Molecular and supramolecular structures of 1-phenyl-4-phenylacetyl-2- thiosemicarbazide (H2L) and its complexes with diphenyllead(IV) chloride and acetate

Article abstract of DOI:10.1002/zaac.200570052

Reaction of 1-phenyl-4-phenylacetyl-2-thiosemicarbazide (H₂L) with diphenyllead(IV) dichloride and acetate afforded the complexes [PbPh ₂Cl₂(H₂L)₂] and [PbPh₂L]. The ligand and the complexes were characterized by elemental analyses, ¹H and ¹³C NMR spectroscopy and X-ray crystallography. In the asymmetric unit of crystals of the ligand there are four independent molecules of H₂L and four molecules of water, which associate in the lattice as two independent sheets. The complex [PbPh₂Cl ₂(H₂L)₂]·4MeOH has slightly distorted all-trans octahedral geometry around the lead atom, and the fact that the ligand is S-bound rather than O-bound suggests that PbPh₂Cl₂ behaves as a "soft" Lewis acid. Hydrogen bonds involving NH groups, Cl atoms and MeOH molecules form a three-dimensional supramolecular structure. In [PbPh₂L]·Me₂CO, the L^2- anion bridges between two metal centres, binding to one strongly via the N and S atoms and weakly via the O atom, and to the other via the O atom, thus creating polymeric chains along the b axis. The double deprotonation and metallation of H ₂L induce significant changes in its configuration and lengthen the C-S and C-O bonds, suggesting an evolution of the dianion towards a thiol-enol form.

Full text of DOI:10.1002/zaac.200570052

Molecular and Supramolecular Structures of 1-Phenyl-4-phenylacetyl-2-
thiosemicarbazide (H L) and its Complexes with Diphenyllead(IV) Chloride and
2
Acetate
,
a
b
b
a
a
a
a
J. S. Casas* , E. E. Castellano , J. Ellena , M. S. Garc ´ı a-Tasende , A. S a´ nchez , J. Sordo , and A. Touceda
a
Santiago de Compostela/Spain, Departamento de Qu ´ı mica Inorg a´ nica, Universidade de Santiago de Compostela
Sao Carlos/Brazil, Instituto de F ´ı sica de S a˜ o Carlos, Universidade de S a˜ o Paulo
b
Received January 12th, 2005; accepted February 24th, 2005.
Abstract. Reaction of 1-phenyl-4-phenylacetyl-2-thiosemicarbazide
L) with diphenyllead(IV) dichloride and acetate afforded the
complexes [PbPh Cl (H L) ] and [PbPh L]. The ligand and the
complexes were characterized by elemental analyses, H and
NMR spectroscopy and X-ray crystallography. In the asymmetric
unit of crystals of the ligand there are four independent molecules
form
[PbPh
a
three-dimensional supramolecular structure. In
2
Ϫ
(H
2
2
2
L]·Me CO, the L anion bridges between two metal cen-
2
2
2
2
2
tres, binding to one strongly via the N and S atoms and weakly via
the O atom, and to the other via the O atom, thus creating polyme-
ric chains along the b axis. The double deprotonation and metalla-
1
13
C
2
tion of H L induce significant changes in its configuration and
of H
2
L and four molecules of water, which associate in the lattice
Cl (H L) ]·4MeOH
lengthen the C-S and C-O bonds, suggesting an evolution of the
dianion towards a thiol-enol form.
as two independent sheets. The complex [PbPh
2
2
2
2
has slightly distorted all-trans octahedral geometry around the lead
atom, and the fact that the ligand is S-bound rather than O-bound
suggests that PbPh
bonds involving NH groups, Cl atoms and MeOH molecules
2
Cl
2
behaves as a “soft” Lewis acid. Hydrogen
Keywords: Diphenyllead(IV) complexes; Thiosemicarbazide com-
plexes; Crystal structures; H, C and Pb NMR
1
18
207
Introduction
That diorganolead dichlorides behave as Lewis acids has
long been known [1]. Pfeiffer et al. have prepared the adduct
[
PbPh Cl (Py) ] in 1916 [2]. However, it was not until almost
2 2 4
fifty years later that more systematic exploration of this type
of complex began with the synthesis and identification, usu-
ally by analytical and spectroscopic methods, of several 1:1
and 1:2 adducts [3], and the first X-ray diffraction study of
one of these adducts was not published until the end of the
eighties [4]. Even today only a limited number of structures
of these compounds have been identified [5].
1
use of IR and H NMR spectroscopy [7, 8]. As far as we
know, no H L complex has hitherto been studied by X-ray
crystallography. Here we report the structures of H L and
of the complexes [PbPh Cl (H L) ]·4MeOH and
PbPh L]·Me CO, the latter of which contains the L
2
2
2
2
2
2
2Ϫ
[
2 2
In continuance of our work on the coordination chemis-
try of diorganolead(IV) compounds, and searching specifi-
cally for chelating agents that may prove useful for treating
organolead poisoning (currently an unresolved and almost
unexplored therapeutic challenge [6]), we have studied the
anion. The structure of [PbPh Cl (H L) ] shows that
2
2
2
2
PbPh Cl coordinates via S in preference to O, whereas the
2
2
[
PbPh L] complex displays a new lead coordination sphere
2
and a ligand configuration that differs significantly from
that of the free ligand. However, the ligand did not cyclize
as do certain closely related thiosemicarbazones [9] and
other ligands with extended urea-like chains of more than
five atoms [10].
interaction of PbPh X (X ϭ Cl, AcO) with the title thiose-
2
2
micarbazide, H L.
2
Neutral H L has several basic centres through which it
2
can form stable adducts with Lewis acids, and the depro-
tonability of two of its N-H groups opens up interesting
additional possibilities. Several transition metal complexes
Experimental Section
of H L have in fact been isolated and analysed, mainly by
2
Phenylacetylhydrazine (Aldrich), phenylisothiocyanate (Aldrich)
and dichlorodiphenyllead (ABCR) were all of reagent grade and
were used without further purification. Diphenyllead(IV) acetate
solution was freshly prepared by reacting dichlorodiphenyllead(IV)
with silver acetate in methanol and removing the precipitated sil-
ver chloride.
*
Prof. Dr. Jos e´ S. Casas
Departamento de Qu ´ı mica Inorg a´ nica
Facultade de Farmacia
Universidade de Santiago de Compostela
E-15782 Santiago de Compostela, Galicia/Spain
e-mail: qiscasas@usc.es
Elemental analyses for C, H, N and S were performed with a Fi-
sons 1108 microanalyser. Melting points were determined with a
Z. Anorg. Allg. Chem. 2005, 631, 2247Ϫ2252
DOI: 10.1002/zaac.200570052
© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
2247

J. S. Casas, E. E. Castellano, J. Ellena, M. S. Garc ´ı a-Tasende, A. S a´ nchez, J. Sordo, A. Touceda
2 2
Table 1 Crystal and refinement data for H L·H O and the complexes
H
2
L·H
2
O
[PbPh
2
Cl
2
(H
2
L)
2
]·4MeOH
Pb
[PbPh
2
L]·Me
2
CO
Molecular formula
Molecular weight
Temperature /K
C
60
H
68
N
12
O
8
S
4
C
46
H56Cl
2
N
6
O
6
S
2
30 29 3 2
C H N O PbS
1213.50
120(2)
1131.18
100(2)
0.71073
702.81
293(2)
˚
Wavelength /A
0.71073
triclinic
0.71073
monoclinic
P2 /c
Crystal system
Space group
monoclinic
P2 /c
¯
P1
10.2860(2)
1
1
˚
a /A
8.11300(10)
9.44600(10)
31.5070(4)
11.102(2)
10.2641(14)
23.865(3)
˚
b /A
10.33970(10)
29.5301(4)
99.2417(4)
99.4960(4)
92.3462(6)
3050.06(8)
2
0.220
0.925 / 0.983
1280
˚
c /A
α /°
β /°
γ /°
91.6770(10)
92.366(3)
˚
3
V /A
2413.52(5)
2
3.745
0.552 / 0.929
1140
2717.2(7)
4
6.318
0.570 / 1
1376
Z
Ϫ1
Absorption coefficient /mm
Tmin / Tmax
F(000)
Crystal size /mm
θ Range for data collection /°
Index ranges
Reflections collected
Independent reflections / Rint
Goodness-of-fit on F2
R1, wR2 [I>2σ(I)]
0.36 x 0.14 x 0.08
2.01Ϫ25.00
Ϫ12, 12; Ϫ12, 12; Ϫ34, 35
21025
10681 / 0.067
1.081
0.0552, 0.1402
CCDC-259878
0.18 x 0.12 x 0.02
2.25Ϫ27.52
Ϫ10, 10; Ϫ12, 12; Ϫ40, 40
15252
5528 / 0.071
1.079
0.29 x 0.16 x 0.04
1.71Ϫ26.37
Ϫ13, 13; 0, 12; 0, 28
10485
5382 / 0.036
1.028
0.0343, 0.0720
CCDC-259880
0.0377, 0.0816
CCDC-259879
Deposit No.
Gallenkamp electrically heated apparatus. Electrospray mass spec-
tra (ESMS) of 5x10 M solutions in mixtures of methanol and
Data: C42
H
40
N
6
O
2
S
2
Cl
2
Pb (1003.4); C 50.4 (calc. 50.3); H 4.0 (4.0);
Ϫ3
N 8.5 (8.4); S 6.5 (6.4) %. ESMS: m/z ϭ 647 (PbPh
2
LϩH, 100 %),
): δ ϭ 10.16 (s, 1 H,
N(3)H), 9.66 (s, 1 H, N(2)H), 9.60 (s, 1 H, N(1)H), 8.11 (Ho-Ph Pb,
Pb, J( H- Pb) ϭ 83 Hz),
1
1
% or 2 % formic acid were recorded on a Hewlett-Packard
2 6
286 (H LϩH, 75 %). H NMR (DMSO-d
HP1100 in positive ion mode with a quadrupole analyser using a
2
Ϫ1
3
1
207
4
1
207
7
L min flow of nitrogen as both drying gas (temperature 325 °C)
J( H- Pb) ϭ 205 Hz), 7.60 (Hm-Ph
7.00-7.50 (m, 12 H, Ph-H and Hp-Ph
NMR (DMSO-d
(C2), 133.5 (Co-Ph
2
1
3
and nebulizing gas (nebulizer pressure 30 psi); the capillary voltage
was 4.0 kV, collision-induced dissociation voltages were typically
varied from 10 to 200 V, and samples were automatically injected
2
Pb), 3.50 (s, 2H, C(2)H
2
).
C
6
): δ ϭ 181.1 (C1), 170.4 (Cipso-Ph
2
Pb), 169.9
Pb), J( C- Pb) ϭ 127.2 Hz), 129.6 (Cm-
Pb), J( C- Pb) ϭ 199.8 Hz), 129.3 (Cp-Ph Pb), 139.5-126.8
2
13 207
2
Ϫ1
3
13 207
into the spectrometer at a flow rate of 0.2 mL min . The stated
Ph
2
2
2
07
masses of the metal-containing species are based on the isotope
(C-Ph), 40.3 (C3). Pb NMR (DMSO): δ ϭ Ϫ511. Recrystalliza-
tion of this solid from 1:1 ethanol/acetone afforded single crystals
208
1
13
207
Pb. H, C and Pb NMR spectra were recorded at room tem-
perature in DMSO using Bruker AMX 300 or AMX 500 spec-
trometers. Chemical shifts in ppm were referred to TMS using the
of [PbPh
fractometry.
2 2 2 2
Cl (H L) ]·4MeOH that were suitable for X-ray dif-
1
13
solvent signal for H and C spectra and using a saturated solution
of PbPh in CDCl (δ ϭ Ϫ178.0 ppm) as external reference for
Pb spectra. Elemental analyses and all spectroscopic measure-
[
(
PbPh
2
L]·Me
0.17 g, 0.35 mmol, 20 mL of methanol) was slowly added to a sus-
L (0.10 g, 0.35 mmol, 5 mL of methanol). The yellow
2 2 2
CO. A solution of freshly prepared PbPh (OAc)
4
3
207
pension of H
2
ments were carried out in the RIAIDT services of the University
of Santiago de Compostela.
solution obtained was heated and stirred for 9 hours. After cooling
to room temperature, the solvent was partially removed in a high-
vacuum line, leaving a green oil that was dissolved in acetone. Slow
evaporation of the solvent afforded a yellow crystalline solid that
was filtered out and dried under vacuum. Yield: 20 %. M.p. 187 °C
2
H L. The ligand was prepared following a published method [7] by
reacting phenylacetylhydrazine (15.60 g, 0.10 mol) and phenyliso-
thiocyanate (13.60 mL, 0.10 mol) in refluxing ethanol (75 mL) for
half an hour. Upon cooling, the reaction mixture afforded a white
crystalline solid that was filtered out and recrystallized from etha-
(
D). Analytical Data: C30
29 3 2
H N O SPb (702.81); C 50.9 (calc. 51.2);
H 3.9 (4.3); N 5.8 (5.9); S 4.5 (4.5) %. ESMS: m/z ϭ 646
1
(
PbPhLϩH, 100 %). H NMR (DMSO-d
6
): δ ϭ 8.56 (s, 1 H,
Pb, J( H- Pb) ϭ 155 Hz), 7.55 (d,
Pb), 7.40 (t, 2 H, Hp-Ph Pb), 7.21,
nol. Yield: 85 %. M.p. 165 °C. Analytical Data: C15
H
15
N
3
OS
285.4); C 63.1 (calc. 63.2); H 5.4 (5.2); N 14.8 (14.8); S 11.1
11.3) %. ESMS: m/z ϭ 285 (MϩH, 55 %), 151 (M-SCNPh, 20 %).
3
1
207
N(1)H), 7.75 (d, 2 H, Ho-Ph
2
(
(
4
H, Ph-H), 7.51 (t, 4 H, Hm-Ph
2
2
1
7.18, 6.75 (6 H, Ph-H), 3.87 (s, 2 H, C(2)H ), 2.10 (6 H, (CH ) CO).
H NMR (DMSO-d
6
): δ ϭ 10.21 (s, 1 H, N(3)H), 9.71 (s, 1 H,
2
3 2
1
1
3
13
C NMR (DMSO-d
Pb) ϭ 955 Hz), 148.1 (C2), 134.8 (Co-Ph Pb, J( C- Pb) ϭ
2
6
): δ ϭ 172.0 (C1), 160.3 (Cipso-Ph
2
Pb, J( C-
N(2)H), 9.65 (s, 1 H, N(1)H), 7.00-7.75 (m, 10 H, Ph-H), 3.60 (s,
2
07
2
13 207
1
3
2
1
H, C(2)H
2
). C NMR (DMSO-d
6
): δ ϭ 181.5 (C1), 169.4 (C2),
L·H O that
3
13 207
113 Hz), 130.1 (Cm-Ph
2
Pb, J( C- Pb) ϭ 148 Hz], 129.8 (Cp-
39.5-125.5 (C-Ph), 40.3 (C3). Single crystals of H
2
2
Ph Pb), 142.5, 117.5 (C-Ph), signals for C3 and DMSO overlap.
2
were suitable for X-ray diffractometry were obtained from the
mother liquor.
2
07
Pb NMR (DMSO): δ ϭ Ϫ229.
[
PbPh
2
Cl
Cl
2
(H
2 2 2
L) ]. A suspension of H L (0.10 g, 0.35 mmol) and
X-ray structure determinations
PbPh
2
2
(0.07 g, 0.17 mmol) in 10 mL of methanol was stirred at
room temperature for 9 hours, and the white precipitate was filtered
2 2 2 2 2
X-ray data for H L and [PbPh Cl (H L) ]·4MeOH were collected
out and dried under vacuum. Yield: 50 %. M.p: 155 °C. Analytical
at the S a˜ o Carlos Institute of Physics of the University of S a˜ o
2248
© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
zaac.wiley-vch.de
Z. Anorg. Allg. Chem. 2005, 631, 2247Ϫ2252

Structures of 1-Phenyl-4-phenylacetyl-2-thiosemicarbazide (H
2
L) and its Complexes with Diphenyllead(IV) Chloride and Acetate
˚
2 2
Table 3 Hydrogen bonds and angles in H L·H O (in A, °)
D-H···A
d(D-H)
d(H···A)
d(D···A)
<(DHA)
N(11)-H(11)···O(1W)
N(11)-H(11)···N(13)
N(12)-H(12)···S(1)
0.88
0.88
0.88
0.88
0.81
0.97
0.88
0.88
0.88
0.88
0.85
0.85
0.88
0.88
0.88
0.88
0.91
0.87
0.88
0.88
0.88
0.88
0.85
0.85
1.99
2.35
2.40
2.59
2.08
1.88
1.99
2.36
2.39
2.67
2.07
1.99
2.00
2.34
2.41
2.68
1.98
1.96
1.99
2.36
2.40
2.58
2.07
2.15
2.828(2)
2.740(3)
3.2547(19)
3.3690(19)
2.882(2)
2.846(2)
2.822(2)
2.747(3)
3.229(2)
3.426(2)
2.837(2)
2.806(2)
2.834(2)
2.728(3)
3.246(2)
3.4295(19)
2.860(2)
2.820(2)
2.821(2)
2.744(3)
3.250(2)
3.3559(19)
2.841(2)
2.859(2)
158.4
106.7
164.5
148.8
170.8
172.2
157.9
106.6
160.5
145.3
149.9
160.4
158.3
106.8
158.7
144.3
161.4
172.5
158.0
106.7
163.4
148.3
150.6
140.9
i
N(13)-H(13)···S(3)
ii
O(1W)-H(11W)···O(3)
O(1W)-H(12W)···O(3)
iii
iv
N(21)-H(21)···O(2W)
N(21)-H(21)···N(23)
v
N(22)-H(22)···S(2)
iv
N(23)-H(23)···S(4)
2 2
Figure 1 Molecular structure of H L·H O. Displacement ellipsoids
iv
O(2W)-H(21W)···O(4)
O(2W)-H(22W)···O(4)
N(31)-H(31)···O(3W)
N(31)-H(31)···N(33)
are drawn at the 30 % probability level (for the sake of clarity only
one of the four molecules in the asymmetric unit is shown, mol-
ecule 1).
ii
iii
N(32)-H(32)···S(3)
N(33)-H(33)···S(1)
i
Paulo using a Nonius Kappa CCD diffractometer, and X-ray data
for [PbPh L]·Me CO were collected at the RIAIDT services of the
2 2
O(3W)-H(31W)···O(1)
O(3W)-H(32W)···O(1)
vi
iv
N(41)-H(41)···O(4W)
N(41)-H(41)···N(43)
University of Santiago de Compostela using a Bruker SMART
CCD-1000 diffractometer. Data were corrected for absorption by
multi-scan [11]. The structures were solved by the Patterson method
and refined using SHELXS-97 [12]. All the H atoms were intro-
duced in calculated positions. Molecular graphics were obtained
with ORTEP [13] and PLATON [14]. Crystal data, experimental
details and refinement results are listed in Table 1. Additional infor-
mation on the structure determinations has been deposited at the
Cambridge Crystallographic Data Centre (see Table 1).
iv
N(42)-H(42)···S(4)
iv
N(43)-H(43)···S(2)
v
O(4W)-H(41W)···O(2)
O(4W)-H(42W)···O(2)
ii
Symmetry operators: Ϫx,Ϫyϩ1,Ϫzϩ1, x,yϩ1,z; iii Ϫxϩ1,Ϫyϩ1,Ϫzϩ1;
Ϫxϩ1,Ϫyϩ1,Ϫz; Ϫxϩ2,Ϫyϩ1,Ϫz; x,yϪ1,z.
i
ii
iv
v
vi
molecular structure, hydrogen bonds involving the N(2)H
group and the S atom link the two enantiomers of each
molecule in dimers (see Table 3 and Fig. 2), and additional
hydrogen bond connect the dimers of molecule 1 with those
of molecule 3 [N(13)H···S(3) and N(33)H···S(1)] and the di-
mers of molecule 2 with those of molecule 4 [N(23)-
H(23)···S(4) and N(43)-H(43)···S(2) ], giving rise to two
similar but independent staircase-like chains (1 and 2,
respectively; see Fig. 2 for chain 1). Finally, chains of the
same type are linked in sheets via water molecules (see Table
Results and Discussion
Crystal structures
H L·H O. The molecular structure of the monohydrate of
2
2
H L is shown in Figure 1, and selected distances and angles
iv
iv
2
are listed in Table 2.
Not surprisingly in view of the highly flexible backbone
of H L, the asymmetric unit contains four independent
2
molecules (molecules 1 to 4), and since the space group is
centrosymmetric each of these four molecules exists in both
enantiomeric forms. However, all four have very similar
conformations, differing only slightly in bond distances,
bond angles and dihedral angles. The C-S and C-O bond
3
and Fig. 3), so that sheets of type 1 chains alternate with
sheets of type 2 chains parallel to ab plane. There are no
significant interactions between sheets.
˚
˚
lengths, 1.699(2)-1.702(2) A and 1.226(3)-1.231(3) A,
respectively, suggest double bond character. In the supra-
˚
Table 2 Selected bond lenghts/A and angles/° in H
2
L·H
2
O
Parametera
Mol. 1
Mol. 2
Mol. 3
Mol. 4
S-C(1)
O-C(2)
N(1)-C(1)
N(2)-C(1)
N(2)-N(3)
N(3)-C(2)
N(1)-C(1)-S
N(1)-C(1)-N(2)
N(2)-C(1)-S
C(1)-N(2)-N(3)
N(2)-N(3)-C(2)
C(3)-C(2)-O
N(3)-C(2)-O
N(3)-C(2)-C(3)
1.700(2)
1.231(3)
1.336(3)
1.348(3)
1.387(3)
1.347(3)
125.21(17)
117.6(2)
117.20(16)
123.75(18)
120.54(18)
122.5(2)
1.702(2)
1.230(3)
1.330(3)
1.351(3)
1.390(3)
1.350(3)
124.65(18)
117.8(2)
117.57(17)
123.78(19)
120.63(19)
122.9(2)
122.7(2)
114.4(2)
1.699(2)
1.226(3)
1.334(3)
1.350(3)
1.383(3)
1.355(3)
125.01(18)
117.4(2)
117.62(17)
123.39(19)
120.79(19)
122.8(2)
1.702(2)
1.226(3)
1.333(3)
1.353(3)
1.390(2)
1.348(3)
125.38(18)
117.56(19)
117.04(16)
123.78(19)
120.40(18)
123.2(2)
Figure 2 Part of one of the staircase-like chains (chain 1) showing
122.2(2)
115.18(19)
122.8(2)
114.34(19)
122.4(2)
114.4(2)
the hydrogen bonds between dimers 1 and 3 in H
2
L·H
2
O (for the
sake of clarity the phenyl groups have been omitted).
Z. Anorg. Allg. Chem. 2005, 631, 2247Ϫ2252
zaac.wiley-vch.de
© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
2249

J. S. Casas, E. E. Castellano, J. Ellena, M. S. Garc ´ı a-Tasende, A. S a´ nchez, J. Sordo, A. Touceda
˚
Table 4 Bond lenghts/A and angles/° in [PbPh
2
Cl
2
(H
2
L)
2
]·4MeOH
Pb-C(31)
Pb-Cl
Pb-S
2.186(4)
2.7449(10)
2.8237(11)
1.716(5)
1.219(5)
1.378(6)
1.425(6)
180.0(2)
90.53(11)
89.47(11)
180.00(5)
90.71(11)
89.29(11)
95.13(3)
84.87(3)
180.00(3)
N(1)-C(1)
1.332(6)
1.429(6)
1.328(5)
1.389(5)
1.360(6)
1.512(6)
N(1)-C(4)
N(2)-C(1)
N(2)-N(3)
N(3)-C(2)
C(2)-C(3)
S-C(1)
O(1)-C(2)
O(1S)-C(1S)
O(2S)-C(2S)
C(31)-Pb-C(31)
i
N(1)-C(1)-S
N(1)-C(1)-N(2)
N(2)-C(1)-S
C(1)-N(2)-N(3)
N(2)-N(3)-C(2)
O(1)-C(2)-C(3)
O(1)-C(2)-N(3)
N(3)-C(2)-C(3)
121.0(3)
117.5(4)
121.5(3)
120.1(4)
120.9(4)
123.5(5)
122.6(4)
113.9(4)
i
C(31)-Pb-Cl
C(31)-Pb-Cl
i
Cl -Pb-Cl
i
C(31)-Pb-S
C(31)-Pb-S
Cl-Pb-S
i
Cl-Pb-S
S -Pb-S
i
Symmetry operators: i Ϫx,Ϫy,Ϫz
as in the free ligand, and, as the result of rotation about
C(1)-N(2), to the C-S bond. This configuration allows each
Cl atom to form hydrogen bonds both with the nearest
N(1)-H group of its own molecule (which reinforces the
rather weak monodentate S-coordination of the ligand) and
with an N(3)-H group belonging to a neighbouring mol-
ecule (which links the molecules in polymeric chains); see
Figure 5 and Table 5. The phenyl groups prevent the forma-
tion of more complex supramolecular structure by direct
interaction among these chains, but the presence of the
methanol molecules allows indirect interactions, a sequence
of three hydrogen bonds linking the N(2)-H groups on each
side of one chain to the O(1) atoms on the nearest side
of another via two methanol molecules (see Figure 6 and
Table 5).
Figure 3 Hydrogen bonding involving the water molecules in
L·H O (phenyl groups have been omitted).
H
2
2
[
PbPh Cl (H L) ]·4MeOH. The molecular structure of
2 2 2 2
[
PbPh Cl (H L) ]·4MeOH is shown in Figure 4, and selec-
2 2 2 2
IV
ted distances and angles are listed in Table 4. The Pb has
an all-trans octahedral C Cl S environment, with the main
2
2 2
distortions affecting the angles Cl-Pb-S [95.13(3)°] and Cl-
i
Pb-S [84.87(3)°]. A similar environment has been observed
in [PbPh Cl (HSTSC) ] (HSTSC ϭ salicylaldehyde thiose-
2
2
2
micarbazone) [15], in which the Pb-C and Pb-S distances
are very similar to, and the Pb-Cl bonds a little shorter than
those of the the new complex. In the case of this new ad-
duct, the fact that coordination via the O atom instead of
the S atom would probably not have meant significant
changes in the steric demands of the ligand (see the formula
[
PbPh L]·Me CO. Unlike the reaction of H L with di-
2 2 2
phenyllead(IV) chloride, its reaction with diphenyllead(IV)
acetate results in its double deprotonation and the forma-
of H L in the Introduction) suggests that the observed co-
2
tion of [PbPh L]. The asymmetric unit of this complex,
2
ordination via the S atom is due to PbPh Cl behaving as a
2
2
which also includes an acetone molecule, is shown in Figure
“soft” Lewis acid [16].
7
, and selected distances and angles are listed in Table 6.
The coordination of H L to the Pb atom induces only
2Ϫ
IV
2
In [PbPh L], the L ligand bridges between two Ph Pb
2
2
minor changes in its bond lengths (the largest concern the
C-S bonds, as is natural), but the configuration of the ace-
tylthiosemicarbazide chain is significantly altered. Apart
from rotations of the phenyl groups minimizing steric inter-
actions, the N(2)-N(3) bond is now cis to both C(2)-O(1),
units, coordinating to one strongly through its S and N(3)
atoms and more weakly through the O atom, and to the
other rather strongly via the O atom. Probably because of
IV
the bulkiness of the ligand, the Pb has a very distorted
C NO S environment, which could be described as an octa-
2
2
hedron or a trapezoidal bipyramid with the main distor-
tions in the angles C-Pb-C [143.5(2)°], O-Pb-N(3)
Figure 4 Molecular structure of [PbPh
2
Cl
2
(H
2
L)
2
]·4MeOH (solvent
Figure 5 Intra- and intermolecular N-H···Cl hydrogen bonds in
molecules were omitted for clarity).
[PbPh
2 2 2 2
Cl (H L) ]·4MeOH (see Table 5).
2250
© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
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Z. Anorg. Allg. Chem. 2005, 631, 2247Ϫ2252

2
Structures of 1-Phenyl-4-phenylacetyl-2-thiosemicarbazide (H L) and its Complexes with Diphenyllead(IV) Chloride and Acetate
Figure
PbPh
omitted.
6
N(2)H···MeOH···MeOH···O(1) hydrogen bridges in
(H L) ]·4MeOH (see Table 5). Phenyl groups have been
[
2
Cl
2
2
2
i
[
47.14(3)°] and O-Pb-O [163.35(7)°]. No previous X-ray
IV
study of a Pb complex has ever found an environment of
this kind [17]. The arrangement of the donor atoms of the
ligand in about one half of the equatorial plane of the com-
plex leaves enough room for the C(Ph)-Pb-C(Ph) unit to
bend about 40° from linear which prevents the sulphur
atom of a neighbouring molecule from approching the me-
tal (Pb-S ϭ 4.037 A). The Pb-C bonds are similar in
strength to those previously found in diphenyllead(IV) com-
plexes [15].
ii
˚
2 2
Figure 7 The asymmetric unit of [PbPh L]·Me CO (solvent mol-
ecule omitted).
The coordination pattern described above gives rise to a
polymeric chain running in the b direction (see Figure 8).
probably dissociates in DMSO. This conclusion is sup-
ported by the 2 Pb NMR chemical shift, Ϫ511 ppm, being
very close to that of PbPh Cl in DMSO (Ϫ508.4 ppm).
07
The solvent molecule is attached to this chain by an NH···O
ii
hydrogen
bond
[N(1)-H(1)···O(1S) ,
ii
ϭ
2
2
1
Ϫxϩ1,Ϫyϩ2,Ϫzϩ1: N(1)-H(1) 0.86, H(1)···O(1S) 2.19,
In the H NMR spectrum of [PbPh L]·Me CO there are
2 2
˚
N(1)···O(1S) 3.000(7) A, N(1)-H(1)···O(1S) 157.6°].
no signals corresponding to N(2)H and N(3)H (in keeping
with the double deprotonation of the ligand) and the N(1)H
signal shifts to higher field. The main effects of depro-
tonation and coordination on the 13C NMR spectrum are
the shielding of C(2) (by about 20 ppm) and C(1) (by about
10 ppm), these shifts suggest a very significant evolution of
the ligand towards the thiol-enol form.
The double deprotonation of H L and the coordination
2
of the resulting dianion to the diphenyllead(IV) causes
major bond lenght and configuration changes in the ligand.
The changes in configuration place the C-S and C-O bonds
respectively cis and trans to N(2)-N(3), with
O,C(2),N(3),N(2),C(1),S and N(1) all coplanar. The main
changes in bond length lengthen the S-C(1), O-C(2) and
N(1)-C(1) bonds and shorten N(2)-C(1) and N(3)-C(2).
The coupling constants corresponding to the organome-
tal moiety, 3J( H- Pb) ϭ 155 Hz and 1J( C- Pb) ϭ
1
207
13 207
955 Hz are smaller than is usual for coordination number
NMR studies
˚
2 2
Table 6 Bond lengths/A and angles/° in [PbPh L]·Me CO
1
The H NMR spectrum of H L was interpreted as pre-
2
1
3
viously [8] and in the C NMR spectrum, the most deshi-
elded signals were assigned to CS and CO (in that order)
Pb-C(31)
Pb-C(41)
Pb-N(3)
Pb-S
Pb-O
Pb-O
2.169(6)
2.196(6)
2.281(5)
2.5492(17)
2.579(4)
3.011(5)
1.768(7)
143.5(2)
103.6(2)
O-C(2)
1.276(7)
1.388(8)
1.404(8)
1.287(9)
1.382(7)
1.322(8)
N(1)-C(1)
N(1)-C(4)
N(2)-C(1)
N(2)-N(3)
N(3)-C(2)
and the least deshielded to the ϪCH Ϫ group.
2
i
1
13
In the H and C NMR spectra of [PbPh Cl (H L) ],
2
2
2
2
n
1
207
n
13
both the chemical shifts and the J( H- Pb) and J( C-
S-C(1)
2
07
Pb) coupling constants practically coincide with those of
PbPh Cl [14] and free H L, suggesting that the complex
C(31)-Pb-C(41)
C(31)-Pb-N(3)
C(41)-Pb-N(3)
C(31)-Pb-S
C(41)-Pb-S
N(3)-Pb-S
C(31)-Pb-O
C(41)-Pb-O
N(3)-Pb-O
S-Pb-O
N(3)-Pb-O
N(1)-C(4)-C(9)
N(2)-C(1)-S
N(1)-C(1)-S
O-C(2)-N(3)
47.14(15)
117.5(6)
127.8(6)
112.4(5)
117.4(6)
121.6(6)
121.1(6)
129.6(6)
114.5(6)
120.4(5)
114.7(4)
124.9(4)
119.8(7)
2
2
2
98.9(2)
106.69(17)
106.68(17)
74.96(13)
88.02(19)
87.05(19)
149.30(16)
122.08(10)
74.49(11)
88.28(19)
86.31(18)
163.35(7)
˚
2 2 2 2
Table 5 Hydrogen bonds (in A, °) in [PbPh Cl (H L) ]·4MeOH
O-C(2)-C(3)
i
N(3)-C(2)-C(3)
C(1)-N(1)-C(4)
C(1)-N(2)-N(3)
C(2)-N(3)-N(2)
C(2)-N(3)-Pb
N(2)-N(3)-Pb
N(2)-C(1)-N(1)
i
D-H···A
d(D-H)
d(H···A)
d(D···A)
<(DHA)
i
N(1)-H(1)···Cl
0.88
0.88
0.88
0.84
0.84
2.35
1.93
2.46
1.93
2.04
3.210(4)
2.749(5)
3.268(4)
2.736(5)
2.825(5)
166.0
154.5
152.4
160.6
154.7
N(2)-H(2)···O(1S)
S-Pb-Oi
C(31)-Pb-O
C(41)-Pb-O
ii
N(3)-H(3)···Cl
iii
O(1S)-H(1S)···O(2S)
O(2S)-H(2S)···O(1)
i
O-Pb-O
Symmetry operators: ii: xϩ1,y,z; iii: Ϫxϩ1,yϪ1/2,Ϫzϩ1/2
Symmetry operators: i Ϫxϩ2,yϩ1/2,Ϫzϩ3/2
Z. Anorg. Allg. Chem. 2005, 631, 2247Ϫ2252
zaac.wiley-vch.de
© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
2251

J. S. Casas, E. E. Castellano, J. Ellena, M. S. Garc ´ı a-Tasende, A. S a´ nchez, J. Sordo, A. Touceda
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2
Ϫ
donor capacity and steric hindrance of the L ligand.
[
[
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Acknowledgements. We thank the Spanish Ministry of Science and
Technology and the Xunta de Galicia, Spain, for financial support
under Projects BQ2002-04524-C02-01 and PGIDT00PX120301PR.
[18] M. Schürmann, F. Huber, J. Organomet. Chem. 1997, 530, 121.
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2252
© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
zaac.wiley-vch.de
Z. Anorg. Allg. Chem. 2005, 631, 2247Ϫ2252