A seven membered chelate ring complex of Mn(II) derived from bis(5-phenyl-2H-1,2,4-triazole)-3-yl-disulfane and cleavage of the S-S bond in a Co(II) complex: Synthesis, spectral and structural characterization

Article abstract of DOI:10.1016/j.poly.2011.03.050

The reaction of Mn(OAc)₂.4H₂O with bis(5-phenyl-2H-1,2,4-triazole)-3-yl-disulfane (H₂ptds.2H ₂O) (1) yielded new complex [Mn(ptds)(o-phen)₂] (2). It is observed that under similar conditions the react

Full text of DOI:10.1016/j.poly.2011.03.050

Polyhedron 30 (2011) 1927–1934
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Polyhedron
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A seven membered chelate ring complex of Mn(II) derived from
bis(5-phenyl-2H-1,2,4-triazole)-3-yl-disulfane and cleavage of the S–S bond
in a Co(II) complex: Synthesis, spectral and structural characterization
A. Singh a, M.K. Bharty a, S.K. Kushawaha a, R.J. Butcher b, N.K. Singh a,
⇑
a Department of Chemistry, Banaras Hindu University, Varanasi 221 005, India
b Department of Chemistry, Howard University, 525 College Street NW, Washington, DC 20059, USA
a r t i c l e i n f o
a b s t r a c t
Article history:
The reaction of Mn(OAc)2ꢀ4H2O with bis(5-phenyl-2H-1,2,4-triazole)-3-yl-disulfane (H2ptdsꢀ2H2O) (1)
yielded new complex [Mn(ptds)(o-phen)2] (2). It is observed that under similar conditions the reaction
of Co(OAc)2 with H2ptdsꢀ2H2O (1) leads to thermolysis of the S–S bond of the disulfane to yield
[Co(pts)(o-phen)2]ꢀH2Oꢀ0.5C2H5OH, with the newly generated organic ligand 5-phenyl-2H-1,2,4-tria-
zole-3-sulfinate, (pts)2ꢁ. The ligand H2ptdsꢀ2H2O (1), [Mn(ptds)(o-phen)2] (2) and [Co(pts)(o-phen)2]ꢀ
H2Oꢀ0.5C2H5OH (3) crystallized into monoclinic, trigonal and triclinic crystal systems, respectively. The
triazole ring nitrogen of the bidentate ligand chelates the Mn(II) center forming a seven membered
chelate ring, while N, O donor sites of the resulting triazole sulfinate bond Co(II) to form a five membered
chelate. The resulting complexes are paramagnetic and have a distorted octahedral geometry.
Ó 2011 Elsevier Ltd. All rights reserved.
Received 4 January 2011
Accepted 18 March 2011
Available online 19 May 2011
Keywords:
Seven membered chelate ring
Triazole complexes
Thermolysis
Mn(II) and Co(II) complexes
Mixed ligand complexes
o-Phenanthroline
1. Introduction
different thermolysis conditions with different metal salts, H2ptds
may undergo either S–S bond cleavage or C–S bond scission [17,18]
1,2,4-Triazoles and their derivatives represent an interesting
class of heterocyclic compounds possessing a wide spectrum of
biological activities. A large number of 1,2,4-triazoles are known
to exhibit bactericidal, fungicidal, antitubercular, analgesic, anti-
inflammatory, antitumor, anticonvulsant, antiviral, insecticidal,
antidepressant and central nervous system (CNS) activities [1–
11]. Derivatives of 1,2,4-triazole were synthesized by intramolecu-
lar cyclization of substituted thiosemicarbazides [12]. A series of
alkyl/aryl-2,4-dihydro-5-(2-furyl)-3H-1,2,4-triazole-3-thione have
been reported [13] and the thione form was proposed as the most
stable form in the solid state. The disulfanes behave as bidentate
N-donor ligands, although the sulfur atom has additional reactivity
[14]. Metal–ligand reactions under thermolysis conditions offer a
promising technique for the design and syntheses of novel coordi-
nation architectures, especially for those that are inaccessible by
direct preparations. In recent years, organic disulfide compounds
such as 4,40-dipyridinedisulfine, 2,20-dipyridinedisulfine and
bis((4-pyridin-2-yl)pyrimidin-2-yl) disulfane have received
increasing attention since they are capable of displaying different
reactions in various circumstances, giving rise to metal organic
frameworks with fascinating structures [15,16]. Likewise, under
to produce complexes of a newly generated ligand. Additionally
even in normal solution reactions, extrusion or insertion of one sul-
fur atom may take place [19]. Irrespective of increasing research
enthusiasm on the reactions of organic disulfide compounds with
metal ions, the ambiguous reactivity of disulfides in the presence
of different metal ions, to the best of our knowledge, is rarely no-
ticed. Herein, we report our results on the reactivity of a newly
synthesized ligand, bis(5-phenyl-2H-1,2,4-triazole)-3-yl-disulfane
(H2ptds)ꢀ2H2O, its Mn(II) complex and the Co(II) complex of the
thermolytic product, containing o-phen as a coligand.
2. Experimental
2.1. Materials and methods
Commercial reagents were used without further purification
and all experiments were carried out in the open atmosphere. Thi-
osemicarbazide, benzoyl chloride (SD Fine Chemicals, India) and
NaOH (Qualigens, India) were used as received. All the solvents
were purchased from Qualigens Chemicals, India and used after
purification.
2.2. Preparation of 1-(2-phenyl)-3-thiosemicarbazide
⇑
Corresponding author. Tel.: +91 542 6702452.
E-mail addresses: mkbharty@bhu.ac.in (M.K. Bharty), singhnk_bhu@yahoo.com,
Thiosemicarbazide (2.73 g, 20 mmol) was dissolved in aqueous
sodium hydroxide (10%, 20 ml) and the resulting solution was
nksingh@bhu.ac.in (N.K. Singh).
0277-5387/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2011.03.050

1928
A. Singh et al. / Polyhedron 30 (2011) 1927–1934
filtered off. Benzoyl chloride (4.0 ml) was added dropwise to the
above solution, shaken continuously for 15 min, cooled in ice and
acidified with dil. HCl. A white precipitate was obtained which
was filtered, washed with water and air dried. Yield 87% ; m.p.
440 K.
whereupon it changed into a clear solution which was filtered and
kept for crystallization. After slow evaporation of the solution for
10 days, yellow crystals of 2 suitable for X-ray analyses were ob-
tained. Yield 55%; m.p. 573 K. Anal.
(765.79): C, 62.73; H, 3.42; N, 18.28; S, 8.37. Found: C, 62.55; H,
3.50; N, 18.36; S, 8.30%. IR ( (C@N) 1578s; (N–N)
/cmꢁ1, KBr):
1098; (C–S) 982. UV–Vis (kmax, Nujol mull, nm): 450, 427, 362,
Calc. for C40H26MnN10S2
m
m
m
m
2.3. Synthesis of bis(5-phenyl-2H-1,2,4-triazole)-3-yl-disulfane
(H2ptdsꢀ2H2O) (1)
339, 306, 271.
Bis(5-phenyl-2H-1,2,4-triazole)-3-yl-disulfane was synthesized
by dissolving the freshly prepared 1-(2-phenyl)-3-thiosemicarba-
zide (3.9 g, 20 mmol) in aqueous NaOH (10%, 10 ml) and refluxing
the solution for 2–3 h until it turned green due to evolution of H2S
gas. The solution was cooled in ice and acidified with conc. HCl. The
white precipitate so obtained was filtered, washed with water, air
dried and crystallized from ethanol. Yield 70%; m.p. 538 K. Anal.
Calc. for C16H16N6S2O2 (388.46): C, 49.46; H, 4.11; N, 21.62; S,
2.5. Preparation of [Co(pts)(o-phen)2]ꢀH2Oꢀ0.5C2H5OH (3)
A methanolic solution of Co(OAc)2 (0.178 g, 1 mmol) was added
to a methanol solution of bis(5-phenyl-2H-1,2,4-triazole)-3-yl-
disulfane (0.384 g, 1 mmol) with continuous stirring for 30 min.
The resulting green color precipitate was filtered and washed with
ethanol and air dried. The precipitate was suspended in methanol
and refluxed with a methanolic solution of o-phen (0.400 g,
2 mmol). The suspension changed to a reddish-brown clear solu-
tion which was filtered and kept for crystallization. Orange crystals
of 3 suitable for X-ray analyses were obtained by slow evaporation
of its MeOH solution over a period of 14 days. Yield 60%; m.p.
579 K. Anal. Calc. for C66H52Co2N14O7S2 (1335.20): C, 59.31; H,
3.89; N, 14.67; S, 4.79. Found: C, 59.25; H, 4.00; N, 14.75; S,
16.50. Found: C, 49.50; H, 4.05; N, 21.55; S, 16.45%. IR (
KBr): (OH) 3430; (NH) 3363s; (N–N) 1078; (C@N) 1608s;
m ,
/cmꢁ1
m
m
m
m
m
(C@S) 972. 1H NMR (300 MHz, DMSO-d6; d ppm): 7.51–7.95 (m,
5H, –C6H5), 13.66–13.83 (d, 2H, –NH). 13C NMR (DMSO-d6; d
ppm): 167.06 (˜C@S), 150.32 (˜C@N), 125.5–130.70 (phenyl ring
carbons). UV–Vis (kmax, Nujol mull, nm): 324, 314, 304, 258, 231.
4.70%. IR (
m
/cmꢁ1, KBr):
(C–S) 987. UV–Vis (kmax, Nujol mull, nm):
m(C@N) 1625s; m(N–N) 1101; massy(SO2)
1295; sym(SO2) 1101;
m
m
2.4. Preparation of [Mn(ptds)(o-phen)2] (2)
540, 480, 420, 374, 335, 307.
A methanolic solution of Mn(OAc)2ꢀ4H2O (0.244 g, 1 mmol) was
added to a methanol solution of bis(5-phenyl-2H-1,2,4-triazole)-3-
yl-disulfane (0.384 g, 1 mmol) with continuous stirring for 30 min.
The resulting precipitate was filtered and washed with ethanol and
air dried. The precipitate was suspended in methanol and heated
for 30 min with a methanolic solution of o-phen (0.400 g, 2 mmol),
2.6. Physical measurements
Carbon, hydrogen and nitrogen contents were determined on a
Carlo Erba 1108 model microanalyser. Magnetic susceptibility
measurements were performed at room temperature on a Cahn
S
S
O
H2N
C6H5COCl
H2N
N
H
aq. NaOH
dil. HCl
N
H
N
H
NH2
C6H5
aq.NaOH
Reflux
NH
HN
N
N
.
2H2O
S
S
N
N
H2ptds.2H2O (1)
(i)Mn(OAc)2.4H2O
o
(ii) -phen
MeOH
MeOH
(i)Co(OAc)2
(ii) -phen
(iii) Reflux
o
N
Co
N
N
N
.
N
N
.
.
N
H O 0.5
C2H5OH
N
O
2
S
N
N
N
Mn
O
N
N
N
N
.
[Co(pts)( -phen)2]
o
H2O
.
0.5
C2H5OH
(3)
N
N
S
S
[Mn(ptds)(
Scheme 1. Synthesis of the ligand and the complexes.
o
-phen)2] (2)

A. Singh et al. / Polyhedron 30 (2011) 1927–1934
1929
Table 1
Crystallographic data for H2ptdsꢀ2H2O (1), [Mn(ptds)(o-phen)2] (2), [Co(pts)(o-phen)2]H2Oꢀ0.5C2H5OH (3).
Compound
1
2
3
Empirical formula
Formula weight
T (K)
C
16H12N6O2S2
C40H26MnN10S2
765.79
293
C66H52Co2N14O7S2
1335.20
298
384.46
293
k (Å)
Crystal system
Space group
0.71073
monoclinic
C2/c
0.71073
trigonal
P 31 2 1
0.71073
triclinic
ꢀ
P1
Unit cell dimensions
a (Å)
b (Å)
c (Å)
b (°)
V (Å3)
Z
12.4335(10)
14.7236(9)
10.3007(9)
103.990(9)
1829.8(3)
4
1.396
0.314
792.0
9.8038(3)
9.8038(3)
31.7523(9)
90.000(0)
2642.98(1)
4
1.95
0.721
1611.6
10.4590(5)
12.7063(5)
12.8046(5)
85.016(4)
1542.83(11)
1
1.437
0.673
688
qcalc (g cmꢁ3
(mmꢁ1
F(0 0 0)
)
l
)
Crystal size (mm)
0.66 ꢂ 0.41 ꢂ 0.29
0.30 ꢂ 0.28 ꢂ 0.25
0.29 ꢂ 0.27 ꢂ 0.25
Number of reflections collected
Number of independent reflections (Rint
Number of data/restraints/parameters
2084
3794
11257
)
2438 (0.0236)
2084/0/118
1.051
0.060, 0.162
0.077, 0.174
0.583, ꢁ0.690
3794 (0.0176)
3794/0/240
0.893
0.031, 0.055
0.047, 0.058
0.223, ꢁ0.250
6841 (0.0230)
6841/6/447
0.932
0.050, 0.1267
0.089, 0.1405
0.223, ꢁ0.250
Goodness-of-fit (GOF) on F2
a,b
R1, wR2 [(I > 2
r
(I))]
a,b
R1, wR2 (all data)
Largest difference in peak and hole (e Åꢁ3
)
a
R1
=
R
||Fo| ꢁ |Fc||
R|Fo|.
P
P
2
2 1=2
R2 ¼ ½ wðjF2oj ꢁ jFc2jÞ = wjF2oj ꢃ
.
b
Table 2
Selected bond lengths (Å) and angles (°) for H2ptdsꢀ2H2O.
Faraday balance using Hg[Co(NCS)4] as the calibrant. Electronic
spectra were recorded on a Shimadzu 1700 UV–Vis spectropho-
tometer as Nujol mulls. IR spectra were recorded in the 4000–
400 cmꢁ1 region as KBr pellets on a Varian 3100- FT IR spectropho-
tometer. 1H and 13C NMR spectra were recorded in DMSO-d6 on a
JEOL AL 300 FT NMR spectrometer using TMS as an internal
reference.
Bond lengths
Bond angles
S(1)–C(1)
N(1)–C(1)
S(1)–S(1_2)
N(3)–C(2)
N(3)–C(1)
N(1)–N(2)
N(2)–C(2)
C(3)–C(2)
C(3)–C(8)
1.7574(1)
1.3202(1)
2.0585(2)
1.3329(1)
1.3545(1)
1.3499(1)
1.3424(1)
1.4700(1)
1.3762(1)
C(1)–S(1)–S(1_2)
C(2)–N(3)–C(1)
N(3)–C(2)–C(3)
N(1)–N(2)–C(2)
C(2)–C(3)–C(8)
S(1)–C(1)–N(3)
N(3)–C(2)–N(1)
C(8)–C(3)–C(4)
S(1)–C(1)–N(2)
N(2)–N(1)–C(1)
101.17(10)
103.0(2)
125.9(2)
109.6(2)
120.0(3)
124.3(2)
109.8 (2)
119.1(3)
121.4(2)
103.3(2)
3. Crystal structure determination
Data for the structures 1–3 were obtained at 296(2) K on an Ox-
ford Diffraction Gemini diffractometer equipped with CrysAlis Pro.,
using a graphite mono-chromated Mo Ka (k = 0.71073 Å) radiation
source. The structures were solved by direct methods (SHELXL-2008)
and refined against all data by full matrix least-squares on F2 using
anisotropic displacement parameters for all non-hydrogen atoms.
All hydrogen atoms were included in the refinement at geometri-
cally ideal positions and refined with a riding model [20]. The MER-
CURY package and ORTEP-3 for Windows program were used for
generating molecular graphics [21,22]. In complex 3, the solvent
molecules are not at full occupancy, therefore the occupancy was
tested and the best value was near 0.5. So the occupancy of the sol-
vent was fixed at 0.5.
Table 3
Selected bond lengths (Å) and angles (°) for [Mn(H2ptds)(o-phen)2].
Bond lengths
Bond angles
Mn–N(1)
Mn–N(4)
Mn–N(5)
S(1)–C(1)
S(1)–S(1)
N(1)–C(1)
N(1)–N(2)
N(2)–C(2)
N(3)–C(1)
N(3)–C(2)
C(2)–C(3)
C(3)–C(4)
C(3)–C(8)
N(5)–C(18)
N(5)–C(19)
2.190(15)
2.290(16)
2.309(17)
1.749(2)
2.041(13)
1.345(2)
1.381(2)
1.327(2)
1.333(2)
1.356(2)
1.473(2)
1.377(3)
1.390(3)
1.320(3)
1.350(3)
N(1)–Mn–N(1)
N(1)–Mn–N(4)
N(1)–Mn–N(4)
N(4)–Mn–N(4)
N(1)–Mn–N(5)
N(1)–Mn–N(5)
N(4)–Mn–N(5)
N(4)–Mn–N(5)
C(1)–S(1)–S(1)
C(1)–N(1)–N(2)
C(1)–N(1)–Mn
C(2)–N(2)–N(1)
C(1)–N(3)–C(2)
N(2)–C(2)–C(3)
N(3)–C(2)–C(3)
N(3)–C(1)–N(1)
N(1)–C(1)–S(1)
102.93(8)
97.89(6)
92.41(6)
163.44(9)
88.65(5)
162.07(6)
72.23(6)
95.20(6)
103.90(8)
104.91(15)
135.72(13)
105.47(15)
101.47(16)
123.34(18)
122.64(17)
114.15(17)
124.56(14)
4. Results and discussion
The
ligand
bis(5-phenyl-2H-1,2,4-triazole)-3-yl-disulfane
(H2ptdsꢀ2H2O) (1) reacted with Mn(OAc)2ꢀ4H2O and Co(OAc)2 to
form yellow and green precipitates respectively, which dissolved
in a methanolic solution of o-phen under hot conditions yielding
[Mn(ptds)(o-phen)2] (2) and [Co(pts)(o-phen)2]ꢀH2Oꢀ0.5C2H5OH
(3). Complex 3 is formed after S–S bond cleavage and aerial oxida-
tion of sulfur, whereas such cleavage did not occur in the case of
complex 2 in which only mild heating was required to dissolve
the binary complex of manganese(II). These complexes are stable
towards air and moisture. Scheme 1 depicts the formation of the
ligand and its complexes which contain ptds2ꢁ and (pts)2ꢁ as
ligands and o-phen as the coligand. The ligand is soluble in meth-
anol and ethanol, while the complexes are insoluble even in DMF
and DMSO. The ligand 1 and the complexes 2 and 3 melt at 535,
573 and 578 K, respectively.

1930
A. Singh et al. / Polyhedron 30 (2011) 1927–1934
Fig. 1. ORTEP plot of H2ptdsꢀ2H2O (1) with the atomic numbering scheme at the 30% probability level. Hydrogen atoms and solvent molecules are omitted for clarity.
4.1. IR spectra
and 7.95 ppm. The 13C spectrum of H2ptdsꢀ2H2O shows signals at
d 167.06, 150.32 and 125.5–130.70 ppm due to C–S, C@N and phe-
nyl ring carbons, respectively.
The IR spectrum of the ligand bis(5-phenyl-2H-1,2,4-triazole)-
3-yl-disulfane dihydrate, H2ptdsꢀ2H2O (1) shows absorptions
(cmꢁ1) due to the stretching modes of OH (3430), NH (3363), N–
N (1078) and C–S (972). A band at 3430 cmꢁ1 shows the presence
of a water molecule in the ligand. The IR spectra of complexes 2
and 3 are devoid of any peak in the region 3367–3300 cmꢁ1, and
4.2. Electronic spectra and magnetic moments
[Mn(H2ptds)(o-phen)2] (2) shows a magnetic moment of 5.9 BM
which indicates the presence of five unpaired electrons. The com-
plex shows absorption bands at 450 and 427 nm attributed to
6A1g ? 4A1g and 4Eg(G) transitions respectively for the distorted
octahedral geometry of Mn(II). Other bands at 362, 339, 306 and
271 nm may be assigned to intraligand/charge transfer transitions
[24]. Complex 3 shows a magnetic moment of 5.01 B.M., indicating
its octahedral geometry. It shows two bands at 540 and 480 nm
which may be attributed to d–d transitions of octahedrally coordi-
nated cobalt(II). Other bands at 420, 374, 335 and 307 nm may be
assigned to charge transfer/intraligand transitions.
show positive shifts of 20–23 cmꢁ1 for
m(N–N), indicating the re-
moval of the NH proton of triazole and bonding of the triazole
nitrogen atom to the metal ion. The IR spectrum of [Co(pts)(o-
phen)2]ꢀH2Oꢀ0.5C2H5OH (3) shows a broad band at 3404 cmꢁ1 for
m(OH). Thus, it is clear from the IR data that the ligand acts as
dinegative bidentate in complex 2, bonding through both triazole
nitrogen atoms, and as dinegative bidentate in complex 3 bonding
through the triazole nitrogen and sulfinate oxygen atoms. The
presence of bands at 1295 and 1101 cmꢁ1 in complex 3 may be as-
signed to massy and msym respectively for O-bonded SO2 [23].
4.3. Crystal structure description of H2ptdsꢀ2H2O (1)
4.1.1. 1H and 13C NMR spectra
The 1H NMR spectrum of H2ptdsꢀ2H2O (1) exhibits a signal at d
13.66–13.83 ppm for the proton of the triazole ring and the five
protons of the phenyl ring appear as a multiplet between 7.51
The crystallographic data and structural refinement details are
given in Table 1 and selected bond distances and bond angles are
given in Table 2. Hydrogen bonding parameters of the ligand are
Fig. 2. N–Hꢀ ꢀ ꢀO hydrogen bonding by the H2O molecule leading to a linear chain structure.

A. Singh et al. / Polyhedron 30 (2011) 1927–1934
1931
Fig. 3. ORTEP plot of [Mn(ptds)2(o-phen)2] with the atomic numbering scheme at the 30% probability level. Hydrogen atoms are omitted for clarity.
given in Table 3. Fig. 1 shows the ORTEP diagram of H2ptdsꢀ2H2O (1)
with the atomic numbering scheme. The structure of H2ptdsꢀ2H2O
(1) is stabilized by intermolecular N–Hꢀ ꢀ ꢀO hydrogen bonding,
responsible for producing a linear chain structure (Fig. 2). The N–
Hꢀ ꢀ ꢀO hydrogen bonds are formed between the triazole hydrogen
and oxygen of a water molecule. The C–S bond distance of
1.7574(1) Å in H2ptds agrees well with those in related com-
pounds, being a C–S single bond [25].
related to complex 2 are listed in Table 1 and selected bond dis-
tances and bond angles are given in Table 3. The metal centre in
complex 2 is coordinated in a N6 core by one dinegative bidentate
ligand using both triazole nitrogens (N1 after loss of a proton). The
N donor sites of the dinegative bidentate ligand chelate the Mn(II)
centre to form a seven membered C2N2S2Mn ring. The average
bond lengths in complex
2 are: S1–C1 = 1.7882(1) (L), C1–
N1 = 1.3351(1) (L), C1–N3 = 1.3249(1) (S), N(2)–N(1) = 1.3813 (L),
N(2)–C(2) = 1.3269 (S) Å (L, longer and S, shorter) (Table 3) which
are longer or shorter than those of the corresponding distances
in the free ligand due to bonding of Mn(II) with the ligand. The
resulting complex has a distorted octahedral geometry. The Mn–
N bond lengths in (2) are 2.190 and 2.290 Å for Mn–N (triazole)
4.4. Crystal structure description of [Mn(ptds)(o-phen)2] (2)
Fig. 3 shows the ORTEP diagram of [Mn(ptds)(o-phen)2] (2) with
the atomic numbering scheme. The structural refinement data
Fig. 4. Intermolecular C–Hꢀ ꢀ ꢀC interactions leading to a linear chain structure.

1932
A. Singh et al. / Polyhedron 30 (2011) 1927–1934
Fig. 5. ORTEP plot of [Co(pts)(o-phen)2]ꢀH2Oꢀ0.5C2H5OH with the atomic numbering scheme at the 30% probability level. Hydrogen atoms and solvent molecules are omitted for
clarity.
and Mn–N (o-phen), respectively. The shorter Mn–N (triazole)
bond length as compared to Mn–N (o-phen) indicates that the tri-
azole nitrogen bonds more strongly than the o-phen nitrogen. The
bond angles N(1)–Mn–N(1) 102.94(7)° and N(4)–Mn–N(4)
72.20(7)° indicate distortion from an ideal octahedral geometry
[26]. In the complex the chelate rings and the triazole rings lie
nearly in the same plane forming a dihedral angle of 20.46°. The
bond distances for Mn–N and Mn–N(o-phen) are 2.1904,
2.2902(1) and 2.3094(1) Å, respectively, which are comparable to
the bond lengths reported for [Mn(Hpchce)2(o-phen)] and
{2[Mn(pchcm)(o-phen)2]}ꢀ7H2O [27]. Compound 2 is quite stable
in the solid state due to weak intermolecular C–Hꢀ ꢀ ꢀC interactions
between the carbons of triazole and the phenyl ring and the hydro-
gen atom of the o-phen ring (Fig. 4) forming a linear chain
structure.
Co–O(2) gives the distances 2.056(18) and 2.106(15) Å, (Table 4)
forming a five membered NCSOCo chelate ring with a bite angle
of 81.01(7)° which represents a major deviation from an octahedral
geometry. In complex 3 the –S–S– bond breaks and gives a cobal-
t(II) complex with a newly generated ligand, pts2ꢁ (Scheme 1). The
cobalt(II) ion is octahedrally coordinated by four nitrogen atoms of
two o-phen, one nitrogen of triazole and one oxygen atom of the
newly generated ligand. Thus, the newly generated ligand, contain-
ing a sulfinate group, acts as a dinegative bidentate ligand. The
average bond lengths in complex 3 are: N(2)–N(1) = 1.371(3),
N(1)–C(1) = 1.330(3), N(2)–C(2) = 1.343(3), S(1)–C(1) = 1.800(2)
and S(1)–O(2) = 1.507(16) Å, and these are normal for triazole
complexes. The Co–N and Co–N(phen) bond distances are
2.056(18), 2.137(15) and 2.163(18) Å, respectively, and these val-
Table 4
Selected bond lengths (Å) and angles (°) for [Co(pts)(o-phen)2]ꢀH2Oꢀ0.5C2H5OH.
4.5. Crystal structure description of [Co(pts)(o-phen)2]ꢀH2Oꢀ0.5C2H5OH
(3)
Bond lengths
Bond angles
Co–N(1)
Co–N(4)
Co–N(5)
Co–N(6)
Co–N(7)
Co–O(2)
N(2)–N(1)
N(2)–C(2)
N(1)–C(1)
N(3)–C(1)
N(3)–C(2)
S(1)–C(1)
S(1)–O(2)
S(1)–O(1)
C(33)–C(34)
C(33)–O(5)
2.056(18)
2.137(15)
2.146(18)
2.163(18)
2.121(17)
2.106(15)
1.371(3)
1.343(3)
1.330(3)
1.334(3)
1.356(3)
1.800(2)
1.507(16)
1.481(18)
1.329(11)
1.480(11)
O(2)–Co–N(1)
O(2)–Co–N(6)
O(2)–Co–N(5)
O(2)–Co–N(7)
N(1)–Co–N(5)
N(1)–Co–N(4)
N(4)–Co–N(7)
N(6)–Co–N(7)
Co–N(1)–N(2)
O(1)–S(1)–C(1)
Co–N(1)–C(1)
N(2)–N(1)–C(1)
N(1)–N(2)–C(2)
S(1)–C(1)–N(1)
O(2)–S(1)–C(1)
O(1)–S(1)–O(2)
C(34)–C(33)–O(5)
81.01(7)
92.80(6)
169.46(6)
96.11(7)
96.33(7)
95.68(7)
167.87(7)
77.15(7)
136.06(14)
103.93(10)
117.69(15)
106.24(17)
104.57(17)
119.28(16)
98.66(9)
Fig.
5
shows
the
ORTEP
diagram
of
[Co(pts)(o-
phen)2]ꢀH2Oꢀ0.5C2H5OH (3), together with the atomic numbering
scheme. The crystallographic data and structural refinement de-
tails are given in Table 1 and selected bond distances and bond an-
gles are presented in Table 4. The elements of the structure are
joined to each other in the crystal packing by means of an extended
system of H-bonds, where the hydrogen belonging to the o-phen
participates in the structure. In complex 3 the crystallographic
asymmetric unit consists of [Co(pts)(o-phen)2], one water and half
an ethanol molecule. The ethanol is near a symmetry element and
this has distorted its geometry so that the O–C–C angle is not 109°.
However, the C–O 1.480(11) Å and C–C 1.329(11) Å bond lengths
are reasonable. The bonding of the ligand via Co–N(1) and
109.69(11)
152.0(8)

A. Singh et al. / Polyhedron 30 (2011) 1927–1934
1933
Fig. 6. O–Hꢀ ꢀ ꢀO, C–Hꢀ ꢀ ꢀO and C–Hꢀ ꢀ ꢀS interactions leading to a supramolecular architecture.
ues are comparable to the bond lengths reported for [CoCl(o-
phen)2(H2O)]Clꢀ2ꢀ5H2O [28], [Co(L1)2(NCS)2(H2O)2]ꢀ2H2O and
[Co3(L2)6(NCS)4(H2O)2](NCS)2ꢀH2O (L1 = 4-[3-(1,2,4-triazolyl)-
Appendix A. Supplementary data
CCDC 796493, 796494 and 796495 contain the supplementary
crystallographic data for (H2ptds)ꢀ2H2O (1), [Mn(ptds)(o-phen)2]
(2) and [Co(pts)(o-phen)2]ꢀH2Oꢀ0.5C2H5OH (3). These data can be
obtained free of charge via http://www.ccdc.cam.ac.uk/conts/
retrieving.html, or from the Cambridge Crystallographic Data Cen-
tre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-
033; or e-mail: deposit@ccdc.cam.ac.uk.
1,2,4-triazole] and L2 = 4-aminotriazole) [29]. Due to deprotona-
tion of triazole ring nitrogen, N–Hꢀ ꢀ ꢀO intermolecular hydrogen
bonding present between the hydrogen atom of the triazole ring
and the oxygen of water molecule in the free ligand disappears
in complex 3. One ethanol molecule present between two complex
units is linked to the two water molecules of both units and in turn
both hydrogens of the water molecule are hydrogen bonded to the
sulfinite oxygen of the complex unit (Fig. 6). A C–Hꢀ ꢀ ꢀO interaction
occurs between the CH3 hydrogen and OH2 oxygen and O–Hꢀ ꢀ ꢀO
interactions exist between the H2O hydrogen and sulfinite oxygen,
and the oxygen of ethanol is linked to the other hydrogen of H2O
molecule forming a supramolecular structure. In addition to this
there is a weak intermolecular C–Hꢀ ꢀ ꢀS interaction between the
sulfinite sulfur and the hydrogen atom of the o-phen ring.
References
[1] G. Turan-Zitouni, Z.A. Kaplancikli, M.T. Yildiz, P. Chevallet, D. Kaya, Eur. J. Med.
Chem. 40 (2005) 607.
[2] A.R. Jalilian, S. Sattari, M. Bineshmarvasti, A. Shafiee, M. Daneshtalab, Arch.
Pharm. Med. Chem. 333 (2000) 347.
[3] I. Kucukguzel, S.G. Kucukguzel, S. Rollas, M. Kiraz, Bioorg. Med. Chem. Lett. 11
(2001) 1703.
[4] B. Tozkoparan, E. Kupeli, E. Yesilada, M. Ertan, Bioorg. Med. Chem. 15 (2007)
1808.
[5] S.M. Rabea, N.A. El-Koussi, H.Y. Hassan, T. Aboul-Fadl, Arch. Pharm. Chem. Life
Sci. 339 (2006) 32.
5. Conclusion
[6] B.S. Holla, B. Veerendra, M.K. Shivananda, B. Poojary, Eur. J. Med. Chem. 38
(2003) 759.
[7] A. Almasirad, S.A. Tabatabai, M. Faizi, A. Kebriaeezadeh, N. Mehrabi, A.
Dalvandi, A. Shafiee, Bioorg. Med. Chem. Lett. 14 (2004) 6057.
[8] M.T. Abdel-Aal, W.A. El-Sayed, S.M. El-Kosy, E.S.H. El-Ashry, Arch. Pharm.
Chem. Life Sci. 341 (2008) 307.
[9] B. Chai, X. Qian, S. Cao, H. Liu, G. Song, Arkivoc ii (2003) 141.
[10] A. Varvaresou, T. Siatra-Papastaikoudi, A. Tsotinis, A. Tsantili-Kakoulidou, A.
Vamvakides, Il Farmaco 53 (1998) 320.
[11] B. Modzelewska-Banachiewicz, J. Banachiewicz, A. Chodkowska, E. Jagiello-
Wojtowicz, L. Mazur, Eur. J. Med. Chem. 39 (2004) 873.
[12] A. Cansiz, M. Koparir, A. Demirdag, Molecules 9 (2004) 204.
[13] M. Wujec, P. Paneth, J. Phys. Org. Chem. 20 (2007) 1043.
[14] M.V. Marinho, L. C Visentin, M.C. Souza, R. Diniz, K. Krambrock, M.I. Yoshida,
F.C. Machado, Polyhedron 29 (2010) 2657.
[15] R.A. Michelin, M. Mozzon, R. Bertani, Coord. Chem. Rev. 147 (1996) 229.
[16] Hai-Bin Zhu, Lei Li, Hai Wang, Xin Lu, Inorg. Chem. Commun. 13 (2010) 30.
[17] S. Delgaeo, P.J. Sanz Miguel, J.L. Priego, R. Jimenez-Aparicio, C.J. Gomez-Garcia,
F. Zomara, Inorg. Chem. 47 (2008) 9128.
A
new ligand, bis(5-phenyl-2H-1,2,4-triazole)-3-yl-disulfane
(H2pꢀtdsꢀ2H2O) (1), and the complexes [Mn(ptds)(o-phen)2] (2)
and [Co(pts)(o-phen)2]ꢀH2Oꢀ0.5C2H5OH (3) have been synthesized.
A S–S bond cleavage and aerial oxidation of sulfur was observed in
complex 3, whereas such cleavage did not occur in the case of com-
plex 2. Complex 2 is stabilized through weak intermolecular C–
Hꢀ ꢀ ꢀC interactions between the carbon atoms of the triazole and
the phenyl ring hydrogen atom of the o-phen ring, forming a linear
chain structure. Complex 3 is stabilized by a weak intermolecular
C–Hꢀ ꢀ ꢀS interaction between the sulfinite sulfur atom and the
hydrogen atom of the o-phen ring, and C–Hꢀ ꢀ ꢀO hydrogen bonding
between the oxygen of the water molecule and the hydrogen atom
of the o-phen ring, forming a supramolecular architecture.
[18] J. Wang, S.L. Zheng, S. Hu, Y.H. Zhang, M.L. Tong, Inorg. Chem. 46 (2007) 795.
[19] M.C. Aragoni, M. arca, M. Crespo, F.A. Devillanova, M.B. Hursthous, S.L. Huth, F.
Isaia, V. Lippolis, G. Verani, Cryst. Eng. Commun. 9 (2007) 873.
[20] G.M. Sheldrick, Acta Crystallogr., Sect. A 64 (2008) 112.
[21] I.J. Bruno, J.C. Cole, P.R. Edgington, M. Kessler, C.F. Macrae, P. McCabe, J.
Pearson, R. Taylor, Acta Crystallogr., Sect. B 58 (2002) 389.
Acknowledgment
One of the authors (Aarti Singh) is thankful to the University
Grant Commission, New Delhi for financial support.

1934
A. Singh et al. / Polyhedron 30 (2011) 1927–1934
[22] L.J. Farrugia, J. Appl. Crystallogr. 30 (1997) 565.
[26] A. Sreekanth, U.L. Kala, C.R. Nayar, M.R.P. Kurup, Polyhedron 23 (2004) 41.
[27] N.K. Singh, M.K. Bharty, S.K. Kushawaha, U.P. Singh, Pooja Tyagi, Polyhedron 29
(2010) 1902.
[28] K.A. Kumar, A. Dayalan, K. Sethusankar, Acta Crystallogr., Sect. E E65 (2009)
m1300.
[23] K. Nakamoto, Infrared and Raman Spectra of Inorganic and Coordination
Compounds, 4th ed., Wiley Interscience, New York, 1986. p. 344.
[24] A.B.P. Lever, Inorganic Electronic Spectroscopy, 2nd ed., Elsevier, Amsterdam,
1984.
[25] L.E. Sutton, Tables of Interatomic Distances and Configuration in Molecules
and Ions, Special Publication No. 18, The Chemical Society, London, 1965.
[29] Y.Q. Huang, B. Ding, H.L. Gao, P. Cheng, D.Z. Liao, S.P. Yan, Z.H. Jiang, J. Mol.
Struct. 743 (2005) 201.