Synthesis and spectroscopic characterizations of novel Ni(II) and Co(II) dithiophosphinate complexes, and X-ray studies on the Ni(II) complex

Article abstract of DOI:10.1080/10426507.2011.601239

The reaction of 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4- disulfide (Lawesson's Reagent) with two different Grignard reagents gave the corresponding dithiophos-phinic acids (DTPA), CH₃OC₆H ₄-(R)P(S)SH; [R = iso-butyl (HL¹) and sec-butyl (HL ²)]. HL¹ and HL² were treated with dry ammonia to convert them to the ammonium salts, NH₄L¹ and NH ₄L². Ni(II) and Co(II) complexes of L¹ and L² - [Ni(L¹)₂], [Ni(L²) ₂]; [Co(L¹)₂]₂ and [Co(L ²)₂]₂-were obtained by the reaction of NH ₄L¹ and NH₄L² with NiCl ₂.6H₂O and CoCl₂.6H₂O, respectively, in ethanol. Square-planar nickel complexes [Ni(L¹)₂] and [Ni(L²)₂] were further reacted with pyridine (Py) to obtain the octahedral complexes, [Ni(Py)₂(L¹)₂] and [Ni(Py)₂(L²)₂]. The compounds were characterized by elemental analysis, FTIR, APCI/ESI-MS and ¹H, ¹³C, and ³¹P NMR spectroscopies. The novel nickel(II) complex [Ni(L²)₂] was characterized by X-ray crystallography. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Figures S1-S5.

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Synthesis and Spectroscopic
Characterizations of Novel Ni(II) and
Co(II) Dithiophosphinate Complexes, and
X-Ray Studies on the Ni(II) Complex
Ertuğrul Gazi Sağlam a , Hamza Yılmaz a , Hakan Dal b & Tuncer
Hökelek c
a Department of Chemistry , Ankara University , 06100 , Tandoğan ,
Ankara , Turkey
b Department of Chemistry , Anadolu University , 26470 ,
Yenibağlar , Eskişehir , Turkey
c Department of Physics , Hacettepe University , 06800 , Beytepe ,
Ankara , Turkey
Published online: 05 Jan 2012.
To cite this article: Ertuğrul Gazi Sağlam , Hamza Yılmaz , Hakan Dal & Tuncer Hökelek (2012)
Synthesis and Spectroscopic Characterizations of Novel Ni(II) and Co(II) Dithiophosphinate Complexes,
and X-Ray Studies on the Ni(II) Complex, Phosphorus, Sulfur, and Silicon and the Related Elements,
187:2, 213-224, DOI: 10.1080/10426507.2011.601239
To link to this article: http://dx.doi.org/10.1080/10426507.2011.601239
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Phosphorus, Sulfur, and Silicon, 187:213–224, 2012
Copyright ꢀC Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426507.2011.601239
SYNTHESIS AND SPECTROSCOPIC
CHARACTERIZATIONS OF NOVEL Ni(II) AND Co(II)
DITHIOPHOSPHINATE COMPLEXES, AND X-RAY
STUDIES ON THE Ni(II) COMPLEX
Ertug˘rul Gazi Sag˘lam,1 Hamza Yılmaz,1 Hakan Dal,2
and Tuncer Ho¨kelek3
1Department of Chemistry, Ankara University, 06100 Tandog˘an, Ankara, Turkey
2Department of Chemistry, Anadolu University, 26470 Yenibag˘lar,
Eskis¸ehir, Turkey
3Department of Physics, Hacettepe University, 06800 Beytepe, Ankara, Turkey
GRAPHICAL ABSTRACT
Abstract The reaction of 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide
(Lawesson’s Reagent) with two different Grignard reagents gave the corresponding dithiophos-
phinic acids (DTPA), CH3OC6H4-(R)P(S)SH; [R = iso-butyl (HL1) and sec-butyl (HL2)]. HL1
and HL2 were treated with dry ammonia to convert them to the ammonium salts, NH4L1
and NH4L2. Ni(II) and Co(II) complexes of L1 and L2 – [Ni(L1)2], [Ni(L2)2]; [Co(L1)2]2
and [Co(L2)2]2—were obtained by the reaction of NH4L1 and NH4L2 with NiCl2.6H2O and
CoCl2.6H2O, respectively, in ethanol. Square-planar nickel complexes [Ni(L1)2] and [Ni(L2)2]
were further reacted with pyridine (Py) to obtain the octahedral complexes, [Ni(Py)2(L1)2]
Received 12 May 2011; accepted 23 June 2011.
The authors gratefully acknowledge the financial assistance of the Technical Research Council of Turkey
(grant number TBAG 110T016, TUBITAK) and the Ankara University Research and Development Fund (grant
number DPT-2002-K-120130-5). We thank also Anadolu University and Medicinal Plants and Medicine Research
Center of Anadolu University, Eskis¸ehir, Turkey, for allowing us to use the X-ray facility.
Address correspondence to Hamza Yılmaz, Department of Chemistry, Faculty of Science, Ankara University,
Tandog˘an, 06100 Ankara, Turkey. E-mail: hyilmaz@science.ankara.edu.tr
213

˘
214
E. G. SAGLAM ET AL.
and [Ni(Py)2(L2)2]. The compounds were characterized by elemental analysis, FTIR,
APCI/ESI-MS and 1H, 13C, and 31P NMR spectroscopies. The novel nickel(II) complex
[Ni(L2)2] was characterized by X-ray crystallography.
Supplemental materials are available for this article. Go to the publisher’s online edition of
Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental
resource: Figures S1-S5.
Keywords Dithiophosphinato complexes; dithiophosphinic acids; phosphinodithioates; phos-
phinodithioic acids; X-ray structure
INTRODUCTION
Dithiophosphinic acids (DTPA) and their derivates are of interest for their excellent
metal complexing abilities, especially with soft-acid type cations, such as Ni2+, Co2+, Cu2+
,
Ag+, Au+, and lantanides and actinides. For example, long-alkyl-chain dithiophosphinate
(DTP) anions [R2PS2]− have long been under investigation for the solvent extractions
of metals.1,2 Several patents describe the potential industrial use of DTPA–metal salts as
additives in lubricating oils, plastics, and rubber.3–5 Some DTPA–99Tc complexes have
been introduced as brain imaging agents in radiography.6 Cephalosporin-type chemicals
containing DTPA moieties have been suggested as antibiotics in clinical medicine.7
Depending on the identities of the alkyl/aryl groups attached to the phosphorus, DT-
PAs are grouped as symmetrical and asymmetrical. Several methods have been developed
for the synthesis of both types of compounds.8,9 The reaction of the readily accessible
perthiophosphonic anhydrides such as Lawesson’s Reagent, (LR), with Grignard reagents
(GR) is a general route to prepare DTPAs.10,11 This process is especially useful for the
synthesis of asymmetrical DTPAs because commercially available LRs bear limited num-
ber of aryl/alkyl groups and the preparation of a perthiophosphonic anhydride bearing the
same aryl/alkyl group with the GR may prove to be tedious and time-consuming. Sym-
metrical DTPAs can conveniently be obtained by the treatment of symmetrical secondary
phosphines with elemental sulfur.12
DTPAs are bidentate ligands and are known to form stable complexes with soft acid-
type cations. Square-planar Ni(II)-DTPA complexes, for example, have been prepared,
and some of these have been reported to react further with amines such as pyridine to
yield six-coordinated, hexagonal, mixed-type complexes.13,14 A sharp color change accom-
panies the formation of the six-coordinated complexes. The six-coordinated, mixed-type
complexes are mostly paramagnetic, while the square-planar counterparts are diamagnetic.
These adducts are metastable at ambient temperature and reversibly dissociate into the
corresponding amine and the square-planar precursor.15
In this work, we report the preparation and characterization of some new DTPAs,
namely ammonium iso-butyl(4-methoxyphenyl)dithiophosphinate (NH4L1) and ammo-
nium sec-butyl (4-methoxyphenyl)dithiophosphinate-ligands (NH4L2), as well as the
complexes, bis[iso-butyl(4-methoxyphenyl)dithiophosphinato]nickel(II), [Ni(L1)2], bis[
sec-butyl(4-methoxy-phenyl)dithiophosphinato] nickel (II), [Ni(L2)2]; bis[iso-butyl(4-
methoxyphenyl)-dithiophosphinato] cobalt(II), [Co(L1)2]2, and bis[sec-butyl(4-methoxy
phenyl)dithio-phosphinato]cobalt(II), [Co(L2)2]2 (Scheme 1). In attempts to grow single
crystals of the complexes, we obtained only the single crystals of [Ni(L2)2] suitable for
X-ray analysis. According to the X-ray results, the coordination around the Ni2+ ion was
square planar.

SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATIONS OF NOVEL Ni(II) AND Co(II) 215
R
S
S
S
P
S
+
2 R-MgBr
OCH
P
P
S
H
CO
3
3
+
SH
H , H O / - 2 MgBrOH
2
H CO
3
LR
HL
CH
CH
3
1
CH CH -
=
L
R =
R =
2
2
3
dry NH
3
CH
3
2
I
=
L
CH CH -CH-
3
2
R
S
P
2+
Co , Ni
2+
S NH
4
[NiL ], [Co(L) ]
2 2
2
H CO
3
NH4L
Scheme 1 Synthesis of HL1, HL2, NH4L1, NH4L2, [Ni(L1)2], [Ni(L2)2], [Co(L1)2]2, and [Co(L2)2]2.
On the other hand, octahedral {bis pyridine-bis[iso-butyl(4-methoxyphenyl)
dithiophosp-hinato]}nickel (II) [Ni(Py)2(L1)2] and {bis pyridine-bis[sec-butyl(4-
methoxyphenyl)-dithio-phosphinato]}nickel (II) [Ni(Py)2(L2)2] complexes were prepared
through the reaction of [Ni(L1)2] and [Ni(L2)2] with pyridine in a chloroform–ethanol
mixture (1:1, v/v) (Scheme 2).
The compounds were characterized by elemental analysis, 1H, 13C, and 31P NMR, and
MS and FTIR spectral data. The magnetic susceptibilities of the complexes were measured
to judge the hybridization patterns and the geometries. The spectroscopic data obtained for
the complexes are compared with those in the literature.16
OCH
3
OCH
3
N
R
R
2
S
S
S
S
N
P
P
Ni
Ni
N
P
P
CHCl3 / C2H5OH
S
S
S
S
R
R
H
CO
H
CO
3
3
[Ni(Py) (L) ]
2
2
CH
CH
3
1
2
CH CH
-
2
R =
R =
2
=
L
3
CH
3
I
CH CH -CH-
=
L
3
2
Scheme 2 Synthesis of [Ni(Py)2(L1)2] and [Ni(Py)2(L2)2].

˘
E. G. SAGLAM ET AL.
216
RESULTS AND DISCUSSION
Mass Spectra
The mass spectral data for individual compounds are summarized in the Experimental
section. The spectra of the ligands, NH4L1 and NH4L2, are almost the same as expected.17
The principal features are the molecular peak at m/z 261.0 and another peak at m/z 227,
corresponding to the leaving of an H2S moiety from the molecule. The presence of fairly in-
tense molecular peaks for [Ni(L1)2] and [Ni(L2)2] strongly supports the uninuclear, neutral,
volatile complexes. The intensities of consecutive peaks in the molecular clusters reflect
the isotopic abundance of nickel and sulfur. The patterns of disintegration are compatible
with those reported for similar structures.18,19
[Ni(Py)2(L1)2] and [Ni(Py)2(L2)2] give rise to a mass spectra with no molecular
ions, the most intense signals being at m/z 656.0, which correspond to [NiPy(L1)2] and
[NiPy(L2)2]. Here again, the relative isotopic abundances of nickel and sulfur are traceable.
The mass spectra of [Co(L1)2]2 and [Co(L2)2]2 display [M + Na]+ peaks, sodium
ions coming from the buffer solution used in the ionization process in the APCI/ES system.
The stepwise breakage of the ligands is clearly observable.
IR Spectra
Selected IR data for all the compounds investigated are listed in Table 1. The char-
acteristic asymmetric and symmetric νP bands are observed between 606 cm−1 and 648
S
cm−1 and between 538 cm−1 and 563 cm−1, respectively.
NMR Spectra
The mean features of the 1H NMR spectra with the assignments being made on the
basis of the numbering scheme given in Figure 1 are summarized in Table 2. Figures S1–S4
(Supplemental Materials) show the 1H NMR spectra of the four reported compounds
The 13C NMR spectral data of the four compounds – NH4L1, [Ni(L1)2], NH4L2, and
[Ni(L2)2] – are given in Table 3.
The proton-decoupled 31P NMR spectra of NH4L1, NH4L2, [Ni(L1)2], and [Ni(L2)2]
show singlets at 64.33, 77.99, 88.31, and 99.42 ppm, respectively. Quite noticeably, the
coordination of the sulfur atoms to the metal cations lowers the chemical shift values by
more than 10 ppm.
Table 1 Selected FTIR data (cm−1) assignment of import bands
Compound
ν(as,s) (P S)
ν (N H)
ν (C C)
ν (C H)aliph.
ν (C H)arom
NH4L1
615; 546
606; 563
610; 540
610; 542
617; 538
646; 554
648; 544
611; 538
3171; 3111; 3065
1592; 1496
1591; 1500
1592; 1494
2951; 2835; 2810
2955; 2926; 2834
2951; 2922; 2868; 2837
3005
3003
3011
3022
3003
3007
3013
3023
[Ni(L1)2]
–
–
–
[Ni(Py)2(L1)2]
[Co(L1)2−]2
NH4+L2
1591; 1496; 1458 2955; 2926; 2866; 2834
3163; 3057
1592; 1494
1591; 1498
1594; 1498
2963; 2924; 2810
2965; 2922; 2839
2961; 2926; 2868; 2835
[Ni(L2)2]
–
–
–
[Ni(Py)2(L2)2]
[Co(L2)2]2
1591; 1496; 1456 2963; 2926; 2868; 2834

SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATIONS OF NOVEL Ni(II) AND Co(II) 217
Table 2 1H NMR spectral data for NH4L1, [Ni(L1)2], NH4L2, and [Ni(L2)2]∗
P
CH2
P
CH2
Ar
Ar
Compound
NH4L1
CH(CH3)2
CH
CH
OCH3
Hmeta
Hortho
δ = 0.62
δ = 1.84
δ = 2.06
δ = 3.63
δ = 6.85
δ = 7.86
(d, 6H)
(m, 1H)
(dd, 2H)
(s, 3H)
(d, 2H)
(dd, 2H)
3JH
= 6.56
2JP
=
=
3JH
7.16
=
3JP
12.38
3JH
=
=
H
H
H
H
11.86
3JH
H
H
5.86
8.66
CH(CH3)2
δ = 1.06
(d, 6H)
P
CH2 and CH2 CH
δ = 2.19
OCH3
δ = 3.87
(s, 3H)
Ar Hmeta
δ = 7.01
(d, 2H)
Ar Hortho
δ = 7.75
(dd, 2H)
[Ni(L1)2]
(m and d, 3H)
3JH
= 6.14
3JH
=
3JP
=
H
H
H
8.49
13.05
3JH
=
H
8.64
CH2 CH3
P
CH
P
CH
(CH2)
CH3
δ = 1.64
and 1.82
(m, 1H)
OCH3
Ar Hmeta
Ar Hortho
(CH3)
δ = 0.93
(dd, 3H)
3JP
21.24
3JH
(CH3)
δ = 1.00
(m, 1H)
NH4L2
δ = 0.72
δ = 3.71
δ = 6.90
δ = 7.83
(t, 3H)
(s, 3H)
(d, 2H)
(dd, 2H)
=
3JH
8.56
=
3JP
11.77
3JH
=
H
H
H
=
=
H
H
6.72
8.74
CH2 CH3
P
CH
P
CH
and
(CH2)
CH3
OCH3
Ar Hmeta
Ar Hortho
(CH3)
CH(CH3)
δ = 1.20
(m, 1H)
over-
[Ni(L2)2]
δ = 0.95
δ = 1.15
δ = 1.98
δ = 3.76
δ = 6.98
δ = 7.58
(t, 3H)
(dd, 3H)
(m, 1H)
(s, 3H)
(d, 2H)
(dd, 2H)
3JP
=
=
3JH
=
3JP
=
=
H
H
H
21.78
lapped
7.07
12.32
3JH
3JH
H
H
6.83
8.65
Chemical shifts (δ) are reported in parts per million (ppm). J values are reported in Hertz. s: singlet; d: doublet;
dd: doublet of doublets; m: multiplet.
∗The atom responsible for the signal is boldfaced and underlined.
9
7
8
2
3
2
3
6
S
S
8
6
4
4
7
8'
CH3O
5
CH3O
5
P
P
1
1
S NH4
S NH4
2'
2'
3'
3'
NH4L1
NH4L2
Figure 1 Numbering scheme for NH4L1 and NH4L2.

218

SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATIONS OF NOVEL Ni(II) AND Co(II) 219
Due to the paramagnetic nature of [Ni(Py)2(L1)2] and [Ni(Py)2(L2)2] as well as
1
[Co(L1)2]2 and [Co(L2)2]2, the ambient temperature H, 13C, and 31P NMR spectra are
suitable for discussion.
X-Ray Studies
The x-ray structural determination of [Ni(L2)2] confirms the assignment of its struc-
ture from spectroscopic data. Experimental data are listed in Table 4; selected bond lengths
and angles are given in Table 5. The molecular structure of [Ni(L2)2] along with the atom-
numbering scheme is depicted in Figure 2. The Ni atom is located on an inversion center
and coordinated by the four symmetry-related S atoms. The average Ni S bond length and
S Ni S bond angle are 2.231(3) Å and 90.00(9)◦, while the average P S bond length
and the S1 P1 S2 bond angle are 2.033(4) Å and 100.13(14)◦, respectively, and the av-
erage P S Ni bond angle is 85.33(11)◦ (Table 5). The Ni S and P S bond lengths, and
S Ni S and S P S bond angles are in good agreement with the corresponding average
values [2.233(2) Å and 2.011(3) Å, and 88.17(9)◦ and 101.07(14)◦] in (C24H36O2P2S4Ni)20
and [2.221(8) Å and 1.994(1) Å, and 88.14(3)◦ and 101.57(4)◦] in (C18H24O4P2S4Ni).21
Table 4 X-ray experimental data for [Ni(L2)2]
[Ni(L2)2]
Empirical formula
Color/shape
C22H32NiO2P2S4
Blue/block
Formula weight
Temperature (K)
Radiation used, graphite monochromator
Crystal system
Space group
577.37
100(2)
MoKα (λ = 0.71073 Å)
Triclinic
P –1
a, b, c (Å)
6.9605(3), 9.7211 (4), 11.0216(6)
α, β, γ (∞)
76.624(3), 84.810(4), 69.466(4)
679.40(6)
Volume (Å3)
Z
1
Absorption coefficient (mm−1
)
1.156
1.411
Dcalc (mg m−3
)
Maximum crystal dimension (mm)
θ (max) (o)
0.18 × 0.32 × 0.41
23.51
Reflections measured
Range of h, k, l
5235
−7 < h < 7; −10 < k < 10; −12 < l < 11
Diffractometer/scan
Number of reflections with I >2 σ(I)
Corrections applied
Computer programs
Source of atomic scattering factor
Structure solution
Treatment of hydrogen atoms
No. of parameters var.
GOF
Bruker Kappa APEXII/φ and w
1159
Lorentz polarization
SHELXS-97, 22 SHELXL-97,22 ORTEP-323
International Table for X-Ray Crystallography (1974)24
Direct methods
Geometric calculation
145
1.057
R = ||Fo| – |Fc||/|Fo|
0.0998
0.2446
1.155
−0.947
Rw
(ꢀ/ρ) max (e A−3
(ꢀ/ρ) min (e A−3
)
)

˘
220
E. G. SAGLAM ET AL.
Table 5 Selected bond lengths (Å) and angles (∞) for [Ni(L2)2]
Comparable literature values
Ni1 S1
Ni1 S2
P1 S1
P1 S2
P1 C1
P1 C8
S1 Ni1 S2
S1 Ni1 S2i
S1 P1 S2
C1 P1 S1
C1 P1 S2
2.230(2)
2.231(3)
2.033(4)
2.033(3)
1.787(11)
1.849(10)
88.69(9)
91.31(9)
100.13(14)
111.6(3)
111.2(3)
2.233(2),20 2.221(8)21
O1 C4
O1 C7
C8 C9
C8 C10
C10 C11
1.332 (13)
1.448(16)
1.534(14)
1.47(2)
2.011(3),20 1.994(1)21
1.504(19)
88.17(9),20 88.14(9)21
C1 P1 C8
C8 P1 S1
C8 P1 S2
P1 S1 Ni1
P1 S2 Ni1
106.7(5)
109.9(5)
117.3(4)
85.34(10)
85.32(12)
101.07(14),20 101.57(4)21
Symmetry code: (i) −x + 1, −y, −z + 1.
The four-membered ring B (P1/S1/S2/Ni1) is nearly planar (with a maximum deviation
of 0.055(3) Å for atom P1) and is oriented with respect to ring A (C1–C6) at a dihedral
angle of 56.23(23)◦. Figure S5 (Supplemental Materials) depicts a packing diagram of the
crystals of Ni(L2)2.
Figure 2 An ORTEP-3 drawing of [Ni(L2)2] with the atom-numbering scheme. Displacement ellipsoids are
drawn at the 50% probability level [symmetry code: (ꢁ) −x, −y, −z].

SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATIONS OF NOVEL Ni(II) AND Co(II) 221
CONCLUSIONS
Eight new compounds – NH4L1, NH4L2, [Ni(L1)2], [Ni(L2)2], [Ni(Py)2(L1)2],
[Ni(Py)2(L2)2] [Co(L1)2]2, and [Co(L2)2]2 – have been synthesized. The ammonium salts
of the DTPAs have been characterized by elemental analysis and spectroscopic techniques.
[Ni(L2)2] was investigated by X-ray crystallography and the coordination around the Ni2+
ion was observed to be square planar. Magnetic susceptibility measurements were also
made to confirm the type of coordination in the complexes. Ammonium–DTPA salts and
the DTPA complexes with Ni(II) and Co(II) are stable at room temperature for at least
a period of years, but [Ni(Py)2(L1)2] and [Ni(Py)2(L2)2] are metastable. The pyridine
complexes lose one or two pyridine molecules, and this change is accompanied by a
color change from green to blue, with a transitory brown phase. However, the green,
octahedral dipyridino complex is stable at room temperature if kept in a dessicator under a
pyridine-rich atmosphere.
EXPERIMENTAL
Analytical-grade LR, 1-bromo-2-methylbutane, 2-bromo-2-butane, and pyridine
were purchased from Across and used directly without further purification. Benzene, chlo-
roform, diethyl ether, methanol, ethanol, NiCl2.6H2O, and CoCl2.6H2O were purchased
from Merck. Benzene and diethyl ether were distilled and dried before use.
Mass spectra were recorded on an Agilent 1100 MSD spectrometer with an APCI/ESI
ionizing attachment. Magnetic susceptibilities were measured on a Sherwood Scientific
magnetic susceptibility balance (Model MK1) at room temperature (25 ◦C). Melting
1
points were measured on a Gallenkamp apparatus using a capillary tube. H, 13C, and
31P NMR spectra were recorded on a 400-MHz Bruker DPX FT-NMR spectrometer in D2O
(DTPA–NH4+ salts) and CDCl3 (complexes). SiMe4 for 1H and 13C and 85% H3PO4 for 31
P
NMR were used as internal and external standards, respectively. IR spectra were recorded
on a Mattson 1000 FTIR spectrophotometer (400–4000 cm−1) in KBr pellets (1% w/w)
and were reported in cm−1 units. Microanalyses were performed using a LECO CHNS-932
C elemental analyzer.
Single-crystal X-ray diffraction analysis of [Ni(L2)2] was performed on a Bruker
Kappa APEXII CCD area-detector diffractometer using MoKα radiation (λ = 0.71073 Å)
at a temperature of 100 K.
All the crystals picked proved not to be ideal for diffraction studies as the rather
high R-value (R = 0.0998) indicates. Absorption correction by multi-scan25 was applied.
Structure was solved by direct methods22 and refined by full-matrix least squares against
F2 using all data.22 All non-H atoms were refined anisotropically. H atoms were positioned
geometrically at distances of 0.95 Å (aromatic CH), 1.00 Å (CH), 0.99 Å (CH2), and 0.98
Å (CH3) from the parent C atoms; a riding model was used during the refinement process
and the Uiso(H) values were constrained to be xUeq(carrier atom), where x = 1.2 for CH
and CH2, and x = 1.5 for CH3.
Preparation of Compounds
Preparation of Ligands. NH4L1 and NH4L2 were prepared in accordance with
the literature8 and recrystallized from a diethylether–methanol (3:1, v/v) mixture.

˘
222
E. G. SAGLAM ET AL.
NH4L1: Yield: 0.7 g (25%; notable loses on recrystallization). mp 170–171
◦C. 1H NMR (ppm in D2O, the atom assigned being underlined): δ 0.62 (d,
3JH
= 6.56 Hz, 6H, CH (CH3)2), 1.84 (m, 1H, P CH2 CH), 2.06 (dd, 2JP
H
H
= 11.86 Hz, 3JH
= 5.86 Hz, 2H, P CH2 CH), 3.63 (s, 3H, OCH3), 6.85
H
(d, 3JH
= 7.16 Hz, 2H, Ar Hmeta), 7.86 (dd, 3JP
= 12.38 Hz, 3JH
=
=
H
H
H
8.66 Hz, 2H, Ar Hortho). 13C NMR (1H decoupled; ppm in D2O): δ = 24.30 (d, 3JP
C
9.69 Hz, CH (CH3)2), 25.64 (d, 2JP C = 3.79 Hz, P CH2 CH), 53.44 (d, JP C = 53.80
Hz, P CH2), 55.82 (s, CH3O), 113.82 (d, 3JP C = 13.21 Hz, Ar Cmeta), 132.47 (d, 2JP
=
C
12.41 Hz, Ar Cortho), 133.76 (d, JP = 79.70 Hz, P CAr), 160.87 (d, 4JP = 2.90 Hz,
C
C
CH3O C). 31P NMR (1H-decoupled; ppm in D2O): δ = 64.33. APCI/ESI MS: m/z 261.00
([L1H]+, 100%); 227.00 ([L1H H2S]+, 11.7%). Anal. Calcd. for C11H20NOPS2 (277.4 g
mol−1): C, 47.6; H, 7.3; N, 5.1; S, 23.1; Found: C, ◦47.2; H, 7.1; N, 5.2; S, 22.7.
1
NH4L2: Yield: 1.72 g (55%). mp 206–208 C. H NMR (ppm in D2O): δ = 0.72
(t, 3H, CH2 CH3), 0.93 (dd, 3JP = 21.24 Hz, 3JH = 6.72 Hz, 3H, CH CH3), 1.00
H
H
(m, 1H, P CH(CH3)CH2), 1.64 and 1.82 (both m, 1H each, (CH2) CH3 diastereotopic
protons), 3.71 (s, 3H, OCH3), 6.90 (d, 3JH H = 8.56 Hz, 2H, Ar Hmeta), 7.83 (dd, 3JP
=
H
3
11.77 Hz, JH
= 8.74 Hz, 2H, Ar Hortho). 13C NMR (1H-decoupled; ppm in D2O):
H
δ = 12.28 (d, 3JP = 16.37 Hz, CH2 CH3), 12.78 (s, CH CH3), 23.63 (s, CH2), 45.70
C
(d, JP C = 54.47 Hz, P CH), 55.78 (s, CH3O), 113.70 (d, 3JP C = 12.95 Hz, Ar Cmeta),
2
131.05 (d, JP = 78.45 Hz, P CAr), 132.96 (d, JP = 11.57 Hz, Ar Cortho), 160.89
C
C
4
(d, JP
= 2.75 Hz, CH3O C). 31P NMR (1H-decoupled; ppm in D2O): δ = 77.99.
C
APCI/ESI MS: m/z 261.00 ([L2H]+, 100%); 227.00 ([L1H H2S]+, 13.4%). Anal. Calcd.
for C11H20NOPS2 (277.4 g mol−1): C, 47.6; H, 7.3; N, 5.1; S, 23.1; Found: C, 47.6; H, 7.7;
N, 5.1; S, 23.2.
Preparation of Bis[Iso-Butyl(4-Methoxyphenyl)Dithiophosphinato]
Nickel(II) [Ni(L1)2] and Bis[Sec-Butyl(4-Methoxyphenyl)Dithiophosphinato]
Nickel (II) [Ni(L2)2]
[Ni(L1)2]: A solution of NiCl2.6H2O (0.08 g, 0.3 mmol) in methanol (10 mL) was
added to a solution of NH4L1 (0.2 g, 0.6 mmol) in the same solvent (25 mL). The mixture
was heated gently. The resulting solution was left to stand overnight to obtain needle-like
crystals. The dark blue crystalline solid was filtered off and recrystallized from ethanol.
Yield: 0.18 g (86%). mp 138–140 ◦C. m = −2, 02. 10-4. 1H NMR (ppm in CDCl3): δ =
1.06 (d, 3JH = 6.14 Hz, 6H, CH (CH3)2), 2.19 (m and d, 3H, P CH2 and CH2 CH),
H
3.87 (s, 3H, OCH3), 7.01 (d, 3JH H = 8.49 Hz, 2H, Ar Hmeta), 7.75 (dd, 3JP H = 13.05 Hz,
3JH H = 8.64 Hz, 2H, Ar Hortho). 13C NMR (1H-decoupled; ppm in CDCl3): δ = 24.91 (d
and s superimposed, 3JP = 9.72 Hz with the singlet CH(CH3)2 in between), 51.00 (d,
C
3
JP = 40.46 Hz, P CH2), 55.91 (s, CH3O), 114.51 (d, JP = 14.81 Hz, Ar Cmeta),
C
C
128.50 (d, JP C = 70.24 Hz, P CAr), 131.14 (d, 2JP C = 14.10 Hz, Ar Cortho), 162.83 (s,
CH3O C). 31P NMR (1H-decoupled; ppm in CDCl3): δ = 88.31. APCI/ESI MS: m/z 576.9
([Ni(L1)2]+, 33.2%); 261.0 ([L1H]+, 100.0%). Anal. Calcd. for C24H36NiO2P2S4 (577.4 g
mol−1): C, 45.7; H, 5.5; S, 22.2; Found: C, 45.3; H, 5.4; S, 22.0.
[Ni(L2)2]: [Ni(◦L2)2] was prepared by the same procedure as above. Yield: 0.18 g
1
(86%). mp 109–111 C. m = −1, 79. 10-4. H NMR (ppm in CDCl3): δ = 0.95 (t, 3H,
CH2 CH3), 1.15 (dd, 3JP = 21.78 Hz, 3JH = 6.83 Hz, 3H, P CH CH3); 1.20 (m,
H
H
1H, P CH overlapped with CH(CH3)), 1.98 (m, 1H, (CH2) CH3), 3.76 (s, 3H, OCH3),
3
3
3
6.98 (d, JH = 7.07 Hz, 2H, Ar Hmeta), 7.58 (dd, JP = 12.32 Hz, JH = 8.65
H
H
H

SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATIONS OF NOVEL Ni(II) AND Co(II) 223
Hz, 2H, Ar Hortho). 13C NMR (1H-decoupled; ppm in CDCl3): δ = 11.43 (s, CH2 CH3),
12.49 (d, 2JP = 16.81 Hz, CH CH3), 22.01 (s, CH CH2), 45.16 (d, JP = 40.92 Hz,
C
C
3
P CH), 55.92 (s, CH3O), 114.21 (d, JP = 14.16 Hz, Ar Cmeta), 126.37 (d, JP
=
C
C
67.01 Hz, P Carom), 131.54 (d, 2JP = 13.17 Hz, Ar Cortho), 162.74 (s, CH3O C). 31
P
C
NMR (1H-decoupled; ppm in CDCl3): δ = 99.42. APCI/ESI MS: m/z 576.9 ([Ni(L2)2]+,
27.6%); 261.0 ([L2H]+, 100.0%). Anal. Calcd. for C24H36NiO2P2S4 (577.4 g mol−1): C,
45.7; H, 5.5; S, 22.2; Found: C, 45.3; H, 4.7; S, 21.6.
Preparation of {Bis Pyridine-Bis[Iso-Butyl(4-Methoxyphenyl)
Dithiophosphinato]} Nickel(II) [Ni(Py)2(L1)2] and {Bis
Pyridine-Bis[Sec-Butyl(4-Methoxyphenyl)Dithiophosphinato]} Nickel (II)
[Ni(Py)2(L2)2]
A solution of [Ni(L1)2] or [Ni(L2)2] (0.2 g, 0.35 mmol) was dissolved in CHCl3
(25 mL) while boiling. To this solution, an excess of pyridine in the form of an ethanolic
solution (1:1, v/v) was added dropwise with constant stirring. The color of the mixture
changed immediately from dark blue to light brown. Left aside for two days, a green solid
formed. This solid was filtered and recrystallized from ethanol. When exposed to air or
heated gently, a loss of pyridine occurred and the color reverted to the original dark blue
of the pyridine-free compound. In order to prevent decomposition, the green complex was
kept under pyridine vapors in a dessicator.
[Ni(Py)2(L1)2]: Yield: 0.23 g (92%). mp 140◦C (decomp.). µeff = 2.93 B.M. (para-
magnetic). APCI/ESI MS: m/z 656.0 ([Ni(L1)2Py]+, 100.0%); 576.9 ([Ni(L1)2]+, 48.3%).
Anal. Calcd. for C32H42N2NiO2P2S4 (735.6 g mol−1): C, 52.3; H, 5.8; N, 3.8; S, 17.4;
Found: C, 52.3; H, 5.8; N, 3.9; S, 17.5.
[Ni(Py)2(L2)2]: Yield: 0.24 g (96%). mp 109◦C (decomp.) upon heating. µeff = 2.82
B.M. (paramagnetic). APCI/ESI MS: m/z 656.0 ([Ni(L2)2Py]+, 100.0%); 576.9 ([Ni(L2)2]+,
40.6%). Anal. Calcd. for C32H42N2NiO2P2S4 (735.6 g mol−1): C, 52.3; H, 5.8; N, 3.8; S,
17.4; Found: C, 52.2; H, 6.5; N, 3.8; S, 17.6.
Preparation of Bis[Iso-Butyl(4-Methoxyphenyl)Dithiophosphinato]
Cobalt(II) [Co(L1)2]2, and Bis[Sec-Butyl(4-Methoxyphenyl)
Dithiophosphinato]Cobalt(II) [Co(L2)2]2
[Co(L1)2]2: A solution of CoCl2.6H2O (0.08 g, 0.34 mmol) in ethanol (10 mL)
was added to a solution of NH4L1 (0.08 g, 0.3 mmol) in the same solvent (25 mL).
The mixture was heated gently. The solution was kept overnight at room temperature,
whereupon the complex precipitated as a green crystalline solid, which was filtered off
◦
and recrystallized from ethanol. Yield: 0.18 g (90%). mp 177–179 C. µeff = 4.18 B.M.
(paramagnetic). MS: m/z 1176.9 ([Co2(L1)4+Na]+, 18.9%) (indicating dimeric structure);
894.9 ([Co2(L1)4–L1]+, 64.3%); 838.0 ([Co2(L1)3 – iso C4H9]+, 56.0%); 577.9 ([Co(L1)2]+,
100%); 261.0 ([L1H]+, 94.6%). Anal. Calcd. for C44H64Co2O4P4S8 (1155.3 g mol−1): C,
45.7; H, 5.6; S, 22.2; Found: C, 45.9; H, 5.4; S, 22.1.
[Co(L2)2]2: [(Co(L2)2)2] was prepared by the same procedure as above. Yield: 0.19
◦
g (95%). mp 196–198 C. µeff = 3.85 B.M. (paramagnetic). APCI/ESI MS: m/z 1176.9
([Co2(L2)4+Na]+, 2.5%) (indicating dimeric structure); 894.9 ([Co2(L2)4–L2]+, 100.0%);
838.0 ([Co2(L2)3 – sec C4H9]+, 24.2%); 577.9 ([Co(L2)2]+, 52.4%); 261.0 ([L2H]+, 39.7%).

˘
E. G. SAGLAM ET AL.
224
Anal. Calcd. for C44H64Co2O4P4S8 (1155.3 g mol−1): C, 45.7; H, 5.6; S, 22.2; Found: C,
45.9; H, 5.4; S, 22.0.
Supplementary Data
Crystallographic data (excluding structure factors) have been deposited with the Cam-
bridge Crystallographic Data Centre as the supplementary publication no. CCDC 823741.
Copies of the data can be obtained, free of charge, on application to CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK (fax: +44-1223-336033; E-mail: deposit@ccdc.cam.ac.uk).
Supplementary Materials
Figures S1–S5 are available online in Supplemental Materials.
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