Synthesis and spectral studies on Ni(II) complexes involving N-furfuryl-N-substituted benzyldithiocarbamates and PPh3: Anagostic and C–H…π(chelate) interactions in (N-furfuryl-N-(4-fluorobenzyl)dithiocarbamato-S,S′)(thiocyanato-N)(tr

Article abstract of DOI:10.1080/10426507.2015.1135150

Twelve new nickel(II) complexes of functionalized dithiocarabamates [Ni(S2CNRR?)²](1-6) and [Ni(S2CNRR?)(NCS)(PPh³)](7-12) [where R=furfuryl; R?=2-hydroxy benzyl (1,7), 3-hydroxy benzyl (2,8), 4-hydroxy benzyl (3,9), 4-methoxy benzyl

Full text of DOI:10.1080/10426507.2015.1135150

Phosphorus, Sulfur, and Silicon and the Related Elements
ISSN: 1042-6507 (Print) 1563-5325 (Online) Journal homepage: http://www.tandfonline.com/loi/gpss20
Synthesis and spectral studies on Ni(II)
complexes involving N-furfuryl-N-substituted
benzyldithiocarbamates and PPh3: Anagostic and
C–H…Π(chelate) interactions in (N-furfuryl-N-(4-
fluorobenzyl)- dithiocarbamato-S,S′)(thiocyanato-
N)(triphenylphosphine)nickel(II)
E. Sathiyaraj, S. Thirumaran & Samuele Ciattini
To cite this article: E. Sathiyaraj, S. Thirumaran & Samuele Ciattini (2016): Synthesis and
spectral studies on Ni(II) complexes involving N-furfuryl-N-substituted benzyldithiocarbamates
and PPh3: Anagostic and C–H…Π(chelate) interactions in (N-furfuryl-N-(4-fluorobenzyl)-
dithiocarbamato-S,S′)(thiocyanato-N)(triphenylphosphine)nickel(II), Phosphorus, Sulfur, and
Silicon and the Related Elements, DOI: 10.1080/10426507.2015.1135150
To link to this article: http://dx.doi.org/10.1080/10426507.2015.1135150
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Feb 2016.
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Synthesis
and
spectral
studies
on
Ni(II)
complexes
involving
N-furfuryl-N-substituted benzyldithiocarbamates and PPh3: Anagostic and C–H… (chelate)
interactions
in
(N-furfuryl-N-(4-fluorobenzyl)-
dithiocarbamato-S,S)(thiocyanato-
N)(triphenylphosphine)nickel(II)
E. Sathiyaraja,b, S. Thirumarana* and Samuele Ciattinic
aDepartment of Chemistry, Annamalai University, Annamalinagar 608 002, Tamilnadu,
India.
b Present address: Department of chemistry, Kalasalingam University, Krishnankoil 626 126,
India.
cCentro di Cristallografia Strutturale, Polo Scientifio di Sesto Fiorentino, Via della Lastruccia
No. 3, 50019 Sesto Fiorentino, Firenze, Italy.
*Address for correspondence
Dr. S. Thirumaran
Department of Chemistry
Annamalai University
Annamalainagar 608 002
Tamilnadu, INDIA
Tel: +91 9842897597
E-mail: sthirumaran@yahoo.com
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ABSTRACT
Twelve new
nickel(II) complexes of functionalized dithiocarabamates
[Ni(S2CNRR')2](1-6) and [Ni(S2CNRR')(NCS)(PPh3)](7-12) [where R=furfuryl; R'=2-hydroxy
benzyl (1,7), 3-hydroxy benzyl (2,8), 4-hydroxy benzyl (3,9), 4-methoxy benzyl (4,10), 4-fluoro
benzyl (5,11), 4-chloro benzyl (6,12)] have been prepared and characterized by elemental
analysis, IR, UV-Vis and NMR (1H and 13C) spectroscopy. IR spectra of the complexes
support the bidentate coordination of dithiocarbamate ligands. Electronic spectral
studies on complexes 1-12 indicate square planar geometry around the nickel(II) central atom. In
the 13C NMR spectra, the upfield shift of NCS2 carbon signal for heteroleptic complex (7-12)
compared to homoleptic complexes (1-6) is due to the effect of PPh3 on the mesomeric drift of
electron density toward nickel through thioureide C-N bond. Single crystal X-ray structural
analysis of complex 11 confirms that the coordination geometry about the Ni(II) is distorted
square planar. A rare intramolecular anagostic interaction C–H…Ni [NiH= 2.804 Å] is
observed. The packing of complex 11 is stabilized by non-conventional C–H⋯S, C–H⋯F and
C–H⋯π(chelate, NiS2C) bonding interactions.
Keywords: Ni(II) dithiocarbamate, NMR spectroscopy, X-ray structure, Anagostic interaction
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INTRODUCTION
The chemistry of dithiocarbamate complexes of group-10 metal ions was
extensively studied due to their wide range of applications such as agricultural [1-3], medicine
[4-7], organic synthesis [8] and even as synthetic precursor for metal sulfide nanoparticles [9-
16]. Recently the study of nickel(II) dithiocarbamate complexes has been motivated by their
diverse properties and interesting applications such as visual detection of gaseous NO2 at low
concentrations in live cells [17], antibacterial and antifungal activities [18] catalysts for graphite
oxidation [19] and removal of selected anionic dyes from aqueous solutions [20]. Nickel
complexes containing phosphine ligands are used as catalysts in cross-coupling reactions [21].
Recently, the functionalized dithiocarbamate ligands are utilized to prepare metal-
…
dithiocarbamate complexes with a variety of interactions such as C−H X (X= F, Cl, O, N, S).
C−H and − which leads to the formation of 1D, 2D and 3D supramolecular structure [22,
23]. In addition to these interactions, some homoleptic and heteroleptic dithiocarbamate
complexes of group 10 metal ions exhibited rare C−HM intramolecular anagostic interactions
[24-26]. These anagostic interactions (HNi distance between ≈2.3-2.9 Å) are believed to be
important for catalytic applications [27]. Our aim is to synthesize some new Ni(II) complexes
containing functionalized dithiocarbamate ligands and to study the effect of functionalization of
benzyl group in N-benzyl-N-furfuryldithiocarbamate ligand on supramolecular aggregation.
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RESULTS AND DISCUSSION
Complexes 1-12 were prepared according to the procedure given in Scheme 1.
Furfurylamine was condensed with substituted benzaldehydes (2-OH, 3-OH, 4-OH, 4-CH3O, 4-F
and 4-Cl) to form their respective imine. The imines were reduced with NaBH4 to yield the
secondary amines. The reaction of secondary amine in EtOH with carbon disulfide afforded
dithiocarbamic acid solution. Addition of NiCl2 in water to the dithiocarbamic acid solution gave
complexes 1-6. Complexes 7-12 were prepared by refluxing complexes 1-6, NiCl2, NH4SCN and
PPh3 in acetonitrile-methanol solvent mixture.
[Insert Scheme 1]
Infrared spectral studies
For complexes 1-12, C-N thioureide bands are observed in the region 1487-1514
cm-1. In the case of heteroleptic complexes 7-12, the C-N (thioureide) bands appeared at higher
wavenumbers (1499-1514 cm-1) compared to that observed in the homoleptic complexes 1-6
(1487 to 1503 cm-1) is attributed to the enhanced mesomeric drift of electron density towards the
nickel atom through S2C─N moiety from the dithiocarbamate ligand [28-32]. The C–S stretching
bands are observed around 1010 cm-1 without any splitting, supporting the bidentate coordination
of the N-furfuryl-N-substituted benzyldithiocarbamate moiety [33]. The observed stretching
band around 2090 cm-1 for the complexes 7-12 is attributed to the N-coordinated ionic NCS.
Electronic spectral studies
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The electronic spectra of bis(N-furfuryl-N-substituted benzyldithiocarbamato-
S,S)nickel(II) (1-6) show two bands in the region 450-650 nm that are typical for square planar
nickel complexes and are assigned to d-d transitions [34-39]. In these bands, the lower max band
2
2 2
(~480 nm) is assigned to dz  dx –y transition and the other high max band (~620 nm) is due to
2
2
dxy  dx –y transitions. A strong band observed in the region 475-490 nm for heteroleptic
complexes 7-12 can be attributed to the d−d electron transition for Ni(II) square planar
complexes [28-32]. Square planar geometry around the central atom in homoleptic and
heteroleptic complexes (1-12) may also be supported by electronic absorption spectra. The
occurrence
of
some
common
multiple
absorption
in
the
range
245–400 nm is mainly due to the ligand centered
 * and n * transitions
[40, 41].
NMR spectral studies
1H NMR spectral studies
1H NMR spectra of complexes 1-12 are given in Figures S 1-S 12 (Supplemental
Materials). Two singlets observed in the region 4.65-4.77 ppm for complexes 1-6 are assigned to
the methylene protons of furfuryl and substituted benzyl groups. The chemical shift values of
methylene protons of furfuryl groups are lower than that of benzyl group. This can be explained
as follows; among the resonance structures, which involve the movement of the lone pair of
electrons of oxygen within the furyl ring, the prominent structure [Scheme 2 c] must contribute
to a greater extent than the other resonance structures. Hence, a higher negative charge on C-2
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carbon of furyl ring increases the electron density on methylene of furfuryl group. This lowers
the chemical shift values of protons of methylene of furfuryl group [42].
[Insert Scheme 2]
A very broad signal observed in the region 4.40-4.76 ppm for complexes 7-12 is
due to methylene protons of benzyl and furfuryl groups. This indicates that the isothiocyanate
ligand exchange occur in solution of these complexes [43]. In the case of complexes 1-3, a
singlet observed in the region 9.55-9.95 ppm is assigned to the OH proton of the substituted
benzyl group. Hydroxyl proton signals in the complexes 7-9 merged with the aromatic proton
signals. A singlet observed around 3.80 ppm for complexes 4 and 10 is due to methyl protons of
methoxy group. The signals observed in the downfield region 6.16-7.73 ppm are due to the
aromatic protons of furyl and phenyl rings
13C NMR spectral studies
13C NMR spectra of complexes 1-12 are given in Figures S 13-S 24 (Supplemental
Materials).The thioureide carbon signals of homoleptic complexes 1-6 and heteroleptic
complexes 7-12 appear in the regions 206.7-209.7 and 205.0-206.6 ppm, respectively. The NCS2
chemical shift of dithiocarbamate is also affected by the coordination of phosphorus to nickel.
The NCS2 carbon sites of heteroleptic complexes 7-12 are shielded compared to parent
homoleptic complexes 1-6. The alleviation of excess electron density on nickel by PPh3 results in
a drift of electron density toward the nickel through the thioureide bond and hence, significant
upfield shifts are observed in heteroleptic complexes [44].
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For all the complexes, two carbon signals observed around 44.0 and 51.0 ppm are
assigned to methylene carbon of furfuryl and benzyl groups, respectively. The chemical shift
values of methylene carbons of furfuryl group are lower than that of benzyl group. This is due to
the resonance effect of the furyl ring (Scheme 2). Methyl carbon signal of methoxy group
appears around 55.0 ppm in complexes 4 and 10. In the case of complexes 1-4 and 7-10, a
carbon signal observed in the region 155.3-159.9 ppm is due to the ipso carbon of
substituted benzyl group. Two signals observed around 161.0 and 164.0 ppm for
complexes 5 and 11 are assigned to ipso carbon of substituted benzyl group. Other aromatic
carbons of N-furfuryl-N-substituted benzyldithiocarbamate and triphenylphosphine ligands are
observed in the region of 110.7-147.7 ppm.
Single crystal X-ray structural analysis of complex 11
Details of the crystal data, data collection and refinement parameters for 11 are
summarized in Table 1 and selected bond lengths and angles for 11 are listed in Table 2. ORTEP
diagram is shown in Figure 1. Single crystals of 11 were obtained by the slow evaporation of
dichloromethane: acetonitrile solution of (N-furfuryl-N-(4-fluorobenzyl)dithiocarbamato-
S,S)(thiocyanato-N)(triphenylphosphine)nickel(II).
[Insert Figure 1]
[Insert Table 1]
The structure consists of discrete molecule with each nickel atom coordinated to
two sulfur atoms from the N-furfuryl-N-(4-fluorobenzyl)dithiocarbamate, one phosphorus atom
from triphenylphosphine and one nitrogen atom from thiocyanate. The nickel atom adopts a
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distorted square planar geometry with the cis angles N2–Ni1–P1=95.70(11), S1–Ni1–
P1=91.99(4), N2–Ni1–S2=93.33(11) and S1–Ni1–S2=78.79(4) and trans angles N2–Ni–
S1=171.54(11) and P1–Ni1–S2=170.31(5) Å. The bidentate chelation by two sulfur atoms of the
dithiocarbamate ligand to nickel makes one of the cis angles [S–Ni–S=78.79(4)°] significantly
smaller than square planar (90°). Calculation of (0.12) showed that the geometry of the nickel
4
coordination polyhedron is seesaw structure [45].
The Ni–S bond lengths trans to the phosphorus and nitrogen atoms are 2.2019(11)
and 1.859(4) Å, respectively, that reflect the greater trans influence of triphenylphosphine than
thiocyanate. In this case also, the well-known delocalization of -electron density within the
NCS2 moiety of the dithiocarbamate anion is supported by the C–N and C–S bond length [C–
S=1.719(4)
Å
and
C–N=1.303(6) Å] which are significantly shorter than the single C–N bond (1.47 Å) and C–S
(1.81 Å) -bond length [46, 47]. The Ni–P (2.2019(11) Å) and Ni–N (1.859(4) Å) distances in
complex 11 are similar to Ni(II) complex with Ni(S-S)NP chromophores [28-32].
In transition metal complexes, three types of interactions are observed
(i) agostic (ii) anagostic and (iii) hydrogen bonding. Hydrogen bonds are 3c-4e interactions with
an almost linear geometry [48]. Agostic and anagostic interactions are 3c-2e interactions.
Anagostic interactions are somewhat weaker than agostic interactions. The interaction
parameters of agostic and anagostic interactions are shown in Figure S 25. X-ray structure
showed the close proximity of one of the ortho phenyl protons of the PPh3 ligand to the nickel in
complex
11
exhibiting
existence
of
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C–H∙∙∙Ni anagostic interaction (H18∙∙∙Ni = 2.804 Å and C18–H18∙∙∙Ni =119.70°)
(Figure 2).
Recently, Tiekink and Zukerman-Schpector have reported [27] that
C–H∙∙∙ (chelate) interactions play an important role in stabilizing crystal structures of metal
bis(1,1-dithiolates). The C–H∙∙∙Cg (chelate) interaction parameters are given in Figure 3. A
specific C–H∙∙∙ (chelate) interaction takes place between H9 of phenyl ring of
triphenylphosphine and Cg1(NiS2C) ring (Figure S 26, Table S 1). The packing is stabilized further
by two C-H∙∙∙ interactions between H21A and phenyl ring (C22–C27) of dithiocarbamate
resulting in dimer (Figure S 27). ∙∙∙ interaction are also observed (Figure S 28). Intra- and
intermolecular C–H∙∙∙S interactions are also observed in crystal structure of complex 11 (Figure
S 29). Additionally, the most recognizable feature of the crystal packing in the formation of
layers by C–H∙∙∙F hydrogen bonding (Figure S 30).
Conclusions
Bis(N-furfuryl-N-substituted
benzyldithiocarbamato-S,S)nickel(II)
and
(N-furfuryl-N-substituted benzyldithiocarbamato-S,S)(thiocyanato-N)(triphenylphosphine)- nickel(II)
complexes were prepared and characterized by IR, UV-Vis and NMR spectroscopy.
Interestingly, various interactions such as anagostic, C–H∙∙∙ (chelate) and C–H∙∙∙ interactions
are observed. In addition, due to the presence of fluorine in phenyl ring of dithiocarbamate
ligand
in
(N-furfuryl-N-(4-fluorobenzyl)dithiocarbamato-S,S)(thiocyanato-
N)(triphenylphosphine)nickel(II), C–H∙∙∙F interaction is observed. This confirms that the
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functionalisation of N-bound organic moiety in dithiocarbamate ligand might increase the
intermolecular interactions.
EXPERIMENTAL
Materials and instrumentation
All reagents and solvents were purchased from commercial sources (Merck/sd
Fine/Himedia) and used without further purification. Elemental analysis was performed in a
varioMICRO V2.2.0 apparatus. Infrared spectra were recorded with a Thermo Nicolet 200 FT-IR
1
spectrometer using (range 400-4000 cm-1) the KBr press technique for sample preparation. H
and 13C NMR spectra were recorded on Bruker 400 MHz spectrometer, using DMSO-d6 and
CDCl3 as solvents. In 1H and 13C NMR runs the chemical shifts are referenced to the signal of the
internal tetramethylsilane (TMS) and tetramethylsilane (TMS) as an internal standard.
SHIMADZU UV-1650 PC double beam UV-visible spectrophotometer was used for
recording the electronic spectra of the complexes. The spectra were recorded in
acetonitrile, chloroform and the pure solvents were used as the reference.
X-ray diffraction analysis
A suitable crystal of complex 11 was selected for data collection which was
performed on a Xcalibur, Sapphire3 diffractometer equipped with a graphite-monochromatic
Mo-Kα radiation at 100(2) K. The structure was solved by direct methods using SHELXS-97
[49] and refined by full-matrix least-squares methods on F2 using SHELXL-97 [49] from within
the WINGX suite of software.
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Preparation of complexes
Preparation of bis(N-furfuryl-N-substituted benzyldithiocarbamato-S,S)nickel(II)
Furfurylamine (4.6 mmol, 0.5 mL) and substituted benzaldehyde (2-OH, 3-OH, 4-
OH, 4-OCH3, 4-F and 4-Cl) (5.1 mmol, 0.4 mL) were dissolved in methanol (30 mL). The
solution was stirred well for 2 h and the methanol was then removed by evaporation. Yellow oily
product was obtained. The product was dissolved in 1:1 methanol-dichloromethane solvent
mixture (20 mL) and sodium borohydride (13.8 mmol, 0.5 g) was added. The reaction mixture
was stirred at 5 °C for 2 h and at room temperature for 20 h. The viscous liquid was obtained on
evaporation of the solvent. The viscous liquid was washed with water and CH2Cl2 was added in
order to extract the product. After evaporation of the organic layer, N-furfuryl-N-substituted
benzylamine was obtained as yellow oil. Carbon disulfide (4.0 mmol) was added dropwise to a
ethanolic solution of N-furfuryl-N-substituted benzylamine (4.0 mmol) and the solution was
stirred
for
30
min
under
the
ice
cold
condition.
The
yellow
N-furfuryl-N-substituted benzyldithiocarbamic acid solution was obtained. Complexes
1-6 were prepared by mixing NiCl26H2O (2.0 mmol) in water and N-furfuryl-N-substituted
benzyldithiocarbamic acid in ethanol. The addition of metal ion into the yellow dithiocarbamic
acid solution resulted in the formation of green precipitate immediately. After stirring for 30 min,
the green precipitate was filtered off, washed with cold water and dried.
Preparation of (N-furfuryl-N-substituted benzyldithiocarbamato-S,S)- (thiocyanato-
N)(triphenylphosphine)nickel(II)
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Bis(N-furfuryl-N-substituted benzyldithiocarbamato-S,S)nickel(II) (1.0 mmol) was
dissolved in acetonitrile-methanol solvent mixture (1:1, 50 mL). To this solution, PPh3 (2.0
mmol), NiCl26H2O (1.0 mmol) and NH4SCN (2.0 mmol) were added. The reaction mixture was
refluxed for 3 h. Then the solution was filtered and the filtrate was left to stand at room
temperature for 5 d. The purple red solid product was obtained. It was filtered off and dried
(Scheme 1).
1)
Bis(N-furfuryl-N-(2-hydroxybenzyl)dithiocarbamato-S,S)nickel(II) (1)
Yield 74%, mp 216-219 C. IR (KBr, cm–1):  = 3464 (OH); 1503 (C–N); 1016 (C–
S).
UV-Vis
(CH3CN,
nm):

=
625,
481,
4.7 (s, 4H, (furyl)–CH2–N);
6.40-7.66 (aromatic protons);
395,
336,
303,
258.
1H NMR (400 MHz, DMSO, ppm):
4.76 (s, 4H, 2HO–C6H4–CH2–N);
=
9.90 (s, 2H, 2HO–C6H4–CH2–N); 13C NMR (100 MHz, DMSO, ppm):
 =44.7 (furyl–CH2–N); 47.1 (2HO–C6H4–CH2–N); ipso carbon; 155.3 (Ar-2OH); 110.7, 110.8,
115.3, 119.2, 120.0, 128.9, 129.2, 143.6, 147.5 (other aromatic carbons region); 206.9 (NCS2).
Anal. Calcd. C26H24N2NiO4S4 (%): C, 50.74; H, 3.93; N, 4.55;. Found: C, 50.56; H, 3.92; N, 4.49;
2)
Bis(N-furfuryl-N-(3-hydroxybenzyl)dithiocarbamato-S,S)nickel(II) (2)
Yield 75%, mp 212-214 C. IR (KBr, cm–1):

=
3385 (OH);
1487 (C–N); 1001 (C–S). UV-Vis (CH3CN, nm):  =625, 487, 396, 341, 306, 275.
1H NMR (400 MHz, DMSO, ppm):
=
4.68, 4.69 (s, 4H, (furyl)–CH2–N),
(br, 4H, 3HO–C6H4–CH2–N); 6.44-7.66 (aromatic protons); 9.59 (s, 2H, 3HO–C6H4–CH2–N);
13C
NMR
(100
MHz,
DMSO,
ppm):

=44.4
(furyl–CH2–N);
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51.4 (3HO–C6H4–CH2–N); ipso carbon; 157.7 (Ar-3OH); 110.8, 110.0, 114.4, 115.1, 118.4,
129.9, 135.2, 143.7, 147.1 (other aromatic carbons region); 207.1 (NCS2).
Anal.
Calcd.
C26H24N2NiO4S4
(%):
C, 50.74; H, 3.93; N, 4.55. Found:. C, 50.24; H, 3.83; N, 4.44;
3)
Bis(N-furfuryl-N-(4-hydroxybenzyl)dithiocarbamato-S,S)nickel(II) (3)
Yield 77%, mp 188-190 C. IR (KBr, cm–1):

=
3348 (OH);
1497 (C–N); 1011 (C–S). UV-Vis (CH3CN, nm):  =621, 483, 394, 327, 274, 248.
1H
NMR
(s,
(400
4H,
MHz,
DMSO,
ppm):
=4.61
(s,
4H,
(furyl)–CH2–N);
protons);
4.66
4HO–C6H4–CH2–N);
6.40-7.61
(aromatic
9.82 (s, 2H,4HO–C6H4–CH2–N); 13C NMR (100 MHz, DMSO, ppm):  =44.0
(furyl–CH2–N); 51.2 (4HO–C6H4–CH2–N); ipso carbon; 157.4 (Ar-4OH); 110.8, 111.9, 115.6,
123.9,
129.8,
130.0,
143.7,
147.2
(other
aromatic
carbons
region);
206.4 (NCS2); Anal. Calcd. (%): C, 50.74; H, 3.93; N, 4.55;. Found: C, 50.76; H, 3.79; N, 4.55;
4)
Bis(N-furfuryl-N-(4-methoxybenzyl)dithiocarbamato-S,S)nickel(II) (4)
Yield 69%, mp 212-215 C. IR (KBr, cm–1):  = 1497 (C–N); 1018 (C–S);. UV-Vis
(CHCl3, nm):  =627, 484, 391, 357, 252. 1H NMR (400 MHz, CDCl3, ppm):

=
4.69, 4.70 (s, 4H, (furyl)–CH2–N) (s, 4H, 4CH3O–C6H4–CH2–N);
(aromatic protons); 3.76 (s, 3H,4CH3O–C6H4–CH2–N);
6.45-7.68
13C NMR (100 MHz, CDCl3, ppm):  = 44.2 (furyl–CH2–N); 51.8 (4CH3O–C6H4–CH2–N); 55.1
(4CH3O–C6H4–CH2–N); ipso carbon; 159.0 (Ar-4OCH3); 110.8, 110.9, 114.7, 125.7, 129.5,
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143.6, 147.1 (other aromatic carbons region); 206.7 (NCS2). Anal. Calcd. C28H28N2NiO4S4 (%): C,
52.26; H, 4.39; N, 4.35;. Found: C, 51.97; H, 4.14; N, 4.38.
5)
Bis(N-furfuryl-N-(4-fluorobenzyl)dithiocarbamato-S,S)nickel(II) (5)
Yield 68%, mp 176-179 C. IR (KBr, cm–1):  = 1495 (C–N); 1018 (C–S). UV-Vis
(CHCl3, nm):  =634, 494, 398, 350, 259. 1H NMR (400 MHz, CDCl3, ppm):
 = 4.65 (s, 4H, (furyl)–CH2–N); 4.77 (s, 4H, 4F–C6H4–CH2–N); 6.35-7.39 (aromatic protons);
13C
NMR
(100
MHz,
CDCl3,
ppm):

=
43.4
(furyl–CH2–N);
50.6 (4F–C6H4–CH2–N); ipso carbon; 161.4, 163.9 (Ar-4F); 110.8, 110.9, 115.8, 116.0, 129.7,
130.3, 130.4, 143.2, 147.4 (other aromatic carbons region); 209.5 (NCS2) Anal. Calcd.
C26H22FN2NiO2S4
(%):
C, 50.41; H, 3.58; N, 4.52; Found: C, 50.23; H, 3.48; N, 4.35.
6)
Bis(N-furfuryl-N-(4-chlorobenzyl)dithiocarbamato-S,S)nickel(II) (6)
Yield 69%, mp 208-210 C. IR (KBr, cm–1):  = 1489 (C–N); 1015 (C–S). UV-Vis
(CHCl3, nm):  = 623, 394, 344, 333, 321, 260. 1H NMR (400 MHz, CDCl3, ppm):  = 4.65 (s, 4H,
13
(furyl)–CH2–N); 4.77 (s, 4H, 4Cl–C6H4–CH2–N); 6.36-7.40 (aromatic protons); C NMR (100
MHz,
CDCl3,
ppm):

=
43.6
(furyl–CH2–N);
50.7 (4Cl–C6H4–CH2–N); 110.8, 111.0, 129.2, 129.8, 132.4, 134.3, 143.2, 147.2 (aromatic
carbons region); 209.7 (NCS2). Anal. Calcd. C26H22Cl2N2NiO2S4 (%): C, 47.87; H, 3.40; N, 4.29;
Found: C, 47.52; H, 3.44; N, 4.19;
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7)
(N-furfuryl-N-(2-hydroxybenzyl)dithiocarbamato-S,S)(thiocyanato-
N)(triphenylphosphine)nickel(II) (7)
Yield 75%, mp 196-199 C. IR (KBr, cm–1):

=3395 (OH);
2112 ((NCS)); 1503 (C–N); 1016 (C–S). UV-Vis (CH3CN, nm):  = 478, 325, 247.
1H NMR (400 MHz, DMSO, ppm):

=
4.41-4.64 (b, 2H, (furyl)–CH2–N)
13
(2H, 2HO–C6H4–CH2–N); 6.18-7.61 (aromatic protons); C NMR (100 MHz, DMSO, ppm): 
= 43.1 (furyl–CH2–N); ipso carbon; 157.0 (Ar-2OH); 110.8, 116.1, 128.8, 130.3, 131.6, 132.2,
134.0, 143.3 (other aromatic carbons region); Anal. Calcd. C32H27N2NiO2PS3 (%):
C, 58.46; H, 4.14; N, 4.26;. Found: C, 58.01; H, 4.10; N, 4.23.
8)
(N-furfuryl-N-(3-hydroxybenzyl)dithiocarbamato-S,S)(thiocyanato-
N)(triphenylphosphine)nickel(II) (8)
Yield 76%, mp-175-176 C. IR (KBr, cm–1):

=3424 (OH);
2087 ((NCS); 1508 (C–N); 1011 (C–S). UV-Vis (CH3CN, nm):  = 487, 328, 273.
1H NMR (400 MHz, DMSO, ppm): =4.48, 4.55 (b, 2H, (furyl)–CH2–N)
(b, 2H, 3HO–C6H4–CH2–N); 6.18-7.69 (aromatic protons); 5.29 (s, 1H,4HO–C6H4–CH2–N); 13C NMR
(100 MHz, DMSO, ppm):  =43.5 (furyl–CH2–N); 51.5 (3HO–C6H4–CH2–N); ipso carbon;157.6
(Ar-3OH); 110.8, 111.4, 116.1, 119.63, 128.0, 128.5, 128.6, 128.7, 128.8, 128.9, 130.1, 131.2,
131.6, 132.1,132.2, 132.3, 134.1, 134.1, 134.2, 143.4, 146.8 (other aromatic carbons region);
205.6 (NCS2); Anal. Calcd. C32H27N2NiO2PS3 (%):C, 58.46; H, 4.14; N, 4.26;. Found: C, 58.49;
H, 4.07; N, 4.27.
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9)
(N-furfuryl-N-(4-hydroxybenzyl)dithiocarbamato-S,S)(thiocyanato-
N)(triphenylphosphine)nickel(II) (9)
Yield 74%, mp 180-182C. IR (KBr, cm–1):

=
3337 (OH);
2102 ((NCS)); 1514 (C–N); 1013 (C–S). UV-Vis (CH3CN, nm):  = 476, 325, 245.
1H NMR (400 MHz, CDCl3, ppm):
(b, 2H,4HO–C6H4–CH2–N); 6.16-7.72 (aromatic protons); 13C NMR (100 MHz, CDCl3, ppm): 
=
4.40-4.70 (2H, (furyl)–CH2–N)
=
43.0
(furyl–CH2–N);
50.9,
51.5
(4HO–C6H4–CH2–N);
ipso carbon; 157.0, 157.4 (Ar-4OH); 110.7, 111.1, 116.1, 116.2, 124.8, 127.9, 128.3, 128.5,
128.6, 128.9, 129.0, 129.2, 130.2, 131.2, 131.6, 132.2, 132.4, 132.5, 1333.1, 134.1, 134.2, 143.0,
143.3,
Anal.
147.7
(other
Calcd.
aromatic
carbons
region);
205.0
(NCS2);
C32H27N2NiO2PS3
(%):
C, 58.46; H, 4.14; N, 4.26;. Found: C, 58.10; H, 4.12; N, 4.19;
10)
(N-furfuryl-N-(4-methoxybenzyl)dithiocarbamato-S,S)-(thiocyanato-
N)(triphenylphosphine)nickel(II) (10)
Yield 70%, mp -171-173C. IR (KBr, cm–1):
1499 (C–N); 1013 (C–S). UV-Vis (CHCl3, nm):

=2083 ((NCS));

=
487, 331, 272.
1H NMR (400 MHz, CDCl3, ppm): =4.56 (2H, (furyl)–CH2–N) (b, 2H,4CH3O–C6H4–CH2–N); 6.35-7.64
(aromatic protons); 3.82 (s, 3H,4CH3O–C6H4–CH2–N);
13C NMR (100 MHz, CDCl3, ppm):  = 43.2 (furyl–CH2–N); 51.1 (4CH3O–C6H4–CH2–N); 55.4
(4CH3O–C6H4–CH2–N); ipso carbon;159.9 (Ar-4OCH3); 110.8, 111.3, 114.5, 124.9, 128.5,
128.6, 128.8, 130.3, 130.4, 130.7, 131.6, 132.1, 132.2, 132.3, 133.0, 133.3, 134.1, 143.4, 146.8
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(other
aromatic
carbons
region)
;
205.4
(NCS2);
Anal. Calcd. C33H29N2NiO2PS3 (%): C, 59.03; H, 4.35; N, 4.17;. Found: C, 58.85; H, 4.22; N,
4.00;
11)
(N-furfuryl-N-(4-fluorobenzyl)dithiocarbamato-S,S)-(thiocyanato-
N)(triphenylphosphine)nickel(II) (11)
Yield 69%, mp 188-191C. IR (KBr, cm–1):
1510 (C–N); 1013 (C–S). UV-Vis (CHCl3, nm):

=2093 ((NCS));

=
487, 331, 268.
1H NMR (400 MHz, CDCl3, ppm): =4.43, 4.56 (bd, 2H, (furyl)–CH2–N);
4.61, 4.72 (bd, 2H, 4F–C6H4–CH2–N); 6.16-7.73 (aromatic protons);
13C NMR (100 MHz, CDCl3, ppm):  =43.3, 43.7 (furyl–CH2–N); 50.5, 51.1
(4F–C6H4–CH2–N); ipso carbon; 161.6, 164.0 (Ar-4F); 110.8, 111.2, 111.6, 116.0, 116.2, 127.9,
128.4, 128.4, 128.8, 128.9,130.4,130.7,131.2, 134.1, 134.2, 143.4, 144.1, 146.7 (other aromatic
carbons region); 206.3 (NCS2); Anal. Calcd. C32H26FN2NiOPS3 (%): C, 58.28; H, 3.97; N, 4.25;.
Found: C, 58.03; H, 3.81; N, 4.11;
12)
(N-furfuryl-N-(4-chlorobenzyl)dithiocarbamato-S,S)-(thiocyanato-
N)(triphenylphosphine)nickel(II) (12)
Yield 71%, mp 178-180C. IR (KBr, cm–1):
1503 (C–N); 1011 (C–S). UV-Vis (CHCl3, nm):

=
2091 ((NCS));

=
486, 335, 273.
1H NMR (400 MHz, CDCl3, ppm): =4.52, 4.76 (bd, 2H, (furyl)–CH2–N)
(bd, 2H,2HO–C6H4–CH2–N); 6.34-7.66 (aromatic protons); 13C NMR (100 MHz, CDCl3, ppm):  = 43.6
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(furyl–CH2–N); 50.9 (4Cl–C6H4–CH2–N); 110.9, 111.5, 128.5, 128.6,128.7,129.3,129.6,130.0,
131.6, 131.7, 132.0, 132.1, 132.2, 132.3, 132.4, 138.8, 134.0, 134.3, 134.7, 143.4, 143.5, 146.5
(aromatic
carbons
region);
206.3
(NCS2);
Anal. Calcd. C32H26ClN2NiOPS3 (%):C, 56.87; H, 3.88; N, 4.14; Found: C, 56.29; H, 3.76; N,
4.06.
Supplementary material
CCDC 1037957 contains the supplementary crystallographic data for complex 11.
These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/ retrieving. html,
or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK;
fax: (+44) 1223 336 033; or e-mail: deposit@ccdc.cam.ac.uk.
Acknowledgement
E. Sathiyaraj gratefully acknowledges the University Grants Commission (UGC), India,
for the award of Basic Sciences Research (BSR)-Special Assistant Programme (SAP)
Fellowship.
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References
1.
2.
3.
4.
Heard, P.J.; Prog. Inorg. Chem., 2005, 53, 71–561.
Fujii, S.; Yoshimura, T.; Coord. Chem. Rev., 2000, 198, 89-99.
Cox, M.J.; Tiekink, E.R.T.; Rev. Inorg. Chem., 1997, 17, 1-23.
Bouvet, D.; Michalowicz, A.; Crauste-Manciet, S.; Brossard, D.; Provost, K.; Inorg.
Chem., 2006, 45, 3393-3398.
5.
6.
7.
Ronconi, L.; Giovagnini, L.; Marzano, C.; Bettio, F.; Graziani, R.; Pilloni, G.; Fregona,
D.; Inorg. Chem., 2005, 44, 1867-1881.
Marzano, C.; Ronconi, L.; Chiara, F.; Giron, M.C.; Faustinelli, I.; Cristofori, P.; Trevisan,
A.; Fregona, D.; Int. J. Cancer., 2011, 129, 487-496.
Chatterjee, D.; Moulik, S.K.; Giribabu, L.; Kanaparthi, R., Transition Met. Chem., 2014,
39, 641-646.
8.
R.S Graniger; P. Innocenti; Heteroat.Chem, 2007, 18, 568–571.
Sathiyaraj, E.; Thirumaran, S.; Spectrochim. Acta A, 2012, 97, 575-581.
Regulacio, M.D.; Tomson, N.; Stoll, S.L.; Chem. Mater., 2005, 17, 3114-3121.
Srinivasan, N.; Thirumaran, S.; Superlattices and Microstruct., 2012, 51, 912-920.
Ramasamy, K.; Malik, M.A.; O’Brien, P.; Raftery, J.; Dalton Trans., 2010, 39, 1460-
1463.
9.
10.
11.
12.
13.
14.
Arul Prakasam, B.; Lahtinen, M.; Peuronen, A.; Muruganandham, M.; Kolehmainen, E.;
Haapaniemi, E.; Sillanpaa, M., Polyhedron, 2014, 81, 588–596.
Chauhan, R.; Trivedi, M.; Singh, J.; Molloy, K.C.; Kociok-Kohn, G.; Mulik U.P.;.
Amalnerkar, D.P; Kumar, A.; Inorg. Chim. Acta., 2014, 415 , 69-74.
19
ACCEPTED MANUSCRIPT

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15.
16.
O’Brien, P.; Waters, J.; Chem. Vap. Deposition, 2006, 12, 620–626.
D. C. Onwudiwe; P. A. Ajibade, Int. J. Mol. Sci. 2011, 12, 5538-5551.
17.
18.
19.
Yan, Y.; Krishnakumar, S.; Yu, H.; Ramishetti, S.; Deng, L.W.; Wang, S., Huang, L.;
Huang, D., J. Am. Chem. Soc. 2013, 135, 5312-5315.
Ferreira I.P.; de Lima, G.M.; Paniago, E.B.; Takahashi J.A.; Krambrock, K.; Pinheiro,
C.B.; Wardell, J.L.; Visentin, L.C.; J. Mol. Struct., 2013, 1048, 357–366.
Travnicek, Z.; Pastorek, R.; Starha, P.; Popa, I.; Slovak, V., Z. Anorg, Allg. Chem., 2010,
636, 1557-1565.
20.
21.
22.
Cheng, R.; Xiang, B.; Li, Y.; J. Appl. Polym. Sci., 2012, 123, 2439-2444.
Tasker, S.Z.; Standley, E.A.; Jamison, T.F.; Nature, 2014, 509, 299-309.
Oliver, K.; White, A.J.P.; Hogarth, G.; Wilton-Ely J.D.E.T., Dalton Trans., 2011, 40,
5852–5864.
23.
24.
Tiekink, E.R.T.; Schpector, J.-Z.; Chem. Commun., 2011, 47, 6623-6625.
Brookhart, M.; Green, M.L.H; Parkin, G.; Proc. Natl. Acad. Sci. U.S.A, 2007, 104, 6909–
6914.
25.
26.
Singh, S.K.; Drew, M.G.B.; Singh, N., CrystEngComm, 2013, 15, 10255-10265.
Yadav, M. K.; Rajput, G.; Prasad, L.B.; Drewb M.G.B.; Singh, N.; New J. Chem., 2015,
39, 5493-5499.
27.
H.V. Huynh, L.R. Wong, P. Shuyi Ng, Organometallics, 2008, 27, 2231–2237.
20
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
28.
29.
30.
Valarmathi, P.; Thirumaran, S.; Sarmal L. P.; Kant, R., Spectrochim. Acta, Part A, 2014,
129, 285-292.
Jamuna Rani, P.; Thirumaran S.; S. Ciattini, Phosphorus Sulfur Silicon Relat. Elem.,
2013, 188, 778.
Baskaran, R.; Ramalingam, K.; Bocelli, G.; A. Cantoni; Rizzoli, C., J. Coord. Chem., 2008,
61, 1710-1719.
31.
32.
Srinivasan, S.; Ramalingam K.; C. Rizzoli, Polyhedron, 2012, 33, 60-66.
Arul Prakasam, B.; Lahtinen, M.; Peuronen, A.; Muruganandham, M.; Kolehmainen, E.;
Haapaniemi E.; Sillanpaa, M.; Polyhedron, 2014, 81, 588-596.
33.
34.
Bonati , F.; Ugo, R.; J. Organomet. Chem., 1967, 10, 257-268.
Kumar A.; Chauhan R.; Molly K.C.; Kociok-kohn G.; Bahadur, L; Singh, N.; Chem. Eur.
J., 2010, 16, 4307- 4314.
35.
36.
37.
Bajia, S.C; Mishra, A.; J. Coord. Chem., 2011, 64, 2727-2734.
Pan S.; Wang, Y.; Chin. J. Chem., 2001, 19, 856-859.
Anastasiadis C.; Hogarth G.; Wilton-Ely, J.D.E.T.; Inorg. Chim. Acta, 2010, 363,
3222-3228.
38.
Husain, A.; Nami, S.A.A.; Singh, S.P.; Oves, M; Siddiqi, K.S., Polyhedron, 2011, 30, 33-
40.
21
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
39.
40.
41.
Juhari, W.N.S.W.; Baba, I.; Farina Y; S.W. Ng; Acta Crystallogr. E, 2010, 66, m339.
Manav, N.; Mishra A.K.; Kaushik, N.K.; Spectrochim. Acta A, 2006, 65, 32-35.
Thirumaran, S.; Ramalingam, K.; Transition Met. Chem., 2000, 25, 60-62.
42.
Rajeswari, K.; Pandiarajan, K.; Spectrochim. Acta A, 2011, 78, 1110-1118.
Fackler Jr J.P.; Lin I.J.B.; Andrews, J. Inorg. Chem., 1977, 16, 450–457.
43.
44.
Arul Prakasam, B.; Ramalingam K.; Bocelli G.; Olla, R.Z.; Z. Anorg. Allg. Chem., 2004,
630, 301-304.
45.
46.
47.
Yang, L.; Powell, D.R.; Houser, R.P.; Dalton Trans., 2007, 955-964.
Heard, P.J.; Prog. Inorg. Chem., 2005, 53, 1–69.
Lide (Ed.), D.R., Handbook of Chemistry and Physics, 73rd Edn., CRC, Boca Raton, FA,
1992.
48.
49.
G.
Rajput,
V.
Singh,
A.N.
Gupta,
M.K.
Yadav,
V.
Kumar,
S.K. Singh, A. Prashad, M.G.B. Drew and N. Singh, CrystEngComm., 2013, 15, 4676.
Sheldrick, G.M., Acta Crystallograllogr. A, 2008, 64, 112–122.
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Table 1: Crystal Structure and Data Refinement Parameters for complex 11
Complex
11
C32H26FN2NiOPS3
659.41
Empirical Formula
Formula Weight
Crystal System / Space Group Triclinic/ Pī
a / Å
9.995(1)
b / Å
12.326(1)
13.498(1)
94.891(4)
104.532(3)
109.617(4)
1489.9(2)
2
c / Å
 / °
β / °
γ / °
V / Å3
Z
D calc (g/cm3)
μ (mm-1)
1.470
0.951
Crystal size (mm)
Color / Shape
Temp (K)
0.40  0.35  0.30
dark red/ prismatic
100(2)
Theta range for collection
Reflections collected
Independent reflections
Data/restraints/parameters
Goodness of fit on F2
Final R indices [I > 2σ(I)]
R indices (all data)
Largest difference peak/hole
4.13-28.71
18659
4816
6693/0/370
1.050
0.0894, 0.1834
0.0611, 0.1590
2.433, -0.552
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Table 2.
Selected Bond distances (Å) and angles () for complex 11
11
Bond distances (Å)
Ni1-N2
Ni1-S1
Ni1-P1
Ni1-S2
1.859(4)
2.1801(12)
2.2019(11)
2.2212(11)
1.731(4)
S1-C20
S2-C20
1.708(4)
S3-C19
1.637(5)
N1-C20
1.303(6)
N2-C19
1.154(6)
Bond angles ()
N2-Ni1-S1
N2-Ni1-P1
S1-Ni1-P1
N2-Ni1-S2
S1-Ni1-S2
P1-Ni1-S2
C20-S1-Ni1
C20-S2-Ni1
C19-N2-Ni1
N2-C19-S3
N1-C20-S2
N1-C20-S1
S2-C20-S1
171.54(11)
95.70(11)
91.99(4)
93.33(11)
78.79(4)
170.31(5)
86.66(15)
85.91(14)
173.0(4)
177.8(4)
126.0(3)
125.3(3)
108.6(2)
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Scheme 1.Preparation of homoleptic and heteroleptic nickel(II) complexes 1-12
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Scheme 2. Resonance structures of N-furfuryl-N-substituted benzyl dithiocarbamate anion
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Figure 1.ORTEP of complex 11
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Figure 2.Intramolecular C–H…Ni anagostic interaction in complex 11
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Figure 3.The parameters for C–H∙∙∙Cg (chelate) interactions: d1=2.4-3.6 Å, α<20° and β=110-
180°.
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