Coinage metal derivatives of salicylaldehyde thiosemicarbazones: Synthesis, structures, bond isomerism and H-bonded networks

Article abstract of DOI:10.1016/j.poly.2009.03.019

Reactions of salicylaldehyde thiosemicarbazone {(2-HO-C₆H₄)(H)C²{double bond, long}N³-N²H-C¹({double bond, long}S)N¹H₂, H₂stsc} and salicylaldehyde N-methyl

Full text of DOI:10.1016/j.poly.2009.03.019

Polyhedron 28 (2009) 1583–1593
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Coinage metal derivatives of salicylaldehyde thiosemicarbazones: Synthesis,
structures, bond isomerism and H-bonded networks
a
a
a
a
a
Tarlok Singh Lobana a, , Sonia Khanna , Geeta Hundal , Pavneet Kaur , Bandana Thakur , Shaweta Attri ,
*
Ray Jay Butcher b
a Department of Chemistry, Guru Nanak Dev University, Amritsar 143005, India
b Department of Chemistry, Howard University, Washington, DC 20059, USA
a r t i c l e i n f o
a b s t r a c t
Reactions of salicylaldehyde thiosemicarbazone {(2-HO–C6H4)(H)C2@N3–N2H–C1(@S)N1H2, H2stsc} and
salicylaldehyde N-methyl thiosemicarbazone {(2-HO–C6H4)(H)C2@N3–N2H–C1(@S)N1HMe, H2stscNMe}
with copper(I)/silver(I) halides in presence of PPh3 have yielded complexes of compositions, mononuclear
Article history:
Received 3 February 2009
Accepted 19 March 2009
Available online 28 March 2009
[CuCl(
bridged dimers, [Cu2(
bond isomers, [M2X2 (H2stsc)2(PPh3)2] (M: Cu I 1, Br 2; Ag 7). Complexes 1, 2 and 7 exist as halogen-
bridged [M2( -X)2( -S–
1-S–H2stsc)2(PPh3)2] (M: Cu, 1a, 2a; Ag, 7a), and sulfur bridged [M2(
g
1-S–Htsc)(PPh3)2] (Htsc = H2stsc 3; H2stscNMe, 6), [AgX(H2stscNMe)(PPh3)]2 (Br 9, Cl 10), sulfur-
l-S–H2stscNMe)2X2(PPh3)2] ꢀ 2CH3CN (I 4; Br 5), [Ag2Cl2(
l-S–H2stsc)2(PPh3)2] 8 and
Keywords:
Salicylaldehyde thiosemicarbazone
Bond isomerism
Halogen bridging
Sulfur bridging
l
g
l
H2stsc)2X2(PPh3)2] (M: Cu, 1b, 2b; Ag, 7b) isomers in the same lattice. Among the bond isomers, the
CuꢀꢀꢀCu contacts were found to be shorter in sulfur-bridged isomers (1b, 3.113; 2b, 3.063 Å) vis-à-vis
those in halogen bridged isomers (1a, 3.182; 2a, 3.190 Å). The AgꢀꢀꢀAg contact in sulfur-bridged isomer
7b (3.4223 Å) is longer than in bromo-bridged isomer 7a (3.2021 Å). The complexes form 1D or 2D H-
bonded networks, entrapping solvent molecules in some cases.
Ó 2009 Published by Elsevier Ltd.
1. Introduction
lytic reduction of carbon dioxide [32], and other catalytic activities
[33–35]. Further, the close MꢀꢀꢀM contacts in dimers are anticipated
An assembly of polymetallic systems can occur via coordinate
bond formation (coordination polymers), and via hydrogen bond-
ing or other weaker interactions (supramolecular 1D, 2D or 3D net-
works) [1,2]. The synthesis of coordination polymers has gained
attention for the past several years, for their unique properties,
and fascinating structures [1]. In recent years, several 1D, 2D or
3D polymers with conductivity and magnetic properties have been
reported [3–6]. Supramolecular systems have shown interesting
donor–acceptor interactions, leading to the design of new materi-
als and new carriers for drug delivery resulting in great impact in
the pharmaceutical sciences [7–10].
to promote photoluminiscent properties [36–38].
We have been interested in the importance of the substituents
at C2/N1 atoms of thiosemicarbazones on the nature of bonding,
nuclearity and H-bonded networks. In this paper, we report com-
plexes of salicylaldehyde thiosemicarbazone (H2stsc) and its N1-
methyl substituted ligand (H2stscNMe) (Chart 1) which has
generated 1D and 2D networks, several of which selectively entrap
organic molecules in the voids between parallel chains.
2. Experimental
Thiosemicarbazones {R1R2C2@N3–N(H)–C1(@S)N1HR3} possess-
ing several donor atoms have shown propensity for the formation
of mono-, di- and poly-nuclear complexes with transition metals
[11–17]. These ligands have also displayed ion-sensing ability
[18–21] metal extraction properties, [22,23] and pharmacological
properties [24–28]. The presence of available hydrogen atoms in
the thiosemicarbazones is important for the building of H-bonded
networks [29,30]. Dinuclear copper metal complexes are very
important due to their role in many copper proteins [31], electro-
2.1. General material and techniques
Copper(I) halides were prepared by the reduction of Cu-
SO4 ꢀ 5H2O using SO2 in the presence of NaX (X = Cl, Br, I) in dis-
tilled water. Silver(I) halides were prepared by the reaction of
silver(I) nitrate in methanol with NaX (X = Cl, Br) [39]. Thiosemi-
carbazide, N1-methyl thiosemicarbazide, salicylaldehyde and
Ph3P were procured from Aldrich Sigma Ltd. Thiosemicarbazone li-
gands were prepared by condensation of aldehydes with respective
thiosemicarbazides. Elemental analysis for C, H and N were carried
out using a thermoelectron FLASHEA1112 analyser. The melting
points were determined with a Gallenkamp electrically heated
* Corresponding author. Tel.: +91 183 22 57604; fax: +91 183 22 58820.
E-mail address: tarlokslobana@yahoo.co.in (T.S. Lobana).
0277-5387/$ - see front matter Ó 2009 Published by Elsevier Ltd.
doi:10.1016/j.poly.2009.03.019

1584
T.S. Lobana et al. / Polyhedron 28 (2009) 1583–1593
8.61s (–C2H), 7.25–7.54m (Ph + PPh3), 6.96q (–N1H), 3.19s, 3.20s
OH
OH
S
(–N1–CH3). 31P NMR (CDCl3,
d
ppm): ꢁ143.0,
D
d(dcomplex
ꢁ
S
1
C
2
NH
1
C
2
NH
2
C
3
N
2
C
3
N
dligand) = 2.54 ppm.
1
N1
N
H
H
Me
H
H
2.2.5. [Cu2Br2(
l
-S–H2stscNMe)2(PPh3)2] ꢀ CH3CN (5)
H
Yield, 60%, 0.064 g, m.p. 164–166 °C. Anal. Calc. for
H2stsc
H2stsc-N-Me
C54H52Br2Cu2N6P2S2)2: C, 36.6; H, 3.8; N, 11.2. Found: C, 36.2; H,
3.4; N, 11.4%. Main IR peaks (KBr, cmꢁ1): (N1–H) 3396m, 3357m
m
Chart 1.
(–N1H–), 3159s (–N2H–); 3002s
1571s, 1521s (C@N) + (C@C); 1028s, 813s (thioamide moiety);
1093s
(P–CPh). 1H NMR (CDCl3, d ppm) 9.46b (–OH), 8.61s
m(C–H); 2788s m
(N1–CH3); 1618s,
m
m
apparatus. The I.R spectra of the ligands and the complexes were
recorded in the range, 4000–200 cmꢁ1 (using KBr pellets) on the
FTIR-SHIMADZU 8400 Fourier Transform Spectrophotometer and
on Pye-Unicam SP-3-300 spectrophotometer.
m
(–C2H), 7.25–7.50m (Ph + PPh3), 6.94q (–N1H), 2.02d (–N1–CH3).
31P NMR (CDCl3, d ppm): ꢁ143.04,
D
d(dcomplex ꢁ dligand) = 2.54 ppm.
2.5.6. [CuCl(
g
1-S–H2stscNMe)(PPh3)2] ꢀ CH3CN (6)
2.2. Synthesis of complexes
Yield, 68%, 0.14 g, m.p. 182–184 °C. Anal. Calc. for C47H44ClCuN4-
SOP2: C, 64.60; H, 5.04; N, 6.41. Found: C, 65.1; H, 5.35; N, 6.65%.
2.2.1. [Cu2I2(H2stsc)2(PPh3)2] ꢀ CHCl3 (1)
Main IR peaks (KBr, cmꢁ1): (N1–H) 3392m, 3345m (–N1H–),
m
To copper(I) iodide (0.025 g, 0.131 mmol) in a mixture of aceto-
nitrile (10 mL) and CHCl3 (10 mL) was added H2stsc ligand
(0.025 g, 0.131 mmol), and the contents were stirred for 2 h, fol-
lowed by the addition of PPh3 (0.034 g, 0.131 mmol). The contents
were stirred until a clear solution was obtained which was filtered,
and kept for crystallization for 2–3 days, when yellow colored crys-
tals were formed. Crystals were air sensitive and turned opaque
when taken out of their mother liquor. Yield, 66%, 0.112 g, m.p.
200–202 °C. Anal. Calc. for C52H48Br2Cu2N6O2P2S2. ½CHCl3: C,
46.51; H, 3.58; N, 6.20. Found: C, 46.66; H, 3.43; N, 6.38%. IR data
3165s (–N2H–); 2988s (N1–CH3); 1628s, 1575s
m(C–H); 2780s m
m
(C@N) + m(C@C); 1025s, 820s (thioamide moiety); 1095s m(P–
CPh). 1H NMR (CDCl3, d ppm) 9.47b (–OH), 8.65s (–C2H), 7.28–
7.47m (Ph + PPh3), 6.98q (–N1H), 2.03d (–N1–CH3). 31P NMR
(CDCl3, d ppm): ꢁ3.87 ppm,
D
d(dcomplex ꢁ dligand) = 0.84 ppm.
2.2.7. [Ag2Br2(H2stsc)2(PPh3)2] ꢀ 2CH3CN (7)
To silver(I) bromide (0.025 g, 0.133 mmol) suspended in aceto-
nitrile (15 mL) was added ligand H2stsc (0.026 g, 0.133 mmol), and
stirring was continued for 24 h. To the white solid formed, was
added solid PPh3 (0.035 g, 0.133 mmol), resulting in turbid solu-
tion. Addition of another mole of PPh3 (0.035 g, 0.133 mmol) re-
sulted in the formation of a clear solution, which was kept for
crystallization. Slow evaporation of the solution resulted in two
products, [Ag4Br4(PPh3)4] and [AgBr(H2stsc)(PPh3)]2 (5). The data
for 5 is given. Yield, 0.04 g, 48%, m.p. 200–202 °C. Anal. Calc. for
C52H48Ag2Br2N6O2P2S2: C, 48.39; H, 3.72; N, 6.51. Found: C,
(KBr, cmꢁ1): (O–H) 3433(b);
3163(m), 3124(m) (–NH–);
m
m
(N–H) 3306(m), 3277(s) (–NH2–)
(C–H) 3051(s); (C@N) + dNH2 +
(C@S) 805(s), 845(s) (thioam-
(C–N) 975(s), 1075(s)
(P–CPh) 1095(s). 1H NMR
m
m(C@C) 1597(m), 1547(s), 1458(s); m
ide moiety);
m
m
(CDCl3, d ppm): 6.80–7.45m (PPh3 + N1H2 + Ph), 8.55s (–C2H),
9.41s (OH). 31P NMR (CDCl3, d ppm): 30.06 ppm,
dligand) = 34.78 ppm.
D
d(dcomplex
ꢁ
Complexes 2–6 were prepared similarly.
48.14; H, 3.77; N, 6.53%. IR data (KBr, cmꢁ1):
(N–H) 3300(sh), 3298(b) (–NH2–), 3153(m) (–NH–);
3050(m), 3000(w); (C@N) + dNH2 + (C@C) 1597(m), 1533(s),
m
(O–H) 3450(b),
(C–H)
m
m
2.2.2. [Cu2Br2(H2stsc)2(PPh3)2] ꢀ CHCl3 (2)
m
m
Yield, 51%, 0.11 g, m.p. 210–212 °C. Anal. Calc. for C52H48Br2Cu2-
1477(s); m(C@S) 820(s) (thioamide moiety); m(C–N) 960(s); m(P–
N6O2P2S2. ½CHCl3: C, 49.97; H, 3.84; N, 6.66. Found: C, 49.94; H,
CPh) 1095(s). 1H NMR (CDCl3, d ppm): 12.44sb (–N2H), 11.66s
4.10; N, 6.71%. IR data (KBr, cmꢁ1):
m
(O–H) 3458(sb);
3308(m), 3275(sh) (–NH2–) 3159(s), 3130(m) (–NH–);
3057(s), 2999(s); (C@N) + dNH2 + (C@C) 1614(m), 1599(s),
1551(m); (C@S) 815(s) (thioamide moiety); (C–N) 1020(s),
970(s);
(P–CPh) 1093(s). 1H NMR (CDCl3, d ppm): 6.97–7.48m
(Ph + PPh3 + N1H2), 8.52s (–C2H), 9.45s (OH). 31P NMR (CDCl3, d
ppm): ꢁ3.52 ppm, d(dcomplex ꢁ dligand) = 1.19 ppm.
m(N–H)
(OH), 8.51s (–C2H), 8.21sb, 7.85sb (–N1H2), 6.79–7.49m
m(C–H)
(Ph + PPh3). 31P NMR (CDCl3, d ppm): 29.8, ꢁ9.1 ppm,
plex ꢁ dligand) = 34.4, 13.5 ppm.
Dd(dcom-
m
m
m
m
m
2.2.8. [Ag2Cl2(l-S–H2stsc)2(PPh3)2] (8)
To silver(I) chloride (0.025 g, 0.174 mmol) suspended in aceto-
nitrile (15 mL) was added solid PPh3 (0.045 g, 0.174 mmol), and
the contents were stirred for 24 h. The white solid formed was fil-
tered and dried in vacuo. To this solid (0.050 g, 0.123 mmol), sus-
pended in methanol, was added H2stsc ligand (0.024 g, 0.123
mmol) and the contents were stirred until a clear solution was ob-
tained which was filtered, and kept for crystallization for 2–3 days,
when pale yellow crystals were formed. Yield, 64%, 0.134 g, m.p.
216–218 °C. Anal. Calc. for C54H52Ag2Cl2N6P2S2O2: C, 54.15; H,
4.34; N, 7.02. Found: C, 53.89; H, 4.83; N, 7.28%. IR data (KBr,
D
2.2.3. [CuCl(
g
1-S–H2stsc)(PPh3)2] ꢀ CH3CN (3)
Yield, 52%, 0.110 g, m.p. 180–182 °C. Anal. Calc. for C46H42ClCu-
N4OP2S: C, 64.20; H, 4.88; N, 6.51. Found: C, 64.30; H, 4.69; N,
6.45%. IR data (KBr, cmꢁ1):
m
(O–H) 3470(s);
(–NH2–) 3197(s), 3150(s) (–NH–); (C–H) 3055(s), 2980(s);
(C@C) 1595(m), 1543(s); (C@S) 835(s) (thioam-
m(N–H) 3350(m)
m
m(C@N) + dNH2 +
m
m
ide moiety);
m
(C–N) 1020(s);
m
(P–CPh) 1095(s). 1H NMR (CDCl3, d
ppm): 6.07b (–N1H2), 6.91–7.46m (PPh3 + N1H2), 8.28s (–C2H),
cmꢁ1):
3163(m), 3125(b) (–NH–);
m
(O–H) 3433(sb);
m
(N–H) 3306(sh), 3277(b) (–NH2–)
(C–H) 3051(s); (C@N) + dNH2 +
(C@C) 1596(s), 1547(s), 1458(s); (C@S) 830(s), 815(s); (C–N)
9.56s (OH), 12.90s (–N2H). 31P NMR (CDCl3, d ppm): ꢁ2.97 ppm,
m
m
D
d(dcomplex ꢁ dligand) = 1.74 ppm.
m
m
m
1050(sb), 955(s);
m
(P–CPh) 1095(s). 1H NMR (CDCl3, dmso–d6, d
2.2.4. [Cu2I2(
Yield, 73%, 0.06 g, m.p. 150–152 °C. Anal. Calc. for C54H52 2-
Cu2N6P2S2: C, 53.4; H, 4.9; N, 8.7. Found: C, 53.2; H, 4.8; N, 8.3%.
Main IR peaks (KBr, cmꢁ1): (N1–H) 3367m, 3242sh (–N1H–),
3106b, 3093b (–N2H–); 2958sh (N1–CH3);
(C–H); 2806s, 2780s
1662s, 1618s, 1560m (C@N) + (C@C); 952s, 813s (thioamide
moiety); 1093s
(P–CPh). 1H NMR (CDCl3, d ppm) 9.40b(–OH),
l-S–H2stscNMe)2(PPh3)2] ꢀ CH3CN (4)
ppm): 7.24–7.57m (N1H2 + Ph + PPh3), 7.87sb (–N1H2), 8.57s
I
(–C2H), 9.50s (OH), 12.03s (–N2H). 31P NMR (CDCl3, dmso–d6, d
ppm): ꢁ8.72 ppm,
D
d(dcomplex ꢁ dligand) = 13.37 ppm.
m
m
m
2.2.9. [AgBr(
g
1-S–H2stsc–N–Me)(PPh3)2] ꢀ 3CH3CN (9)
m
m
To silver(I) bromide (0.025 g, 0.13 mmol) suspended in acetoni-
m
trile (15 mL) was added ligand H2stscNMe (0.027 g, 0.13 mmol),

T.S. Lobana et al. / Polyhedron 28 (2009) 1583–1593
1585
and stirring was continued for 24 h. To the white solid formed, was
added solid PPh3 (0.034 g, 0.13 mmol), resulting in turbid solution.
Addition of another mole of PPh3 (0.034 g, 0.13 mmol) resulted in
the formation of a clear solution, which was kept for crystalliza-
tion. Slow evaporation of the solution resulted in formation of
white transparent crystals. Crystals were stored in mother liquor.
Yield, 71%, 0.087 g, m.p. 165–167 °C. Anal. Calc. for C43H41AgBr-
N3OP2S: C, 58.6; H, 4.5; N, 4.4. Found: C, 58.8; H, 5.5; N, 4.5%. IR
tions with respect to the pivot C bearing the imine group. This dis-
order was resolved by splitting the respective oxygen atoms at two
ortho positions with total site occupancy of one. The H atoms were
calculated in structure factor calculations in their idealized
positions.
4. Results and discussion
data (KBr, cmꢁ1):
CH3) 2775(b); (C–H) 3049(s);
1510(s), (C@S) 822(s); m(C–N) 1078(s), 951(m); m(P–CPh)
m
(NH) 3307(s), 3216(s); (–N1H–) 3142(s), (–N1–
4.1. General comments
m
m
(C@N) + (C@C) 1603(s), 1558(s),
m
m
Salicylaldehyde thiosemicarbazone and its N1-methyl substi-
tuted ligands were reacted with copper(I) halides and silver(I) ha-
1094(s). 1H NMR (CDCl3, d ppm): 11.74s (–N2H); 8.60s (–C2H);
7.26–7.49m (PPh3), 6.974–6.90m (–C6,7,8H); 3.16s, 3.15s (–N1–
CH3). 31P NMR (CDCl3, d ppm): ꢁ5.4 ppm,
D
d(dcomplex ꢁ dligand) =
Cl
10.05 ppm.
Complex 10 was prepared similarly.
S
OH
C
X = Cl, n = 2
R
Cu
nPPh3
+
CuX
+
NH
C
PPh3
S
1-S–H2stscNMe)(PPh3)2] ꢀ 3CH3CN (10)
NH2
2.2.10. [AgCl(
g
N
Ph3P
H
Yield, 68%, 0.113 g, m.p. 172–174 °C. Anal. Calc. for C49H47AgCl-
3
N5OP2S: C, 61.34; H, 4.9; N, 7.3. Found: C, 61.51; H, 4.7; N, 7.1%. IR
X = I, Br, n = 1
data (KBr, cmꢁ1):
m
(O–H) 3647(s);
3138(s), 3113(s) (–N–H);
(C–H) 3070(s), 3051(s); (–N1–CH3)
2986(m), 2949(m); (C@N) + (C@C) 1558(s), 1526(s), 1481(s);
m
(NH) 3308(s), 3288(s); (–N1H–)
R
m
R
X
PPh3
S
S
S
X
PPh3
m
m
Cu
Cu
Cu
Cu
m
(P–CPh) 1093(s); m(C–N) 1078(s), 1028(m); m(C@S) 854(s),
R
Ph3P
Ph3P
823(s). 1H NMR (CDCl3, d ppm): 12.10s (–N2H); 9.57s (–C2H);
X
X
S
R
8.55s (OH); 7.28–7.40m (Ph + PPh3), 6.92q (–N1H); 3.18d (–N1–
X = I, 1b, Br, 2b
X = I, 1a, Br, 2a
CH3). 31P NMR (CDCl3, d ppm): ꢁ5.1 ppm,
D
d(dcomplex ꢁ dligand) =
bond-isomers
9.8 ppm.
Scheme 1.
3. Crystal structure determination
The data for 1–6 were collected on a Siemens P4 diffractometer
using XSCANS [40]. The hꢁ2h technique was used to measure the
intensities, up to a maximum of 2h = 50°, with graphite monochro-
R
X
PPh3
S
S
Cu
R
Cu
matised Mo Ka radiator (k = 0.71073 Å). The data were corrected
Ph3P
X
for Lorentz and polarization factors. An empirical psi absorption
correction was applied. The structures were solved by direct meth-
ods and refined by full matrix least squares methods based on F2.
Hydrogen atoms were fixed geometrically and were not refined.
Scattering factors from the International Tables for X-ray crystal-
lography were used [41]. Data reduction, structure solution, refine-
ment and molecular graphics were performed using SHELXTL-PC [42]
and WINGX [43]. As the chloroform molecule in compound 2 is a dis-
ordered molecule, it shows a short distance between C5ꢀꢀꢀCl3,
2.48 Å.
3
X = I, 4, Br, 5
S
OH
nCuX
+
n
NH
C
Cl
C
NHMe
N
H
n
=
Cu
1
PPh3
S
R
Ph3P
X = Cl, 6
Scheme 2.
The data for 10 was measured on Bruker AXS SMART APEX CCD
diffractometer. Data were reduced and corrected for absorption
using SMART and SAINT [44]. The structures were solved by direct
methods and refined by full matrix least squares based on F2 with
anisotropic thermal parameters for non-hydrogen atoms using
SHELXTL (structure solution, refinement and some molecular graph-
ics). All non-hydrogen atoms were refined anisotropically. All
hydrogen atoms were placed in calculated positions and were re-
fined with an isotropic displacement parameter 1.5 (methyl) or
1.2 times (all others) that of the adjacent carbon or oxygen atom.
A prismatic crystal of complex (7–9) were mounted on an Bru-
ker Apex 2 CCD area detector (7) or Oxford Diffraction Gemini-R (8,
9) diffractometer equipped with a graphite monochromator, and
Br
Ag
S
OH
S
PPh3
3
R
NH
C
+
AgX
R
R3 = Me
Ph3P
NHR3
C
N
X = Br, 9; Cl,10
H
R3 = H
3
R
S
X
PPh3
Br
Br
PPh3
S
S
Ag
Ag
Ag
Mo Ka radiation (k = 0.71073 Å). The structures were solved by
Ag
R
Ph3P
Ph3P
S
the direct methods and refined by full matrix least square based
on F2 with anisotropic thermal parameters for non-hydrogen
atoms using XCAD-49 (data reduction), and SHELXL (absorption correc-
tion, structure solution refinement and molecular graphics)
[45].The structure solutions for 7 showed disorder in the hydroxyl
groups of the salicylaldehyde units, being spread at two ortho posi-
X
R
7a
7b (Br); 8 (Cl)
Bond-isomers
Scheme 3.

Table 1
Crystallographic data of complexes 1–10.
Compound
1
2
3
4
5
6
7
8
9
10
Empirical
formula
Molecular
weight
Crystal
system
T (K)
C53H49Cl3CuI2N6O2P2S2 C53H49Br2Cl3Cu- C46H42ClCuN4OP2S C56H56Cu2I2N8O2P2S2 C58H58Cu2Br2N8O2P2S2 C47H44ClCuN4OP2S C56H54Ag2Br2N8O2P2S2 C52H48Ag2Cl2N6O2P2S2 C51H50AgBrN6OP2S C51H50AgClN6OP2S
N6O2P2S2
1415.27
triclinic
296(2)
1321.9
triclinic
296(2)
859.83
triclinic
296(2)
1406.06
triclinic
293(2)
1312.10
triclinic
295(2)
873.85
triclinic
295(2)
1372.68
triclinic
103(2)
1201.66
triclinic
293(2)
1044.75
triclinic
200(2)
1000.29
triclinic
100(2)
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
Space
P1
P1
P1
P1
P1
P1
P1
P1
P1
P1
group
0
a (AÅ)
13.335(5)
13.706(5)
13.367(2)
13.630(2)
11.478(5)
13.311(5)
10.907(5)
11.792(5)
11.023(5)
11.691(5)
11.132(1)
13.620(1)
13.2196(7)
13.9888(7)
13.1828(8)
12.6245(7)
13.1974(6)
12.5853(13)
13.0318(13)
0
b (AÅ)
13.6503(15)
0
c (AÅ)
17.858(5)
77.650(5)
72.350(5)
68.710(5)
2878.1(17)
2
17.613(2)
78.47(1)
72.32(1)
69.43(1)
2846.8(7)
2
16.482(5)
76.550(5)
78.910(5)
65.170(5)
2209.9(14)
2
13.601(5)
71.131(5)
81.855(5)
63.969(5)
1487.4(11)
2
13.484(5)
100.276(5)
98.682(5)
117.343(5)
1463.9(11)
1
17.191(1)
69.37(1)
77.62(1)
66.67(1)
2231.4(3)
2
17.2767(9)
82.150(1)
73.230(1)
69.416(1)
2861.5(3)
4
16.5090(19)
82.967(9)
78.191(8)
63.116(10)
2592.1(4)
2
17.1534(7)
80.698(4)
81.042(4)
62.281(5)
2486.1(2)
2
16.9636(17)
80.7420(10)
80.6590(10)
62.2520(10)
2418.0(4)
2
a
(°)
b (°)
c
(°)
0
V (AÅ3)
Z
Dcalc
1.633
1.541
1.292
1.570
1.488
1.301
1.591
1.540
1.396
1.374
(Mg mmꢁ1
)
l
(mmꢁ1
)
2.124
1.066
2.466
0.810
0.713
1.009
1.925
1.159
2.266
0.936
0.707
1.469
2.258
1.035
1.047
0.982
1.358
1.052
0.625
1.069
Goodness
of fit
(GOF)
on F2
Largest
difference
in peak
0.711 and ꢁ0.979
0.623 and
ꢁ0.798
0.768 and ꢁ0.463 0.629 and ꢁ0.547
0.679 and ꢁ0.961
1.857 and ꢁ3.354 0.643 and ꢁ1.022
1.049 and ꢁ0.597
1.835 and ꢁ0.872 0.724 and ꢁ0.520
and hole
0
(e ÅAꢁ3
)
R1, wR2
[I > 2
R1, wR2
(all data)
0.0666, 0.1514
0.1235, 0.1847
0.0640, 0.1548 0.0811, 0.1689
0.1875, 0.2058 0.2063, 0.2372
0.0364, 0.0977
0.0557, 0.1202
0.0443, 0.1107
0.0822, 0.1416
0.0879, 0.2501
0.1432, 0.3585
0.02228, 0.0561
0.0278, 0.0585
0.0261, 0.0599
0.0434, 0.0636
0.0778, 0.1677
0.1621, 0.2239
0.0257, 0.0683
0.0290, 0.0743
r
(I)]

T.S. Lobana et al. / Polyhedron 28 (2009) 1583–1593
1587
lides in the presence of triphenylphosphine, yielding a number of
compounds (1–10) with variable nuclearities and bridging patterns
Direct reactions of copper(I) halides with thiosemicarbazones gen-
erally yielded insoluble products, which could not be crystallized
and triphenylphosphine was necessary for obtaining crystalline
products. Two procedures were adopted for the preparation of
complexes. One procedure involves reaction of a metal halide with
a thiosemicarbazone followed by the addition of PPh3, and second
procedure involves first reaction of a metal halide with PPh3, and
then with a thiosemicarbazone. IR spectroscopy of all the com-
plexes confirmed the presence of the individual ligands via their
that a significant weakening of the C@S double bond occurs in all
complexes.
Reactions of copper(I) halides with benzaldehyde thiosemicar-
bazone (R1 = Ph, R2 = R3 = H; Hbtsc) in the presence of triphenyl-
phosphine yield tetra-coordinated mononuclear [CuX(
Hbtsc)(Ph3P)2] (X = I, Br), and dinuclear bromo-bridged [Cu2(
Br)2( -S–
1-S–Hbtsc)2(Ph3P)2], and sulfur-bridged [Cu2( 1-Cl)2(
g
1-S–
l
-
g
g
l
Hbtsc)2 (Ph3P)2] ꢀ 2CH3CN complexes in acetonitrile [29,30].
Introduction of 2-hydroxyl phenyl group (R1) at C2 carbon
(R1 = 2-HO–C6H4, R2, R3 = H, H2stsc) has completely changed the
bonding and nuclearity pattern of the resulting complexes. For
m
(N–H),
vibrational modes. The
805–854 cmꢁ1, which suggests (in agreement with the X-ray data)
m
(C–H)Me
,
m
(C–N),
m
(C@C),
m
(C@N),
m
(O–H) and
m
(P–C)
X = Cl, a tetra-coordinated mononuclear complex, [CuCl(g
1-S–
m
(C@S) thioamide bands are located at
H2stsc)(Ph3P)2] ꢀ CH3CN 3, and for X = Br, I, dinuclear complexes,
[Cu2X2(H2stsc)2- (Ph3P)2] ꢀ CHCl3 (X = I, 1; Br, 2) have been ob-
Fig. 1. Molecular structures of two crystallographically independent molecules of [Cu2I2(H2stsc)2(PPh3)2] ꢀ CHCl3 1 in the unit cell (hydrogen atoms are removed for clarity;
complex 2 has a similar structure).
Table 2
Important bond distances (Å) and bond angles (°) for complexes 1–6 with other related compounds.
Complex no.
Cu–S
Cu–X
Cu–P
Cu–X–Cu
72.02(4)
X–Cu–X
CuꢀꢀꢀCu
Halogen-bridged dimers
1aa
2.334(2)
2.6655(14)
2.7448(15)
(I)
2.4932(16)
2.6328(18)
(Br)
2.268(2)
107.98(4)
3.182
2aa
2.303(2)
2.240(3)
76.91(5)
Cu–S–Cu
103.09(5)
S–Cu–S
3.190
Sulfur-bridged dimers
1ba
2.328(2)
2.585(3)
2.316(3)
2.606(3)
2.3718(17)
2.4745(16)
2.3707(17)
2.4945(16)
2.6144(14)
(I)
2.4387(19)
(Br)
2.6171(10)
(I)
2.3707(17)
(Br)
2.255(2)
78.46(8)
76.73(9)
77.09(4)
75.49(6)
101.54(8)
103.27(9)
102.91(4)
104.51(6)
3.113
2ba (Br)
2.244(3)
3.063
4b
5b
2.2650(14)
2.2511(15)
3.0211(15)
2.9798(19)
Mononuclear complexes
Cu–P
Cu–Cl
Cu–S
P–Cu–P
P–Cu–S
P–Cu–Cl
3a
6b
2.281(2)
2.294(2)
2.2780(18)
2.288(2)
2.433(3)
2.387(3)
126.43(9)
103.59(9)
107.56(10)
108.22(7)
112.12(8)
100.46(9)
106.99(9)
102.01(7)
102.02(7)
2.453(2)
2.367(2)
123.68(7)
a
H2stsc.
H2stscNMe.
b

1588
T.S. Lobana et al. / Polyhedron 28 (2009) 1583–1593
Fig. 2. Molecular structure of [Cu2I2(
plex 5 has a similar structure).
l-S–H2stscNMe)2(PPh3)2] ꢀ 2CH3CN 4 (com-
Fig. 3. Molecular structure of [CuCl(
numbering scheme (compound 6 has a similar structure).
g
1-S–H2stsc)(PPh3)2] ꢀ CH3CN 3 with atomic
tained (Scheme 3). Interestingly, 1 and 2 have both halogen-
bridged (1a, 2a), and sulfur-bridged (1b, 2b) dinuclear species in
their respective unit cells (Scheme 1). This phenomenon of bond
isomerism is unprecedented in metal–thiosemicarbazone chemis-
try. In the preparation of 1–3 complexes, the addition of chloro-
form facilitated completion of reaction, which was partial in
acetonitrile.
ride was reacted with PPh3 followed by the reaction with H2stsc
which yielded
a
sulfur-bridged dimer, [Ag2(g l-S–
1-Cl)2(
H2stsc)2(Ph3P)2] 8, with no bond isomerism unlike that in 7. It is
pointed out here that Hbtsc with silver(I) bromide did not exhibit
bond isomerism [17]. Further, introduction of a methyl group at N1
(R3) atom did not exhibit bond isomerism similar to 7, rather
The introduction of methyl substituent (R3) at N1 (R1 = 2-HO–
C6H4, R2 = H, R3 = Me, H2stscNMe) has yielded only sulfur-bridged
1-S–H2stscNMe)(Ph3P)2] ꢀ 3CH3CN
dinuclear
CH3CN (X = I, 4; Br, 5), unlike bond isomers observed in 1 or 2. Cop-
per(I) chloride has formed a mononuclear complex, [CuCl(
1-S–
complexes,
[Cu2(g
1-X)2(
l-S–H2stscNMe)2(Ph3P)2] ꢀ
mononuclear complexes, [AgBr(
g
9 and [AgCl(
g
1-S–H2stscNMe)(Ph3P)2] ꢀ 3CH3CN 10, were obtained.
Bond isomerism in Cu/Ag complexes occurred only for R1 = 2-
OH–C6H4 with R2 = R3 = H only (1, 2, 7) and introduction of substit-
uents at N1 either prevented this isomerism or changed the
nuclearity.
g
H2stscNMe) (Ph3P)2] ꢀ CH3CN 6 similar to 3 (Scheme 2). Thus the
behavior of H2stsc and H2stscNMe towards copper(I) chloride is
similar but different for copper(I) bromide/iodide.
In order to check the generality of bond isomerism in coinage
metals exhibited by H2stsc, reactions were extended to silver(I) ha-
lides (X = Br, Cl). Silver(I) bromide with H2stsc has formed a dinu-
clear complex, [Ag2Br2(H2stsc)2(Ph3P)2] ꢀ 2CH3CN 7, whose crystal
4.2. Crystal structures of complexes (1–10)
The crystal structures of all the complexes (1–10) have been ob-
structure revealed that it has bromo-bridged [Ag2(
l-Br)2(
g
1-S–
tained and crystal data are given in Table 1. All the complexes crys-
1-Br)2(
ꢀ
H2stsc)2(Ph3P)2] 7a and sulfur-bridged, [Ag2(g l-S–H2stsc)2-
tallized in triclinic system with P1 space group.
(Ph3P)2] 7b moieties in same unit cell, thus exhibiting bond isom-
erism similar to 1 or 2 (Scheme 3). Silver(I) chloride with H2stsc did
not react in CH3CN (or CH3CN/CH3OH), and thus first silver(I) chlo-
The X-ray crystal structures of complexes of salicylaldehyde thi-
osemicarbazone (H2stsc, R1 = 2-HO–C6H4, R2 = R3 = H) with cop-
per(I) halides have shown that each of dinuclear complexes,
Fig. 4. Molecular structure of [Ag2Br2(H2stsc)2(PPh3)2] ꢀ 2CH3CN (7) depicting bond isomers (7a and 7b).

T.S. Lobana et al. / Polyhedron 28 (2009) 1583–1593
1589
[Cu2X2(H2stsc)2(PPh3)2]. CHCl3 (X = I 1, Br 2), co-exist as halogen
bridged [Cu2( -X)2(
1-S–H2stsc)2(PPh3)2] (I 1a, Br 2a) and sulfur
bridged [Cu2X2( -S–H2stsc)2(PPh3)2] (I 1b, Br 2b) dimeric moieties
in the same unit cell (bond isomers, Fig. 1). The central cores, Cu(
X)2Cu, of 1a and 2a, and Cu( -S)2Cu, of 1b and 2b, have unequal
4.3. Packing networks (1–10)
l
g
l
Both the halogen-bridged (1a, 2a) and sulfur-bridged (1b, 2b)
moieties involve intramolecular imino hydrogen–halogen hydro-
gen bonding (–N2HꢀꢀꢀX) (Chart 2). Further, the 2-hydroxy group is
engaged in intramolecular hydrogen bonding with azomethine
nitrogen atom (HOꢀꢀꢀN3–). Two isomeric units, (1a, 1b or 2a, 2b)
are interlinked via amino hydrogen of 1b or 2b with sulfur atom
of 1a or 2a (–HN1HꢀꢀꢀS), forming linear chains running along a axis.
These linear chains show mutual phenyl–phenyl interactions (C–
l-
l
Cu–X or Cu–S distances and form parallelograms (Table 2). The
CuꢀꢀꢀCu distances in halogen bridged dimers 1a/2a are somewhat
longer than those in the iodo-bridged dimers in literature. Like-
wise, the CuꢀꢀꢀCu separation in the sulfur bridged moieties 1b/2b
is marginally shorter than in halogen bridged moieties (1a, 2a).
When methyl group was attached at N1 atom, there was no bond
isomerism, and the CuꢀꢀꢀCu contacts decrease in the sulfur-bridged
Hꢀꢀꢀ
p, 2.892 Å, PPh3) leading to the formation of 2D networks.
The chloroform molecules present in the cavities form weak C–
dimers, [Cu2X2(
l
-S–H2stscNMe)2(PPh3)2] ꢀ 2CH3CN (X: I, 4 (Fig. 2),
Hꢀꢀꢀ
p
interactions {Cl3C–Hꢀꢀꢀ
p (Ph–P)} (1, Fig. 6). Bond isomers (1,
Br, 5) versus those in similar dimeric units 1b and 2b. There is a
marginal effect on Cu–P distances as well as on Cu–S–Cu and S–
Cu–S angles with methyl substitution at N1 atom. The angles at
2) have shown stronger –OHꢀꢀꢀN3 hydrogen bonds, resulting in rel-
atively weaker –N2HꢀꢀꢀI/–N2HꢀꢀꢀBr hydrogen bonds (2.47–2.71 Å),
(for other H-bonding parameters, see supplementary) and this
may be responsible for the presence of bond isomerism in the com-
plexes 1 and 2.
copper or halogen/ sulfur atoms of the central Cu(
Cu( -S)2Cu cores vary in the complementary fashion (Table 2).
Both copper(I) chloride complexes with the ligands H2stsc and
H2stscNMe, namely, [CuCl(
1-S–Htsc)(PPh3)2] {3 (Fig. 3), 6} have
l-X)2Cu and
l
The sulfur-bridged complex 4 has no intramolecular imino
g
hydrogen–iodine (–N2HꢀꢀꢀI) hydrogen bonding unlike that in 1 or
distorted tetrahedral structures. The substitution of methyl group
at N1 results in the marginal changes in Cu–Cl, Cu–S bond distances
and P–Cu–P, P–Cu–S bond angles (Table 2).
As regards silver(I), salicylaldehyde thiosemicarbazone (H2stsc)
with silver(I) bromide has formed
[Ag2Br2(H2stsc)2(PPh3)2] ꢀ 2CH3CN (7), co-existing as bromo-
bridged [Ag2( -Br)2(
1-S–H2stsc)2(PPh3)2] (7a), and sulfur-bridged
[Ag2Br2( -S–H2stsc)2(PPh3)2] (7b) moieties (bond isomers) in the
same unit cell similar to 1 or 2 (Fig. 4). No isomerism was observed
a
dinuclear complex,
l
g
l
with silver(I) chloride and only a sulfur-bridged dimer, [Ag2Cl2(
l
-
-
S–H2stsc)2(PPh3)2] (8) was formed. The central cores, {Ag(
l
Br)2Ag} core of 7a, and {Ag(l-S)2Ag}of 7b, form parallelograms
with unequal Ag–Br or Ag–S distances as shown in Table 3. The
AgꢀꢀꢀAg contacts are longer in the sulfur-bridged isomer 7b
(3.4223 Å) vis-à-vis that in bromo-bridged isomer 7a (3.2021 Å),
and this trend is reverse to that in analogous copper(I) complexes
1 and 2. Complex 8 has a similar bonding pattern and structure as
7b, however, the AgꢀꢀꢀAg contact in the former is shorter than in the
latter complex (Table 3).
The substitution of methyl groups at N1 (H2stscNMe) has pre-
vented dimerisation and instead of forming a dimer similar to 7
or 8, mononuclear tetrahedral complexes, [AgX(g
1-S–
H2stscNMe)(PPh3)2] ꢀ 3CH3CN (Br 9, Cl 10) have been obtained.
Fig. 5. Molecular structure of [AgBr(
plex 10 has a similar structure).
g
1-S–H2stscNMe)(PPh3)2] ꢀ 3CH3CN 9 (com-
Fig. 5 shows the molecular structure of compound 9 (Table 3).
Table 3
0
Selected bond distances (AÅ) and bond angles (°) of silver(I) complexes (7–10).
Complex no.
Ag–S
Ag–X
Ag–P
Ag–X–Ag
X–Ag–X
AgꢀꢀꢀAg
Halogen-bridged dimer
7aa
2.5076(8)
2.7044(4)
2.8310(4)
(Br)
2.4288(8)
70.643(11)
(109.358(11))
3.2021(5)
Ag–S–Ag
S–Ag–S
Sulfur-bridged dimers
7ba
2.5491(8)
2.7811(8)
2.6777(6)
2.8054(5)
2.6563(4)
(Br)
2.5169(5)
(Cl)
2.4238(8)
2.4169(5)
79.76(2)
100.24(2)
3.4223(5)
3.1041(5)
8a
69.615(14)
106.043(17)
Ag–P
Ag–X
P–Ag–P
P–Ag–X
P–Ag–S
Mononuclear complexes
9b
2.6008(16)
2.5924(4)
2.4856(15)
2.4884(16)
2.4716(4)
2.4746(4)
2.8094(8)
(Br)
2.7192(4)
(Cl)
121.90(6)
102.24(4)
103.43(4)
102.440(14)
102.716(13)
101.61(5)
123.93(5)
100.634(13)
125.395(14)
10b
122.859(14)
a
H2stsc.
H2stscNMe.
b

1590
T.S. Lobana et al. / Polyhedron 28 (2009) 1583–1593
PPh3
X
PPh3
X
S
I
S
Cu
Cu
Cu
Cu
H
Cu
N
Cu
S
C
X
S
C
PPh3
S
C
N2
H
H
N2
2 H
H
Me
H
N
weaker
weaker
N
N3
N3
stronger
N3
stronger
OH
C
OH
C
OH
C
H
H
H
1b (I), 2b(Br)
1a (I), 2a (Br)
4
PPh3
PPh3
Br
S
Cu
S
Cu
S
PPh3
Cu
Cl
CNH2CH
N2
H
C
H
N2
C
H
N
N3
Me
Cl
N3
HO
C
OH
C
H
H
3, 6
5
Chart 2.
Fig. 6. 2D view of complex [Cu2Br2(H2stsc)2(PPh3)2] ꢀ CHCl3 1 (complex 2 has a similar packing pattern).
2 (Chart 2). Further, the 2-hydroxy group is engaged in intramolec-
ular hydrogen bonding with azomethine nitrogen atom (HOꢀꢀꢀN3–).
The CH3CN molecules are engaged in hydrogen bonding with ami-
no group (–CH3N1HꢀꢀꢀNCCH3, 2.473 Å) as well as with the hydroxyl
addition, it also showed interactions with the bromine atom
(–BrꢀꢀꢀHCH2CN, 2.989 Å) forming a linear chain along a axis
(Fig. 8). These linear chains are further linked via phenyl–phenyl
interactions (–CHꢀꢀꢀ
p, 2.7300 Å, PPh3) resulting in a 2D polymeric
network along b axis (see Supplementary data). The interactions
group interaction with
p
electrons of C„N group (–HOꢀꢀꢀ
p
). The di-
mers are further interlinked via phenyl–phenyl interactions of
of CH3CN are clearly different in these two complexes (4, 5).
PPh3 (C–Hꢀꢀꢀ
p
, 2.738 Å) along a axis resulting in the formation of
The chlorine atom in [CuCl(g
1-S–H2stc)(PPh3)2] 3 is engaged in
1D chains (Fig. 7). However, compound 5 showed intramolecular
imino hydrogen–bromine (–N2HꢀꢀꢀBr) as well as –N3ꢀꢀꢀHO hydrogen
bonding (Chart 2). The CH3CN molecules showed similar intermo-
hydrogen bonding intramolecularly with imino hydrogen
(–N2HꢀꢀꢀCl), and intermolecularly with hydroxyl hydrogen
(–OHꢀꢀꢀCl) and the resulting network entraps two acetonitrile mol-
ecules, the hydrogen atoms of which are involved in hydrogen
lecular CH3N1HꢀꢀꢀNCCH3 (2.541 Å) and –HOꢀꢀꢀ
p interactions. In

T.S. Lobana et al. / Polyhedron 28 (2009) 1583–1593
1591
Fig. 7. Packing diagram of [Cu2I2(l-S–H2stscNMe)2(PPh3)2] ꢀ 2CH3CN 4.
Fig. 8. Packing diagram of [Cu2Br2(l-S–H2stscNMe)2(PPh3)2] ꢀ 2CH3CN 5.
Fig. 9. Packing diagram of [CuCl(
g
1-S–H2stsc)(PPh3)2] ꢀ CH3CN 3 (complex 6 showed similar packing pattern).
bonding with the chlorine atoms (NCCH2HꢀꢀꢀCl).This dimer is fur-
ther connected to the second dimer via amino hydrogen atoms
(–HN1HꢀꢀꢀNCCH3) along a axis, resulting in 2D polymeric network
(Fig. 9). Complex 6 also showed similar interactions and formed
a 2D network.
The packing diagram of compound 7 shows two crystallo-
graphically independent dimeric units, bromo-bridged dimer 7a,
and sulfur-bridged dimer 7b in the same unit cell. In the sul-
fur-bridged (7b) and bromo-bridged isomeric units (7a) have
similar type of intramolecular hydrogen bonding between imino
hydrogen and halogen (–N2HꢀꢀꢀBr) as well as between azomethine
nitrogen and hydroxyl oxygen atoms (OHꢀꢀꢀ N3–). Two isomeric
units are further linked via intermolecular hydrogen bonding be-
tween amino hydrogen of sulfur-bridged isomer 7b with sulfur
atom of bromo-bridged isomer 7a (–HN1HꢀꢀꢀS), forming linear
chains running along a axis. Two H-bonded acetonitrile mole-
cules reside in the interstitial spaces are present in the cavity
created between parallel chains and are involved in acetoni-
trile-terminal bromine interactions(C–HꢀꢀꢀBr) with terminal
bromine (Fig. 10).

1592
T.S. Lobana et al. / Polyhedron 28 (2009) 1583–1593
Fig. 10. 2D network of [Ag2Br2(H2stsc)2(PPh3)2] ꢀ 2CH3CN 7 having alternate bromo-bridged (7a, green) and sulfur-bridged (7b, red) dimeric chains. (For interpretation of the
references to color in this figure legend, the reader is referred to the web version of this article.)
Fig. 11. 1D linear polymeric chain of complex [Ag2Cl2(l-S–H2stsc)2(PPh3)2] 8.
Fig. 12. Packing diagram of complex [AgBr(
g
1-S–H2stscNMe)(PPh3)2] ꢀ 3CH3CN 9 (complex 10 shows similar packing pattern).

T.S. Lobana et al. / Polyhedron 28 (2009) 1583–1593
1593
The sulfur-bridged silver(I) dimer 8 shows intramolecular
Acknowledgements
hydrogen bonding between imino hydrogen and chlorine atoms
(–N2HꢀꢀꢀCl). The dimer units are further linked to each other by
intermolecular OHꢀꢀꢀCl and ClꢀꢀꢀHPh hydrogen bonding, resulting
in a linear polymeric 1D chain (Fig. 11).
The packing diagram of complex 9 reveals the presence of intra-
molecular –N2HꢀꢀꢀBr hydrogen bonding. Two monomer molecules
are interlinked via –HOꢀꢀꢀBr hydrogens generating a 20 membered
cavity. The hydrogen atoms of methyl group at N1 atom exhibit
Financial assistance (SK) from CSIR (F. No. 9/254(159)/2005-
EMR-I), New Delhi, is gratefully acknowledged. The authors thank
Matthias Zeller of Youngstown State University, USA, for X-ray
crystallography.
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6. Conclusion
The presence of 2-hydroxyphenyl (R1) substituent at C2 carbon
(H2stsc, R1 = 2-HO–C6H4, R2 = R3 = H) appears to be responsible for
the bond isomerism (
The introduction of methyl substituent at N1 atom (H2stscNMe)
has led to the formation of only –S bridged dimers (4, 5). Both
H2stsc and H2stscNMe with copper(I) chloride form mononuclear
complexes, 3 and 6. Silver(I) bromide with H2stsc formed 7 which
again showed bond isomerism. Finally, silver(I) chloride with
H2stsc and silver(I) bromide/chloride with H2stscNMe have formed
l-X, l-S bridging) as exhibited by 1 and 2.
l
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Supplementary data
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683846, 683847, 713440 and 713441 contain the supplementary
crystallographic data for 3, 2, 1, 6, 5, 4, 8, 7, 9 and 10, respectively.
These data can be obtained free of charge via http://www.ccdc.ca-
m.ac.uk/conts/retrieving.html, or from the Cambridge Crystallo-
graphic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK;
fax: (+44) 1223-336-033; or e-mail: deposit@ccdc.cam.ac.uk.
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