Syntheses, crystal structure and spectroscopic characterization of novel N-R-sulfonyldithiocarbimate and triphenylphosphine nickel(II) complexes

Article abstract of DOI:10.1016/S0277-5387(02)01176-2

Three new complexes of the general formula: [Ni(PPh₃)₂(RSO₂N=CS₂)] where R = 2-CH₃C₆H₄ (1), 4-CH₃C₆H₄ (2) and 4-BrC₆H₄ (3) were obtained in crystalline form by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimates (K₂(RSO₂N=CS₂)) and triphenylphosphine with nickel(II) chloride in ethanol-water. The 1 complex crystallizes in the centrosymmetric space group of the triclinic system with two molecules per unit cell, while 2 and 3 complexes crystallize in the Pbca space group of the orthorhombic system with eight molecules per unit cell. The X-ray single-crystal analysis showed that all complexes present a similarly distorted square-planar configuration around the nickel atom due to the steric effect of the triphenylphosphine ligands and the didendate chelation by the two sulfur atoms of the dithiocarbimate ligand. The IR and UV-Vis spectral data are consistent with the formation of almost square-planar nickel complexes. The ¹H NMR, ¹³C NMR, ³¹P NMR spectra showed the expected signals for the triphenylphosphine and the dithiocarbimate moieties.

Full text of DOI:10.1016/S0277-5387(02)01176-2

Polyhedron 21 (2002) 2243ꢁ2250
/
www.elsevier.com/locate/poly
Syntheses, crystal structure and spectroscopic characterization of
novel N-R-sulfonyldithiocarbimate and triphenylphosphine nickel(II)
complexes
Marcelo R.L. Oliveira a,*, Heulla P. Vieira b, Genivaldo J. Perpe´tuo c, Jan Janezak d,e,
Vito M. De Bellis e
a Departamento de Qu´ımica, Universidade Federal de Vicosa, Vicosa, MG, CEP 36571-000, Brazil
¸
¸
b Departamento de Qu´ımica, Instituto de Cieˆncias Exatas e Biolo´gicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, CEP 35400-000, Brazil
c Departamento de F´ısica, Instituto de Cieˆncias Exatas e Biolo´gicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, CEP 35400-000, Brazil
d Institute of Low Temperature and Structure Research, Polish Academy of Science, PO Box 1410, 50-950 Wroclaw, Poland
e Departamento de Qu´ımica, Instituto de Cieˆncias Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, CEP 31270-901, Brazil
Received 8 April 2002; accepted 20 July 2002
Abstract
Three new complexes of the general formula: [Ni(PPh3)2(RSO2Nꢀ
(3) were obtained in crystalline form by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimates (K2(RSO2Nꢀ
and triphenylphosphine with nickel(II) chloride in ethanolꢁwater. The 1 complex crystallizes in the centrosymmetric space group of
/
CS2)] where Rꢀ/2-CH3C6H4 (1), 4-CH3C6H4 (2) and 4-BrC6H4
/CS2))
/
the triclinic system with two molecules per unit cell, while 2 and 3 complexes crystallize in the Pbca space group of the orthorhombic
system with eight molecules per unit cell. The X-ray single-crystal analysis showed that all complexes present a similarly distorted
square-planar configuration around the nickel atom due to the steric effect of the triphenylphosphine ligands and the didendate
chelation by the two sulfur atoms of the dithiocarbimate ligand. The IR and UVꢁVis spectral data are consistent with the formation
/
of almost square-planar nickel complexes. The 1H NMR, 13C NMR, 31P NMR spectra showed the expected signals for the
triphenylphosphine and the dithiocarbimate moieties.
# 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Dithiocarbimates; Triphenylphosphine; Nickel complexes; Crystal structures
1. Introduction
obtained by reacting NiX2 with dithiocarbamates and
PR3 (Rꢀalkyl/aryl) [4]. Complexes containing the
NiXS2P chromophore have shown catalytic activity,
especially for oligomerization of olefins [5ꢁ7]. Many
complexes that involve nickel(II), phosphine and dithio-
carbamate ligands, as [Ni(L)(PR3)2]ꢂ, [Ni(L)(PꢁP)]ꢂ,
[NiX(L)(PR3)2] and [NiX(L)(PꢁP)] (Lꢀseveral dithio-
carbamates, Rꢀmany different groups, Xꢀhalides and
pseudohalides and PꢁPꢀdiphosphines) have been
characterized [8,9].
Some complexes of palladium and platinum with
dithiocarbimates and phosphines have been structurally
characterized and using the quantum chemical calcula-
tions (CNDO/2) the mechanism of the formation of the
complexes has been investigated [10,11]. Additionally,
/
We became interested in the syntheses and character-
ization of dithiocarbimate metal complexes due to their
similarities with the dithiocarbamate compounds, which
have a wide range of applications. For example, they are
used in the rubber vulcanization process [1] as well as
several dithiocarbamates salts and complexes have been
used as fungicides [2]. Nickel(II) dithiocarbamates
normally react with phosphines to form complexes
with the NiS2P2 chromophore [3]. Complexes containing
/
/
/
/
/
/
/
/
the NiXS2P chromophore (Xꢀhalide) are usually
/
* Corresponding author. Tel.: ꢂ
3899-3065
E-mail address: marcelor@ufv.br (M.R.L. Oliveira).
/
55-31-3899-3059; fax: ꢂ55-31-
/
dimeric nickel complexes [Ni(PR3)2(R?Nꢀ
/
CS2)] (R and
R?ꢀalkyl/aryl) have been obtained by the reaction of
/
0277-5387/02/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved.
PII: S 0 2 7 7 - 5 3 8 7 ( 0 2 ) 0 1 1 7 6 - 2

2244
M.R.L. Oliveira et al. / Polyhedron 21 (2002) 2243ꢁ2250
/
[Ni(NO2)(R?NHCS2)(PR3)] or [NiBr(R?NHCS2)(PR3)]
with Lewis bases such as (CH3)3N and NH3 [12].
However, their structures were not determined by X-
ray diffraction techniques.
N-R-sulfonyldithiocarbimate dihydrate (1.0 mmol) in
water (10 ml) was added to a solution of triphenylpho-
sphine (2.0 mmol) in ethanol (40 ml). Nickel(II) chloride
hexahydrate (1.0 mmol) was added to the suspension
and the reaction mixture was stirred for 6 h at room
temperature (r.t.). The color of the suspension changed
from green to pink/red. The solid product of the
reaction was filtered, washed with distilled water and
ethanol, and dried under reduced pressure for 1 day
Herein we investigate the three new bis(triphenylpho-
sphine)N-R-sulfonyldithio-carbimatenickel(II)
plexes (Rꢀ2-CH3C6H4, 4-CH3C6H4, 4-BrC6H4) that
were obtained in the crystalline form by the reaction of
NiCl2×6H2O with triphenylphosphine and dithiocarbi-
mate anions derived from sulfonamides. These com-
com-
/
/
yielding [Ni(PPh3)2(RSO2Nꢀ
/
CS2)] (ca. 70%). Suitable
1
plexes were characterized by UVꢁ
/
Vis, IR, H, 13C and
crystals for X-ray structure analysis were obtained after
slow evaporation of solutions of the compounds in
31P NMR, elemental analyses for C, H, N, Ni and by
single crystal X-ray diffraction techniques.
dichloromethaneꢁmethanol and few drops of water.
/
2.2.1. Bis(triphenylphosphine)2-
methylphenyldithiocarbimatenickel(II) (1)
Elemental analysis: Found (Calc.): C, 63.39 (63.78);
H, 4.37 (4.50); N, 1.70 (1.69); Ni, 7.01 (7.08)%. M.p.
2. Experimental
2.1. Methods and materials
(8C): 165.5ꢁ
557. IR (most intense bands) (cmꢃ1): 1440 n(Cꢀ
1300 nass(SO2); 1120 nsym(SO2); 920 nass(CS2) and 345
n(NiS). 1H NMR (d): 7.88ꢁ
7.79 (m, 1H, H2? (R
group)); 7.42ꢁ7.05 (m, 33H, H3?, H4?, H5?, R group
and triphenylphosphine signals) and 2.63 (s, 3H, CH3).
13C{1H} NMR (d): 197.35 (Nꢀ
CS2); 140.77 (C1?);
/
166.0. UVꢁ
/
Vis (nm): 197; 236; 320; 426 and
/
N);
The solvents were purchased from Merck and used
without further purification. The sulfonamides, 4-bro-
mophenylsulphonyl chloride, nickel(II) chloride hexa-
hydrate and triphenylphosphine were purchased from
Aldrich. Carbon disulfide and potassium hydroxide
were purchased from Vetec. The 4-bromobenzenesul-
phonamide was prepared from the 4-bromobenzenesul-
phonyl chloride as described elsewhere [13]. The N-R-
sulfonyldithiocarbimate potassium salts dihydrate were
prepared in dimethylformamide from sulfonamides
analogously as described in the literature [14,15]. These
salts, which are soluble in water and insoluble in most of
the organic solvents, were re-crystallized from hot
/
/
/
137.98 (C2?); 131.49 (C3?); 129.02 (C5?); 127.94 (C6?);
125.09 (C4?) and 20.84 (CH3). Triphenylphosphine
signals: 134.39 (t, Jꢀ
/
7, C2ƒ and C6ƒ); 130.89 (s, C4ƒ);
129.35 (d, Jꢀ
/
31, C1ƒ); 128.45 (t, Jꢀ
/
7, C3ƒ and C5ƒ).
31P NMR (d): 31.69 (s).
2.2.2. Bis(triphenylphosphine)4-
methylphenyldithiocarbimatenickel(II) (2)
Elemental analysis: Found (Calc.): C, 63.91 (63.78);
H, 4.39 (4.50) N, 1.72 (1.69); Ni, 7.11 (7.08)%. M.p.
ethanolꢁ
with a Mettler FP5 equipment. Microanalyses for C, H
and N were obtained from a PerkinꢁElmer 2400 CHN.
/water. Melting points (m.p.) were determined
/
(8C): 166.5ꢁ
557. IR (most intense bands) (cmꢃ1): 1445 n(Cꢀ
1300 nass(SO2); 1135 nsym(SO2); 910 nass(CS2) and 344
n(NiS). 1H NMR (d): 7.69ꢁ
7.57 (m, 2H, H2? and H6? (R
group)); 7.44ꢁ7.20 (m, 30H triphenylphosphine signals);
7.17ꢁ7.15 (m, 2H, H3? and H5? (R group)) and 2.39 (s,
3H, CH3). 13C{1H} NMR (d): 197.37 (Nꢀ
CS2); 142.58
/
167.0. UVꢁ/Vis (nm): 197; 234; 320; 429 and
Nickel was analyzed by atomic absorption with a
Hitachi Z-8200 Atomic Absorption Spectrophotometer.
/
N);
The IR spectra were recorded with a Perkinꢁ
B infrared spectrophotometer using CsI pellets. The
UVꢁVis spectra were recorded with a Beckman DU 640
/Elmer 283
/
/
/
1
/
spectrometer using nujol mull suspension. The H (400
MHz), 13C (100 MHz) and 31P (162 MHz) NMR spectra
of the complexes were recorded on a Bruker Advance
RX-400 spectrophotometer in CDCl3 with TMS (H3PO4
for 31P NMR spectra) as internal standard.
/
(C1?); 139.42 (C4?); 128.94 (C3? and C5?); 127.49 (C2?
and C6?); 21.78 (CH3). Triphenylphosphine signals:
134.29 (t, Jꢀ
/
6, C2ƒ and C6ƒ); 130.64 (s, C4ƒ); 129.25
(d, Jꢀ
/
46, C1ƒ); 128.27 (t, Jꢀ
/
5, C3ƒ and C5ƒ). 31P
NMR (d): 30.47 (s).
2.2. Syntheses
2.2.3. Bis(triphenylphosphine)4-
bromophenyldithiocarbimatenickel(II) (3)
Found (Calc.): C, 57.29 (57.80); H, 3.79 (3.84); N,
The syntheses of the nickel(II) complexes were
performed according to the Scheme 1. A solution of
1.60 (1.57); Ni, 6.61 (6.57)%. M.p. (8C): 169.0ꢁ
UVꢁVis (nm): 193; 247; 308; 426 and 557. IR (most
intense bands) (cmꢃ1): 1435 n(Cꢀ
N); 1310 nass(SO2);
1135 nsym(SO2); 915 nass(CS2) and 335 n(NiS). 1H NMR
(d): 7.68ꢁ7.65 (m, 2H, H2? and H6? (R group)); 7.45ꢁ
/
170.5.
/
/
Scheme 1.
/
/

M.R.L. Oliveira et al. / Polyhedron 21 (2002) 2243ꢁ
/2250
2245
7.19 (m, 32H, H3?, H5? R group and triphenylphosphine
signals). 13C{1H} NMR (d): 145.00 (C1?); 131.93 (C3?
and C5?); 128.88 (C2? and C6?); 127.50 (C4?). Triphe-
3. Results and discussion
The compounds are quite stables at the ambient
conditions. In contrast to the dithiocarbamate Ni-
complexes with the general formula of [Ni(PR3)2(RNꢀ
CS2)] which are soluble in THF, benzene and dichlor-
omethane [12], these N-R-sulfonyldithiocarbimate Ni-
complexes characterized in this paper are insoluble in
most organic solvents and are slightly soluble in chloro-
form and dichloromethane. These complexes are stable
up to the melting point without decomposition. At-
tempted to prepare the monotriphenylphosphine Ni-
nylphosphine signals: 134.29 (t, Jꢀ
/
6, C2ƒ and C6ƒ);
/
130.75 (s, C4ƒ); 129.33 (d, Jꢀ
/
54, C1ƒ); 128.33 (t, Jꢀ
/5,
C3ƒ and C5ƒ). 31P NMR (d): 31.75 (s).
2.3. X-ray crystallography
X-ray intensity data for all crystals were collected
using graphite monochromatic Mo Ka radiation on a
four circle KUMA KM-4 diffractometer with a two-
dimensional area CCD detector. The v-scan technique
complexes like K[NiCl(PPh3)(N-RSO2Nꢀ
same conditions described above, with 1 equiv. of
triphenylphosphine was unsuccessful.
/
CS2)] in the
with Dvꢀ0.758 for each image was used for data
/
The electronic spectra of the complexes show two
shoulders (ca. 426 and 557) that are typical for square-
collection. The 960 images for six different runs covered
over 90% of the Ewald sphere were performed. Initially
the lattice parameters were refined on about 200
reflections obtained from 40 images for eight runs with
different orientation in the reciprocal space. Finally the
lattice parameters were refined by least-squares method
planar nickel complexes and are assigned to dꢁ
/
d
transitions [9]. The 190ꢁ300 nm region in the spectra
/
of the complexes is dominated by three very intense
bands of the triphenylphosphine and the dithiocarbi-
mate ligands.
based on the all reflection with I ꢀ
4s(F2). One image
/
There are no strong or medium bands in the 1400ꢁ
1600 cmꢃ1 region in the IR spectra of the potassium
3, the
/
was used as standard for monitoring the data collection
after every 40 images, and no correction on the relative
intensity variation was necessary. Integration of the
intensities, correction for Lorenz and polarization
effects were performed using a KUMA KM-4 CCD
program system [16]. Total of 18 419 (9819 independent,
dithiocarbimates related to the complexes 1ꢁ
/
n(CN) band being observed around 1260 cmꢃ1
[14,19]. This low value indicates a great contribution
of the canonical forms (a) and (b) for the resonance
hybrid (Fig. 1). A strong band observed around 1455
cmꢃ1 in the spectra of the complexes was assigned to the
n(CN). In the spectrum of the complex [Ni(PPh3)2(4-
Rint
0.0750) and 55 811 (9891 independent, Rint
reflections were collected for the complexes 1ꢁ
ꢀ
/
0.0294), 27 613 (10 354 independent, Rint
0.0773)
3, respec-
ꢀ
/
ꢀ
/
CH3C6H4Nꢀ
nitrogen atom, this band is located at 1500 cmꢃ1 [12]. In
CS2)2]2ꢃ
/
CS2)] that has no SO2 group linked to the
/
tively. The face-indexed analytical absorption was
calculated using the SHELXTL program [17].
the case of the complex [Ni(4-CH3C6H4SO2Nꢀ
/
this band is observed around 1345 cmꢃ1 [20]. This fact
is probably due to a major negative charge on the Ni
atom in this anionic complex in comparison to the
complexes here synthesized. The substitution of one
dithiocarbimate ion by two triphenylphosphine mole-
cules is expected to result in a greater drift of electrons
from the remainder dithiocarbimate ion to the metal.
This effect is also observed, for example when the
The structures were solved by a Patterson heavy-atom
method using the SHELXL-97 program [18]. The Patter-
son map revealed the positions of the nickel, sulfur,
bromide (3) and some of the P and C atoms. The
remaining non-hydrogen atoms were located from
difference Fourier synthesis. The structures were refined
with anisotropic thermal parameters. Difference Fourier
maps gave electron density concentrations approxi-
mately located for all hydrogen atom positions; these
positions were idealized (HFIX 43 for all hydrogen
atoms of the phenyl rings with isotropic thermal
parameters of 1.2 Ueq of the carbon atoms joined
directly to the hydrogen atoms, and HFIX 137 for the
CH3 group in the complexes 1 and 2 with isotropic
thermal parameters of 1.5 Ueq of the methyl carbon
atom). Final differences Fourier maps showed no peaks
of chemically significance. Details of data collection
parameters and final agreement factors are collected in
Table 1. Selected bond lengths and angles are listed in
Table 2.
spectrum of the complex [Ni(dtc)2] (dtcꢀ
dithiocarbamate) (n(CN) band is observed in 1518
cmꢃ1
is compared with the spectrum of
/
N,N-diethyl-
)
[Ni(dtc)(PPh3)2]ꢂ (n(CN) band is observed in 1530
cmꢃ1) [8]. The nass(CS2) were observed at higher
frequency in the spectra of the potassium salts of
dithiocarbimates (ca. 955 cmꢃ1) [19] than that in the
spectra of the complexes here studied (ca. 915 cmꢃ1).
The shifts observed in the nass(CS2) and n(CN) in the
spectra of the complexes when compared with the
spectra of the ligands, are consistent with the increased
importance of the canonical form (c) after complexation
(Fig. 1). The spectra of the complexes also show the
expected medium band in the 300ꢁ
400 cmꢃ1 range
/

2246
M.R.L. Oliveira et al. / Polyhedron 21 (2002) 2243ꢁ2250
/
Table 1
Crystallographic data
Complex
1
2
3
Chemical formula
Formula weight
Crystal dimensions (mm)
Crystal system
C
828.61
44H37NNiO2P2S3
C44H37NNiO2P2S3
828.61
C43H34BrNNiO2P2S3
893.48
0.30ꢄ0.28ꢄ0.14
triclinic
0.24ꢄ0.18ꢄ0.14
orthorhombic
Pbcn
0.36ꢄ0.16ꢄ0.06
orthorhombic
Pbcn
¯
Space group
˚
P
/1/
a (A)
˚
10.000(2)
13.923(3)
14.953(3)
100.16(3)
103.28(3)
95.20(3)
1975.7(7)
2
16.556(3)
18.333(4)
25.412(5)
16.497(3)
18.556(4)
25.364(5)
b (A)
˚
c (A)
a (8)
b (8)
g (8)
V (A )
Z
3
˚
7713(3)
7764(3)
8
1.42
8
1.52
Dobsd (g cmꢃ3
)
1.39
1.393
Dcalc (g cmꢃ3
)
1.427
295
1.529
295
T (8C)
295
0.71073
0.769
˚
l (A)
0.71073
0.788
0.71073
1.812
m (cmꢃ1
)
Transmission factors: min, max
0.8020, 0.8999
0.0433
0.1104
0.8334, 0.8977
0.0540
0.1385
0.5616, 0.8991
0.0449
0.0639
R(F2)
Rw(F2)
S
1.015
ꢂ0.524 and ꢃ0.552
1.140
ꢂ0.656 and ꢃ0.611
1.004
ꢂ0.819 and ꢃ1.454
ꢃ3
˚
Residual electron density (e A
)
aFunction minimized: a w(½Fo½ꢃ½Fc½)2, where wꢀ4Fo2/s2(Fo2); [a w(½Fo½ꢃ½Fc½)2/(NoꢃNv)]1/2, where No, number of observations, Nv, number of
] .
2 1/2
variables. The final discrepancy factors: Rꢀa½Fo½ꢃ½Fc½/a½Fo½ and Rwꢀ[a w(½Fo½ꢃ½Fc½)2/a wFo
assigned to the NiS vibrations [21]. The n(NiP) band
was not observed above 200 cmꢃ1
The NMR spectra of 1ꢁ3 were typical for diamag-
square-planar geometry for the complexes. Doublets
or pseudo triplets are commonly observed in the 13C
NMR spectra of bis-phosphine transition metal cis-
complexes [23]. As expected, the 31P NMR spectra
exhibited only one signal (ca. 30 d) indicating that all
phosphorus atoms in the molecules are magnetically
equivalent.
.
/
1
netic species. The H NMR spectra of the complexes
showed the signals for the hydrogen atoms of the
triphenylphosphine. The remaining signals could be
assigned to the CH3 group of the aromatic moiety and
the other aromatic hydrogen atoms. The integration
The X-ray molecular structures of the 1ꢁ/3 complexes
1
curves on the H NMR spectra were consistent with a
are illustrated in Fig. 2(aꢁc), respectively. In all com-
/
2:1 proportion between the triphenylphosphine ligands
and the dithiocarbimate anion. The signals in the
spectra of the free dithiocarbimates [19] and in the
complexes show approximate the same chemical shifts.
The chemical shifts of the aromatic carbon atoms of the
dithiocarbimate anions in the complexes are similar to
plexes, the nickel cation is coordinated by two triphe-
nylphosphine ligands and chelated by two sulfur atoms
of the N-R-sulfonyldithiocarbimate anion into a simi-
larly distorted square-planar configuration. The P(1)ꢁ
Ni(1)ꢁS(1) and P(2)ꢁNi(1)ꢁS(2) angles are less dis-
torted from 908 than the P(1)ꢁNi(1)ꢁP(2) and S(1)ꢁ
Ni(1)ꢁS(2) angles. The P(1)ꢁNi(1)ꢁP(2) angle is sig-
/
/
/
/
/
/
/
those of the corresponding sulfonamides [22]. The Nꢀ
/
/
/
/
CS2 (C1) signal is shifted in the spectra of the complexes
to higher field if compared with the spectra of the
ligands (this signal is too weak and was not observed for
3). Although the solvents are, necessarily different, this
shift is expected. If the canonical form (c) (Fig. 1) is
more important for the complexes than for the ligands,
then the C1 carbon atom is expected to be more shielded
in the complexes. The C1 signal for the complex 2 is also
shifted to higher field when compared with the spectrum
of the correspondent anionic complex [Ni(4-
nificantly greater than 908 in all complexes due to the
steric effect of the large triphenylphosphine ligands and
the S(1)ꢁ
/
Ni(1)ꢁS(2) angle is smaller than 908 due to the
/
chelation of the N-R-sulfonyldithiocarbimate ligand.
The N-R-sulfonyldithiocarbimate anion (RSO2Nꢀ
/
CS2)2ꢃ as an asymmetric didentate ligand forms a
stable four membered ring by chelation through the
two sulfur atoms (NiS2C). The Ni(1)ꢁ
of 2.190(1) in 1, 2.179(1) in 2 and 2.178(1) in 3 A are
shorter than the Ni(1)ꢁS(2) [2.220(1), 2.219(1) and
/S(1) bond lengths
˚
/
CS2)2]2ꢃ [20]. Most of the triphenyl-
2.224(1) A in 1, 2 and 3, respectively]. These deviations
are more obvious than those found in the
˚
CH3C6H4SO2Nꢀ
/
phosphine signals in the 13C NMR spectra appeared as
pseudo triplets or doublets. This is consistent with
[Ni(CH3SO2Nꢀ
/
CS2)2]2ꢃ [24]. This fact may be ex-

M.R.L. Oliveira et al. / Polyhedron 21 (2002) 2243ꢁ
/2250
2247
Table 2
˚
Selected bond lengths (A) and angles (8)
1
2
3
Bond lengths
Ni(1)ꢁS(1)
Ni(1)ꢁS(2)
Ni(1)ꢁP(1)
Ni(1)ꢁP(2)
P(1)ꢁC(11)
P(1)ꢁC(21)
P(1)ꢁC(31)
P(2)ꢁC(41)
P(2)ꢁC(51)
P(2)ꢁC(61)
C(1)ꢁS(1)
C(1)ꢁS(2)
C(1)ꢁN(1)
N(1)ꢁS(3)
O(1)ꢁS(3)
O(2)ꢁS(3)
C(2)ꢁS(3)
C(3)ꢁC(8)
C(5)ꢁC(8)
C(5)ꢁBr(1)
2.190(1)
2.220(1)
2.206(1)
2.224(1)
1.833(3)
1.837(3)
1.825(3)
1.838(3)
1.852(3)
1.834(3)
1.751(3)
1.740(3)
1.279(3)
1.631(2)
1.441(2)
1.431(2)
1.783(3)
1.497(4)
2.179(1)
2.219(1)
2.134(1)
2.230(1)
1.846(4)
1.805(3)
1.829(4)
1.821(4)
1.812(4)
1.830(4)
1.739(4)
1.743(4)
1.288(5)
1.655(3)
1.435(3)
1.441(3)
1.767(4)
2.178(1)
2.224(1)
2.227(1)
2.184(1)
1.840(4)
1.808(3)
1.823(4)
1.820(3)
1.837(3)
1.834(4)
1.764(3)
1.725(3)
1.296(4)
1.626(3)
1.430(2)
1.422(2)
1.776(4)
1.505(7)
1.890(5)
Bond angles
P(1)ꢁNi(1)ꢁP(2)
S(1)ꢁNi(1)ꢁS(2)
S(1)ꢁNi(1)ꢁP(1)
S(1)ꢁNi(1)ꢁP(2)
S(2)ꢁNi(1)ꢁP(1)
S(2)ꢁNi(1)ꢁP(2)
S(1)ꢁC(1)ꢁS(2)
S(1)ꢁC(1)ꢁN(1)
S(2)ꢁC(1)ꢁN(1)
C(1)ꢁN(1)ꢁS(3)
N(1)ꢁS(3)ꢁO(1)
N(1)ꢁS(3)ꢁO(2)
O(1)ꢁS(3)ꢁO(2)
N(1)ꢁS(3)ꢁC(2)
O(1)ꢁS(3)ꢁC(2)
O(2)ꢁS(3)ꢁC(2)
98.48(4)
77.87(4)
92.31(4)
168.21(3)
167.92(3)
91.96(4)
105.1(2)
132.0(2)
122.9(2)
120.7(2)
111.9(1)
106.0(1)
116.9(1)
105.7(1)
108.2(1)
107.5(1)
98.84(4)
78.18(4)
90.76(4)
168.58(4)
167.01(4)
92.94(4)
105.6(2)
132.2(3)
122.1(3)
120.6(3)
111.6(2)
104.2(2)
118.7(2)
107.3(2)
108.0(2)
106.5(2)
98.92(4)
78.14(3)
91.16(4)
167.95(4)
167.42(4)
92.53(4)
105.3(2)
131.0(3)
123.6(3)
121.5(2)
111.5(2)
105.8(2)
117.7(2)
107.7(2)
106.9(2)
106.8(2)
Fig. 1. Some possible canonical forms for the N-R-sulfonildithiocar-
bimate anion.
plained by the stereochemistry affecting the phenyl ring
of the N-R-sulfonyldithiocarbimate ligand, which is
located in cis position to the S1 atom. The C1ꢁ
bond lengths of 1.279(3), 1.288(3) and 1.296(4) in 1ꢁ
respectively, are shorter than the normal single C(sp2)ꢁ
/
N1
/3,
/
2
˚
N(sp ) bond length (ca. 1.35 A), and similar to that of
˚
the double bond Cꢀ
C(1)ꢁS(1) and C(1)ꢁS(2) averaged bond lengths (1.745
A) are slightly shorter than the typical CꢁS single bond
length (ca. 1.81 A) due to partial p-delocalization in the
SꢁCꢁS group. The S(1)ꢁC(1)ꢁN(1) angles of 132.0(2)8,
/
N (1.275ꢁ
/
1.295 A) [25,26]. The
/
/
˚
/
˚
Fig. 2. View of the molecular structure of the complexes 1 (a), 2 (b)
and 3 (c).
/
/
/
/

2248
M.R.L. Oliveira et al. / Polyhedron 21 (2002) 2243ꢁ2250
/
132.2(3)8 and 131.0(3)8 in the complexes 1ꢁ
/
3, respec-
electron at the N(1) atom and the S(2) atom is greater
than the steric effect and the angle S(2)ꢁC(1)ꢁN(1) is
greater than the angle S(1)ꢁC(1)ꢁN(1). In other dithio-
tively, are significantly greater than S(2)ꢁC(1)ꢁ
/
/N(1)
/
/
[122.9(2) in 1, 122.1(3)8 in 2 and 123.6(3)8 in 3] due to
the interaction between the SO2R group and the S(1)
atom, which are joined in cis position in relation to the
/
/
carbimate complexes with larger R groups, the steric
effect between S(1) and R group is more important and
C(1)ꢁ
group is greater than the effect of the lone-pair of
electron at the N(1) atom, since the C(1)ꢁN(1)ꢁS(3)
angle is greater than 1208 in all complexes. If R is a small
N [27] the repulsive
/
N(1) bond. The steric effect of the R-sulfonyl
similarly as in the 1ꢁ
N(1) is greater than S(2)ꢁ
The C(1)ꢁN(1)ꢁS(3) fragment of the N-R-sulfonyl-
dithiocarbimate ligand (Fig. 2(aꢁc)) is coplanar with the
NiS2P2 fragment, thus the P(1)P(2)Ni(1)S(1)S(2)C(1)-
N(1)S(3) atoms lie in plane. The phenyl ring of the N-R-
sulfonyldithiocarbimate ligand is inclined by about
/
3 complexes the angle S(1)ꢁ
/
C(1)ꢁ
/
/
C(1)ꢁN(1) [29].
/
/
/
/
/
/
group such as ꢁ
/
SO2CH3 [24] or ꢁ
/
Cꢂ
/
interaction predicted by the valence-shell electron pair
repulsion theory (VSEPR) [28] between the lone-pair of
Fig. 3. Molecular arrangements of the complexes 1 (a), 2 (b) and 3 (c) in the unit cells.

M.R.L. Oliveira et al. / Polyhedron 21 (2002) 2243ꢁ
/2250
2249
Table 3
Comparison between selected crystallographic and spectroscopic data for the CN bond in compound 2 and related compounds
a
Parameters
2
[Ni(4-CH3C6H4SO2NꢀCS2)]2ꢃ b
(4-CH3C6H4SO2NꢀCS2)2ꢃ
˚
CN length (A)
n(CN) (cmꢃ1
1.288(5)
1445
197.37
1.35(2)
1390
210.07
)
1260
225.19
13C chemical shift (NCS2) (ppm)
a
Ref. [19].
Ref. [20].
b
88.6(2)8 in the complex 1, and 78.1(2)8 and 79.1(2)8 in
the isostructural crystals of the 2 and 3 complexes,
Although the intermolecular Cꢁ
/
HÁ Á ÁO are weak, we
suppose that they are important for the crystal packing,
since this can be the reason for the more compacted
arrangement of the molecules in 2 and in 3 in relation to
respectively. The torsion angle of C(1)ꢁ
describing the conformation of the ligand along the
N(1)ꢁS(3) bond is more similar in the complexes 1 and 2
[ꢃ65.2(2)8 and ꢃ65.0(1)8], since both have a methyl
group in the phenyl ring, than in 3 [ꢃ61.4(2)8], contain-
/
N(1)ꢁ
/
S(3)ꢁ
/
C(2)
/
the crystal of 1, in which the Cꢁ
/
HÁ Á ÁO interactions were
/
/
not observed.
/
ing a Br-substituted aromatic ring. The S(3) atom has an
expected slightly distorted tetrahedral geometry. The
S(3)ꢁ
double bond character (Sꢀ
double SꢀO bond ranging from 1.431 to 1.442 A [27].
The S(3)ꢁC(2) bond with a distance ranging from
1.767(4) to 1.783(3) A is well correlated with the CAr
S bond length in the related complexes which comprise
the CAr N(1) bond
/
O(1) and S(3)ꢁ
/
O(2) bond lengths indicate their
4. Conclusion
/O); a typical distance of the
˚
/
Three novel bis(triphenylphosphine)N-R-sulfonyl-
dithiocarbimatenickel(II) complexes were prepared and
characterized by UVꢁ
elemental analyses for C, H, N, Ni and by single crystal
X-ray diffraction techniques.
The spectroscopic and X-ray data for the complex
[Ni(4-CH3C6H4SO2]2ꢃ [20] show an interesting relation
with the data obtained for compound 2 (Table 3). The
/
˚
ꢁ
/
1
/
Vis, IR, H, 13C and 31P NMR,
ꢁ
/
SO2ꢁ
/
N fragment [26]. The S(3)ꢁ
/
˚
length with a value ranging from 1.626(3) to 1.655(3) A
indicates a single bond nature; the typical value of the
˚
1.659 A [26]. Both P
N(sp2)ꢁ
/
S bond distance is 1.623ꢁ
/
atoms of the triphenylphosphine ligands have similar
tetragonal geometry. The phenyl ring C(21)ꢁC(26) of
the P(1) triphenylphosphine is almost parallel to the
phenyl ring C(41)ꢁC(46) of the P(2) triphenylphosphine,
C(1)ꢁ
/
N(1) bond length in 2 is shorter than in [Ni(4-
CS2)2]2ꢃ [20]. The wavenumber for the
/
CH3C6H4SO2Nꢀ
/
n(CN) in the IR spectrum of 2 is greater than that in the
spectrum of the related anionic complex and this band is
observed in smaller wavenumber in the spectrum of the
parent dithiocarbimate ligand [19]. The NMR spectra
show that the carbon atom of the dithiocarbimate group
of 2 is more shielded than that of the anionic complex
and in the parent ligand. These facts are in accord with
an increase of the contribution of the (c) canonical form
(Fig. 1) to the resonance hybrid from the ligands to the
complexes, with a consequent increase of the CN double
bond character.
/
the dihedral angle being equal to 9.3(2)8 in the complex
1, and 15.2(2)8 and 15.8(2)8 in isostructural 2 and 3
complexes. Although the crystal of the complex 1, is not
isostructural with the crystals of 2 and 3 the structure
analysis clearly shows that the geometry of the mole-
cules of the compound 1 is quite similar to that of 2 and
3. The differences between the 1 and 2 and/or 3 may be
found in the molecular arrangement and the crystal
packing. The complexes 1 and 2 differ only in the
position of the methyl group substituted in the aromatic
ring of the N-R-sulfonyldithiocarbimate ligands (1 in
ortho and 2 in para position). The crystal of the isomer 2
is more compacted since the molecules interact more
effectively than in compound 1. The arrangement of
molecules in both 2 and 3 crystals is quite similar since
both have para-substituents. These structures are
5. Supplementary material
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC Nos. 181695, 181696 and 181697
for the compounds 1ꢁ3, respectively. Copies of this
information may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge, CB2
slightly stabilized by weak Cꢁ
hydrogen interactions of neighbouring molecules to
form a polymeric structure. The Cꢁ
/
HÁ Á ÁO intermolecular
/
HÁ Á ÁO interactions
/
˚
with CÁ Á ÁO of approximately 3.37 and 3.36 A distances
in 2 and 3 compounds, respectively, lead to the
formation of the pseudo mono-dimensional columns
1EZ, UK (fax: ꢂ
/
44-1223-336033; e-mail: deposit@
aligned along the a-axis in the crystal (Fig. 3(bꢁc)).
/
ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).

2250
M.R.L. Oliveira et al. / Polyhedron 21 (2002) 2243ꢁ2250
/
[13] A.I. Vogel, A Textbook of Practical Organic Chemistry Including
Qualitative Organic Analysis, Longmans, Green, London, 1966.
[14] K. Hartke, Arch. Pharm. 299 (1966) 164.
Acknowledgements
This work has been supported by CNPq, CAPES and
FAPEMIG (Brazil).
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[17] G.M. Sheldrick, SHELXTL. Program System, Siemens Analytical
X-ray Instruments, Madison, WI, 1990.
[18] G.M. Sheldrick, SHELXL97: Program for the Solution and
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