2[CdCl4]·
0.5CH2Cl2·H2O(2), [Co(S2CNEt2)2(dppe)]2[Cl3ZnO(Ph)2PCH2CH2P(Ph)2OZnCl3]·6CHCl3 (3) and [Pd(S2CNnBu2)(bipy)]2[CdCl4]·2MeCN (4)
1
2
3
4
Empirical formula
Formula weight
Temperature (K)
C62H68Br4HgN2Ni2P4S4
1730.95
293(2)
C
125H142Cd2Cl10N4O2P8Pt4S8 C52H59Cl12CoN2OP3S4Zn
C42H58CdCl4N8Pd2S4
1270.20
100(2)
3594.31
173(2)
1498.86
173(2)
,
Wavelength (A)
Crystal system
0.71070
monoclinic
0.71070
monoclinic
0.71070
triclinic
0.71070
orthorhombic
Fd2d
(
Space group
Unit cell dimensions
P21/c
P21/a
P1
,
a (A)
10.9720(2)
39.3870(8)
15.4790(3)
21.7506(6)
14.3867(4)
21.9300(3)
11.7318(10)
16.5257(13)
18.8520 (13)
64.965(1)
80.620(1)
86.457(1)
3267.2(4)
2
18.6817(5)
20.3727(11)
57.560 (3)
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
V (A )
90.953(1)
94.269(1)
3
,
6688.4(2)
4
1.719
5.496
6843.3(3)
2
1.744
4.838
21907.3(17)
16
1.540
Z
Dcalc (Mg m−3
)
1.524
1.351
Absorption coefficient
(mm−1
F(000)
Crystal size (mm)
q Range for data collection 2.42–21.24
(°)
1.418
)
3416
0.50×0.10×0.10
3520
0.20×0.20×0.05
3.39–26.00
1526
0.20×0.20×0.10
3.29–25.00
10208
0.40×0.40×0.40
3.04–25.00
Index ranges
05h511, 05k540,
−155l515
7326
−265h526, −175k517,
−265l526
24 816
−135h513, −185k519, −215h520, −245k524,
−215l522
24 513
−685l567
9215
Reflections collected
Independent reflections
Refinement method
7326 [Rint=0.0000]
Full-matrix
12 920 [Rint=0.0616]
Full-matrix
10 540 [Rint=0.1017]
Full-matrix
9215 [Rint=0.0000]
Full-matrix
least-squares on F2
least-squares on F2
12 920/0/748
least-squares on F2
10 540/0/713
least-squares on F2
9215/19/559
Data/restraints/parameters 7326/0/713
Final R indices
R1=0.0347,
wR2=0.0806
R1=0.0436,
wR2=0.0868
1.048
R1=0.0410,
wR2=0.1000
R1=0.0506,
wR2=0.1070
1.036
R1=0.0806, wR2=0.1452 R1=0.0533,
wR2=0.1271
R1=0.1250, wR2=0.1586 R1=0.0625,
wR2=0.1327
R indices (all data)
Goodness-of-fit on F2
1.092
1.088
Largest difference peak and 0.747 and −0.656
1.794 and −4.278
0.706 and −0.520
0.881 and −0.795
−3
,
hole (e A
)
[Pt(S2CNEt2)(dppe)]+ typically display proton reso-
previously observed [1] with the corresponding palla-
dium complexes, [PdX2(dppe)]. In all cases halometallic
salts of the complex cations [M(S2CNEt2)(dppe)]+ are
obtained in virtually quantitative yield. All the salts
prepared were characterised by spectroscopic means
and by comparison with their palladium analogues,
however, only those fully described in Section 2 were
submitted for elemental analysis. The cations present in
nances at l 1.34 (t), CH3CH2N; 3.72 (q), CH3CH2N;
2
2.90 (d, JHP=18.8 Hz), PCH2CH2P; 7.53 (m) and 7.75
(m), C6H5 and a 31P resonance at l 43.25 (s) with
platinum-195 satellites (1JPPt=3120 Hz). Variations as-
sociated changes in the nature of the counter-anion
were similar in magnitude to those observed for the
nickel complex cation. The NMR data for the platinum
complex cation are in good agreement with a previously
published spectrum [7]. In those instances where analyt-
ical data indicated the presence of solvent of crystallisa-
tion confirmation was provided by detection of the
1
each complex, were identified by H and 31P{1H} NMR
spectroscopy. Typically the [Ni(S2CNEt2)(dppe)]+
cations display proton resonances at l 1.23 (t),
CH3CH2N; 3.70 (q), CH3CH2N; 3.00 (d, 2JHP=19.1
Hz), PCH2CH2P; 7.46 (m) and 7.81 (m), C6H5, and a
31P resonance at l 62.3 (s). Variations associated with
changes in the nature of the anion present were 90.1
and 90.5 ppm for the 1H and 31P{1H} resonances,
respectively. The corresponding platinum cations
1
appropriate H NMR resonance (l CH2Cl2, 5.3 ppm; l
CHCl3, 7.27 ppm). The complex cations were further
characterised by infrared spectroscopy. All salts of the
[Ni(S2CNEt2)(dppe)]+ cation displayed absorptions
(cm−1) at 1528(s), w(CꢀN); approximately 998(s) and

G. Exarchos et al. / Polyhedron 20 (2001) 2951–2963
2957
hedral [M%X4]2− anions (M%=Pb, Zn, Cd, Hg, Ni, Co,
Fe, Mn) in the respective complexes. Reactions involv-
ing the tris(dithiocarbamato) complexes [M%(S2CNEt2)3]
(M%=Co, Fe, Mn) are again accompanied by reduction
of these metals to the divalent state and the concomi-
tant formation of tetraethylthiuram disulfide. In the
case of the relatively inert Co(III) precursor a reaction
time of 10 h was allowed to ensure complete conver-
sion. Likewise reactions involving copper(II) di-
ethyldithiocarbamate were accompanied by reduction
of that metal to the mono-valent state, and yielded salts
containing the linear [CuX2]− anions, similar to those
previously characterised in salts of the palladium com-
plex cation [Pd(S2CNEt2)(dppe)]+ [1]. Finally reactions
involving Ag(S2CNEt2) were accompanied by the depo-
sition of silver halide. The amounts recorded are less
than anticipated for reaction (1) alone, however they
are consistent with a combination of reactions (1)–(3)
910(m), w(CꢀS); approximately 394(w), w(NiꢀP); and
approximately 355(m), w(NiꢀS). Those containing the
[Pt(S2CNEt2)(dppe)]+ cation displayed absorptions
(cm−1) at approximately 1533(s), w(CꢀN); approxi-
mately 998(s) and 910(m), w(CꢀS); approximately 399
(w), w(PtꢀP); approximately 376 (m), w(PtꢀS). Varia-
tions associated with changes in the nature of the
counter-anions at 91 cm−1 were well within experi-
mental error limits. The halometallate counter-anions
were also characterised by infrared spectroscopy (Table
1). With the exception of the [PbX4]2− anions, for
which no reliable data could be found, and the
[HgX4]2− anions where the literature data display seri-
ous inconsistencies [8–10], the absorptions attributed to
the halometallate anions agree well with those reported
by previous authors [9,10]. Our data for the mercury
anions are at variance with those given in some recent
data compilations [9,10] which assign almost identical
values to w3(ZnꢀCl) and w3(HgꢀCl)! However, our re-
sults are well supported by the earlier work of Adams
et al. [8]. Finally, the structures of two salts,
2[MX2(dppe)]+2[Ag(S2CNEt2)]
“[M(S2CNEt2)(dppe)]2[AgX3]+AgX
(1)
[Ni(S2CNEt2)(dppe)]2[HgBr4]
[Pt(S2CNEt2)(dppe)]2[CdCl4], were confirmed by X-ray
diffraction methods (see below).
and
[M(S2CNEt2)(dppe)]2[AgX3]
“[M(S2CNEt2)(dppe)] [AgX2]
+[M(S2CNEt2)(dppe)]X
As noted above the salts of the nickel and platinum
complex cations are essentially similar to those of their
palladium analogues. The relative inertness of platinu-
m(II) species and the relative hardness of nickel(II)
centres do not appear to materially alter the rate or
outcome of the ligand exchange processes. In particular
the nickel(II) centres, presumably softened by the pres-
ence of the ancillary diphosphine ligand, were able to
abstract dithiocarbamate ligands from their complexes
with even the ‘softest’ metals, notably Pb(II), Hg(II)
and Ag(I).
(2)
(3)
[MX2(dppe)]+[Ag(S2CNEt2)]
“[M(S2CNEt2)(dppe)][AgX2]
Analytical data support this conclusion and suggest
that salts of the dihalo anions [AgX2]− are the major
products present. Rather similar behaviour was previ-
ously noted [1] for chloroargentate salts of the corre-
sponding palladium cation.
The crystal structures of the salts [Ni(S2CNEt2)-
(dppe)]2[HgBr4] (1) and [Pt (S2CNEt2)(dppe)]2[CdCl4]·
0.5CH2Cl2·H2O (2) are shown in Figs. 1 and 2, respec-
tively. Selected bond lengths and angles for the two
complexes are collated in Table 4. Both complexes
As in the case of the corresponding salts of the
palladium complex cation [1], the infrared data are
consistent with the presence of square pyramidal
[VOX4]2−, octahedral cis-dioxo [MoO2X4]2− and tetra-
Fig. 1. Molecular structure of [Ni(S2CNEt2)(dppe)]2[HgBr4] (1) showing atom labelling scheme.

2958
G. Exarchos et al. / Polyhedron 20 (2001) 2951–2963
Fig. 2. Molecular structure of [Pt(S2CNEt2)(dppe)]2[CdCl4] (2) showing atom labelling scheme.
feature essentially square planar cations and tetrahedral
anions. Comparison of structural data recorded here
for the nickel and platinum complex cations with those
previously reported for the corresponding palladium
complex cation [1] reveals the expected trends in
metalꢀligand bond lengths and chelate angles. Gener-
ally increases in the former and decreases in the latter
accompany increases in metal ion size NiBPdBPt. As
expected differences between the nickel and palladium
complex cations are much more pronounced than those
between the palladium and platinum species. Thus av-
in excellent yield. The salts, which were isolated as pale
yellow, air stable crystals, were characterised by in-
frared and NMR data. The stoichiometry and structure
of one example, [Ru(S2CNEt2)(dppm)2]2[CdCl4] were
confirmed by elemental analysis and a partial X-ray
Table 4
,
Selected bond lengths (A) and bond angles (°) for the complex salts
[Ni(S2CNEt2)(dppe)]2[HgBr4] (1) and [Pt(S2CNEt2)(dppe)]2[CdCl4]·
0.5CH2Cl2·H2O (2)
1
2
,
erage MꢀP distances are 2.165, 2.265 and 2.256 A and
Bond lengths
Ni(1)ꢀS(1)
Ni(1)ꢀS(2)
Ni(1)ꢀP(1)
Ni(1)ꢀP(2)
Ni(2)ꢀS(3)
Ni(2)ꢀS(4)
Ni(2)ꢀP(3)
Ni(2)ꢀP(4)
S(1)ꢀC(1)
,
average MꢀS distances are 2.202, 2.333 and 2.360 A for
2.1942(19) Pt(1)ꢀS(1)
2.3488(14)
2.3723(13)
2.2587(13)
2.2533(14)
2.3464(17)
2.3613(15)
2.2458(15)
2.2484(15)
1.737(6)
1.741(6)
1.728(7)
1.733(7)
1.296(8)
1.481(8)
1.469(8)
1.307(8)
1.471(10)
1.475(10)
2.4369(17)
2.4721(17)
2.4678(18)
2.4642(16)
Ni, Pd and Pt, respectively. Increases in metalꢀligand
bond lengths lead to decreases in chelate angles, and as
anticipated, these are more pronounced for the very
acute SꢀMꢀS angles of the dithiocarbamate ligands
which display values of 79.59, 75.73 and 74.97° for the
nickel, palladium and platinum complexes respectively.
Structural data for the nickel complex cation are essen-
tially similar to those previously reported [11] for the
closely related cation [Ni(S2CNiPr2)(dppe)]+ save for a
slight asymmetry in the NiꢀS and NiꢀP bond lengths,
possibly due to packing forces, apparent in the former.
2.211(2)
Pt(1)ꢀS(2)
2.1480(18) Pt(1)ꢀP(1)
2.1810(19) Pt(1)ꢀP(2)
2.2117(19) Pt(2)ꢀS(3)
2.2074(18) Pt(2)ꢀS(4)
2.1847(18) Pt(2)ꢀP(3)
2.1651(18) Pt(2)ꢀP(4)
1.719(7)
1.719(7)
1.720(7)
1.719(7)
1.310(8)
1.472(9)
1.542(10)
1.311(8)
1.465(9)
1.497(10)
2.6515(8)
2.6284(9)
2.5659(9)
2.5986(9)
S(1)ꢀC(1)
S(2)ꢀC(1)
S(2)ꢀC(1)
S(3)ꢀC(32)
S(4)ꢀC(32)
N(1)ꢀC(1)
N(1)ꢀC(2)
N(1)ꢀC(4)
N(2)ꢀC(32)
N(2)ꢀC(33)
N(2)ꢀC(35)
Hg(1)ꢀBr(1)
Hg(1)ꢀBr(2)
Hg(1)ꢀBr(3)
Hg(1)ꢀBr(4)
S(3)ꢀC(32)
S(4)ꢀC(32)
N(1)ꢀC(1)
N(1)ꢀC(2)
N(1)ꢀC(4)
N(2)ꢀC(32)
N(2)ꢀC(33)
N(2)ꢀC(35)
Cd(1)ꢀCl(1)
Cd(1)ꢀCl(2)
Cd(1)ꢀCl(3)
Cd(1)ꢀCl(4)
A
similar asymmetry observed for the cation
[Ni(S2CNEt2)(PPh3)2]+ has been attributed to steric
interaction between the bulky PPh3 ligands [12]. The
platinum cation [Pt(S2CNEt2)(dppe)]+ also displays
asymmetric coordination about the platinum centre,
notably in the PtꢀS bond lengths. The [HgBr4]2− an-
ions are essentially tetrahedral with only minor distor-
tions and display bond lengths and bond angles in good
agreement with data previously recorded [13,14]. Like-
wise the [CdCl4]2− anions deviate little from tetrahedral
symmetry and have bond length and bond angle data
similar to those previously reported for this anion
[2,15,16].
Bond angles
P(1)ꢀNi(1)ꢀP(2)
P(1)ꢀNi(1)ꢀS(1)
P(2)ꢀNi(1)ꢀS(2)
S(1)ꢀNi(1)ꢀS(2)
P(3)ꢀNi(2)ꢀP(4)
P(3)ꢀNi(2)ꢀS(3)
P(4)ꢀNi(2)ꢀS(4)
S(3)ꢀNi(2)ꢀS(4)
86.47(7)
96.07(7)
99.79(7)
79.57(7)
87.16(7)
97.48(7)
96.07(7)
79.18(7)
P(1)ꢀPt(1)ꢀP(2)
P(1)ꢀPt(1)ꢀS(1)
P(2)ꢀPt(1)ꢀS(2)
S(1)ꢀPt(1)ꢀS(2)
P(3)ꢀPt(2)ꢀP(4)
P(3)ꢀPt(2)ꢀS(3)
P(4)ꢀPt(2)ꢀS(4)
S(3)ꢀPt(2)ꢀS(4)
85.84(5)
98.24(5)
100.92(5)
75.00(5)
85.66(5)
98.35(6)
101.28(5)
74.85(6)
3.2. Ruthenium dithiocarbamato complexes
Br(1)ꢀHg(1)ꢀBr(2) 110.64(3)
Br(1)ꢀHg(1)ꢀBr(3) 108.06(3)
Br(1)ꢀHg(1)ꢀBr(4) 110.09(3)
Br(2)ꢀHg(1)ꢀBr(3) 108.29(4)
Br(3)ꢀHg(1)ꢀBr(4) 114.79(3)
Cl(1)ꢀCd(1)ꢀCl(2) 112.27(7)
Cl(1)ꢀCd(1)ꢀCl(3) 107.12(7)
Cl(1)ꢀCd(1)ꢀCl(4) 113.45(7)
Cl(2)ꢀCd(1)ꢀCl(3) 108.79(8)
Cl(3)ꢀCd(1)ꢀCl(4) 108.02(7)
The ruthenium complex cis-[RuCl2(dppm)2] reacts
with dithiocarbamates of zinc, cadmium, mercury and
lead, [M%(S2CNEt2)2] in boiling acetonitrile to afford
salts of the general form [Ru(S2CNEt2)(dppm)2]2[M%Cl4]

G. Exarchos et al. / Polyhedron 20 (2001) 2951–2963
2959
3.3. Cobalt dithiocarbamato complexes
The cobalt(II) halides [CoX2(dppe)] react with dithio-
carbamates [M%(S2CNEt2)2] (M%=Cd, Hg) undergoing
oxidation to afford cobalt(III) salts [Co(S2CNEt2)2-
(dppe)]2 [M%X4] in moderate yield as dark red powders.
Addition of the appropriate amount of the correspond-
ing thiouram disulfide (Et2NCS2)2 as an oxidising agent
and source of extra dithiocarbamate anions gave the
products in essentially quantitative yield (Eq. (4)).
2[CoCl2(dppe)]+[M%(S2CNEt2)2]+(S2CNEt2)2
“2[Co(S2CNEt2)2(dppe)]2[M%Cl4]
(4)
The cobalt(III) complex salts were characterised by
their infrared (Table 2) and NMR spectra; the stoi-
chiometry and stereochemistry of the tetrachlorocad-
mate salt were confirmed by elemental analysis and
X-ray diffraction methods. The [Co(S2CNEt2)2(dppe)]+
cation has previously been characterised as its [BF4]−
salt. Our infrared and NMR data are in good agree-
ment with those presented by the previous authors [17]
and clearly establish the presence of the [Co(S2CNEt2)2-
(dppe)]+ cation in each case. A typical data set is as
1
follows: H NMR: l 0.75 and 0.87 (t, CH3CH2N), 3.06
and 3.32 (m, CH3CH2N), 2.72 (br d, PCH2CH2P), 7.10
(m), 7.26 (m), 7.55 (m) and 7.85 (m) C6H5.
31P{1H}NMR: l 60.3 (s). Changes associated with vari-
ations in the identity of the counter anion present are
Fig. 3. (A) Molecular structure of cation [Co(S2CNEt2)2(dppe)]+
from salt (3) showing atom labelling scheme. (B) Molecular structure
of anion [Cl3ZnO:(Ph)2PCH2CH2P(Ph)2:OZnCl3]2− from salt (3)
showing atom labelling scheme.
1
90.1 and 90.5 ppm for H and 31P{1H} resonances,
respectively. All the NMR resonances show broadening
attributable to coupling with the 59Co quadrupole mo-
ment. An attempted X-ray crystal structure determina-
tion for the complex [Co(S2CNEt2)2(dppe)]2[CdCl4]
revealed severe disordering and variable amounts of
chloroform of crystallisation, consequently only unit
crystal structure determination. The infrared data
(Table 2) are in each case consistent with the presence
of coordinated diothiocarbamate ligands (w(CꢀN) ca.
1500 cm−1; w(CꢀS) ca. 1000 and 915 cm−1; w(RuꢀS)
ca. 380 cm−1) and discrete tetrahedral [M%Cl4]2− an-
1
ions. All the salts displayed essentially identical H and
,
cell parameters could be determined (a=23.6388(10) A,
31P{1H} NMR data consistent with the presence of
[Ru(S2CNEt2)(dppm)2]+ cations. A typical data set is
,
,
b=11.4468(4) A, c=47.2679(2) A, i=104.0990°).
The reaction of [CoCl2(dppe)] with [Zn(S2CNEt2)2]/
(S2CNEt2)2 afforded as the only isolated product a dark
red crystalline solid, which on the basis of elemental
analysis and spectroscopic evidence was not the ex-
pected salt [Co(S2CNEt2)2(dppe)]2[ZnCl4]. In addition
1
as follows: H NMR: l 1.06 (t, CH3CH2N), 3.50 (m,
CH3CH2N), 4.60 and 4.91 (m, PCH2P); 6.45 (m), 7.0
(m), 7.25 (m) and 7.64 (m, C6H5). 31P{1H} NMR: l
−4.8 and −17.5 (t, PCH2P). Anion dependent varia-
tions do not exceed 90.1 ppm (1H) and 90.3 ppm
31P{1H}. An X-ray crystallographic study of
[Ru(S2CNEt2)(dppm)2]2[CdCl4] was undertaken, unfor-
tunately the molecules were severely disordered and the
crystals contained large amounts of chloroform which
was readily lost when they were removed from the
mother liquor. A complete structure determination was
not possible however, the partial data set obtained was
sufficient to provide unit cell parameters (a=15.2087
to the H and 31P{1H} NMR resonances typical of the
1
[Co(S2CNEt2)2(dppe)]+ cation the spectra displayed a
1H NMR signal at l 2.20 (broadened doublet) and a
31P{1H} signal at l 42.4 (s). An X-ray crystal structure
determination revealed a 2:1 salt containing the ex-
pected cation [Co(S2CNEt2)2(dppe)]+ and the novel
anion [Cl3ZnO:(Ph)2PCH2CH2P(Ph)2:O ZnCl3]2− (Fig.
3(A) and (B)). Bond length and angle data are given in
Table 5.
The cation [Co(S2CNEt2)2(dppe)]+ has not previ-
ously been structurally characterised, however a crystal
structure determination has been reported for the
,
,
,
A, b=15.3479 A, c=17.1224 A, h=73.218°, i=
83.073°, k=19.732°) and confirm the proposed stoi-
chiometry and stereochemistry.

2960
G. Exarchos et al. / Polyhedron 20 (2001) 2951–2963
[BPh4]− salt of the closely related cation [Co-
(S2CNMe2)2(dmpf)]+
[dmpf=1,1%-bis(dimethylphos-
phino)ferrocene] [18]. The two cations have very similar
the ionic salt [Co(CO)(dppe)2]2[Cl3CoO:(Ph)2PCH2-
CH2P(Ph)2:OCoCl3] [22]. Since analogous Zn(II) and
Co(II) complexes are often isostructural, it seems par-
ticularly appropriate to compare the zinc and cobalt
CoꢀS and CoꢀP bond lengths with CoꢀS trans to P
,
approximately 0.03 A longer than CoꢀS trans to S in
complex
anions
[Cl3MO:(Ph)2PCH2CH2P(Ph)2:
each case. The difference no doubt reflecting the greater
trans influence of the P-donor. The CoꢀS distances
trans to S are very similar to those previously reported
for [Co(S2CNEt2)3] [19]. The angle subtended at cobalt
by the dmpf ligand (102.3(1)°) is substantially larger
than that subtended by the dppe ligand (87.01(2)°).
However, this difference is not reflected in the angles
subtended at cobalt by the dithiocarbamate ligands
which remain essentially constant at approximately 76°
for the two complexes.
OMCl3]2−. Both anions are centrosymmetric with a
fully staggered arrangement of the diphosphine and the
attached OMCl3 groups. The PꢁO bond length
,
(1.520(5) A) and PꢀOꢀM bond angle (141.1(3)°) in the
zinc anion are significantly greater than the correspond-
,
ing parameters for the cobalt anion (1.477(5) A and
133.8(3)°) [22]. Coordination geometry at the zinc and
cobalt atoms is essentially tetrahedral with angles sub-
tended at the metal by adjacent ligands ranging from
102.45(15) to 115.78(8)° in the case of zinc and from
101.0(1) to 117.86(8)° in the case of cobalt. The ZnꢀO
and ZnꢀCl bonds in the (Cl3ZnO:(Ph)2PCH2CH2P-
(Ph)2:OZnCl3]2− dianion are all significantly (ca. 0.05
The
anion,
[Cl3ZnO:(Ph)2PCH2CH2P(Ph)2:
OZnCl3]2− provides a rare example of the bridging
1,2-bis(diphenylphosphinoyl)ethane ligand. To the best
of our knowledge the only previously reported exam-
ples are three cobalt(II) species—the cyclic dimer
[CoCl2{O:(Ph)2PCH2CH2P(Ph)2:O}]2 [20], the linear
polymer [CoCl2{O:(Ph)2PCH2CH2P(Ph)2:O}]n [21] and
,
and 0.04 A) longer than the corresponding bonds in the
neutral complex [ZnCl2(OPPh3)2] [23], the differences
can probably be attributed to the presence of negative
charges on the former species.
In the light of this structure it is possible to assign the
1
additional H and 31P{1H} NMR resonances reported
Table 5
,
Selected bond lengths (A) and bond angles (°) for the salt
[Co(S2CNEt2)2(dppe)]2[Cl3ZnO:(Ph)2PCH2CH2P(Ph)2:OZnCl3] (3)
above to the methylene protons and P (V) atoms of the
complex anion.
Cation
Anion
3.4. Palladium dithiocarbamato complexes
Bond lengths
Co(1)ꢀP(1)
Co(1)ꢀP(2)
Co(1)ꢀS(1)
Co(1)ꢀS(2)
Co(1)ꢀS(3)
Co(1)ꢀS(4)
S(1)ꢀC(1)
S(2)ꢀC(1)
S(3)ꢀC(6)
S(4)ꢀC(6)
N(1)ꢀC(1)
N(2)ꢀC(6)
P(1)ꢀC(12)
P(2)ꢀC(11)
C(11)ꢀC(12)
2.2370(18)
2.2415(19)
2.2931(19)
2.2703(18)
2.2653(19)
2.3044(18)
1.727(6)
1.713(7)
1.719(6)
1.705(6)
1.316(8)
Zn(1)ꢀCl(1)
Zn(1)ꢀCl(2)
Zn(1)ꢀCl(3)
Zn(1)ꢀO(1)
P(3)ꢀO(1)
P(3)ꢀC(37)
C(37)ꢀC(37A)
2.229(2)
2.238(2)
2.2533(19)
2.009(5)
1.520(5)
1.796(7)
1.531(12)
In order to ascertain if the presence of a chelate
diphosphine ligand was an essential prerequisite for
ligand cross transfer to occur, reactions of the bipyridyl
complexes [PdX2(bipy)] with a range of dithiocarba-
mates was investigated. The low solubility of the
bipyridyl precursors necessitated the use of boiling ace-
tonitrile as reaction medium. Furthermore, in order to
facilitate crystallisation of the products it was found
convenient to use di-n-butyldithiocarbamates which
possess a suitable solubility profile. The ligand cross
transfer reactions proceeded smoothly to afford tetra-
halometallate salts [Pd(S2CNnBu2)(bipy)]2 [M%X4]
(M%=Zn, Cd, Hg; X=Cl, Br, M%=Pb, X=Cl) in
good yield. Changing the relatively soft diphosphine
ligand for the somewhat harder bipyridyl does not, in
the present instance at least, alter the course of the
ligand transfer process. The tetrahalometallate salts
formed are air-stable solids which are moderately solu-
ble in boiling solvents of high polarity, and crystallise
1.347(8)
1.826(6)
1.815(6)
1.534(9)
Bond angles
P(1)ꢀCo(1)ꢀP(2)
P(1)ꢀCo(1)ꢀS(1)
P(1)ꢀCo(1)ꢀS(2)
P(1)ꢀCo(1)ꢀS(3)
P(1)ꢀCo(1)ꢀS(4) 172.19(7)
P(2)ꢀCo(1)ꢀS(1) 173.54(7)
P(2)ꢀCo(1)ꢀS(2)
P(2)ꢀCo(1)ꢀS(3)
P(2)ꢀCo(1)ꢀS(4)
S(1)ꢀCo(1)ꢀS(2)
S(1)ꢀCo(1)ꢀS(3)
S(1)ꢀCo(1)ꢀS(4)
87.01(7)
89.85(7)
90.54(7)
98.86(7)
O(1)ꢀZn(1)ꢀCl(1)
O(1)ꢀZn(1)ꢀCl(2)
O(1)ꢀZn(1)ꢀCl(3)
Cl(1)ꢀZn(1)ꢀCl(2)
Cl(1)ꢀZn(1)ꢀCl(3)
Cl(2)ꢀZn(1)ꢀCl(3)
102.45(15)
106.09(15)
109.44(14)
115.78(8)
112.50(8)
109.98(8)
98.28(7)
89.50(7)
89.87(7)
76.10(7)
96.48(7)
93.94(7)
well
therefrom.
One
representative
example,
[Pd(S2CNnBu2)(bipy)]2[CdCl4], was characterised by ele-
mental analysis and X-ray crystal structure determina-
tion; the remainder were identified by spectroscopic
1
methods. The recording of the H NMR spectra was
S(2)ꢀCo(1)ꢀS(3) 169.44(7)
S(2)ꢀCo(1)ꢀS(4)
S(3)ꢀCo(1)ꢀS(4)
hampered by the relatively low solubility of the com-
96.99(7)
75.97(6)
1
plex salts. However, H data of acceptable quality were
collected and these confirm the presence of dipyridyl

G. Exarchos et al. / Polyhedron 20 (2001) 2951–2963
2961
numbering scheme and the arrangement of cation pairs
are shown in Fig. 4(A) and (B). Selected bond length
and bond angle data are presented in Table 6.
The core of the palladium(II) cation is strictly planar
with the Pd atom situated in the plane defined by the
bipy ligand and the S2CN skeleton of the dithiocarba-
,
mate ligand. Differences of ca. 0.02 and 0.03 A in the
length of the PdꢀN and PdꢀS bonds, respectively, be-
stow a slight asymmetry on the cation coordination
sphere with the shortest PdꢀN bond trans to the longest
PdꢀS bond. The PdꢀS distances in the present complex
are slightly shorter than those found for the complex
[Pd(S2CNnBu2)2] [24], the difference probably being at-
tributable in part to the presence of a positive charge
on the cation. The bipyridyl and dithiocarbamate lig-
ands displaying typical narrow ‘bite’ angles of 80.1(3)
and 75.66(8)°, respectively. The cations are stacked in
mutually parallel pairs. However, the PdꢀPd distance of
,
3.376 A is too great for significant PdꢀPd bonding
interaction. Likewise, the closest intermolecular PdꢀS
,
distance (4.261 A) clearly indicates the absence of any
significant PdꢀS interaction. To minimise steric interac-
tions between S2CNnBu2 groups within the cation pairs
each cation is rotated through 117.4° relative to its
partner. The [CdCl4]2− anions have almost ideal tetra-
hedral symmetry with CdꢀCl bond lengths in the range
,
2.451(3)–2.485 (2) A and ClꢀCdꢀCl bond angles in the
range 106.11(9)–110.01(10)°. Their values lie well
Table 6
,
Selected bond length (A) and bond angle (°) data for the salt
[Pd(S2CNBun2)(bipy)]2[CdCl4].2MeCn (4)
Cation
Anion
Bond lengths
Pd(1)ꢀN(1)
Pd(1)ꢀN(2)
Pd(1)ꢀS(1)
Pd(1)ꢀS(2)
Pd(2)ꢀN(4)
Pd(2)ꢀN(5)
Pd(2)ꢀS(3)
Pd(2)ꢀS(4)
S(1)ꢀC(11)
S(2)ꢀC(11)
N(3)ꢀC(11)
S(3)ꢀC(30)
S(4)ꢀC(30)
N(6)ꢀC(30)
2.038(8)
2.067(7)
2.303(2)
2.282(2)
2.058(2)
2.033(7)
2.277(2)
2.290(2)
1.725(10)
1.708(10)
1.337(12)
1.721(9)
1.732(9)
1.287(12)
Cd(1)ꢀCl(1)
Cd(1)ꢀCl(2)
Cd(1)ꢀCl(3)
Cd(1)ꢀCl(4)
2.454(3)
2.456(3)
2.450(3)
2.484(2)
Fig. 4. (A) Molecular structure for cation [Pd(S2CNnBu2(bipy)]+
from salt (4) showing atom labelling scheme. (B) Arrangement of
cation pairs in salt (4).
and dithiocarbamate ligands in the correct 1/1 ratio. A
1
typical NMR data set is as follows: H NMR: l 0.90 (t,
CH3CH2CH2CH2N), 1.30 (m, CH3CH2CH2CH2N),
1.61 (m, CH3CH2CH2CH2N), 3.68 (t, CH3CH2CH2-
CH2N), 7.70 (m), 8.24 (m) and 8.46 (m) (C5H4N)2.
Variations associated with changes in the nature of the
counteranion were within the range 90.1 ppm. In-
frared data are given in Table 2. The complex
Bond angles
N(1)ꢀPd(1)ꢀN(2) 80.2(3)
N(1)ꢀPd(1)ꢀS(1) 175.6(2)
N(1)ꢀPd(1)ꢀS(2) 100.4(2)
Cl(1)ꢀCd(1)ꢀCl(2) 110.99(10)
Cl(1)ꢀCd(1)ꢀCl(3) 110.35(10)
Cl(1)ꢀCd(1)ꢀCl(4) 106.12(9)
Cl(2)ꢀCd(1)ꢀCl(3) 109.83(12)
Cl(2)ꢀCd(1)ꢀCl(4) 108.55(10)
Cl(3)ꢀCd(1)ꢀCl(4) 110.94(10)
[Pd(S2CNnBu2)(bipy)]2[CdCl4]
crystallises
from
CH3CN–C6H5CH3 with two molecules of CH3CN per
anion, these are lost on drying the crystals in vacuo
prior to analysis. The X-ray crystal structure determi-
nation was performed on fully solvated crystals. The
molecular structure of the cation showing the atom
S(1)ꢀPd(1)ꢀS(2)
75.67(8)
N(4)ꢀPd(2)ꢀN(5) 79.0(3)
N(4)ꢀPd(2)ꢀS(3) 176.9(2)
N(4)ꢀPd(2)ꢀS(4) 101.8(2)
S(3)ꢀPd(2)ꢀS(4)
75.91(9)

2962
G. Exarchos et al. / Polyhedron 20 (2001) 2951–2963
within the range of values previously reported for this
anion [2,15,16].
ions functioning as alkyl cation abstractors [28,29]. It
therefore seems probable that in our systems the con-
version proceeds so long as labile EtOCS2− anions are
present but it is inhibited once they are all bound in the
palladium product. It is also possible that the presence
of the chelating diphosphine on the palladium precur-
sor may play a part in inhibiting the conversion.
3.5. Palladium complexes of other S-donor chelate
ligands
Finally, in order to further explore the generality of
these halide/S chelate ligand cross transfers the reaction
of the palladium complexes [PdX2(dppe)] with a range
of transition metal xanthates (O-ethyldithiocarbonates),
3.5.2. Palladium dithiophosphinate complexes
Reactions of the palladium complexes [PdX2(dppe)]
with metal diphenyldithiophosphinates [M%(S2PPh2)2]
(M%=Zn, Cd, Hg, Pb, Co, Ni) in dichloromethane at
room temperature gave fine pale yellow or light green
(M%=Co, Ni) powdery products in good yield. These
were characterised primarily by spectroscopic methods.
Infrared data (Table 2) are consistent with the presence
of [M%X4]2− anions. NMR data for the complex
diphenyldithiophosphinates
and
diethyldithiophosphates were examined.
3.5.1. Palladium O-ethyldithiocarbonate and
dithiocarbonate complexes
Reaction between the palladium dihalide complexes
[PdX2(dppe)] and transition metal O-ethyldithiocarbon-
ate [M%(S2COEt)2] (M%=Zn, Cd, Hg, Pb, Fe and Ni) in
cold dichloromethane all afforded fine yellow or pale
green (M%=Fe, Ni) powdery products in good yield.
However, on examination by infrared and NMR spec-
troscopy it became apparent that each was a approxi-
mately 30/70 mixture of two components—the
anticipated salt [Pd(S2COEt)(dppe)]2[M%X4] and the
neutral dithiocarbonate complex [Pd(S2CO)(dppe)]. A
cation—1H NMR:
l
3.25 (d, 2JHP=24.7 Hz,
PCH2CH2P), 7.48 and 7.75 (m, C6H5). 31P{1H} NMR:
l 66.6 (s, PCH2CH2P), 88.57 (s, Ph2PS2)—are consis-
tent with the proposed stoichiometry and structure.
Anion dependent variations are less that 90.1 and
90.5 ppm for 1H and 31P{1H} spectra, respectively.
Confirmation of stoichiometry was obtained for one
complex, [Pd(S2PPh2)(dppe)]2[CdCl4], by elemental
analysis.
1
typical set of NMR data comprised H resonances at l
1.52 (t) CH3CH2O; 2.56 (d, 2JHP=19.8 Hz) and 3.27 (d,
2JHP=23.4 Hz) PCH2CH2P; 4.74(q) CH3CH2O; 7.42
(m) and 7.73 (m) C6H5 and 31P{1H} resonances are l
64.5 (s) and 53.0 (s). On the basis of integration data
and by comparison with related complexes it is possible
to assign the triplet at l 1.51, the quartet at l 4.74, the
doublet at l 3.27 and the 31P{1H} singlet at l 53.0 to
the O-ethyldithiocarbonate complex salt. The remain-
ing doublet at l 2.56 and the 31P{1H} singlet at l 64.5
are attributed to the dithiocarbonate complex
[Pd(S2CO)(dppe)].
3.5.3. Palladium dithiophosphato complexes
The palladium complex [PdX2(dppe)] reacted in simi-
lar fashion with the dithiophosphate complex
[M%{S2P(OEt)2}2] (M%=Zn, Cd, Hg, Pb, Fe, Ni) to
afford the salts [Pd{S2P(OEt)2}(dppe)]2[M%X4] in good
yield as pale yellow or green (M%=Fe, Ni) air stable
powders. Characterisation was by spectroscopic meth-
ods. Infrared data (Table 2) are consistent with the
proposed structures of the complex cation
[Pd{S2P(OEt)2}(dppe)]+ and the various anions
[MX4]2−. NMR data for the complex cation—1H
A further indication of the presence of the dithiocar-
bonate complex [Pd(S2CO)(dppe)] was provided by the
appearance of sharp bands at approximately 1675 and
1603 cm−1 in the infrared spectra of the product mix-
2
NMR: l 1.35 (t, CH3CH2O), 3.35 (d, JHP=24.4 Hz,
PCH2CH2P) 4.12 (q, CH3CH2O), 7.48 and 7.78 (m,
C6H5). 31P{1H} NMR: l 67.0 (s, PCH2CH2P), 100.1 (s,
S2P(OEt)2). Anion dependent variations are less than
tures. A similar pair of bands (1681 and 1603 cm−1
)
1
have been reported for the related palladium complex
[Pd(S2CO)(PMePh2)2] [25]. Attempts to complete the
conversion of the product mixtures to the pure dithio-
carbonato complex [Pd(S2CO)(dppe)] in boiling aceto-
nitrile were unsuccessful. At first sight this failure is
unexpected given the very facile conversion of the O-
alkyldithiocarbonates [M%(S2COR)2] (M%=Ni, Pt) to
90.1 and 90.3 ppm for H and 31P(1H} resonances,
respectively. The NMR spectra revealed no evidence to
suggest that significant conversion to Pd{S2P(O)-
OEt}(dppe)] had occurred in any of the syntheses. Since
free S2P(OEt)-2 anions have previously been implicated
in these reactions as ethyl cation acceptors [30] it seems
likely that their absence in the present systems inhibited
the conversion.
the
corresponding
dithiocarbonato
complexes
[M(S2CO)(dppe)] accomplished by addition of the
diphosphine to cold dichloromethane solutions of the
former complexes [26,27]. However, it has previously
been suggested that mechanisms of O-alkyldithiocar-
bonate“dithiocarbonate conversion in complexes of
the nickel triad involve free O-alkyldithiocarbonate an-
4. Supplementary material
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic

G. Exarchos et al. / Polyhedron 20 (2001) 2951–2963
2963
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Data Centre, CCDC Nos. 141135, 141134, 158199 and
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Copies of this information may be obtained free of
charge from The Director, CCDC, 12 Union Road,
Cambridge, CB2 1EZ, UK (fax: +44-1223-336033;
e-mail: deposit@ccdc.cam.ac.uk or www: http://
www.ccdc.cam.ac.uk).
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Acknowledgements
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We thank the EPSRC and King’s College London
for funding of the diffractometer system. Grateful ac-
knowledgement is also given to the Nuffield Founda-
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