Synthesis, spectral and single crystal structure determination of [1,3-bis(diphenylphosphino-kP,P′)propane (4-morpholinecarbodithioato-S,S′) nickel(II) perchlorate and [1,4-bis(diphenylphosphino-kP,P′)butane (4-morpholinecarbodithioato-S,S′)nickel(II) perchlorate complexes

Article abstract of DOI:10.1016/S0020-1693(00)00293-0

[Ni(mdtc)(1,3-dppp)]ClO₄ (1), and [Ni(mdtc)(1,4-dppb))ClO₄ (2) [(mdtc^-=4-morpholinecarbodithioato anion, 1,3-dppp=1,3-bis(diphenylphosphino)propane, 1,4-dppb=1,4-bis(diphenylphosphino)butane)] have been prepared from their parent dithiocarbamate. The planar complexes were characterized by electronic and IR spectra. Single crystal X-ray structures of compounds 1 and 2 were determined. Both the complexes have planar NiS₂P₂ chromophores in keeping with the observed diamagnetism. In complexes 1 and 2 the Ni-S and Ni-P distances are symmetric. The thioureide C-N distances of both the complexes show a decreasing trend compared to the C-N distance in the parent Ni(mdtc)₂. The resulting P-Ni-P angles are higher in both the complexes (96.5(1)° in 1, 101.4(8)° in 2) due to puckering of propane and the butyl alkyl chain associated with 1,3-dppp and 1,4-dpppb.

Full text of DOI:10.1016/S0020-1693(00)00293-0

www.elsevier.nl/locate/ica
Inorganica Chimica Acta 314 (2001) 172–176
Note
Synthesis, spectral and single crystal structure determination of
[1,3-bis(diphenylphosphino-kP,P%)propane(4-morpholinecarbo-
dithioato-S,S%) nickel(II) perchlorate and
[1,4-bis(diphenylphosphino-kP,P%)butane
(4-morpholinecarbodithioato-S,S%)nickel(II) perchlorate complexes
Arumugam Manohar a, Kuppukkannu Ramalingam a,*, Gabriele Bocelli b, Lara Righi b
a Department of Chemistry, Annamalai Uni6ersity, Annamalainagar 608 002, India
b Consiglio Nazionale Delle Ricerche, Parma, Italy
Received 4 February 2000; accepted 9 August 2000
Abstract
[Ni(mdtc)(1,3-dppp)]ClO4 (1), and [Ni(mdtc)(1,4-dppb))ClO4 (2) [(mdtc−=4-morpholinecarbodithioato anion, 1,3-dppp=1,3-
bis(diphenylphosphino)propane, 1,4-dppb=1,4-bis(diphenylphosphino)butane)] have been prepared from their parent dithiocar-
bamate. The planar complexes were characterized by electronic and IR spectra. Single crystal X-ray structures of compounds 1
and 2 were determined. Both the complexes have planar NiS2P2 chromophores in keeping with the observed diamagnetism. In
complexes 1 and 2 the NiꢀS and NiꢀP distances are symmetric. The thioureide CꢀN distances of both the complexes show a
decreasing trend compared to the CꢀN distance in the parent Ni(mdtc)2. The resulting PꢀNiꢀP angles are higher in both the
complexes (96.5(1)° in 1, 101.4(8)° in 2) due to puckering of propane and the butyl alkyl chain associated with 1,3-dppp and
1,4-dpppb. © 2001 Elsevier Science B.V. All rights reserved.
Keywords: Dithiocarbamate; Thioureide; 1,3-Bis(diphenylphosphino)propane; 1,4-Bis(diphenylphosphino)butane; X-ray structures
mophores. The planar dithiocarbamates prefer to react
with soft Lewis bases such as phosphines rather than
1. Introduction
hard nitrogenous bases such as NH3 and pyridine, due
Group VIII dithiolates containing planar MS4. chro-
to symbiotically induced softness [7,8]. On reaction with
mophores show interesting variations in their reactions
PR3 or dppe, they form complexes with chromophore
with Lewis bases [1,2]. Soft Pd(II) and Pt(II) dithiolates
NiS2P2 which are diamagnetic in nature [9–11]. Mixed
preferably interact with soft phosphines to give rise to
complexes of the type [Ni(S2CNR2)X(PR3)] were ob-
planar MS2P2 chromophores [3,4]. Detailed structural
tained by reacting NiX2 with dithiocarbamate and PR3
studies on a variety of MS2P2 chromophores have also
[12] Complexes of the type [Ni(dtc)Cl(PPh3)] and
been made [5,6]. Unlike its congeners, Ni(II) is a border
line acceptor. Ni(II) complexes of dithiocarbamates are
typical planar complexes containing NiS4 chro-
[Ni(dtc)(PPh3)2]ClO4 (where dtc−=[S2CN(C2H5)2]−,
[S2CNH(CH4OH)]−,
[S2CN(C2H4OH)2]−,
[S2CN-
(C4H8O)]− and [S2CN(C5H10]−) have also been re-
ported from our laboratory [13]. Recently, single crystal
structural studies of the following complexes
[Ni(dipdtc)(PPh3)2]ClO4, [Ni(dipdtc)(dppe)]ClO4, [Ni-
* Corresponding author. Tel.: +91-41-3202 834; fax: +91-41-
4422 265.
E-mail address: aulib@hotmail.com (K. Ramalingam).
0020-1693/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0020-1693(00)00293-0

A. Manohar et al. / Inorganica Chimica Acta 314 (2001) 172–176
173
2. Experimental
(padtc)(PPh3)2]ClO4, [Ni(padtc)(dppe)]BPh4, [Ni(mdtc)2-
(dppe)]ClO4, [Ni(pipdtc)(PPh3)2]ClO4, Ni(nmedtc)-
(PPh3)2]ClO4, [Ni(nmedtc)(dppe)]BPh4 have been re-
ported from our laboratory [14–18] (where dipdtc−=
All the reagents and solvents employed were com-
mercially available high-grade purity materials (E.
Merck) used as supplied without further purification.
diisopropyldithiocarbamato
anion;
padtc−=
N,N%-iminodiethylene bisphthalimidedithiocarbamato
anion; pipdtc−=piperidinedithiocarbamato anion and
nmedtc−=N-methyl, N-ethanoldithiocarbmato an-
ion).
In continuation of our interest in planar NiS2P2
chromophores, the present study was undertaken to
understand the puckering effect of propyl and butyl
backbones of 1,3-dppp and 1,4-dppb on NiS2P2 chro-
mophores. Synthesis, spectral and single crystal struc-
ture determination of [Ni(mdtc)(l,3-dppp)]ClO4 (1) and
Ni(mdtc)(l,4-dppb)]ClO4 (2) are reported in this paper
for the first time.
2.1. Physical measurements
IR spectra were recorded on a JASCO IR-700 spec-
trophotometer (range 4000–400 cm−1) as KBr pellets.
The UV–Vis spectra in CH2Cl2 were recorded on a
JASCO-UVIDEC 340 double beam spectrophotometer.
2.2. Preparation of the complexes
2.2.1. [1,3-Bis(diphenylphosphino-kP,P%)propane]-
(4-morpholinecarbodithioato-S,S%)nickel(II)perchlorate,
[Ni(mdtc)(1,3-dppp)]ClO4 (1)
A mixture of Ni(mdtc)2 [19] (382 mg, 1 mmol),
1,3-dppp (414 mg, 1 mmol) NiCl2·6H2O (120 mg, 0.5
mmol) and NaClO4 (125 mg, 1 mmol) in acetonitrile–
methanol (1:1, 50 cm3) was refluxed for about 3 h
followed by concentration to ca. 25 cm3. The precipi-
tated orange–red compound was filtered and dried over
anhydrous calcium chloride. Single crystals suitable for
X-ray work were obtained by recrystallization from
acetonitrile (yield 70%, m.p. 258°C).
Table 1
X-ray data collection, solution and refinement details for compounds
1 and 2
Compound
1
2
Empirical formula
C32H34ClNO5P2
S2Ni
C33H36ClNO5P2
S2Ni
2.2.2. [1,4-Bis(diphenylphosphino-kP,P%)butane]-
(4-morpholinecarbodithioato-S,S%)nickel(II)perchlorate,
[Ni(mdtc)(1,4-dppb)]ClO4 (2)
M
732.8
orthorhombic
Pnma
21.617(3)
14.882(3)
10.611(3)
90
90
90
3413
4
746.9
monoclinic
P21/c
18.636(3)
21.417(2)
18.476(4)
90
111.35(2)
90
6868
8
1.444
8.921
Crystal system
Space group
a (A)
b (A)
c (A)
h (°)
i (°)
~ (°)
,
,
A mixture of Ni(mdtc)2 (382 mg, 1 mmol), 1,4-dppb
(428 mg, 1 mmol), NiCl2·6H2O (120 mg, 0.5 mmol) and
NaClO4 (125 mg, 1 mmol) in acetonitrile–methanol
(2:1, 75 cm3) was refluxed for about 3 h followed by
concentration to ca. 25 cm3. A red–orange solution was
filtered and left for evaporation. After 2 days, red–or-
ange crystals suitable for X-ray structural analysis were
obtained directly (yield 60%, m.p. 250°C).
,
3
,
U (A )
Z
Dcalc (g cm−3
)
1.4258
17.945
3040
v (cm−1
F(000)
)
3056
,
u (A)
Mo Ka (0.71069)
3–30
w−2q
Mo Ka (0.71069)
3–28
w−2q
2.3. X-ray crystallography
q range (°)
Scan type
Details of the crystal data, data collection and refine-
ment parameters for complexes 1 and 2 are summarized
in Table 1. The intensity data were collected at ambient
temperature (295 K) on a Philips PW1100 diffractome-
ter (for complex 1) and Siemens AED single crystal
diffractometer (for complex 2) with Mo Ka radiation
Index range
05h530
05k520
−145l50
−245h523
−145k528
−245l520
17579
Reflections collected 5516
Observed reflections
[F\6|(F)]
Parameters refined
Final R, wR
(observed data)
Weighting scheme
2667
291
16652
1100
,
(u=710 690 A). Structure 1 was solved by direct meth-
0.0469; 0.1361
0.0498, 0.1378
ods with the SIR92 [20] program and was refined by
SHELXL93 [21]. After the isotropic refinement, the data
were corrected for absorption using the DIFABS pro-
gram [22] following the method of Walker and Stuart
[23]. For structure 2, one check reflection was measured
every 100 reflections without any variation and was
w=A/[|2(Fo)2
+(BP)2+0.00P
A=1, B=0.0421
w=A/[|2(Fo2)
+(BP)2+0.00P]
A=1, B=0.0849
P=(max(Fo2+2Fc2)/3) P=(max(Fo2+2Fc2)/3)
Goodness-of-fit
0.831
0.631

174
A. Manohar et al. / Inorganica Chimica Acta 314 (2001) 172–176
Table 2
bond parameter because the asymmetric unit contains
two molecules.
,
Selected bond distances (A) and bond angles (°) for complex 1
Ni1ꢀS2
Ni1ꢀP4
S2ꢀC6
P4ꢀC14
P4ꢀC17
P4ꢀC23
C6ꢀN7
N7ꢀC8
C8ꢀC9
C9ꢀO10
2.214(1)
2.180(1)
1.722(2)
l.826(4)
l.821(3)
1.825(3)
1.305(5)
l.478(4)
1.516(6)
1.419(6)
C18ꢀC19
C19ꢀC20
C21ꢀC22
C20ꢀC21
C23ꢀC24
C23ꢀC28
C24ꢀC25
C25ꢀC26
C26ꢀC27
1.415(9)
1.358(10)
1.389(6)
l.345(8)
1.373(4)
1.390(5)
l.391(6)
l.349(7)
1.354(6)
3. Results and discussion
3.1. IR and electronic spectra
IR spectra of complexes 1 and 2 show w(CꢀN) bands
at 1523 and 1527 cm−1, respectively. The shifts in
w(CꢀN) values to higher wave numbers compared with
the parent dithiocarbamate (1494 cm−1) are due to the
mesomeric drift of electrons from the dithiocarbamate
moiety to the metal center. The w(CꢀS) bands appear at
997 and 992 cm−1 in 1 and 2, respectively without any
splitting, supporting the isobidentate coordination of
the dithiocarbamate moiety [26]. The electronic absorp-
tion bands at 450 and 470 nm for complex 1 and the
band at 460 nm for complex 2 are due to d–d transi-
tions [13].
S2ꢀNi1ꢀP4%
P4ꢀNi1ꢀP4%
P4ꢀNi1ꢀS2
S2ꢀNi1ꢀS2%
Ni1ꢀS2ꢀC6
Ni1ꢀP4ꢀC23
Ni1ꢀP4ꢀC17
Ni1ꢀP4ꢀC14
C17ꢀP4ꢀC23
C14ꢀP4ꢀC23
C14ꢀP4ꢀC17
S2ꢀC6ꢀS2
170.8(1)
96.5(1)
92.2(1)
79.1(1)
85.2(1)
111.2(1)
111.9(1)
116.5(1)
104.6(1)
105.1(1)
106.6(1)
109.8(1)
125.1(1)
125.1(1)
123.6(1)
N7ꢀC8ꢀC9
108.6(3)
110.3(3)
110.5(2)
113.2(2)
118.9(2)
122.3(2)
118.5(2)
120.1(3)
121.4(3)
119.2(4)
121.1(4)
119.6(3)
85.2(1)
C8ꢀC9ꢀO10
C9ꢀO10ꢀC9%
P4ꢀC14ꢀC15
P4ꢀC23ꢀC28
P4ꢀC23ꢀC24
C24ꢀC23ꢀC28
C23ꢀC24ꢀC25
C24ꢀC25ꢀC26
C25ꢀC26ꢀC27
C26ꢀC27ꢀC28
C23ꢀC28ꢀC27
Ni1ꢀS2ꢀC6
3.2. Structure analysis
S2ꢀC6ꢀN7
N7ꢀC6ꢀ82
C6ꢀN7ꢀC8
Ni1ꢀP4ꢀC14
C15ꢀC14ꢀP4
116.4(1)
113.3(2)
The structure of complex 1, along the numbering
scheme is shown in Fig. 1. The crystal contains discrete
mononuclear [Ni(mdtc)(1,3-dppp]+ units which have
no significant intermolecular contacts. The complex
contains planar NiS2P2 chromophore in keeping with
the observed diamagnetism of the compound. Four
formula units are present in the unit cell. The Ni, S and
P atoms are coplanar. NiꢀS distances are equal;
solved using SIR97 [24], PARST [25] programs, and
refined by SHELXL93 [21]. All the non-hydrogen atoms
were refined anisotropically and the hydrogen atoms
were fixed isotropically. Selected bond distances and
angles are presented in Tables 2 and 3. For complex 2;
two values are (primed, unprimed) are given for each
,
2.214(1) A, indicating the symmetric bidentate bonding
Table 3
,
Selected bond distances (A) and bond angles (°) for complex 2
Unprimed
Primed
Unprimed
Primed
Ni1ꢀS2
Ni1ꢀS3
Ni1ꢀP4
Ni1ꢀP5
S2ꢀC6
2.212(1)
2.216(1)
2.201(1)
2.195(1)
1.708(5)
1.713(5)
1.839(5)
1.806(4)
1.825(5)
2.217(1)
2.210(1)
2.202(1)
2.193(1)
1.713(5)
1.710(5)
1.838(5)
1.822(5)
1.825(5)
P5ꢀC16
P5ꢀC29
P5ꢀC35
C6ꢀN7
N7ꢀC8
N7ꢀCl2
C8ꢀC9
C9ꢀO10
1.806(4)
1.819(4)
1.821(5)
1.304(4)
1.465(7)
1.480(8)
1.514(9)
1.410(10)
1.808(5)
1.831(4)
1.821(5)
1.307(5)
1.479(7)
1.472(7)
1.507(8)
1.422(8)
S3ꢀC6
P4ꢀC13
P4ꢀC17
P4ꢀC23
P4ꢀNi1ꢀP5
S3ꢀNi1ꢀP5
S3ꢀNi1ꢀP4
S2ꢀNi1ꢀP5
S2ꢀNi1ꢀP4
S2ꢀNi1ꢀS3
C13ꢀP4ꢀC23
C13ꢀP4ꢀC17
Ni1ꢀP5ꢀC35
Ni1ꢀP5ꢀC29
Ni1ꢀP5ꢀC16
C29ꢀP5ꢀC35
101.5(1)
166.7(1)
91.1(1)
89.0(1)
169.5(1)
78.3(1)
101.3(2)
106.2(2)
112.5(2)
110.5(2)
119.7(2)
104.7(2)
101.1(1)
89.7(1)
168.8(1)
167.1(1)
90.7(1)
C16ꢀP5ꢀC35
C16ꢀP5ꢀC29
S2ꢀC6ꢀS3
S3ꢀC6ꢀN7
S2ꢀC6ꢀN7
C6ꢀN7ꢀC12
C6ꢀN7ꢀC8
C8ꢀN7ꢀC12
N7ꢀC8ꢀC9
C9ꢀO10ꢀC11
O10ꢀC11ꢀC12
N7ꢀC12ꢀC11
104.5(2)
103.5(2)
109.7(3)
125.2(4)
125.1(4)
123.1(5)
123.4(4)
113.4(4)
107.2(5)
110.4(6)
111.5(7)
107.6(5)
105.2(2)
102.7(2)
109.2(3)
125.5(4)
125.3(4)
123.2(4)
122.9(4)
113.3(4)
108.7(4)
109.8(5)
111.2(5)
108.3(5)
78.2(1)
101.5(2)
106.9(3)
112.3(2)
110.3(2)
118.7(2)
106.4(2)

A. Manohar et al. / Inorganica Chimica Acta 314 (2001) 172–176
175
The structure of 2, along with the numbering scheme
is shown in Fig. 2. The complex is monomeric. The
molecule is planar, in keeping with the observed dia-
,
magnetism. The two NiꢀS bonds 2.212(1), 2.216(1) A
are not different though the two NiꢀP distances
,
2.201(1), 2.195(1) A are slightly different. There is a
very significant reduction of thioureide CꢀN bond dis-
,
tance (1.304(4) A) in [Ni(mdtc)(1,4-dppb)]ClO4 com-
,
pared to the distance (1.330(1) A) in the parent
compound [19].
The PꢀNiꢀP angles and NiꢀP distances show gradual
increase with increase in the back bone length between
the two phosphorous atoms. The NiꢀP distance re-
ported is relatively a very short distance because of
chelation. Lengthening of NiꢀP distances, shortening of
CꢀN distance and widening of PꢀNiꢀP bond angle
(101.4°) in the present compound are as a result of the
presence of flexible alkyl chain connecting the two
phosphorous atoms. A similar trend was observed in
[Ni(dedtc-)(l,4-dppb)]+ complex [28]. The butyl chain
lies below the plane of the NiS2P2 chromophore with
normal PꢀC and CꢀC distances.
Fig. 1.
Complexes 1 and 2 are symmetric with respect to
NiꢀS and NiꢀP distances. The NiꢀS distances of com-
plexes 1 and 2 are normal as found in the parent
Ni(mdtc)2 and similar NiS2P2 chromophores. Bond
parameters in a series of different bisdithiocarbamates
and phosphate-substituted planar nickel complexes are
given in Table 4.
The PꢀNiꢀP angle and NiꢀP distances of complex 2
are significantly higher than those found in complex 1
which are in turn higher than [Ni(mdtc)(1,2,dppe)]+
and other 1,2-bis(diphenylphosphino)ethane–nickel
chelate. Relative lengthening of NiꢀP distances and
widening of PꢀNiꢀP bond angles in the present com-
plexes are due to the presence of flexible propyl or butyl
alkyl back bones connecting the two phosphorus atoms
of complexes 1 and 2, respectively. A similar trend was
found in [Ni(dedtc)(l,4-dppb)]+ complex [28].
Fig. 2.
Major structural effect of the butyl back bone (in
complex 2) in the place of propyl group (in complex 1)
is the widening of PꢀNiꢀP angle and reduction of
SꢀNiꢀS angle. There is also significant increase in NiꢀP
distance in 2. Another important aspect of comparison
is with respect to the thioureide bonds. In complexes 1
and 2 the thioureide CꢀN distances are relatively short
compared to long CꢀN distance reported in the parent
Ni(mdtc)2, which is due to the puckering effect of alkyl
back bones associated with 1,3-dppp and 1,4-dppb.
to nickel ion. The observed NiꢀP distance is relatively
,
short compared to a long NiꢀP, 2.40 A bonded distance
reported in the literature [27]. Interestingly, the PꢀNiꢀP
angle in the present compound is larger than the angles
observed in 1,2-bis(diphenylphosphino)ethane–nickel
chelate [16]. In this complex, thioureide CꢀN bond
,
distance is 1.305(5) A, which is significantly different
,
from the distance, 1.330(1) A observed in the parent
Ni(mdtc)2 [19]. The widening of PꢀNiꢀP angle and
shortening of CꢀN distance in the present complex is as
a result of the presence of flexible long alkyl chain
connecting the two phosphorous atoms [28]. Other
bond parameters of the dithiocarbamate moiety are
normal. The ClO4− ion shows large disorder as ob-
served in similar complexes [14–17].
4. Supplementary material
Crystallographic deposition of data: The crystallo-
graphic data on compounds 1 and 2 are deposited at

176
A. Manohar et al. / Inorganica Chimica Acta 314 (2001) 172–176
Table 4
a
,
Comparison of bond distances (A) and angles (°)
Complex
NiꢀS(1)
NiꢀS(2)
NiꢀP(1)
NiꢀP(2)
CꢀN
P(1)ꢀNiꢀP(2)
SꢀNiꢀS
Reference
Ni(dipdtc)2
2.183(3)
2.209(3)
2.194(2)
2.192(2)
2.190(2)
2.213(6)
2.194(12)
2.214(1)
2.212(1)
2.182(3)
2.201(3)
2.196(2)
2.209(2)
2.239(2)
2.212(7)
2.213(1)
2.214(1)
2.216(1)
1.307(4)
1.321(1)
1.316(8)
1.314(6)
1.307(1)
1.330(1)
1.351(1)
1.305(5)
1.304(4)
79.6(1)
77.7(1)
79.0(1)
78.2(1)
78.2(1)
79.16(2)
79.7(4)
79.1
[29]
[14]
[14]
[30]
[13]
[19]
[16]
this work
this work
[Ni(dipdtc)(PPh3)2]+
[Ni(dipdtc)(dppe)]+
[Ni(dipdtc)(1,3-dppp)]+
[Ni(dedtc)(PPh3)2]+
Ni(mdtc)2
2.215(2)
2.165(2)
2.190(2)
2.200(2)
2.224(3)
2.160(2)
2.191(2)
2.230(3)
99.4(1)
87.3(1)
93.8(1)
99.7(1)
[Ni(mdtc)(dppe)]+
[Ni(mdtc)(1,3-dppp)]+
[Ni(mdtc)(1,4-dppb)]+
2.160(1)
2.180(1)
2.201(1)
2.167(1)
2.180(1)
2.195(1)
86.8(4)
96.5
101.4(8)
78.3(7)
a dedtc−
,
−S2CN(CH2CH3)2; nmedtc−
,
−S2CN(CH3)CH2CH2OH; dipdtc−
,
−S2CN(CH(CH3)2); mdtc−
,
S2CN(C4H8O); pipdtc−
,
−S2CN(C5H10); padtc−, S2CN(CH2CH2N(CO)2C6H4)2.
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CCDC with the following numbers CCDC 147 185 and
CCDC 147 186, respectively. Copies of this informa-
tion may be obtained free of charge from The Director,
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK
(fax: +44-1223-336 033; e-mail: deposit@ccdc.
cam.ac.uk or www: http://www.ccdc.cam.ac.uk).
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