Four novel sulfur-rich complexes: Syntheses, crystal structures of three nickel(II) and one cobalt(II) complex with derivatives of Lawesson's Reagent

Article abstract of DOI:10.1016/j.poly.2004.04.008

The reaction of 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4- disulfide (Lawesson's Reagent, LR) with NiCl₂ or Co(CH ₃COO)₂ in methanol or ethanol gives novel sulfur-rich complexes: C₁₆H₂₀

Full text of DOI:10.1016/j.poly.2004.04.008

Polyhedron 23 (2004) 1799–1804
www.elsevier.com/locate/poly
Four novel sulfur-rich complexes: syntheses, crystal structures
of three nickel(II) and one cobalt(II) complex with derivatives of
Lawesson’s Reagent q
*
Hong-Lei Liu, Hong-Yan Mao, Chen Xu, Hong-Yun Zhang , Hong-Wei Hou,
Qing-an Wu, Yu Zhu, Bao-Xian Ye, Li-Jie Yuan
Department of Chemistry, Zhengzhou University, Da Xue Road, Zhengzhou 450052, PR China
Received 8 January 2004; accepted 13 April 2004
Available online 4 May 2004
Abstract
The reaction of 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide (Lawesson’s Reagent, LR) with NiCl2 or
Co(CH3COO)2 in methanol or ethanol gives novel sulfur-rich complexes: C16H20NiO4P2S4 (1), C18H24NiO4P2S4 (2) and
C24H30CoO6P3S6 (4). With the presence of ethylenediamine under the same conditions, complex C24H48N6NiO4P2S4 (3) is also
obtained. These four novel sulfur-rich complexes were characterized by IR and X-ray crystallography, which indicate that the
solvent can influence the crystal structure of complexes in the reaction between LR and metal.
Ó 2004 Published by Elsevier Ltd.
Keywords: Lawesson’s Reagent; Thiophosphoryl compound; Sulfur-rich complex; Nickel(II) complex; Cobalt(II) complex
1. Introduction
It has been reported that the P–S bonds in LR can
easily be cleaved to offer MeOC6H4PS2 as a ligand [9].
We found that LR can decompose into an alco-
hol derivative when heated in alcohol solvent (see
Scheme 2).
Although a great deal of work has been reported
[10–12] on thiophosphoryl compounds, these four
complexes have not been reported before. We studied
the syntheses and crystal structures of some metal
complexes with MeOC6H4P(OR)S2 (R ¼ CH3– or
C2H5–) using the direct reaction of LR with transition
metal salts. In this paper, the syntheses and crystal
structures of three nickel(II) and one cobalt(II) com-
plex are reported.
There is much literature that reports that 2,4-bis(4-
methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disul-
fide (Lawesson’s Reagent, LR, see Scheme 1) is a most
effective thiation reagent for ketones, carboxamides,
esters, S-substituted thioesters and a variety of other
compounds [1–4]. LR can also participate in the prep-
aration of many thiophosphoryl complexes [5,6]. It has
been reported by Shabana and Atrees [7] and Fahmy [8]
that thiophosphoryl compounds are of potential interest
as fungicides, insecticide and herbicides. In order to
study the influence of the thiophosphoryl metal on their
biological activity, research of the syntheses and crystal
structures of these thiophosphoryl metal compounds has
an important role.
2. Experimental
q Supplementary data associated with this article can be found, in the
online version, at doi:10.1016/j.poly.2004.04.008.
* Corresponding author. Tel.: +86-371-7763675; fax: +86-371-
7761744.
2.1. Materials and physical measurements
All chemicals except Lawesson’s Reagent were of
reagent analytical grade, purchased from Zhengzhou
E-mail address: wzhy917@zzu.edu.cn (H.-Y. Zhang).
0277-5387/$ - see front matter Ó 2004 Published by Elsevier Ltd.
doi:10.1016/j.poly.2004.04.008

1800
H.-L. Liu et al. / Polyhedron 23 (2004) 1799–1804
S
Complex 2. With the same method mentioned above,
toluene
reflux
S
S
purple crystals of complex 2 suitable for X-ray analysis
were got using the mixed solution of ethanol and DMF
(1:1, v/v).
CH
3O
O
+ P S5
2
CH3
P
S
P
OCH3
Scheme 1. Lawesson Reagent.
Complex 3. 3.0 ml (0.04 mol) of ethylenediamine and
8.10 g (0.02 mol) of LR were refluxed in 180 ml anhy-
drous toluene at 110 °C with stirring for about 6 h. After
cooling to room temperature, insoluble materials were
filtered off. Then the reaction mixture was concentrated
to about 20 ml with a vacuum rotary evaporator. This
20 ml oil liquid was diluted with 80 ml methanol, and 5
ml of the diluted solution and 5ml methanol solution of
NiCl2 (0.2 mmol) were mixed and run into a small vial
and allowed to evaporate slowly at room temperature.
Filtered, washed with anhydrous ethanol and dried
naturally, pink crystals of 3 suitable for single-crystal X-
ray diffraction analyses were obtained in about two
weeks.
Complex 4. Complex 4 can be obtained by the
method used in the preparation of complex 1. 5 ml of
0.02 M solution of LR in methanol and 5 ml of 0.02 M
solution of Co(CH3COO)2 Æ 4H2O in methanol were put
into sealed vials, respectively, which were connected via
a thin tube full of anhydrous ethanol. Red crystals of 4
suitable for X-ray analysis were obtained in about three
days.
methanol
or ethanol
S
P
S
S
CH
3O
CH
3O
OCH3
P
S
P
S
reflux
S
OR
or
R = CH3
C2 H5
Scheme 2. The thermal decomposition reaction of Lawesson’s Reagent
in alcohol solvent.
Chemical Reagent Company and were used without any
purification. Lawesson’s Reagent (R ¼ p-MeOC6H4)
was prepared as described in the literature [13]. The
single crystal structures were measured on a Rigaku-
Raxis-IV X-ray diffractometer and IR spectra were re-
corded on a FTS-40 infrared spectrophotometer as KBr
pellets in the range 4000–400 cmꢀ1
.
2.2. Preparation of complexes 1, 2, 3 and 4
Complex 1. 5 ml of 0.02 M solution of LR in meth-
anol and 5 ml of 0.02 M solution of NiCl2 in methanol
were put into sealed vials, respectively, which were
connected via a thin tube full of anhydrous ethanol.
Purple crystals of complex 1 suitable for X-ray analysis
were obtained in about three days.
2.3. X-ray crystallography
Intensity data of these complexes were measured with
a Rigaku-Raxis-IV X-ray diffractometer using mono-
Table 1
Crystallographic data and structure refinement for complexes 1, 2, 3 and 4
Complex 1
16H20NiO4P2S4
291(2)
Complex 2
Complex 3
Complex 4
Formula
T (K)
C
C18H24NiO4P2S4
291(2)
553.26
C24H48N6NiO4P2S4
291(2)
733.57
C24H30CoO6P3S6
291(2)
758.68
Molecular weight
Crystal system
Space group
525.21
monoclinic
P21=c
11.974(2) A
6.6343(13) A
14.750(3) A
90
triclinic
P1ꢀ
monoclinic
P21=c
15.364(3)
18.929(4)
12.459(3)
90
monoclinic
P21=n
9.0075(18)
16.076(3)
23.034(5)
90
ꢁ
a (A)
6.5023(13)
7.6448(15)
13.109(3)
99.37(3)
99.72(3)
104.09(3)
608.6(2)
1.509
ꢁ
b (A)
ꢁ
c (A)
a (°)
b (°)
c (°)
109.69(3)
90
94.76(3)
90
98.11(3)
90
3
ꢁ
V (A )
1103.3(4)
1.581
3610.8(13)
1.349
3302.1(11)
1.526
Dcalc (Mg mꢀ3
)
Z
2
1.422
1
1.293
4
0.894
4
1.081
Absorption coefficient (mmꢀ1
)
Reflections collected/unique (Rint
Data/restraints/parameters
Ra
)
3234/1958 (0.0697)
1958/0/125
0.0417
1598/1598 (0.0000)
1598/8/134
0.0737
7464/4408 (0.0455)
4408/0/419
0.0382
8216/4758 (0.0591)
4758/0/362
0.0454
b
Rw
0.0867
0.970
0.2060
1.122
0.0796
0.897
0.1133
0.987
Goodness-of-fit on F 2
ꢀ3
ꢁ
Dqmax and Dqmin (e A
)
0.310 and )0.336
1.097 and )0.696
0.372 and )0.215
0.423 and )0.482
P
P
a R ¼ jjFoj ꢀ jFcjj= jFoj.
P
P
2
2 1=2
b Rw ¼ ½ ðjjFoj ꢀ jFcjjÞ = wjFoj ꢁ
.

H.-L. Liu et al. / Polyhedron 23 (2004) 1799–1804
1801
ꢁ
chromated Mo Ka (k ¼ 0:71073 A) radiation. Raw data
as shown in Scheme 3, may have one self-coordinating
catalyst course. The sulfur atoms of the LR molecule
have a strong coordinating tendency with the metal ion
and the P–S bond of LR may easily be cleaved [9]. When
Lawesson’s Reagent was heated in alcohol solvent with
transition metals, the fragment CH3OC6H4PS2, cleaved
from LR, was produced and some alcohol molecules
(such as methanol) were deprotonated in order to keep
the phosphorus atoms with a five valence state. Finally,
the fragments CH3OC6H4PS2 connect with a deproto-
nated alcohol molecule and coordinate to the metal ion.
Therefore, the four title complexes (as shown in Scheme
3) are formed.
were corrected and the structures were solved using the
SHELXL-97 program. Non-hydrogen atoms were located
by direct phase determination and subjected to aniso-
tropic refinement. The full-matrix least-squares calcu-
lation on F 2 was applied on the final refinement. Details
of the crystal structure determination are summarized in
Table 1. Full atomic data are available as a file in CIF
format.
The IR spectra of the four complexes contain the
expected bands due to the C6H4OMe groups. LR has
two bands at 1267(s) and 1293(m) cmꢀ1 due to mas(C–O–
C) and a band at 2837(w) cmꢀ1 of ms(CH3). All these
bands can be observed in complexes 1–4. In the IR
spectra of complex 1, there are bands present at 1004(s),
1010(s), 1025(m) 829(w), 792(s), 666(m) and 644(m)
cmꢀ1 for ms(P–S). In that of complex 4, the bands at
1025(m), 789(s) and 663(m) are for ms(P–S). All these are
consistent with the literature [12]. As far as the IR
spectra of the complex 3 is concerned, the bands at
3280(s) cmꢀ1 for mas(NH2), 2975(w) cmꢀ1 for mas(CH2),
and 1028(vs) cmꢀ1 for ms(CN) are also consistent with
the literature [14] (s, strong; m, medium; w, weak; vs,
very strong).
3.2. The crystal structure description of complexes 1, 2, 3
and 4
Crystallographic data and structure refinement for
complexes 1–4 are given in Table 1. For complex 1, it
can be seen from Fig. 1 that the structural unit contains
a crystallographic center of symmetry at the center of
the four-member rings, and is therefore planar. Four
sulfur atoms from two MeOC6H4P(OCH3)S2 ligands
describe a parallelogram environment around the nickel
atom, as is shown in these angles: S2AA–Ni1A–
S2A ¼ 180°, S1A–Ni1A–S1AA ¼ 180° and S2AA–
Ni1AA–S1A ¼ 91.25°. Selected bond distances and an-
gles for complex 1 are shown in Table 2. The two ben-
zene rings of a certain crystal unit are parallel. The
triangle P1A–S1A–S2A and another P1AA–S1AA–
S2AA in the same unit lie trans-parallel along the central
four-member ring S1A–S2A–S2AA–S1AA plane, and
the dihedral angle is 19.2°.
3. Results and discussion
3.1. The possible reaction mechanism of LR with transi-
tion metals
When Lawesson’s Reagent and transition metals re-
act in alcohol solvent the four above-mentioned com-
plexes were obtained. The possible reaction mechanism,
From Figs. 1 and 2, it can be found that the molec-
ular structure of complex 2 is similar to that of complex
1. The only difference lies in the fact that the OCH3 in
complex 1 is replaced by OC2H5 in complex 2. The
ꢁ
nickel–sulfur bond lengths in complex 2 {2.2257(17) A
S
ꢁ
for Ni1A–S1AA and Ni1A–S1A; 2.2237(17) A for
Ni1A–S2AA and Ni1A–S2A} are a little shorter than
ꢁ
those of complex 1 {2.2307(13) A for Ni1A–S2AA and
S
methanol
CH
3O
P
S
P
OCH3
+
MX2
S
reflux
ꢁ
Ni1A–S2A; 2.2426(13) A for Ni1A–S1AA and Ni1A–
CH3
O
H
S1A}. Selected bond distances and angles for complex 2
are shown in Table 3.
As for complex 3, it is in fact the complex
S
P
S
CH
3O
P
OCH3
MX2
+
2þ
S
S
H
Ni(II)(en)3 (en ¼ ethylenediamine). The MeOC6H4P-
O
CH3
(C2H5O)S2 can be seen as a substituted thiophosphate
group which exists in the crystal structure as an electron-
balancing anion. It can be seen from Fig. 3 that for
every nickel(II), such as Ni1, three ethylenediamines
offer four nitrogen atoms N1, N2, N4 and N5, existing
in the equatorial geometry and forming a parallelogram,
with the other two nitrogen atoms N3 and N6 from two
ethylenediamines occupying the axial sites. So the Ni(II)
ion is six-coordinated, in the center of a distorted
CH3
O
S
S
CH
3O
P
M
P
OCH3
S
S
O
CH3
In which,
MX2
)2 4H2O
or Co(CH3COO
NiCl2 6H
2O
Scheme 3. The possible reaction mechanism of LR with transition
metals.

1802
H.-L. Liu et al. / Polyhedron 23 (2004) 1799–1804
Fig. 1. The crystal structural unit of complex 1.
Table 2
Table 3
ꢁ
ꢁ
Selected bond distances (A) and angles (°) for complex 1
Selected bond distances (A) and angles (°) for complex 2
Ni1A–S2AA
Ni1A–S2A
Ni1A–S1A
Ni1A–S1AA
Ni1A–P1AA
Ni1A–P1A
2.2307(13) S1A–Ni1A–P1AA
2.2307(13) S1AA–Ni1A–P1AA
2.2426(13) S2AA–Ni1A–P1A
2.2426(13) S2A–Ni1A–P1A
2.8098(15) S1A–Ni1A–P1A
2.8098(15) S1AA–Ni1A–P1A
P1AA–Ni1A–P1A
134.99(5)
45.01(5)
135.00(4)
45.00(4)
45.01(5)
134.99(5)
180.00(7)
180.00(5)
45.00(4)
135.00(4)
NiA–S1AA
NiA–S1A
NiA–S2A
NiA–S2AA
NiA–P1A
NiA–P1AA
2.2257(17) S1A–NiA–P1AA
2.2257(17) S2A–NiA–P1AA
2.2273(17) S2AA–NiA–P1AA
2.2273(17) S2A–NiA(1)-P1A
2.8311(19) S1AA–NiA–S2AA
2.8311(19) S1A–NiA–S2AA
S2A–NiA–S2AA
135.63(6)
135.18(6)
44.82(6)
180.00(5)
88.04(7)
91.96(7)
180.00(11)
135.63(6)
44.37(6)
S2AA–Ni1A–S2A 180.00(10) S1A–Ni1A–S1AA
S2AA–Ni1A–P1AA
S2A–Ni1A–P1AA
S1AA–NiA–S1A
S1AA–NiA–S2A
S1A–NiA–S2A
180.00(13) S1AA–NiA–P1A
S1A–NiA–P1A
S2AA–Ni1A–S1A
S2A–Ni1A–S1A
91.25(5)
88.75(5)
91.96(7)
88.04(7)
S2AA–Ni1A–S1AA 88.75(5)
Symmetry transformations used to generate equivalent atoms: #1,
ꢀx; ꢀy; ꢀz.
Symmetry transformations used to generate equivalent atoms: #1,
ꢀx; ꢀy; ꢀz.
octahedron. The selected bond distances and angles for
complex 3 are shown in Table 4a. It is evident that
in the crystal structure of complex 3 there exist nu-
merous N–H–S hydrogen bonds which stabilize the
crystal structure. The hydrogen bonds are stated in
Table 4b.
For complex 4, it can be seen from Fig. 4 that for
every Co(II), such as Co1, three MeOC6H4P(CH3O)S2
Fig. 2. The crystal structural unit of complex 2.

H.-L. Liu et al. / Polyhedron 23 (2004) 1799–1804
1803
Fig. 3. The crystal structural unit of complex 3.
Table 4a
Selected bond distances (A) and angles (°) for complex 3
3.3. Discussion
ꢁ
Ni1–N3
Ni1–N4
Ni1–N1
Ni1–N6
Ni1–N5
Ni1–N2
2.113(4)
2.115(4)
2.122(4)
2.136(4)
2.145(4)
2.150(5)
N1–Ni1–N6
N3–Ni1–N5
N4–Ni1–N5
N1–Ni1–N5
N6–Ni1–N5
N3–Ni1–N2
N4–Ni1–N2
N1–Ni1–N2
N6–Ni1–N2
N5–Ni1–N2
94.24(19)
92.28(19)
92.7(2)
Through the research of the syntheses and crystal
structures of these four novel sulfur-rich complexes, we
found that the product can be influenced by the sort of
solvent used in the preparation of such complexes of
LR derivatives. For example, when the solvent is
methanol or ethanol, the deprotonated methanol or
ethanol can attack the phosphorus atom of LR, and the
product cleaved from LR containing methoxy or eth-
oxy was produced. It is suggested that when LR is he-
ated in a solvent containing an active proton, solvation
decomposition can easily take place.
94.50(19)
80.92(19)
93.9(2)
91.8(2)
N3–Ni1–N4
N3–Ni1–N1
N4–Ni1–N1
N3–Ni1–N6
81.51(17)
93.04(18)
171.1(2)
81.54(19)
93.3(2)
172.8(2)
170.4(2)
groups offer four sulfur atoms S1, S4, S3 and S6, existing
in the equatorial geometry and forming a parallelogram,
with the other two sulfur atoms S2 and S5 occupying the
axial sites. So the Co(II) ion is six-coordinated, in the
center of a distorted octahedron. Selected bond dis-
tances and angles are shown in Table 5.
4. Supplementary material
Crystallographic data for the structural analyses have
been deposited with the Cambridge Crystallographic
Table 4b
ꢁ
Hydrogen-bond distances (A) and angles (°) for complex 3
D–H
d(D–H)
d(Hꢂ ꢂ ꢂA)
\DHA
d(Dꢂ ꢂ ꢂA)
Assignment
N5–H5F
N4–H4F
N1–H1F
N3–H3E
N1–H1E
N6–H6F
N2–H2E
N6–H6E
N4–H4E
N5–H5E
N3–H3F
N2–H1F
0.797
0.900
0.954
0.864
1.020
0.923
0.953
0.936
0.864
0.884
0.994
0.915
2.862
2.610
2.581
2.908
2.586
2.907
163.69
154.76
153.18
140.57
153.08
171.65
3.635
3.446
3.459
3.617
3.525
3.823
S1
S4 [x; ꢀy þ 3=2; z þ 1=2]
S2
S2
S3
S3
2.523
2.654
2.692
2.628
2.732
157.24
147.61
148.20
148.74
147.50
3.405
3.415
3.475
3.516
3.538
S3 [x; ꢀy þ 3=2; z þ 1=2]
S1 [x; ꢀy þ 3=2; z þ 1=2]
S1 [x; ꢀy þ 3=2; z þ 1=2]
S4 [ꢀx þ 1; y þ 1=2; ꢀz þ 3=2]
S4 [ꢀx þ 1; y þ 1=2; ꢀz þ 3=2]

1804
H.-L. Liu et al. / Polyhedron 23 (2004) 1799–1804
Fig. 4. The crystal structural unit of the complex 4.
Table 5
ꢁ
Selected bond distances (A) and angles (°) for complex 4
Bond lengths
Co1–S1
Co1–S4
Co1–S6
Co1–S3
Co1–S5
Co1–S2
2.3029(17)
2.3042(16)
2.3190(16)
2.3211(17)
2.3292(15)
2.3362(15)
S1–Co1–S4
S1–Co1–S6
S4–Co1–S6
S1–Co1–S3
S4–Co1–S3
S6–Co1–S3
88.21(6)
97.43(6)
171.50(6)
169.98(6)
83.85(6)
91.16(6)
S1–Co1–S5
S4–Co1–S5
S6–Co1–S5
S3–Co1–S5
S1–Co1–S2
S4–Co1–S2
89.42(6)
89.76(6)
83.97(5)
96.62(6)
84.05(6)
98.31(6)
Bond angles
S3–Co1–S2
91.06(6)
S5–Co1–S2
169.42(6)
S6–Co1–S2
88.63(5)
[2] A.A. El-Barbary, S.-O. Lawesson, Tetrahedron 37 (15) (1981)
2641.
Data Center, CCDC Nos. 222648, 222650 222647 and
228385 for complexes 1, 2, 3 and 4, respectively. 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; email: deposit@ccdc.cam.ac.
uk or www:http://www.ccdc.cam.ac.uk).
[3] B.S. Pedersen, S.-O. Lawesson, Tetrahedron 35 (1979) 2433.
[4] M. St John Foreman, R.J. Mortimen, A.M.Z. Slawin, J. Derek
Woollins, J. Chem. Soc., Dalton Trans. (1999) 3419.
[5] R.A. Cherkasov, G.A. Kutyrev, A.N. Pudovik, Tetrahedron 41
(1985) 2567.
[6] Y.-G. Li, X.-F. Zhu, H.-J. Zhou, J. Org. Chem (Chinese) 15
(1995) 461.
Acknowledgements
[7] R. Shabana, S.S. Atrees, Phosphorus, Sulfur and Silicon 105
(1995) 57.
[8] A.A. Fahmy, Phosphorus, Sulfur and Silicon 68 (1992) 139.
[9] Y.-Z. Ning, B.-F. Wu, S.-T. Liu, GaoDengXueXiaoHuaXueX-
ueBao (Chinese) 22 (8) (2001) 1286.
This work was supported by the Natural Science
Foundation of China (20271046), the Natural Science
Foundation of Henan Education Department
(200011500027) and the Natural Foundation of Henan
Province (0211020300).
[10] J.R. Wasson, G.M. Waltermann, A.J. Stoklosa, Topics Current
Chem. 35 (1973) 65.
[11] W. Kuchen, H. Hertel, Angew. Chem. Int. Ed. Engl. 8 (1969)
89.
[12] R.G. Cavell, W. Byers, E.D. Day, P.M. Watkins, Inorg.Chem. 11
(1972) 1598.
References
[13] K. Clausen, A.A. El-Barbary, S.-O. Lawesson, Tetrahedron 37
(1981) 1019.
[14] R.W. Berg, K. Rasmussen, Spectrochim. Acta A 30 (1974) 1881.
[1] L.-N. He, R.-Y. Chen, R.-X. Zhuo, GaoDengXueXiaoHuaXu-
eXueBao (Chinese) 18 (12) (1997) 1969.