Binuclear zinc(II) complexes with the anti-inflammatory compounds salicylaldehyde semicarbazone and salicylaldehyde-4-chlorobenzoyl hydrazone (H2LASSBio-1064)

Article abstract of DOI:10.1016/j.poly.2011.04.024

Complexes [Zn₂(HL¹)₂(CH ₃COO)₂] (1) and [Zn₂(L²) ₂] (2) were synthesized with salicylaldehyde semicarbazone (H ₂L¹) and salicylaldehyde-4-chlorob

Full text of DOI:10.1016/j.poly.2011.04.024

Polyhedron 30 (2011) 1891–1898
Contents lists available at ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
Binuclear zinc(II) complexes with the anti-inflammatory compounds
salicylaldehyde semicarbazone and salicylaldehyde-4-chlorobenzoyl hydrazone
(H2LASSBio-1064)
Gabrieli L. Parrilha a, Rafael P. Vieira a, Anayive P. Rebolledo a, Isolda C. Mendes b, Lidia M. Lima c,
Eliezer J. Barreiro c, Oscar E. Piro d, Eduardo E. Castellano e, Heloisa Beraldo a,
⇑
a Departamento de Química, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil
b Escola de Belas Artes, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil
c LASSBio Laboratório de Avaliação e Síntese de Substâncias Bioativas (LASSBio)1, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, P.O. Box 68024,
21944-971 Rio de Janeiro, RJ, Brazil
d Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata and Instituto IFLP (CONICET – CCT La Plata), C.C. 67, 1900 La Plata, Argentina
e Instituto de Física de São Carlos, Universidade de São Paulo, 13560-970 São Carlos, SP, Brazil
a r t i c l e i n f o
a b s t r a c t
Complexes [Zn2(HL1)2(CH3COO)2] (1) and [Zn2(L2)2] (2) were synthesized with salicylaldehyde semicar-
bazone (H2L1) and salicylaldehyde-4-chlorobenzoyl hydrazone (H2LASSBio-1064, H2L2), respectively.
The crystal structure of (1) was determined. Upon recrystallization of previously prepared
[Zn2(HL2)2(Cl)2] (3) in 1:9 DMSO:acetone crystals of [Zn2(L2)2(H2O)2]ꢀ[Zn2(L2)2(DMSO)4] (3a) were
obtained. The crystal structure of 3a was also determined. All crystal structures revealed the presence
of phenoxo-bridged binuclear zinc(II) complexes.
Article history:
Received 17 February 2011
Accepted 19 April 2011
Available online 27 April 2011
Keywords:
Hydrazones
Semicarbazones
Crystal structures
Binuclear Zn(II) complexes
Ó 2011 Elsevier Ltd. All rights reserved.
1. Introduction
noyl hydrazone derivatives were shown to possess anti-
tubercular activity [23]. Acyl hydrazones have shown to possess
Semicarbazones constitute an interesting class of compounds
with versatile structural features and several pharmacological
applications as anticonvulsant [1–7], antiproliferative [8], antima-
larial [9], antimicrobial [10], antiprotozoal [11], antinociceptive
[12], and antiangiogenic agents [12]. Semicarbazones and their
metal complexes also show antitumor [13], antimicrobial
[10,14,15], and antioxidant [16] activities, among others.
Hydrazones present chemical as well as pharmacological appli-
cations. Aromatic hydrazones dispersed in a binder polymer pos-
sess hole-transporting properties and are used in electro-
photographic photoreceptors of laser printers [17]. Hydrazones
are also used as analytical reagents for the determination of trace
amounts of metal ions [18]. In addition, these compounds exhibit
antimicrobial, anticonvulsant, analgesic [19], anti-inflammatory
[20], and antitumoral [21] properties. Hydrazones are used for con-
trolling agricultural and horticultural insect pests [22]. Isonicoti-
analgesic [24,25], anti-inflammatory [25], vasodilator [26] and try-
panocidal activities [27].
Metal complexes of hydrazones proved to have potential appli-
cations as catalysts [28], luminescent probes [29], and molecular
sensors [30]. Moreover, it has been recently shown that hydra-
zones such as pyridoxal isonicotinoyl hydrazone derivatives are
effective iron chelators in vivo and in vitro, and could be used in
the treatment of iron overload [31]. Metal complexes with hydra-
zones also show antimicrobial [32], anticancer [33], and DNA-
binding [34] activities.
In another work we reported an evaluation of the analgesic and
anti-nociceptive activities of salicylaldehyde 2-chlorobenzoyl
hydrazone (H2LASSBio-466), its regioisomer salicylaldehyde 4-
chlorobenzoyl hydrazone (H2LASSBio-1064), and their zinc(II)-
complexes [Zn(LASSBio-466)H2O] and [Zn(HLASSBio-1064)Cl]
[35]. In the present work we report a study on binuclear zinc(II)
complexes with salicylaldehyde semicarbazone (hereafter named
H2L1) and with H2LASSBio-1064 hereafter named H2L2 (Fig. 1). Both
ligands were shown to possess analgesic and antinociceptive
activities [36,37].
⇑
Corresponding author. Tel.: +55 31 34095740, fax: +55 31 34095700.
E-mail address: hberaldo@ufmg.br (H. Beraldo).
http://www.farmacia.ufrj.br/lassbio/.
1
0277-5387/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2011.04.024

1892
G.L. Parrilha et al. / Polyhedron 30 (2011) 1891–1898
Table 1
Crystal data and structure refinement.
Compound
[Zn2(HL1)2
(CH3COO)2] (1)
[Zn2(L2)2(H2O)2]
ꢀ[Zn2(L2)2(DMSO)4]
(3a)
Empirical formula
Formula weight
C
10H11N3O4Zn
C64H62Cl4N8O14S4Zn4
1700.75
302.59
(g molꢁ1
)
T (K)
298(2)
294(2)
Crystal system
Space group
Crystal size (mm)
Unit cell dimensions
a (Å)
orthorhombic
Pbac
triclinic
ꢀ
P1
0.15 ꢂ 0.12 ꢂ 0.10 0.12 ꢂ 0.14 ꢂ 0.22
Fig. 1. Structural representation of salicylaldehyde semicarbazone (H2L1) and
12.1734(10)
12.8476(8)
15.1288(7)
90
90
90
2366.1(3)
8
1.699
8.914(1)
14.808(1)
15.598(1)
61.933(4)
77.560(4)
80.875(5)
1770.2(3)
1
salicylaldehyde-4-chlorobenzoylhydrazone (H2LASSBio-1064, H2L2).
b (Å)
c (Å)
2. Experimental
a
(°)
b (°)
c
(°)
2.1. Physical measurements
V (Å3)
Z
Dcalc (Mg mꢁ3
)
1.595
1.676
All common chemicals were purchased from Aldrich and used
without further purification. Partial elemental analyses were per-
formed on a Perkin Elmer CHN 2400 analyzer. An YSI model 31
conductivity bridge was employed for molar conductivity mea-
surements. Infrared spectra were recorded on a Perkin Elmer FT-
Absorption coefficient
(mmꢁ1
F(0 0 0)
2.086
)
1232
2.69–26.37
868
3.42–26.00
h Range for data
collection (°)
Limiting indices
IR Spectrum GX spectrometer using KBr plates (4000–400 cmꢁ1
)
ꢁ9 6 h 6 15
ꢁ14 6 k 6 16
ꢁ18 6 l 6 15
7600/2411
ꢁ10 6 h 6 10
and nujol mulls between CsI plates (400–200 cmꢁ1). NMR spectra
were obtained with a Bruker DPX-200 Avance (200 MHz) spec-
trometer using DMSO-d6 as the solvent and TMS as internal
reference.
ꢁ18 6 k 6 18
ꢁ19 6 l 6 19
Reflections collected/
12 607/6595 (0.083)
unique (Rint
)
(0.0208)
Completeness
Refinement method
h = 26.37° 100.0%
full-matrix least-
squares on F2
2411/0/173
h = 26.00° 95.0%
full-matrix least
-squares on F2
6595/0/448
2.2. X-ray crystallography
Data/restraints/
parameters
Crystals of [Zn2(HL1)2(CH3COO)2] (1) were obtained from a
methanol solution. Upon recrystallization of previously prepared
[Zn2(HL2)2Cl2] (3) [35] in 1:9 DMSO:acetone, crystals of
[Zn2(L2)2(H2O)2]ꢀ[Zn2(L2)2(DMSO)4] (3a) were obtained. Single
crystals of [Zn2(HL1)2(CH3COO)2] (1) and [Zn2(L2)2(H2O)2]ꢀ[Zn2(L2)2
(DMSO)4] (3a) were mounted on a glass fiber and examined by
structural X-ray diffraction methods.
Goodness-of-fit on F2
Final R indices
0.941
1.092
R1 = 0.0222,
wR2 = 0.0547
R1 = 0.0321,
wR2 = 0.0560
R1 = 0.0845,
wR2 = 0.2328
R1 = 0.1030,
wR2 = 0.2536
[I > 2r(I)]
R indices (all data)
Largest difference in
peak and hole
0.228 and ꢁ0.330 2.588 and ꢁ1.433
(e Aꢁ3
)
X-ray diffraction data for 1 were collected on an Oxford-Diffrac-
tion GEMINI diffractometer (LabCri) using graphite-Enhance Source
Mo K
a radiation (k = 0.71069 Å) at 293(2) K. Data collection, inte-
optimized by treating them as a rigid group which was allowed
to rotate around the corresponding CAS bond. The water H-atoms
could not be located reliably in the final residual electron density
map. Their presumed positions were obtained by a procedure
based on combined geometrical and force-field (Coulomb and
van der Waals) calculations as reported in the literature [44] and
implemented in the WINGX suit of programs [45]. A final difference
Fourier map showed a residual electron density of about 2.6 e Åꢁ3
near the less bonded to the metal DMSO molecule that can be
attributed to disorder of this ligand in the lattice.
gration and scaling of the reflections were performed with the Cry-
sAlis suite programs [38].
X-ray diffraction measurements of 3a were performed on an En-
raf-Nonius Kappa-CCD diffractometer employing graphite-mono-
chromated Mo K
gathered ( and
gration and scaling of the reflections were performed with HKL
DENZO-SCALEPACK [40] suite of programs. The unit cell parame-
ters were obtained by least-squares refinement based on the angu-
lar settings for all collected reflections using HKL SCALEPACK [40].
Data were corrected empirically for absorption with PLATON [41].
Final unit cell parameters were based on the fitting of all reflec-
tions positions. The structures were solved by direct methods
using the program SHELXS-97 [42] and refined by full-matrix least-
squares techniques against F2 using SHELXL-97 [43].
a
x
(k = 0.71073 Å) radiation. Diffraction data were
scans with -offsets) with COLLECT [39]. Inte-
u
j
In both complexes, molecular graphics were obtained from OR-
TEP [45–47]. Crystal data and structure refinement results for both
compounds are summarized in Table 1.
2.3. Synthesis
Positional and anisotropic atomic displacement parameters of 1
were refined for non-hydrogen atoms. Although all hydrogen
atoms could be identified in a Fourier difference map, in the final
model only nitrogen H-atoms were refined positionally and iso-
tropically. The other hydrogen atoms of HL1 were included in the
molecular model at stereo-chemical positions and refined with
the riding method.
2.3.1. Synthesis of salicylaldehyde semicarbazone (H2L1) and
salicylaldehyde 4-chlorobenzoyl hydrazone (H2L2)
Salicylaldehyde semicarbazone and salicylaldehyde 4-chloro-
benzoyl hydrazone were prepared as previously described [35,48].
2.3.2. Synthesis of [Zn2(HL1)2(CH3COO)2] (1), [Zn2(L2)2] (2) and
[Zn2(HL2)2(Cl)2] (3)
The hydrogen atoms of H2L2 in 3a were included in the molec-
ular model at stereo-chemical positions and refined with the riding
method. The methyl H-atoms of both DMSO ligands were
Complex (1) was obtained by refluxing a methanol suspension
of H2L1 with zinc acetate, in 1:4 ligand-to-metal molar ratio, while

G.L. Parrilha et al. / Polyhedron 30 (2011) 1891–1898
1893
complex (2) was obtained by refluxing a methanol solution of H2L2
with zinc acetate in 1:1 ligand-to-metal molar ratio. The resulting
solids were filtered off and washed with methanol followed by
diethylether and then dried in vacuum. Complex (3) was obtained
as previously described [35].
and H2L2, respectively, shifts to 1601 and 1611 cmꢁ1 in those of
complexes (1) and (2), in agreement with coordination through
the azomethine nitrogen [32,50–52].
New absorptions at 334 and 311 cmꢁ1 in the spectra of 1 and 2,
respectively, were attributed to the m(MAO) vibration mode while
absorptions at 465 and 473 cmꢁ1 were attributed to the
mode [53].
m(MAN)
2.3.2.1. [Zn2(HL1)2(CH3COO)2] (1). White solid. Anal. Calc. for
The NMR spectra of the ligands and their zinc(II) complexes
were recorded in DMSO-d6. The 1H resonances were assigned on
the basis of chemical shifts and multiplicities. The carbon type
(C, CH) was determined by using distortionless enhancement by
polarization transfer (DEPT 135) experiments. The assignments of
the protonated carbons were made by 2D hetero-nuclear multiple
quantum coherence experiments (HMQC).
The signal of O(1)AH was absent in the spectra of complexes (1)
and (2), in agreement with deprotonation and formation of a phe-
nolate group. In addition, the signals of N(2)AH disappear in the
spectra of both complexes, suggesting deprotonation. Hence disso-
lution of complex (1) occurs with deprotonation at N(2)AH and
dissociation of the acetate ligand, probably promoted by DMSO-
d6 as described in Fig. 2. In fact, in the spectrum of 1 the signal
of the hydrogens from the acetate group (d 1.81 ppm) is character-
istic of free acetate (d 1.79 ppm).
The molar conductivity of complex (1) in non-coordinating
methanol is characteristic of a non-electrolyte while in DMSO it re-
veals the presence of a 1:1 electrolyte, which is compatible with
formation of acetic acid. Hence complex (1) is protonated at N(2)
in the solid (as confirmed by its crystal structure, see Section 3.3)
as well as in non-coordinating solvents such as methanol. How-
ever, coordination of DMSO-d6 to the zinc(II) center results in re-
lease of the acetate group as acetic acid with deprotonation at
N(2)AH. In previous works we demonstrated that coordination of
DMSO to zinc(II) complexes with hydrazones results in release of
a co-ligand [51,52].
C10H11N3O4Zn (302.60): C, 39.69; H, 3.66; N, 13.89. Found: C,
39.35; H, 3.79; N, 13.48%. Molar conductivity (1 ꢂ 10ꢁ4 mol Lꢁ1
,
methanol):
52.8
X
ꢁ1 cm2 molꢁ1
.
Molar
conductivity
(1 ꢂ 10ꢁ3 mol Lꢁ1, DMSO): 35.9
X
ꢁ1 cm2 molꢁ1. IR (KBr or CsI/nu-
(ZnAN) 465, (ZnAO)
jol, cmꢁ1):
m
(C@O) 1674,
m(C@N) 1619,
m
m
334. The main signals in 1H NMR (DMSO-d6): d (ppm) = 8.13 (1H,
H7), 7.07–6.90 (2H, N(3)AH), 7.05 (1H, H5), 6.95 (1H, H6), 6.71
(1H, H3), 6.44 (1H, H4), 1.81 (3H, s, CH3acetate). 13C NMR (DMSO-
d6): d (ppm) = 175.74 (C1), 166.65 (C8), 149.18 (C7), 133.06 (C6),
131.35 (C5), 121.52 (C3), 118.17 (C2), 113.86 (C4), 22.88
(CH3acetate). Yield 54%.
2.3.2.2. [Zn2(L2)2] (2). Yellow solid. Anal. Calc. for C28H18N4O4Cl2Zn2
(676.15): C, 49.74; H, 2.68; N, 8.29. Found: C, 49.50; H, 2.35; N,
8.40%.
13.75
m
Molar
conductivity
(0.5 ꢂ 10ꢁ3 mol Lꢁ1
DMF):
(C@N) 1601,
X
ꢁ1 cm2 molꢁ1. IR (KBr or CsI/nujol, cmꢁ1):
m
(ZnAN) 473, m
(ZnAO) 311. 1H NMR (DMSO-d6): d (ppm) = 8.61
(1H, H7), 8.09 (2H, H11, H13), 7.47 (2H, H10, H14), 7.28 (1H,
H3), 7.15–7.25 (2H, H5, H6), 6.59 (1H, H4). Yield 91%.
3. Results and discussion
3.1. Formation of the zinc(II) complexes
Microanalyses and molar conductivity data are compatible with
the formation of [Zn(HL1)(CH3COO)]n (1) and [Zn(L2)]n (2). In 1 a
mono-anionic semicarbazone is attached to the metal center to-
gether with an acetate ligand. Crystal structure determination of
complex (1) revealed that it is a dimer (see Section 3.3). In complex
(2) the metal center is coordinated only by the di-anionic triden-
tate hydrazone, suggesting that 2 could as well be a dimer. In fact,
coordination number three is very unlikely for zinc(II).
In the 1H NMR spectra of complexes (1) and (2) the signals of all
hydrogen atoms undergo significant shifts in relation to their posi-
tions in the free ligands. In the 13C NMR spectrum of 1 the signals
of C(7)@N, C(8)@O and the aromatic carbons undergo significant
shifts, indicating coordination through the OANAO chelating sys-
tem. The 13C NMR spectrum of 2 was not obtained due to its low
solubility. The significant shifts of all hydrogens upon complexa-
tion and the absence of the N(2)AH and O(1)AH signals in 2 sug-
gest OANAO coordination. Hence in 1 and 2 the ligands adopt
the E configuration [35].
3.2. Spectroscopic characterization
The absorptions attributed to the m(OAH) stretching vibration
at 3468 and 3436 cmꢁ1 in the infrared spectra of H2L1 and H2L2 dis-
appear in those of the complexes, in accordance with deprotona-
tion of the phenol group [35,49].
3.3. X-ray diffraction analysis
The absorption attributed to m
(C@O) at 1674 cmꢁ1 in the spec-
trum of H2L1 shifts to 1676 cmꢁ1 in the spectrum of 1 indicating
Fig. 3 contains perspective views of complexes (1) and (3a).
Crystal data and refinement results are listed in Table 1. The crystal
structures of H2L1 and H2L2 have been previously determined
[48,54]. Tables 2 and 3 present selected intra-molecular bond dis-
tances and angles for H2L1 [48] and H2L2 [54] and their zinc(II)
complexes (1) and (3a).
coordination through the carbonyl oxygen [50–52]. The absorption
assigned to
found in the spectrum of 2, in accordance with coordination of the
enolate oxygen [32,52]. The absorption attributed to the (C@N)
vibration mode at 1599 and 1624 cmꢁ1 in the spectra of H2L1
m
(C@O) at 1676 cmꢁ1 in the spectrum of H2L2 was not
m
Fig. 2. Interaction of complex (1) with DMSO.

1894
G.L. Parrilha et al. / Polyhedron 30 (2011) 1891–1898
In [Zn2(HL1)2(CH3COO)2] (1) the zinc(II) centers of the bi-
Considering that complex (1) crystallizes as a dimer, we may
suggest that it might be binuclear in the powder. Since acetate is
monodentately coordinated, it is easily released upon dissolution
of complex (1) in DMSO. Moreover, release of acetate (as acetic
acid) was probably induced by the bulkiness of the DMSO ligand,
and was probably favored by the basicity of acetate together with
its mono-dentate character.
A twisting of approximately 180° in the N(2)AC(8) bond of the
H2L1 to match the steric requirements of tridentate coordination
was evidenced. Therefore, the semicarbazone conformation varies
from EE when free [48] to EZ in complex (1).
nuclear complex are in a five-fold trigonal bipyramidal environ-
ment. Each trigonal plane is occupied by an anionic semicarbazone
coordinated through the imine nitrogen, N(1) and the carbonyl
oxygen O(8), together with a phenolate O(1i) atom of the second
semicarbazone [d(ZnAN1) = 2.074(2) Å, d(ZnAO) = 2.058(1) and
1.990(1) Å, respectively]. O(2) from acetate and O(1) from pheno-
late occupy the apical sites [ZnAO distances of 1.956(1) and
2.054(1) Å, respectively]. The metal ion departs from the trigonal
plane in 0.0793(8) Å toward the O(8) atom. The metal–metal dis-
tance within the dimer is 3.0560(4) Å. Two phenoxo bridges con-
nect the metal centers in the bimetallic complex. The ligand is
nearly planar (rms deviation of atoms C7AN1AN2AC8AO8AN3
from the least-squares plane of 0.012 Å) and the metal ion departs
from this plane in 0.078(2) Å.
Upon coordination some angles undergo significant changes.
The N(1)AN(2)AC(8) angle goes from 121.4(2)° in H2L1 [48] to
116.1(2)° in 1. In addition, C(7)AN(1)AN(2) varies from 116.4(2)°
in H2L1 [48] to 118.1(2)° in 1. In complex (1) the O(1)AZnAO(8)
Fig. 3. Molecular plot of [Zn2(HL1)2(CH3COO)2] (1) and [Zn2(L2)2(H2O)2]ꢀ[Zn2(L2)2(DMSO)4] (3a) binuclear complexes, showing the labeling of the non-H atoms and their
displacement ellipsoids at the 50% probability level.
Table 2
Selected bond distances (Å) and angles (°) of H1L1 [48] and [Zn2(HL1)2(CH3COO)2] (1).
Atom
H1L1 [48]
(1)
Atom
H1L1 [48]
(1)
C(1)–O(1)
C(2)–C(7)
C(7)–N(1)
N(1)–N(2)
N(2)–C(8)
1.353(3)
1.446(3)
1.284(3)
1.371(2)
1.358(3)
1.243(2)
1.327(3)
1.345(2)
1.443(3)
1.283(2)
1.376(2)
1.348(2)
1.249(2)
1.320(2)
1.9895(11)
2.0541(12)
2.0582(12)
1.9561(12)
1.9895(11)
2.0735(15)
3.0560(4)
N(2)–C(8)–O(2)
N(2)–C(8)–N(3)
N(3)–C(8)–O(8)
118.4(2)
118.5(2)
123.1(2)
120.55(16)
117.37(17)
122.04(18)
115.29(5)
97.11(5)
O(3)–Zn(1)–O(1)#1
O(3)–Zn(1)–O(1)
O(1)#1–Zn(1)–O(1)
O(3)–Zn(1)–O(8)
O(1)#1–Zn(1)–O(8)
O(1)–Zn(1)–O(8)
O(3)–Zn(1)–N(1)
O(1)#1–Zn(1)–N(1)
O(1)–Zn(1)–N(1)
O(8)–Zn(1)–N(1)
O(3)–Zn(1)–Zn(1)#1
O(1)#1–Zn(1)–Zn(1)#1
O(1)–Zn(1)–Zn(1)#1
O(2)–Zn(1)–Zn(1)#1
N(1)–Zn(1)–Zn(1)#1
C(8)–O(8)
C(8)–O(3)
81.83(5)
96.76(5)
O(1)–Zn(1)#1
O(1)–Zn(1)
O(8)–Zn(1)
O(3)–Zn(1)
Zn(1)–O(1)#1
Zn(1)–N(1)
Zn(1)–Zn(1)#1
102.95(5)
161.63(5)
119.71(6)
124.53(5)
84.96(5)
77.72(5)
111.18(4)
41.71(3)
C(2)–C(7)–N(1)
C(7)–N(1)–N(2)
N(1)–N(2)–C(8)
122.5(2)
116.4(2)
121.4(2)
124.21(17)
118.07(16)
115.99(15)
40.12(3)
141.60(4)
108.06(4)

G.L. Parrilha et al. / Polyhedron 30 (2011) 1891–1898
1895
Table 3
Selected bond distances (Å) and angles (°) of H1L2 [54] and [Zn2(L2)2(H2O)2]ꢀ[Zn2(L2)2(DMSO)4] (3a).
Atom
H2L2 [54]
Atom
[Zn2(L2)2(H2O)2]
Atom
[Zn2(L2)2(DMSO)4]
C(1)–O(1)
C(2)–C(7)
C(7)–N(1)
N(1)–N(2)
N(2)–C(8)
C(8)–O(8)
C(8)–C(9)
1.340(5)
1.426(6)
1.280(5)
1.391(5)
1.330(5)
1.245(5)
1.481(6)
C(11)–O(11)
C(12)–C(17)
C(17)–N(11)
N(11)–N(12)
N(12)–C(18)
C(18)–O(18)
C(18)–C(19)
O(11)–Zn(1)#1
O(11)–Zn(1)
O(18)–Zn(1)
Zn(1)–O(1W)
Zn(1)–O(11) #1
Zn(1)–N(11)
Zn(1)–Zn(1) #1
1.343(8)
1.462(11)
1.285(9)
1.378(8)
1.328(9)
1.266(8)
1.486(10)
1.994(4)
2.066(5)
2.022(5)
1.982(5)
1.993(5)
2.060(5)
3.1218(15)
C(21)–O(21)
C(22)–C(27)
C(27)–N(21)
N(21)–N(22)
N(22)–C(28)
C(28)–O(28)
C(28)–C(29)
O(21)–Zn(2)#2
O(21)–Zn(2)
O(28)–Zn(2)
O(1)–Zn(2)
1.336(8)
1.438(10)
1.287(9)
1.382(8)
1.325(9)
1.278(8)
1.466(10)
2.024(5)
2.070(5)
2.098(5)
2.258(6)
2.137(5)
2.024(5)
2.056(5)
3.1178(16)
O(2)–Zn(2)
Zn(2)–O(21)#2
Zn(2)–N(21)
Zn(2)–Zn(2)#2
C(2)–C(7)–N(1)
C(7)–N(1)–N(2)
N(1)–N(2)–C(8)
N(2)–C(8)–O(8)
N(2)–C(8)–C(9)
C(9)–C(8)–O(8)
123.0(4)
115.6(3)
120.0(3)
121.7(4)
117.8(4)
120.5(4)
C(12)–C(17)–N(11)
C(17)–N(11)–N(12)
N(11)–N(12)–C(18)
N(12)–C(18)–O(18)
N(12)–C(18)–C(19)
C(19)–C(18)–O(18)
O(18)–Zn(1)–N(11)
O(11)#1–Zn(1)–O(18)
O(11)#1–Zn(1)–O(11)
O(11)–Zn(1)–O(18)
N(11)–Zn(1)–O(11)
O(11)#1–Zn(1)–N(11)
O(11)#1–Zn(1)–Zn(1)#1
O(18)–Zn(1)–Zn(1)#1
N(11)–Zn(1)–Zn(1)#1
O(11)–Zn(1)–Zn(1)#1
O(1W)–Zn(1)–O(11)#1
O(1W)–Zn(1)–O(18)
O(1W)–Zn(1)–N(11)
O(1W)–Zn(1)–O(11)
O(1W)–Zn(1)–Zn(1)#1
123.9(6)
117.3(6)
109.2(5)
125.2(7)
118.7(6)
116.1(6)
76.5(2)
105.3(2)
79.5(2)
148.6(2)
86.9(2)
155.5(2)
40.59(14)
137.20(16)
123.05(17)
38.90(12)
107.0(2)
101.2(2)
96.4(2)
C(22)–C(27)–N(21)
C(27)–N(21)–N(22)
N(21)–N(22)–C(28)
N(22)–C(28)–O(28)
N(22)–C(28)–C(29)
C(29)–C(28)–O(28)
O(28)–Zn(2)–N(21)
O(21)#2–Zn(2)–O(28)
O(21)#2–Zn(2)–O(21)
O(21)–Zn(2)–O(28)
N(21)–Zn(2)–O(21)
O(21)#2–Zn(2)–N(21)
O(21)#2–Zn(2)–Zn(2)#2
O(28)–Zn(2)–Zn(2)#2
N(21)–Zn(2)–Zn(2)#2
O(21)–Zn(2)–Zn(2)#2
O(21)#2–Zn(2)–O(2)
N(21)–Zn(2)–O(2)
O(21)–Zn(2)–O(2)
126.0(6)
116.6(5)
112.1(5)
124.6(7)
116.2(6)
119.1(6)
76.9(2)
116.32(19)
80.9(2)
162.94(18)
86.2(2)
165.5(2)
40.89(13)
157.21(13)
125.75(17)
39.84(12)
89.2(2)
97.9(2)
93.9(2)
86.3(2)
87.8(2)
87.8(2)
97.6(2)
107.0(2)
112.43(16)
O(28)–Zn(2)–O(2)
O(21)#2–Zn(2)–O(1)
N(21)–Zn(2)–O(1)
O(21)–Zn(2)–O(1)
O(28)–Zn(2)–O(1)
84.1(2)
O(2)–Zn(2)–O(1)
167.5(2)
Primed and double primed atoms are obtained from the unprimed ones through the inversion symmetry operations ꢁx, ꢁy + 2, ꢁz + 1 (#1) and ꢁx + 1, ꢁy + 1, ꢁz (#2),
respectively.
angle of 161.63(5)° deviates markedly from the ideal value of 180°,
probably due to the spatial requirements of the ligand chelating
system. In H2L1 the C(8)AO(8) bond distance is 1.243(2) Å, while
in complex (1) this distance is 1.249(2) Å due to the formation of
the ZnAO bond which makes the CAO bond weaker.
The molecular packing of complex (1) shows hydrogen bonding
interactions of considerable strength involving N, H and O atoms
(Table 4) with formation of tridimensional molecular chains as
shown in Fig. 4.
As already mentioned, upon recrystallization of previously pre-
pared [Zn2(HL2)2Cl2] (3) [35] in 1:9 DMSO:acetone, crystals of
[Zn2(L2)2(H2O)2]ꢀ[Zn2(L2)2(DMSO)4] (3a) were obtained (see
Fig. 3). In 3a two center symmetric binuclear zinc(II) complexes
are hosted in the same lattice. In [Zn2(L2)2(H2O)2] a coordination
water molecule, probably from DMSO, is attached to each zinc(II)
center.
Table 4
Hydrogen bonds [Å and °] in the structure of [Zn2(HL1)2(CH3COO)2] (1).
DAHꢀ ꢀ ꢀA
d(DAH)
d(Hꢀ ꢀ ꢀA)
d(Dꢀ ꢀ ꢀA)
\(DHA)
N(2)AH(2A)ꢀ ꢀ ꢀO(4)#1
N(3)AH(3A)ꢀ ꢀ ꢀO(3)#1
N(3)AH(3B)ꢀ ꢀ ꢀO(4)#2
0.79(2)
0.91(2)
0.84(2)
1.94(2)
1.98(2)
2.03(2)
2.729(2)
2.885(2)
2.840(2)
177(2)
172(2)
162(2)
Symmetry transformations used to generate equivalent atoms: #1: ꢁx, y + 1/2,
ꢁz + 3/2; #2: ꢁx + 1/2, y + 1/2, z.
Fig. 4. Molecular packing of [Zn2(HL1)2(CH3COO)2] (1).

1896
G.L. Parrilha et al. / Polyhedron 30 (2011) 1891–1898
The compound crystallizes with two different zinc(II) center
Acknowledgements
symmetric binuclear complexes in the crystal asymmetric unit,
namely [Zn2(L2)2(H2O)2] and [Zn2(L2)2(DMSO)4], where L2 is the
di-anionic ligand that results from deprotonation of the acylhyd-
razone at O(1)AH and N(2)AH. Thus once again coordination of
DMSO to the zinc(II) center results in deprotonation at N(2)AH
with release of the chloride co-ligand as HCl. In addition, coordina-
tion of water also resulted in deprotonation with release of HCl
(see Fig. 3).
The authors are grateful to CNPq, INCT-INOFAR/CNPq
(proc.573.364/2008-6) and FAPESP (Brazil) and to CONICET
(Argentina) for financial support. O.E.P. is a Research Fellow of
CONICET, Argentina.
Appendix A. Supplementary data
In both complexes the ligands are nearly planar (rms deviation
of atoms from the least-squares plane of 0.074 Å for
[Zn2(L2)2(H2O)2] and 0.082 Å for [Zn2(L2)2(DMSO)4]) and close to
perpendicularity [dihedral angle of 86.3(1)°]. The expected length-
ening of the C(8)AO(8) bond from 1.245(5) Å in H2L2 [54] to
1.266(8) and 1.277(8) Å in the two dimers of 3a was observed,
indicating that C(8)AO(8) bond changes from a double to a pre-
dominantly single bond due to deprotonation at N(2) and forma-
tion of N(2)@C(8) bond. H2L2 [54] and all ligands in (3a) present
EZ conformation.
CCDC 808099 and 808944 contain the supplementary
crystallographic data for [Zn2(HL1)2(CH3COO)2] (1) and [Zn2(L2)2
(H2O)2]ꢀ[Zn2(L2)2(DMSO)4] (3a). 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.
References
In the [Zn2(L2)2(H2O)2] binuclear complex, the zinc(II) center is
in a five-fold square pyramidal environment, coordinated at the
pyramid basis to the dianionic hydrazone which binds to the metal
through the phenolate and carbonyl oxygen atoms (ZnAO dis-
tances of 2.066(5) and 2.022(5) Å, respectively), and the imine
nitrogen (ZnAN distances of 2.060(5) Å). The fourth coordination
position is occupied by the phenolate oxygen of the dimer in-
verted-related L molecule [d(ZnAOph0) = 1.993(4) Å]. A water mol-
ecule is at the pyramid axis [d(ZnAOw) = 1.982(5) Å]. The metal
ion departs from the pyramid basis in 0.597(4) Å toward the water
ligand. The metal–metal distance within the dimer is 3.122(2) Å.
In the [Zn2(L2)2(DMSO)4] binuclear complex, the zinc(II) center
[1] H. Beraldo, D. Gambino, Mini-Rev. Med. Chem. 4 (2004) 159.
[2] H. Beraldo, R.D. Sinisterra, L.R. Teixeira, R.P. Vieira, M.C. Doretto, Biochem.
Biophys. Res. Commun. 296 (2002) 241.
[3] L.R. Teixeira, R.D. Sinisterra, R.P. Vieira, A. Scarlatelli-Lima, M.F.D. Moraes, M.C.
Doretto, A.M. Denadai, H. Beraldo, J. Inclusion Phenom. Macrocyclic Chem. 54
(2006) 133.
[4] M. Kaiser, F.J. Azeredo, F.T. Uchôa, H.O. Beraldo, T.D. Costa, Eur. J. Pharm. Sci. 39
(2010) 355.
[5] J.R. Dimmock, K.K. Sidhu, R.S. Thayer, P. Mack, M.J. Duffy, R.S. Reid, J.W. Quail,
U. Pugazhenthi, A. Ong, J.A. Bikker, D.F. Weaver, J. Med. Chem. 36 (1993) 2243.
[6] J.R. Dimmock, K.K. Sidhu, S.D. Tumber, S.K. Basran, M. Chen, J.W. Quail, J. Yang,
I. Rozas, D.F. Weaver, Eur. J. Med. Chem. 30 (1995) 287.
[7] J.R. Dimmock, S.C. Vashishtha, J.P. Stables, Eur. J. Med. Chem. 35 (2000) 241.
[8] S. Dutta, S. Padhye, K.I. Priyadarsini, C. Newton, Bioorg. Med. Chem. Lett. 15
(2005) 2738.
[9] R.B. de Oliveira, E.M. de Souza-Fagundes, R.P.P. Soares, A.A. Andrade, A.U.
Krettli, C.L. Zani, Eur. J. Med. Chem. 43 (2008) 1983.
is similarly coordinated to two inversion-related
L ligands
conforming an equatorial plane [d(ZnAOph) = 2.070(5) Å,
d(ZnAOcarb) = 2.098(5) Å, d(ZnAN) = 2.056(5) Å, and d(ZnAOph0)
= 2.024(5) Å], but now two DMSO molecules complete the axial
positions of a distorted octahedral coordination around the metal
(ZnAO distances of 2.137(5) and 2.258(6) Å). Here, the zinc ions
lie nearly onto the equatorial coordination plane (at 0.024(4) Å).
Intra-dimer ZnAZn distance is 3.118(2) Å.
The 3a crystal is further stabilized by a pair of OwAHꢀ ꢀ ꢀN bonds
of [Zn2(L2)2(H2O)2] with a neighboring symmetry related molecule
[d(O1wꢀ ꢀ ꢀN120) = 2.66 Å, \(O1wAH1wꢀ ꢀ ꢀN120) = 175°] and with a
[Zn2(L2)2(DMSO)4] complex [d(O1wꢀ ꢀ ꢀN2200) = 2.81 Å, \(O1wA
H2wꢀ ꢀ ꢀN2200) = 175°].
[10] V.L. Siji, M.R.S. Kumar, S. Suma, M.R.P. Kurup, Spectrochim. Acta, Part A 76
(2010) 22.
[11] H. Cerecetto, R. Di Maio, M. González, M. Risso, G. Sagrera, G. Seoane, A.
Denicola, G. Peluffo, C. Quijano, A.O.M. Stoppani, M. Paulino, C. Olea-Azar, M.A.
Basombrío, Eur. J. Med. Chem. 35 (2000) 343.
[12] L.T.S. Rocha, K.A. Costa, A.C.P. Oliveira, E.B. Nascimento, C.M. Bertollo, F.
Araujo, L.R. Teixeira, S.P. Andrade, H. Beraldo, M.M. Coelho, Life Sci. 79 (2006)
499.
[13] P. Noblía, M. Vieites, B.S. Parajón-Costa, E.J. Baran, H. Cerecetto, P. Draper, M.
González, O.E. Piro, E.E. Castellano, A. Azqueta, A.L. de Ceráin, A. Monge-Veja,
D. Gambino, J. Inorg. Biochem. 99 (2005) 443.
[14] N.C. Kasuga, K. Sekino, C. Koumo, N. Shimada, M. Ishikawa, K. Nomiya, J. Inorg.
Biochem. 84 (2001) 55.
[15] N.C. Kasuga, K. Sekino, M. Ishikawa, A. Honda, M. Yokoyama, S. Nakano, N.
Shimada, C. Koumo, K. Nomiya, J. Inorg. Biochem. 96 (2003) 298.
[16] Y. Li, Z.-Y. Yang, Z.-C. Liao, Z.-C. Han, Z.-C. Liu, Inorg. Chem. Commun. 13 (2010)
1213.
[17] V. Getautis, M. Daskeviciene, T. Malinauskas, V. Jankauskas, J. Sidaravicius,
Thin Solid Films 516 (2008) 8979.
[18] J.J. Pinto, C. Moreno, M. Garcia-Vargas, Talanta 64 (2004) 562.
[19] S. Rollas, Sß.G. Küçükgüzel, Molecules 12 (2007) 1910. and references therein.
[20] P. Vicini, M. Incerti, I.A. Doytchinova, P. La Colla, B. Busonera, R. Loddo, Eur. J.
Med. Chem. 41 (2006) 624. and references therein.
Since 3a consists of two binuclear phenoxo-bridged zinc(II)
complexes, we may suggest that complex (3) could also be a dimer
in the powder, [Zn2(HL2)2(Cl)2]. Moreover, since coordination num-
ber three is very unlikely for zinc(II), and considering that com-
plexes (2) and (3) were formed with the same acylhydrazone, it
is reasonable to assume that 2 is also a phenoxo-bridged binuclear
zinc(II) complex. In fact, the geometry of the OANAO chelating
system of L2 would disfavor adoption of coordination number three
by the zinc(II) center.
[21] L. Savini, L. Chiasserini, V. Travagli, C. Pellerano, E. Novellino, S. Cosentino, M.B.
Pisano, Eur. J. Med. Chem. 39 (2004) 113.
[22] N. Aggarwal, R. Kumar, C. Srivastva, P. Dureja, J.M. Khurana, J. Agric. Food
Chem. 58 (2010) 3056.
[23] R.S. Hunoor, B.R. Patil, D.S. Badiger, R.S. Vadavi, K.B. Gudasi, V.M.
Chandrashekhar, I.S. Muchchandi, Spectrochim. Acta, Part A 77 (2010) 838.
[24] H.J.C. Bezerra-Netto, D.I. Lacerda, A.L.P. Miranda, H.M. Alves, E.J. Barreiro,
C.A.M. Fraga, Bioorg. Med. Chem. 14 (2006) 7924. and references therein.
[25] Y.K.C. Da Silva, C.V. Augusto, M.L.C. Barbosa, G.M.A. Melo, A.C. De queiroz,
T.L.M.F. Dias, W. Bispo Jr., E.J. Barreiro, L.M. Lima, M.S. Alexandre-Moreira,
Bioorg. Med. Chem. 18 (2010) 5007.
[26] A.E. Kümmerle, J.M. Raimundo, C.M. Leal, G.S. Da Silva, T.L. Balliano, M.A.
Pereira, C.A. De Simone, R.T. Sudo, G. Zapata-Sudo, C.A.M. Fraga, E.J. Barreiro,
Eur. J. Med. Chem. 44 (2009) 4004.
[27] N.C. Romeiro, G. Aguirre, P. Hernández, M. González, H. Cerecetto, I. Aldana, S.
Pérez-Silanes, A. Monge, E.J. Barreiro, L.M. Lima, Bioorg. Med. Chem. 17 (2009)
641.
[28] O. Pouralimardan, A.-C. Chamayou, C. Janiak, H. Hosseini-Monfared, Inorg.
Chim. Acta 360 (2007) 1599.
4. Conclusion
The above mentioned results indicate that the presence of the
phenol group favors the formation of phenoxo-bridged-binuclear
zinc(II) complexes. The literature reports other examples of phen-
oxo-bridged core dimers [55–57]. In addition, as previously ob-
served by some of us for zinc(II) complexes with hydrazones
[51,52], coordination of DMSO to the zinc(II) center may lead to
deprotonation at NAH with release of a co-ligand. Coordination
of water also resulted in deprotonation at N(2)AH with release of
a co-ligand.
[29] C. Basu, S. Chowdhury, R. Banerjee, H.S. Evans, S. Mukherjee, Polyhedron 26
(2007) 3617.

G.L. Parrilha et al. / Polyhedron 30 (2011) 1891–1898
[30] M. Bakir, O. Green, W.H. Mulder, J. Mol. Struct. 873 (2008) 17.
[31] J.L. Buss, J. Neuzil, P. Ponka, Biochem. Soc. Trans. 30 (2002) 755.
[32] A.A.R. Despaigne, L.F. Vieira, I.C. Mendes, F.B. Da Costa, N.L. Speziali, H. Beraldo,
J. Braz. Chem. Soc. 21 (2010) 1247.
[33] V. Mahalingam, N. Chitrapriva, F.R. Fronczek, K. Natarajan, Polyhedron 27
(2008) 1917.
[34] Q. Wang, Z.-Y. Yang, G.-F. Qi, D.-D. Qin, Eur. J. Med. Chem. 44 (2009) 2425.
[35] W. Bispo Jr., M.S. Alexandre-Moreira, M.A. Alves, A. Perez-Rebolledo, G.L.
Parrilha, E.E. Castellano, O.E. Piro, E.J. Barreiro, L.M. Lima, H. Beraldo, Eur. J.
Med. Chem., submitted for publication.
1897
Anayive Perez-Rebolledo received her B.Sc degree in
Chemistry from Universidad del Valle (1988). She
earned her Master’s Degree in Chemistry from the same
institution (2000) and her PhD degree from Universid-
ade Federal de Minas Gerais (2004). She is currently
doing a pos doctoral stage at Centro de Desenvolvi-
mento da Tecnologia Nuclear (CDTN), Brazil. Her expe-
riences involve Coordination Chemistry and Medicinal
Inorganic Chemistry with emphasis in the syntheses
and investigation of pharmacological activities of bio-
active organic molecules and their metal complexes.
She is also involved with nuclear medicinal chemistry.
[36] C.A.M. Fraga, E.J. Barreiro, Curr. Med. Chem. 13 (2006) 167.
[37] R.P. Vieira, J.A. Lessa, W.C. Ferreira, F.B. da Costa, L.F.S. Bastos, W.R. Rocha,
M.M. Coelho, H. Beraldo, Unpublished results.
[38] CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.32.38.SCALE3 ABSPACK
Scaling Algorithm, CrysAlis RED, Oxford Diffraction Ltd., Version 1.171.32.38.
[39] Enraf-Nonius (1997–2000), COLLECT, Nonius BV, Delft, The Netherlands.
[40] Z. Otwinowski, W. Minor, in: C.W. Carter Jr., R.M. Sweet (Eds.), Methods in
Enzymology, vol. 276, Academic Press, New York, 1997, pp. 307–326.
[41] A.L. Spek, PLATON, A Multipurpose Crystallographic Tool, Utrecht University,
Utrecht, The Netherlands, 1998.
[42] G.M. Sheldrick, SHELXS-97; Program for Solution of Crystal Structures,
University of Göettingen, Göettingen, Germany, 1997.
[43] G.M. Sheldrick, SHELXL-97; Program for Crystal Structures Analysis, University
of Göettingen, Germany, 1997.
[44] M. Nardelli, J. Appl. Crystallogr. 32 (1999) 563.
[45] L.J. Farrugia, J. Appl. Crystallogr. 32 (1999) 837.
[46] L.J. Farrugia, J. Appl. Crystallogr. 30 (1997) 565.
[47] C.K. Johnson, ORTEP, Report ORNL-3794, Oak Ridge, TN, 1965.
[48] J. Valdés-Martínez, R.A. Toscano, R. Salcedo, R. Cea-Olivares, A. Meléndez,
Monatsh. Chem. 121 (1990) 641.
Isolda Maria Castro Mendes received her B.Sc. (1998)
and PhD (2007) in Chemistry from Universidade Federal
de Minas Gerais, Brazil. She has experience in Inorganic
Chemistry, Bio-Inorganic Chemistry and Scientific Con-
servation of Art Objects, Archaeological Sites, and
Monuments. She carries on research in X-rays diffrac-
tion and fluorescence, crystal structure determination,
coordination chemistry, and deterioration mechanisms
of art objects. Member of the Brazilian Chemical Society,
The Brazilian Association of Crystallography and The
International Council of Museums – ICOM. Now work-
ing at the School of Fine Arts of Universidade Federal de
Minas Gerais, Brazil, as conservation scientist.
[49] M. Salavati-Niasari, A. Amiri, Appl. Catal. A – Gen. 290 (2005) 46.
[50] A.A.R. Despaigne, J.G. da Silva, A.C.M. do Carmo, O.E. Piro, E.E. Castellano, H.
Beraldo, J. Mol. Struct. 920 (2009) 97.
[51] A.A.R. Despaigne, J.G. da Silva, A.C.M. do Carmo, O.E. Piro, E.E. Castellano, H.
Beraldo, Inorg. Chim. Acta 362 (2009) 2117.
[52] A.A.R. Despaigne, J.G. da Silva, A.C.M. do Carmo, F. Sives, O.E. Piro, E.E.
Castellano, H. Beraldo, Polyhedron 28 (2009) 3797.
[53] K. Nakamoto, Infrared and Raman Spectra of Inorganic and Coordination
Compounds, fourth ed., Wiley, New York, 1986.
[54] J.-L. Lu, S.-T. Min, X.-H. Ji, Z.-H. Dang, Acta Crystallogr., Sect. E: Struct. Rep.
Online 64 (2008) O1694.
[55] N.V. Kulkarni, G.S. Kurdekar, S. Budagumpi, V.K. Revankar, J. Coord. Chem. 63
(2010) 3301.
[56] S. Ay, R.E. Ziegert, H. Zhang, M. Nieger, K. Rissanen, K. Fink, A. Kubas, R.M.
Gschwind, S. Bräse, J. Am. Chem. Soc. 132 (2010) 12899.
Lidia Moreira Lima Earned a B.Sc degree in Pharmacy
from Federal University of Rio de Janeiro (UFRJ, Brazil,
1994). M.Sc in Organic Chemistry (UFRJ, 1997) and PhD
in Medicinal Chemistry (UFRJ, 2001). Post-Doctorate in
Medicinal Chemistry from University of Navarra (UNAV)
Spain. Associate Professor at Faculty of Pharmacy UFRJ.
She is ‘‘Young Scientist of Rio de Janeiro State’’ (FAPERJ,
BR). Has productivity grant of National Council for Sci-
entific and Technological Development (CNPq, BR). Is
currently Secretary of the Brazilian Chemical Society Rio
de Janeiro. Guides undergraduate and graduate students
in Medicinal Chemistry projects aiming the discovery of
[57] J.-H. Wang, P.-F. Yan, G.-M. Li, J.-W. Zhang, P. Chen, M. Suda, Y. Einaga, Inorg.
Chim. Acta 363 (2010) 3706.
new drugs candidates.
Eliezer J. Barreiro is Pharmacist and M.Sc in Chemistry
of Natural Products (1973) from Federal University of
Rio de Janeiro (UFRJ, Brazil) and Docteur ès Sciences d’
État (1978) in Medicinal Chemistry from Université
Scientifique et Médicale de Grenoble (France). He is
Professor of Medicinal Chemistry at UFRJ since 1986.
Published over 210 articles. He is guest author of several
book chapters in Medicinal Chemistry, and author of 2
books in this field. His research interests lie in the area
of Medicinal Chemistry or Pharmaceutical Chemistry.
Currently, is the scientific coordinator of LASSBioÒ
(www.farmacia.ufrj.br/lassbio) which was founded in
Gabrieli Lessa Parrilha received her B.Sc degree in
Chemistry from Universidade Estadual do Norte Flu-
minense Darcy Ribeiro, Rio de Janeiro (2005). She
earned her Master’s Degree in Natural Sciences from the
same institution (2008). She is currently a PhD student
in Chemistry at Universidade Federal de Minas Gerais.
Her experiences involve Coordination Chemistry and
Medicinal Inorganic Chemistry with emphasis in the
syntheses and investigation of pharmacological activi-
ties of bioactive organic molecules and their metal
complexes.
1994.
Oscar E. Piro received his PhD degree in Physics from
the National University of La Plata (UNLP), Argentina, in
1977. He made postdoctoral research at the University
of Chicago, USA, working on X-ray Crystallography of
Rafael Pinto Vieira received his B.Sc degree in Phar-
macy from Universidade Federal de Minas Gerais
(2003). He worked for five years in Brazilian Pharma-
ceutical companies. He earned his Master’s Degree in
Pharmaceutical Sciences from Universidade de São
Paulo (2008). He is currently a PhD student in Chemistry
at Universidade Federal de Minas Gerais. His experi-
ences involve Pharmacology, Pharmaceutical Technol-
ogy, Coordination Chemistry and Medicinal Inorganic
Chemistry with emphasis in the syntheses and investi-
gation of pharmacological activities of bioactive organic
molecules and their metal complexes.
biological macromolecules (1978–1980). He is
a
Research Fellow of CONICET, Argentina, and Full Pro-
fessor of UNLP. His research interest is grounded in Solid
State Physics, particularly in Structural Crystallography
by X-ray diffraction methods and also in the optical and
spectroscopic (mainly infrared and Raman) properties
of crystals. Currently, he works on the structure–phys-
icochemical properties relationship of inorganic,
organic, metal–organic, bioorganic and bioinorganic, and supra-molecular materi-
als.

1898
G.L. Parrilha et al. / Polyhedron 30 (2011) 1891–1898
Eduardo Ernesto Castellano received his B.Sc (1965)
Heloisa Beraldo received her PhD degree (Docteur d’
État ès Sciences Physiques) from Université Paris VI
(1984). She is presently Professor of Chemistry at Uni-
versidade Federal de Minas Gerais, Brazil. Her research
interests are centered on Inorganic Medicinal Chemis-
try, with emphasis on metal-based drugs design, and
the effects of metal coordination on the pharmacologi-
cal profile of organic compounds, antimicrobials, cyto-
toxic/antitumoral agents and anti-inflammatory agents.
and PhD (1968) degrees in Physics from Universidad
Nacional de La Plata, Argentina (1965). He has a pos doc
from University of Oxford (1970). He is presently Pro-
fessor of Physics at Universidade de São Paulo. His
interests are centered in Physics of Condensed Matter.