Syntheses, crystal structures and properties of Zn(II) and Cd(II) complexes derived from N-(o-nitrophenyl)-N′-(methoxycarbonyl) thiourea(H2omt) and 2,2′-bipyridine(bpy) or o-phenanthroline(phen)

Article abstract of DOI:10.1016/S0277-5387(98)00208-3

The chelating properties of N-(o-nitrophenyl)-N′-(methoxycarbonyl)thiourea (H₂omt) were investigated through the study of the crystal structures of Cd(Homt)₂(bpy), 1, Zn(Homt)₂(phen), 2 and H₂omt (bpy=2,2′-bipyridine, phen=o-phenanthroline). The cadmium(II) ion in 1 is in a distorted octahedral geometry contributed by the two N atoms from bipyridine and the two S and the two deprotonated amine N atoms from two Homt groups [Cd-N(bpy)=2.329(3), Cd-N(amine)=2.360(3) and Cd-S=2.690(1) A]. The Zn(II) ion in complex 2 is four-coordinated by the two N atoms from the o-phenanthroline and the two deprotonated amine N atoms from two Homt groups in a distorted tetrahedral fashion, in which the binding of S atom to the metal is not involved [Zn-N(phen)=2.088(4), Zn-N(amine)=1.998(3) A].

Full text of DOI:10.1016/S0277-5387(98)00208-3

Polyhedron Vol[ 06\ No[ 12Ð13\ pp[ 3938Ð3947\ 0887
Þ 0887 Elsevier Science Ltd
Pergamon
All rights reserved[ Printed in Great Britain
9166Ð4276:87 ,08[99¦9[99
\
PII] S9166Ð4276"87#99197Ð2
Syntheses\ crystal structures and properties of
Zn"II# and Cd"II# complexes derived from
N!"o!nitrophenyl#!N?!"methoxycarbonyl#
thiourea"H1omt# and 1\1?!bipyridine"bpy# or
o!phenanthroline"phen#
Xu Shen\ꢀa Xianfa Shi\a Beisheng Kang\b\ Yu Liu\b Yexiang Tong\b\
Hualiang Jiangc and Kaixian Chenc
aDepartment of Chemistry\ Tongji University\ Shanghai 199981\ People|s Republic of China
bDepartment of Chemistry\ Zhongshan University\ Guangzhou 409164\ People|s Republic of China
cShanghai Institute of Materia Medica\ Chinese Academy of Sciences\ Shangahi 199920\ People|s Republic
of China
"Received 6 January 0887^ accepted 07 May 0887#
Abstract*The chelating properties of N!"o!nitrophenyl#!N?!"methoxycarbonyl#thiourea "H1omt# were inves!
tigated through the study of the crystal structures of Cd"Homt#1"bpy#\ 0\ Zn"Homt#1"phen#\ 1 and H1omt
"bpyꢁ1\1?!bipyridine\ phenꢁo!phenanthroline#[ The cadmium"II# ion in 0 is in a distorted octahedral geometry
contributed by the two N atoms from bipyridine and the two S and the two deprotonated amine N atoms from
Ä
two Homt groups ðCdÐN"bpy#ꢁ1[218"2#\ CdÐN"amine#ꢁ1[259"2# and CdÐSꢁ1[589"0# AŁ[ The Zn"II# ion in
complex 1 is four!coordinated by the two N atoms from the o!phenanthroline and the two deprotonated amine
N atoms from two Homt groups in a distorted tetrahedral fashion\ in which the binding of S atom to the metal
Ä
is not involved ðZnÐN"phen#ꢁ1[977"3#\ ZnÐN"amine#ꢁ0[887"2# AŁ[ Þ 0887 Elsevier Science Ltd[ All rights
reserved
Keywords] syntheses^ crystal structures^ cadmium"II# complex^ zinc"II# complex^ N?!"o!nitrophenyl#!N?!
"methoxycarbonyl#thiourea^ bipyridine^ o!phenanthroline[
———————————————————————————————————————————————
INTRODUCTION
reduction in the presence of these thiourea derivatives[
In fact\ the biological activities of complexes with
thiourea derivatives have been well documented and
thiourea derivatives have been successfully screened
for various biological actions ð2Ð5Ł and some N!sub!
stituted!N?!alkoxycarbonyl thioureas have been used
in commercial fungicides[ To date\ plenty of transition
metal complexes with such thiourea derivatives have
been reported and the structures with O\S!binding to
the metal ions were well proposed in alkaline media
based on a series of physicochemical properties ð6Ð8Ł[
Now\ it has been a common knowledge that com!
plexation with metal ions may enhance the biological
activity of a wide variety of organic compounds[ For
example\ the copper"II# complex of 1!ace!
Recently\ the derivative N!"o!nitrophenyl#!N?!
"ethoxycarbonyl#thiourea "H1oet# was isolated from
the leaves of resistant Pyricuiria oryzae cav[ rice var!
iety ð0Ł and the preliminary pharmacological tests
showed its high antibacterial activity[ In our previous
work ð1Ł\ several ligands similar to the basic structure
of H1oet were prepared and their Cu"I# complexes
were prepared and crystallographically characterized[
It is interesting to _nd that copper"I# complexes can
be obtained from the copper"II# salts by in situ
ꢀ Author to whom correspondence should be addressed[
3938

3949
Xu Shen et al[
tyloxybenzoic acid "aspirin#\ a ligand used as an anal! X!ray crystallo`raphy
gesic since the last century\ was reported to be
signi_cantly more active as an anti!in~ammatory
Pertinent crystal data\ basic information about the
agent than the free ligand "Refs ð09\00Ł[ and references data collection and structure re_nement of the crystals
cited therein#[ Complexes of metal ions containing a of 0\ 1 and H1omt are given in Table 0[
bidentate organic compound such as 1\1?!bipyridine
The structures were all solved by direct methods[
"bpy# and phenanthrolinine "phen# have been well Re_nements were carried out by full!matrix least
reported ð01\02Ł and they serve as interesting models squares using anisotropic thermal parameters for all
for the understanding enzymeÐmetal ionÐsubstrate the non!hydrogen atoms[ The hydrogen atoms were
relationship\ thus playing an important role in met! included as _xed contributions in structure factor cal!
alloenzyme!catalyzed biochemical reactions ð03\04Ł[ culations but not re_ned[ All calculations were per!
In our previous work\ the chloroform solvated Cd"II# formed on a Compaq computer using the TEXSAN
complex with the ligand N!"o!nitrophenyl#!N?! program package[
"methoxycarbonyl#thiourea "H1omt# and o!phen!
anthroline was reported ð05Ł and Zn"II# and other
transition metal complexes ðe[g[ Cu"II#\ Co"II#Ł with Biolo`ical activity
H1omt and bipyridine "bpy# were synthesized ð06Ł[ To
make such work more complete\ in this paper we
The antibacterial and antifungal activities of the
report the crystal structures of Zn"II# and Cd"II# com! ligand H1omt and the metal complexes against the
plexes with H1omt and bpy for Cd"II# and phen for standard strains of B[ subtilis 5522\ S[ lutea\ S[ aureus
Zn"II#[
198p\ P[ diploccus\ E[ coli and P[ aeru`inosa x202 and
S[ Yake Sake were determined using the plate method
ð07Ł[ Each of the compounds was prepared at a con!
centration of 9[44 mM during the tests and the results
are listed in Table 5[
EXPERIMENTAL
Chemicals
Preparations
All reactants were reagent grade and used without
further puri_cation[
N!"o!Nitrophenyl#!N?!"methoxycarbonyl#!thiourea
"H1omt#[ The preparation of the ligand H1omt was
according to our previous method ð6Ð8Ł[
Physical measurements
General preparation method for Cd"Homt#1"bpy#\ 0\
and Zn"Homt#1"phen#\ 1[ A solution of M"ClO3#1 =
C\ H and N analyses were carried out on a Carlo 5H1O "MꢁCd and Zn# "2 mmol# in 19 cm2 of methanol
Erba 0095 elemental analyzer[ IR spectra were rec! was added slowly to a methanolic solution of 1\1?!
orded on a Magna 649 spectrometer\ UV spectral data bipyridine or o!phenanthroline "2 mmol in 04 cm2#[
were collected by a Shimadzu UV!299 spectrometer[ This was warmed by stirring at 39Ð34>C for 29 min
NMR "0H and 02C# spectra were determined with a to give a clear solution which was cooled to room
Bruker AM 499 instrument in DMSO!d5 solution[ temperature and to it was added the clear methanolic
Cyclic voltammetry was performed with a HDV!6B solution "19 cm2# containing H1omt "5 mmol# and
Potentiostat and LZ2Q!193 XÐY recorder with an NaOH "5 mmol#[ A large amount of yellowish solids
electrochemical cell containing a Pt wire working elec! were precipitated\ this resulting mixture was stirred at
trode\ a Pt plate auxiliary electrode and an SCE ref! room temperature for a further 2 h and the solids were
erence electrode[
collected by _ltration\ washed thoroughly with water

Zn"II# and Cd"II# complexes
3940
Table 0[ Summary of crystallographic data and structural parameters of the compounds H1omt\ 0 and
1
Compound
H1omt
0
1
Formula
M
C8H8N2O3S
144[14
C17H13N7O7CdS1
666[97
C29H11N7O7S1Zn
641[94
Crystal size "mm2#
Crystal color and shape
Crystal system
Space group
9[14×9[19×9[04
yellow\ prism
monoclinic
C1:c "( 04#
20[319 "4#
3[561"1#
04[115"1#
86[36"0#
1105"0#
7
9[34×9[34×9[14
yellow\ prism
monoclinic
C1:c "( 04#
11[352 "4#
8[570"3#
04[201"4#
001[53"2#
2962 "1#
3
9[14×9[04×9[04
yellow\ prism
monoclinic
C1:c "( 04#
19[800 "4#
09[737"3#
04[497"3#
002[49"1#
2115"2#
Ä
a "A#
Ä
b "A#
Ä
c "A#
b ">#
V "A #
2
Ä
Z
3
Dc "g = cm−2
F"999#
#
0[429
0945
1[75
0[57
0457
7[88
0[437
0425
8[52
m "cm−0
#
Di}ractometer
1u max[ ">#
Rigaku AFC4R
49[9
Enraf!Nonius CAD3
38[8
Enraf!Nonius CAD3
38[8
Scan width ">#
9[74¦9[24 tan u
³01[9
9[84¦9[24 tan u
³4[74
9[74¦9[34 tan u
³6[73
Scan speed "min−0
#
No[ of unique re~ections
No[ of observations
No[ of variables
Temperature ">#
R
1106
0359 ðI×1s"I#Ł
043
12
9[930
1777
1215 ðI×2s"I#Ł
149
12
9[922
2903
0816 ðI×1s"I#Ł
111
12
9[940
Rw
9[948
9[930
9[942
GOF
0[51
0[15
0[14
Max[ shift in _nal cycle
9[991
9[10\ −9[13
9[99
9[82\ −9[59
9[9993
9[18\ −9[26
−2
Ä
Dr max[\ min[ "e A
#
and methanol and dried in vacuo[ Complex 0\ m[p[ structural data within the 1\1?!bypyridine molecule
Ä
132>C "decomp[#[ Yield\ 78)[ Found] C\ 32[5^ H\ 3[0^
N\ 03[5[ Calc[ for C17H13N7O7CdS1] C\ 32[1^ H\ 2[0^
N\ 03[3)[ Complex 1\ m[p[ 116>C "decomp#[ Yield\
80)[ Found] C\ 36[7^ H\ 09^ N\ 03[5[ Calc[ for
C29H11N7O7S1Zn] C\ 36[8^ H\ 1[8^ N\ 03[8)[
Single crystals suitable for X!ray analyses were
obtained by slow di}usion of diethyl ether into the
solution of 0 or 1 in chloroform over several weeks[
are normal and CdÐN"3# of 1[218"2# A is comparable
to the reported values of CdÐN"bipy# elsewhere ð10\
11Ł[ The geometry of the six!coordinated cadmium"II#
atom is distorted with the bond angles N"0#ÐCdÐ
S"0#ꢁ50[48"6#>\ N"0#ÐCdÐN"3#ꢁ88[1"0#> and N"0#Ð
CdÐN"3a#ꢁ099[1"0#>[ The molecule contains two
four!membered "from Homt# and one _ve!membered
chelate rings "from phen# and the metal ion deviates
Ä
by 9[9202"1# A from the plane N"0#C"1#S"0#Cd[ The
dihedral angle between the least squares planes
N"0#C"1#S"0#Cd and N"3#C"03#C"03a#N"3a#Cd is
099[27"6#>[
RESULTS AND DISCUSSION
Crystal structures
The structure of complex Zn"Homt#1"phen#\ 1\ is
shown in Fig[ 1\ and selected bond distances and
angles are also listed in Table 1[ The Zn"II# atom is
four!coordinated by the two N atoms from the o!
phenanthroline molecule and the two deprotonated
amine N atoms from two Homt groups in a distorted
tetrahedral geometry with N"3#ÐZnÐN"0#ꢁ004[7>\
N"3#ÐZnÐN"3a#ꢁ68[7"2#> and N"0#ÐZnÐN"0a#ꢁ
017[8"1#>[ The Homt ligand is monodentately coor!
dinated to Zn"II# atom with the deprotonated amine
nitrogen atom where the S atom does not bind to the
metal ion\ which is di}erent from that in complex 0[
The structure of complex Cd"Homt#1"bpy#\ 0\ is
depicted in Fig[ 0\ which shows that the Cd"II# ion is
six!coordinated by two N atoms from bipyridine and
two S and two N atoms from two Homt groups[
Selected atomic distances and bond angles are listed
in Table 1[
Ä
The bond lengths CdÐS"0# of 1[589"0# A and CdÐ
Ä
N"0# of 1[259"2# A are well within the range of the
published results dealing with CdÐS "thiocarbonyl#
ð08Ł and CdÐN"amine# ð19Ł and are also comparable
Ä
to CdÐS "thiocarbonyl# ð1[576"1# AŁ and CdÐN"amine#
Ä
ð1[215"3#\ 1[229"3# AŁ in our previous work ð05Ł[ The As Zn"II# ion is a harder acid relative to Cd"II# and

3941
Xu Shen et al[
Fig[ 0[ ORTEP drawing of complex 0 with ellipsoids at 24) probability[
Ä
Table 1[ Selected bond lengths "A# and angles "># of complexes 0 and 1
0
N"0#ÐCd
1[259"2#
045[1"0#
88[1"0#
50[48"6#
090[96"7#
81[78"4#
N"3#ÐCd
1[218"2#
099[2"0#
69[9"0#
090[10"7#
048[02"6#
S"0#ÐCd
1[589"0#
024[7"1#
79[9"0#
099[7"1#
011[7"2#
007[1"1#
N"0#ÐCdÐN"0a#
N"0#ÐCdÐN"3#
N"0#ÐCdÐS"0#
N"0a#ÐCdÐS"0#
S"0a#ÐCdÐS"0#
N"3#ÐCdÐN"0a#
N"3#ÐCdÐN"3a#
N"3#ÐCdÐS"0#
N"3#ÐCdÐS"0a#
C"0#ÐN"0#ÐCd
C"1#ÐS"0#ÐCd
C"1#ÐN"0#ÐCd
C"09#ÐN"3#ÐCd
C"03#ÐN"3#ÐCd
1
ZnÐN"0#
0[887"2#
004[7"0#
092[0"1#
017[8"1#
ZnÐN"3#
N"3#ÐZnÐN"0#i
N"3#ÐZnÐN"3#i
1[977"3#
092[9"1#
68[7"2#
N"0#ÐZnÐN"3#
N"0#ÐZnÐN"3#i
N"0#ÐZnÐN"0#i
C"0#ÐN"0#ÐZn
C"1#ÐN"0#ÐZn
C"09#ÐN"3#ÐZn
C"04#ÐN"3#ÐZn
011[8"2#
002[0"2#
017[5"3#
001[6"3#
Symmetry operator] a] 0−x\ y\ 0:1−z^ i] 0−x\ −y\ −z[
Ä
thus less thiophilic\ the Homt ligand tends to ligate much change and the bond ZnÐN"3# of 1[977"3# A is
Ä
only through the N atoms with ZnÐN"0# 0[887"2# A well within the values ZnÐN"phen# ð13Ł[
like a normal ZnÐN"amine# bond ð12Ł[ The structural
The structure of the ligand H1omt is shown in Fig[
data within the phenanthroline molecule are without 2[ The coordination behavior of the Homt group is

Zn"II# and Cd"II# complexes
3942
Fig[ 1[ ORTEP drawing of complex 1 with ellipsoids at 24) probability[
Fig[ 2[ ORTEP drawing of H1omt with ellipsoids at 49) probability[
di}erent in each of the complexes\ with either mono! plane
and
the
least
squares
plane
or bidentate coordination[ In the free ligand H1omt\ SO"0#O"1#N"0#N"1#C"0#C"1# is 69[40>[ With respect
the thiourea moiety SO"0#O"1#N"0#N"1#C"0#C"1#C"8# to complex 1\ the dihedral angle between the plane of
is almost planar and N"2# is in the plane of the phenyl N"1# and the phenyl group and the plane
group\ these two planes form a dihedral angle of O"0#O"1#N"0#C"0#C"1#C"8# is 43[44>[ Comparative
33[26>[ In complex 0\ N"1# is also in the plane of the bond distances and angles involving Homt group for
phenyl group\ and the dihedral angle between this the free ligand H1omt and complexes 0 and 1 are listed

3943
Xu Shen et al[
Ä
Table 2[ Comparative bond distances "A# and angles ">#
Spectroscopic properties of the compounds
involving Homt group for the compounds H1omt\ 0 and 1
IR and UV spectra For the compounds of H1omt\ 0
and 1\ the bands at ca[ 2039 cm−0 are usually attri!
buted to the stretching frequency n"NH#\ while for
complex 2\ the band above 2099 cm−0 was not
observed\ indicating the absence of NH group[ The
intense band arising from the amide!I stretching
vibration at 0621 cm−0 for H1omt is red!shifted when
ligation occurs in the Cd"II# "0537 cm−0# and Zn"II#
H1omt
0
1
C"8#ÐO"0#
O"0#ÐC"0#
C"0#ÐO"1#
C"0#ÐN"0#
N"0#ÐC"1#
C"1#ÐS
C"1#ÐN"1#
N"1#ÐC"2#
C"2#ÐC"3#
C"3#ÐC"4#
C"4#ÐC"5#
C"5#ÐC"6#
C"6#ÐC"7#
C"7#ÐC"2#
C"3#ÐN"2#
N"2#ÐO"2#
N"2#ÐO"3#
0[333"3#
0[211"2#
0[199"2#
0[263"2#
0[263"2#
0[555"2#
0[231"2#
0[310"2#
0[391"3#
0[274"3#
0[268"3#
0[272"4#
0[265"3#
0[268"3#
0[360"2#
0[114"2#
0[106"2#
0[317"4#
0[230"3#
0[100"3#
0[255"3#
0[234"3#
0[609"2#
0[236"3#
0[310"3#
0[274"4#
0[271"4#
0[259"6#
0[250"6#
0[281"5#
0[264"4#
0[344"4#
0[101"4#
0[109"4#
0[322"5#
0[239"4#
0[109"4#
0[252"5#
0[250"4#
0[563"3#
0[237"4#
0[285"4#
0[289"5#
0[263"6#
0[243"7#
0[250"7#
0[252"6#
0[282"5#
0[353"6#
0[103"5#
0[111"4#
"0550 cm−0# complexes[ The C S band at 756 cm−0
1
for the free ligand H1omt has shifted to 744 cm−0 in
complex 0\ indicative of the binding via the thiolato
sulfur atom to Cd"II# ion\ which is also indicated by
the presence of a band of 209 cm−0\ assignable to
n"CdÐS# ð14Ł[ Therefore\ the nearly unchanged n"C S#
1
band at 757 cm−0 in complex 1 implicates the non!
coordination of thiolate sulfur\ in agreement with the
X!ray crystallographic results[ In addition\ the coor!
dination of nitrogen atom to Cd"II# or Zn"II# ion in
complex 0 or 1 is observed by the presence of bands
at ca[ 219½224 cm−0\ assignable to n"CdÐN# or n"ZnÐ
N# ð15Ł[
C"8#ÐO"0#ÐC"0#
O"0#ÐC"0#ÐO"1#
O"0#ÐC"0#ÐN"0#
O"1#ÐC"0#ÐN"0#
C"0#ÐN"0#ÐC"1#
N"0#ÐC"1#ÐS
N"0#ÐC"1#ÐN"1#
N"1#ÐC"2#ÐC"3#
N"1#ÐC"2#ÐC"7#
C"2#ÐC"7#ÐC"6#
C"7#ÐC"6#ÐC"5#
C"6#ÐC"5#ÐC"4#
C"5#ÐC"4#ÐC"3#
C"4#ÐC"3#ÐC"2#
C"2#ÐC"3#ÐN"2#
C"4#ÐC"3#ÐN"2#
C"3#ÐN"2#ÐO"2#
C"3#ÐN"2#ÐO"3#
O"2#ÐN"2#ÐO"3#
SÐC"1#ÐN"1#
005[0"1#
013[8"2#
098[8"1#
014[1"2#
017[4"1#
007[1"1#
004[0"1#
010[6"1#
010[1"1#
010[8"2#
019[0"2#
008[7"2#
008[2"2#
010[6"1#
011[0"1#
005[1"1#
008[9"1#
007[9"2#
011[8"1#
015[5"1#
006[0"2#
015[2"1#
005[9["2#
010[8"2#
097[4"2#
018[6"2#
010[5"2#
005[1"1#
011[0"2#
010[0"2#
010[2"2#
008[7"3#
010[9"3#
019[3"3#
007[5"4#
011[4"3#
019[8"2#
005[4"3#
007[7"3#
006[2"3#
012[7"3#
010[5"1#
006[6"2#
012[3"2#
006[2"3#
011[4"3#
097[9"3#
018[3"3#
012[9"3#
006[1"2#
008[9"3#
011[3"3#
019[5"3#
019[6"4#
019[6"4#
019[4"4#
008[4"4#
010[5"4#
019[5"3#
006[7"4#
006[2"4#
007[2"4#
013[2"4#
012[6"2#
006[9"3#
018[4"3#
The UV spectra of the ligand H1omt and complexes
0 and 1 are shown in Fig[ 3[ For all three compounds\
the bands at about 167 nm are ascribed to 0L"b#
absorption of the aromatic ring[ The signals around
C"7#ÐC"2#ÐC"3#
C"1#ÐN"1#ÐC"2#
in Table 2[ As shown in Table 2\ there is general
agreement of the values[ The shorter bond N"0#ÐC"1#
for complex 0 can be caused by the formation of SÐ
Cd bond[ For the same reason\ complex 0 has the
longest C"1#ÐS bond[ The di}erent conformation of
the compounds arising from the binding of the metal
ions to H1omt gives rise to the following bond angles
sequences] "i# O"0#ÐC"0#ÐO"1#] "H1omt#×"0#¼"1#^ "ii#
O"1#ÐC"0#ÐN"0#] "H1omt#³"0#¼"1#^ "iii# C"0#ÐN"0#Ð
C"1#] "H1omt#×"0#×"1#^ "iv# N"0#ÐC"1#ÐN"1#]
"H1omt#³"1#³"0#^ "v# SÐC"1#ÐN"1#] "H1omt#×
"1#×"0#^ "vi# C"1#ÐN"1#ÐC"2#] "1#×"H1omt#×"0#[
Fig[ 3[ UV spectra of the compounds in chloroform "a\
H1omt^ b\ 0^ c\ 1#[

Zn"II# and Cd"II# complexes
3944
Table 3[ 0H NMR spectra of compounds H1omt\ 0 and 1 "in ppm#
Compound
Assignmenta
ArÐNHC"S#
HNC"O#
OCH2
aromatic ring
H1omt
0
1
01[41 "s\ 0H#
01[70 "s\ 0H#
01[84 "s\ 0H#
7[2 "s\ 0H#
−
−
2[8 "s\ 2H#
2[4 "s\ 2H#
2[2 "s\ 2H#
6[28½7[36 "m\ 3H#
6[16½8[95 "m\ 01H#
6[13½8[47 "m\ 01H#
asꢁsingle\ mꢁmultiple[
299 nm are attributed to the absorption of the NO1 tions at a scan rate of 9[0 V s−0 in the scan ranges 9 to
group[ As for the n:pꢀ absorptions of C O\ they are ¦0[7 and −0[7 to 9 V are shown in Figs 4 and 5\
1
respectively[ As can be seen from Fig[ 4\ it is found
that each of three compounds exhibit two irreversible
cathodic peaks with −9[32 and −0[42 V for H1omt\
−9[29 and −0[39 V for 0 as well as −9[42 and
−0[46 V for 1\ and one reversible redox couples at
−0[02 and −0[97 V for H1omt\ −9[82 and −9[89 V
for 0 and −0[02 and −0[94 V for 1[ Thus\ it is ten!
tatively suggested that all these peaks are ascribed to
the reduction and oxidation process of the Homt
group[ In terms of the cyclic voltammograms of the
compounds in CH2CN solution as shown in Fig[ 5\
each of the compounds display an anodic peak
"H1omt\ 0[17 V^ 0\ ¦0[28 V^ 1\ ¦0[28 V# one cathodic
peak "H1omt\ −9[72 V^ 0\ −9[44 V^ 1\ −9[4 V# and
one reversible redox couple "H1omt\ −0[04 and
−0[02 V^ 0\ −9[89 and −9[74 V^ 1\ −9[81 and
−9[76 V#[ In addition\ it is interesting to _nd that
there is a cathodic peak appearing at −0[49 V for
H1omt\ while such a peak is absent for either of the
two complexes\ suggesting that the cyclic vol!
tammogramms of the compounds are a}ected by the
solvent[
near 234 nm[ All the absorptions shown a batho!
chromical shift for the complexes relative to those of
the free ligand are caused by the coordination of metal
ions to the ligand[ The n:pꢀ excitation of C S is not
1
observed in any of the compounds\ in agreement with
that reported by Barret et al[ ð16Ł[
0
0H and 02C NMR spectra The H and 02C NMR
spectra of the ligand H1omt and complexes 0 and 1
are listed in Tables 3 and 4\ respectively[
As shown in Table 3\ most of their proton signals
are observed to shift to down _elds in complexes 0
and 1 relative to those of the free ligand due to the
binding of the metal ions[ The absence of d"NH# ðs\
0H\ HNÐC"O#Ł in the complexes shows the coor!
dination of deprotonated amine to Cd"II# or Zn"II#
ion[
In comparison with the 02C NMR spectrum of the
ligand H1omt "Table 4#\ C1 has shifted to a lower _eld
at d 075[23 for 0 and 075[87 for 1^ C2 to d 048[20 "0#
and 048[03 "1#[ However\ C0 is found to have shifted
to a higher _eld at d 40[74 for 0 and 40[57 for 1[
Electrochemical studies
Biolo`ical activities
The cyclic voltammograms of the compounds
The antibacterial and antifungal activities of the
H1omt\ 0 and 1 are shown in DMF and CH2CN solu! compounds are listed in Table 5\ showing that the free
Table 4[ 02C NMR spectra of the compounds H1omt\ 0 and 1 "in ppm#
Compound
Assignmenta
C4
b
C0
C1
C2
C3
C5
C6
C7
C8
H1omt
0
1
42[67
40[74
40[57
067[57
075[23
075[87
041[37
048[20
048[03
031[10
030[85
030[65
014[04
013[58
013[58
022[38
024[93
023[80
015[62
014[28
015[50
017[05
017[39
017[41
021[37
022[94
021[86
a The signals of 1\1?!bipyridinyl ring for 0 appear at d 049[60\ 038[85\ 028[26\ 010[04 and 019[63\ while the ones of o!
phenanthrolinyl ring for 1 are observed at d 038[65\ 039[87\ 027[16\ 021[05\ 014[96 and 013[59[
b The positions of the carbon atoms are denoted in the structure of the free ligand H1omt[

3945
Xu Shen et al[
Table 5[ Antibacterial and antifungal activity of the com!
ligand H1omt was inactive against B[ subtilis 5522\ S[
lutea\ S[ aureus 198p\ P[ diploccus and P[ aeru`inosa
x202\ but slightly active against E[ coli and S[ Yake
Sake[ Both the metal complexes exhibited inhibition
activities against the tested bacteria and fungus\ indi!
cating that the enhancement of the biological activities
of the complexes is related to the coordination of the
metal ion and the bpy or phen molecule[
pounds H1omt\ 0 and 1a
Bacterium or fungus
H1omt
0
1
B[ subtilis 5522
S[ lutea
S[ aureus 198p
P[ diploccus
E[ coli
9
9
9
9
4[9
9
2[1
4[2
6[4
8[4
8[1
6[0
8[2
5[9
2[7
6[3
00[0
5[4
6[6
8[2
P[ aeru`inosa x202
S[ Yake Sake
5[8
Acknowled`ements*The _nancial supports from the NNSF
of China\ Developing Foundation of Tongji University and
the Natural Science Foundation of Guangdong Province are
appreciated[
a"0# The concentration of each tested compound was given
in 9[44 mM[ "1# The inhibition zone was given in mm[
Fig[ 4[ Cyclic voltammograms of compounds H1omt "a#\ 0 "b#\ 1 "c#[ "Measured in DMF\ 0×09−3 mol = dm−2\ scan rate
099 mV = s−0#[

Zn"II# and Cd"II# complexes
3946
Fig[ 5[ Cyclic voltammograms of compounds H1omt "a#\ 0 "b#\ 1 "c#[ "Measured in CH2CN\ 0×09−3 mol = dm−2\ scan rate
099 mV = s−0#[
REFERENCES
8[ Guilion\ E[\ Mohamadou\ A[\ Dechamps!Olivier\
I[ and Barbier\ J[ P[\ Polyhedron\ 0885\ 04\ 836[
0[ Huang\ Z[\ Wu\ L[\ Xiao\ J[\ Huang\ Q[\ Liu\ Y[ 09[ Ranford\ J[ D[\ Sadler\ P[ J[ and Tocher\ D[ A[\
and Gu\ L[\ Youji Huaxue\ 0884\ 04\ 110[ J[ Chem[ Soc[ Dalton Trans[\ 0882\ 2282[
1[ Shen\ X[\ Wen\ T[ B[\ Liu\ Q[ T[\ Huang\ X[ Y[\ 00[ Korolkiewicz\ Z[\ Hac\ E[\ Gagalo\ L[\ Gorezyca\
Kang\ B[ S[\ Wu\ X[ L[\ Huang\ Z[ S[ and Gu\ L[
Q[\ Polyhedron\ 0886\ 05\ 1594[
P[ and Lodzinska\ A[\ A`ents Actions\ 0878\ 15\ 244[
01[ Sundberg\ R[ J[ and Martin\ R[ B[\ Chem[ Rev[\
0863\ 35\ 460[
02[ Abdel!Rahman\ L[ H[\ Battaglia\ L[ P[ and Mah!
moud\ M[ R[\ Polyhedron\ 0885\ 04\ 216[
03[ Bradshaw\ R[ A[\ Shearer\ W[ T[ and Gurd\ P[ R[
N[\ J[ Biol[ Chem[\ 0857\ 132\ 2706[
2[ French\ F[ A[\ Blanz\ E[ J[\ Amaral\ J[ R[ D[ and
French\ D[ A[\ J[ Med[ Chem[\ 0869\ 02\ 0006[
3[ Mohapatra\ B[ B[\ Guru\ S[ and Mohapatra\ B[
K[\ J[ Inor`[ Nul[ Chem[\ 0866\ 28\ 1180[
4[ Antholine\ W[ and Taketa\ F[\ J[ Inor`[ Biochem[\
0871\ 05\ 034[
04[ Freedmann\ T[ B[\ Loehr\ J[ S[ and Loehr\ T[ M[\
J[ Am[ Chem[ Soc[\ 0865\ 87\ 1798[
5[ Petering\ D[ H[\ Metal Ions in Biolo`ical Systems\
Vol[ 00\ Chap[ 3\ ed[ H[ Sigel[ Marcel Dekker\ 05[ Shen\ X[\ Kang\ B[ S[\ Liu\ Y[\ Gu\ L[ Q[ and
New York\ 0879[ Huang\ X[ Y[\ J[ Coord[ Chem[ In press[
6[ Shoukry\ M[ M[\ Mahgoub\ A[ S[ and Elnagdi\ 06[ Shen\ X[\ Shi\ X[ F[\ Liu\ Y[ S[ and Kang\ B[ S[\
M[ H[\ J[ Inor`[ Nul[ Chem[\ 0879\ 31\ 0060[ Chem[ J[ Chin[ Uni[ In press[
7[ Mohamadou\ A[\ Dechamps!Olivier\ I[ and 07[ Gerhardt\ P[\ Manual of Methods for General Bac!
Barbier\ J[ P[\ Polyhedron\ 0883\ 02\ 0252 and
2166[
teriolo`y\ ed[ R[ N[ Castello[ American Society
for Micrology\ 0870\ pp[ 54Ð197[

3947
Xu Shen et al[
08[ Castro\ J[ A[\ Romero\ J[\ Garcia!Vazquez\ J[\
Sousa\ A[\ Zubieta\ J[ and Chang\ Y[\ Polyhedron\
0885\ 04\ 1630[
G[\ Jing\ D[ H[ and Zheng\ J[ M[\ Chin[ J[ Struct[
Chem[\ 0885\ 04\ 393[
13[ Baggio\ R[\ Baggio\ S[\ Pardo\ M[ I[ and Garland\
M[ T[\ Acta Cryst[ C\ 0885\ 41\ 719[
19[ Castro\ R[\ Duran\ M[ L[\ Garcia!Vazquez\ J[ A[\
Sousa\ A[\ Castineiras\ A[\ Hiller\ W[ and Strahle\ 14[ Speca\ A[ N[\ Karayannis\ N[ M[ and Pytlewski\
J[\ Z[ Naturforsch[\ 0881\ 36b\ 0956[ L[ L[\ Inor`[ Chim[ Acta\ 0865\ 06\ 18[
10[ Santos\ R[ A[\ Koch\ E[ S[ and Harbison\ G[ S[\ 15[ Noboru\ O[ and Nakamoto\ K[\ Inor`[ Chem[\
J[ Am[ Chem[ Soc[\ 0889\ 001\ 8146[
11[ Dakternieks\ D[\ Aust[ J[ Chem[\ 0871\ 24\ 358[
12[ Zhang\ W[ X[\ Ma\ C[ Q[\ Wang\ X[ N[\ Yu\ Z[
0864\ 09\ 687[
16[ Barret\ J[ and Deghaidy\ F[ S[\ Spectrochim[ Acta\
0864\ 20A\ 696[