Syntheses and study on nickel and copper complexes with 1,3,5-benzenetricarboxylic acid. Crystal and molecular structure of [Cu3(mdpta)3(btc)](ClO4)3 · 4H2O

Article abstract of DOI:10.1016/j.poly.2006.08.010

Nickel and copper complexes containing 1,3,5-benzenetricarboxylic acid, with a combination of selected N-donor ligands and Schiff bases, of the composition Ni₃(bimz)₆(btc)₂ · 12H₂O (1), Ni₃(btz)₉(btc)₂ · 12H₂O (2), Ni₂(L₁)(btc) · 7H₂O (3), Ni₃(L₂)₂(Hbtc) · 9H₂O (4), Ni₂(L₃)(btc) · 4H₂O (5), Cu₂(L₄)(btc) · 7H₂O (6), [Cu₃(pmdien)₃(btc)](ClO₄)₃ · 6H₂O (7) and [Cu₃(mdpta)₃(btc)](ClO₄)₃ · 4H₂O (8); H₃btc = 1,3,5-benzenetricarboxylic acid, bimz = benzimidazole, btz = 1,2,3-benztriazole, L₁ = 2-[(phenylimino)methyl]phenol, L₂ = N,N′-bis-(salicylidene)propylenediamine, L₃ = 2-{[(2-nitrophenyl)methylene]amino}phenol, L₄ = 2-[(4-methoxy-phenylimino)methyl]phenol, pmdien = N,N,N′,N″,N″-pentamethyldiethylenetriamine, mdpta = N,N-bis-(3-aminopropyl)methylamine, have been synthesized. The complexes have been studied by elemental analysis, IR, UV-Vis spectroscopies, magnetochemical and conductivity measurements and selected compounds also by thermal analysis. The crystal and molecular structure of complex 8 was solved. The complex is trinuclear with btc^3--bridge. The coordination polyhedron around each copper atom can be described as a distorted square with a CuON₃ chromophore formed by one oxygen atom of carboxylate and three nitrogen atoms of mdpta. The magnetic properties of 8 have been studied in the 1.8-300 K temperature range revealing a very weak antiferromagnetic exchange interaction with J = -0.56 cm^-1 for g = 2.13(9). The antimicrobial activities against selected strains of bacteria were evaluated. It was found that only complex 5 is able to inhibit the growth of Staphylococcus strains.

Full text of DOI:10.1016/j.poly.2006.08.010

Polyhedron 26 (2007) 535–542
www.elsevier.com/locate/poly
Syntheses and study on nickel and copper complexes with
,3,5-benzenetricarboxylic acid. Crystal and molecular structure
of [Cu (mdpta) (btc)](ClO ) Æ 4H O
1
3
3
4 3
2
a,
a
b
a
*
Pavel Kopel , Ji rˇ ´ı Kamen ´ı cˇ ek , V a´ clav Pet rˇ ´ı cˇ ek , Ale sˇ Kure cˇ ka ,
c
c
Bo zˇ ena Kalinska , Jerzy Mrozinski
a
Department of Inorganic Chemistry, Faculty of Science, Palack y´ University, K rˇ ı´ zˇ kovsk e´ ho 10, CZ-771 47 Olomouc, Czech Republic
b
Institute of Physics, Academy of Science, Na Slovance 10, CZ-18221 Prague, Czech Republic
Faculty of Chemistry, University of Wroclaw, 14 F. Joliot-Curie, PL-50 383 Wroclaw, Poland
c
Received 26 May 2006; accepted 4 August 2006
Available online 18 August 2006
Abstract
Nickel and copper complexes containing 1,3,5-benzenetricarboxylic acid, with a combination of selected N-donor ligands and Schiff
bases, of the composition Ni (bimz) (btc) Æ 12H O (1), Ni (btz) (btc) Æ 12H O (2), Ni (L )(btc) Æ 7H O (3), Ni (L ) (Hbtc) Æ 9H O (4),
3
6
2
2
3
9
2
2
2
1
2
3
2 2
2
Ni
2
(L
3
)(btc) Æ 4H
2
O (5), Cu
2
(L
4
2
)(btc) Æ 7H O (6), [Cu
3
(pmdien)
3
(btc)](ClO
4
)
3
Æ 6H
2
O (7) and [Cu
3
(mdpta)
3 4 3 2
(btc)](ClO ) Æ 4H O (8);
H
3
btc = 1,3,5-benzenetricarboxylic acid, bimz = benzimidazole, btz = 1,2,3-benztriazole, L
1
= 2-[(phenylimino)methyl]phenol, L =
2
0
N,N -bis-(salicylidene)propylenediamine, L = 2-{[(2-nitrophenyl)methylene]amino}phenol, L = 2-[(4-methoxy-phenylimino)methyl]-
3
4
0
00
00
phenol, pmdien = N,N,N ,N ,N -pentamethyldiethylenetriamine, mdpta = N,N-bis-(3-aminopropyl)methylamine, have been synthe-
sized. The complexes have been studied by elemental analysis, IR, UV–Vis spectroscopies, magnetochemical and conductivity measure-
ments and selected compounds also by thermal analysis. The crystal and molecular structure of complex 8 was solved. The complex is
3
ꢀ
trinuclear with btc -bridge. The coordination polyhedron around each copper atom can be described as a distorted square with a CuON3
chromophore formed by one oxygen atom of carboxylate and three nitrogen atoms of mdpta. The magnetic properties of 8 have been
ꢀ
1
studied in the 1.8–300 K temperature range revealing a very weak antiferromagnetic exchange interaction with J = ꢀ0.56 cm for
g = 2.13(9). The antimicrobial activities against selected strains of bacteria were evaluated. It was found that only complex 5 is able to
inhibit the growth of Staphylococcus strains.
ꢀ
2006 Elsevier Ltd. All rights reserved.
Keywords: Nickel(II); Copper(II); 1,3,5-Benzenetricarboxylic (trimesic) acid complexes; X-ray structure; Magnetic properties
1
. Introduction
1,3,5-Benzenetricarboxylic acid (trimesic acid) is a tri-
carboxylic acid with potentially six oxygen donor atoms,
which can be coordinated to the central atoms in different
coordination modes. Transition metal complexes with the
1,3,5-benzenetricarboxylate anion which is not coordinated
to central atom are rather rare [4,5]. Many polynuclear
complexes with a btc bridge have been studied and different
coordination modes of carboxylato groups have been
proved by X-ray analysis: (a) tris-monodentate [6–8]; (b)
tris-bidentate [9]; (c) chelating bidentate and bis-monoden-
tate [10]; (d) chelating bis-bidentate and monodentate [11];
Transition metal complexes with N-donor ligands
bridged by carboxylic acids are studied not only for inter-
esting magnetic and spectral properties, but also as cata-
lysts or nano-materials precursors and for applications in
pharmaceutical industry for their potential antibacterial,
antiviral and antitumour effects [1–3].
*
Corresponding author. Tel.: +420 585634354; fax: +420 585225737.
E-mail address: pavel.kopel@upol.cz (P. Kopel).
0
277-5387/$ - see front matter ꢀ 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2006.08.010

536
P. Kopel et al. / Polyhedron 26 (2007) 535–542
(
e) chelating tris-bidentate [12]; chelating/bridging biden-
in Scheme 2). The ligands were used to block coordination
sites of the central atoms and to prevent formation of poly-
mers. We prepared also trinuclear species and solved the
X-ray structure of complex 8. EPR and magnetic study
of the complex proved that the benzenetricarboxylate
bridge is not suitable for exchange interactions between
the central atoms.
tate and monodentate [13] (see Scheme 1). Nickel com-
plexes with btc in combination with tetraaza- and
hexaazamacrocyclic ligands, pyridine derivatives or poly-
basic alcohols, have been prepared and structurally charac-
terized [14–19]. The hydrothermal method has been used
for the preparation of Mn, Co and Zn complexes with a
btcH bridge. The structures consist of double stranded
chains of dianions and dimeric units. Magnetic studies
showed that a ferromagnetic interaction occurs in Mn
and Co complexes [20]. Synthesis and study of copper com-
plexes containing btc bridges and N-heterocyclic amines
have been reported [21–23]. Comba et al. have prepared
2
ꢀ
2. Experimental
2.1. Materials and methods
All chemicals and solvents were supplied from Aldrich,
Carlo Erba and Lachema (Czech Republic) and were used
3
ꢀ
a copper complex; X-ray analysis confirmed that the btc
anion is situated outside the coordination sphere [24].
as received. Compound Ni(Hbtc) Æ 12H O was prepared by
2
The aim of our work was the preparation and study of
nickel and copper complexes containing a combination of
btc anion and selected N-donor ligands or Schiff bases
in the coordination sphere (the used ligands are depicted
the reaction of NiCO Æ 2Ni(OH) Æ 4H O (6.76 g, 30 mmol)
3
2
2
3
and H btc (7.10 g, 20 mmol) in water (50 cm ). The reac-
3
3
ꢀ
tion mixture was refluxed for 5 h. After cooling, a green
precipitate was filtered off, washed with water and dried
in air. Schiff base L was obtained by condensation of
2
3
salicylaldehyde (4.18 cm , 20 mmol) with 1,3-diaminopro-
3
3
M
M
M
pane (1.66 cm , 20 mmol) in ethanol (100 cm ). Na btc
3
was prepared by neutralization of H btc (2.1 g, 10 mmol)
with NaOH (1.2 g, 30 mmol) in water (100 cm ).
3
O
O
O
O
3
C
C
The C, H, N analyses were carried out on an EA 1108
instrument (Fisons). The content of nickel and copper was
determined by chelatometric titration on murexid as an indi-
cator. UV–Vis spectra were recorded on an UV–Vis Spec-
trometer Lambda 35 (Perkin–Elmer) and IR spectra on a
FT-IR Spectrometer Spectrum One (Perkin–Elmer) using
KBr pellets. The molar conductivity was measured on a
Conductivity Meter LF 340 (WTW, Germany). Thermal
analysis was performed on an Exstar (Seiko Instruments
Inc.). Magnetochemical data at room temperature were
O
O
O
O
C
C
O
C
C
M
M
O
O
O
M
M
M
M
a
b
M
M
O
O
O
O
C
obtained by the Faraday method. Hg[Co(SCN) ] was used
4
C
as a calibrant. Magnetization measurements at a magnetic
field of 0.5 T in the temperature range 1.8–300 K were
performed using
a Quantum Design SQUID-based
O
O
O
M
O
C
O
C
O
MPMSXL-5-type magnetometer. The SQUID magnetome-
ter was calibrated with a palladium rod sample (Materials
Research Corporation, measured purity 99.9985%). The
superconducting magnet was generally operated at a field
strength ranging from 0 to 5 T. Corrections are based on
C
O
C
O
M
M
M
c
d
subtracting the sample-holder signal and contribution v
M
D
ꢀ1
M
ꢀ
6
3
estimated from Pascal constants (ꢀ401 · 10 cm mol
O
O
O
O
per trimer). A temperature-independent paramagnetism of
C
C
ꢀ6
3
ꢀ1
6
0 · 10 cm K mol for the copper(II) ion was used.
Additional magnetization measurements were made at 2 K
in a magnetic field from 0 to 5 T. EPR spectra were recorded
at 293 and 77 K on a Bruker ESP 300 spectrometer operat-
ing at X-band equipped with an ER 035M Bruker NMR
gaussmeter and an HP 5350B Hewlett–Packard microwave
frequency counter. The spectrum at 4.2 K was measured
with an X-band Radiopan SE/X 2543 Spectrometer.
The antimicrobial activities of the complexes against
Staphylococcus aureus CCM 3953, Enterococcus faecalis
CCM 4224, Escherichia coli CCM 3954, Pseudomonas
O
O
O
M
O
M
C
O
C
C
O
C
O
M
O
M
M
e
f
Scheme 1. Coordination modes of benzene-1,3,5-tricarboxylic acid
btc).
(H
3

P. Kopel et al. / Polyhedron 26 (2007) 535–542
537
N
N
N
N
H
N
H
bimz
btz
CH3
CH3
N
H C
N
N
N
CH3
3
H N
NH2
2
CH3
H C
3
pmdien
mdpta
CH
OH
N
CH
OH
N
(CH2)3 N
CH
HO
L1
L2
CH
N
CH
OH
N
OMe
NO2
HO
L3
L4
Scheme 2. Structural formulas of used ligands.
3
aeruginosa CCM 3955, Staphylococcus epidermidis, S.
aureus MRSA, Enterococcus faecium VRE and Klebsiella
pneumoniae ESBL were estimated and expressed as
2 mmol) dissolved in hot water (25 cm ) a violet-blue pre-
cipitate was formed. It was filtered off, washed with water
and dried at room temperature. Yield: 56%.
ꢀ
1
minimal inhibitory concentrations MIC (lg mL ). The
bacteria were inoculated into a liquid medium (Mueller–
Hinton or Brain Heart Infusion broth). The test com-
plexes were dissolved in DMSO and diluted by water.
2.2.3. Ni (L )(btc) Æ 7H O (3)
2
1
2
NiCl Æ 6H O (0.24 g, 1 mmol) was dissolved in ethanol
(25 cm ). After addition of Schiff base L (0.20 g, 1 mmol)
a yellow-green solution was obtained. Triethylamine
(0.14 cm , 1 mmol) was added and solution color changed
2
2
3
1
ꢀ
1
Solutions with concentrations 100–0.78 lg mL
used for testing. Bacteria were cultured for 24 h at
7 ꢁC; then the growth of microorganisms was observed.
were
3
3
to dark green. After addition of a solution of Na btc
3
3
3
When no growth of microorganisms was observed in the
medium containing the lowest concentration of test mate-
rials, the MIC of the test material was defined at this
point of dilution. All compounds were tested two times
and results are given as an average of two independent
experiments [25].
(0.1 mol/dm , 3.3 cm ) a green precipitate was formed. It
was filtered off, washed with water and ethanol and dried
at room temperature. Yield: 44%.
2.2.4. Ni (L ) (Hbtc) Æ 9H O (4)
3
2 2
2
NiCl Æ 6H O (0.23 g, 1 mmol) was dissolved in ethanol
25 cm ). After addition of a solution of Schiff base L
(0.2 mol/dm , 5 cm ), a dark green solution was obtained.
Triethylamine (0.14 cm ) was added and the solution color
2
2
3
(
2
3
3
2
2
2
.2. Syntheses
3
.2.1. Ni (bimz) (btc) Æ 12H O (1)
turned brown-red. After addition of a solution of Na btc
3
6
2
2
3
3
3
Bimz (0.47 g, 4 mmol), dissolved in ethanol (96%,
(0.1 mol/dm , 3.3 cm ) a green precipitate was obtained.
It was filtered off, washed with water and ethanol and dried
at room temperature. Yield: 71%.
3
5 cm ) was added to a suspension of Ni(Hbtc) Æ 12H O
2
3
(
0.48 g, 1 mmol) in water (50 cm ). The reaction mixture
was refluxed for 5 h. After cooling a violet-blue precipitate
was filtered off, washed with small amounts of ethanol and
dried at room temperature. Yield: 64%.
2.2.5. Ni (L )(btc) Æ 4H O (5)
2
3
2
Ni(ClO ) Æ 6H O (0.37 g, 1 mmol) was dissolved in
4
2
2
3
ethanol (50 cm ). After addition of Schiff base L (0.49 g,
3
2
.2.2. Ni (btz) (btc) Æ 12H O (2)
2 mmol) a brown-yellow solution was obtained. Triethyl-
amine (0.28 cm ) was added and the solution color turned
3
9
2
2
3
A solution of Ni(ClO ) Æ 6H O (0.37 g, 1 mmol) in
4
2
2
3
water (25 cm ) was mixed with a solution of Na btc
dark red. After addition of a solution of Na btc (0.1 mol/
3
3
3
3
3
3
(
0.1 mol/dm , 3.3 cm ). After addition of btz (0.24 g,
dm , 3.3 cm ) a brown precipitate was formed. It was

538
P. Kopel et al. / Polyhedron 26 (2007) 535–542
filtered off, washed with water and ethanol and dried at
room temperature. Yield: 69%.
2.3. X-ray crystallography
X-ray data were collected using a four circle j-axis dif-
TM
fractometer Xcalibur 2 (Oxford Diffraction) equipped
2
.2.6. Cu (L )(btc) Æ 7H O (6)
2 4 2
with a Sapphire2 CCD detector, a monochromator
Enhance and a Cryojet cooler system, using Mo Ka radia-
tion at 107 K. The CrysAlis program package (1.171.7
version) was used for data reduction. Details of the struc-
ture are discussed in Section 3.2.
CuCl Æ 2H O (0.17 g, 1 mmol) was dissolved in metha-
2
2
3
nol (25 cm ). After addition of Schiff base L (0.23 g,
1
amine (0.14 cm ) was added and the solution color turned
dark brown. After addition of a solution of Na btc
4
mmol) a brown-yellow solution was obtained. Triethyl-
3
3
3
3
(
0.1 mol/dm , 3.3 cm ) a brown precipitate was obtained.
3. Results and discussion
It was filtered off, washed with water and ethanol and dried
at room temperature. Yield: 77%.
3.1. Physical techniques
2
.2.7. [Cu (pmdien) (btc)](ClO ) Æ 6H O (7)
3 3 4 3 2
Pmdien (0.21 cm , 1 mmol) was added to a solution of
The results of the elemental analyses and physico-
3
chemical study are listed in Tables 1 and 2. The IR spectra
of all the complexes show the characteristic bands of
3
Cu(ClO ) Æ 6H O (0.37 g, 1 mmol) in water (25 cm ).
After addition of Na btc solution (0.1 mol/dm , 3.3 cm ),
a dark blue precipitate was formed. It was filtered off,
washed with ethanol and dried at room temperature.
Yield: 56%.
4
2
2
3
3
ꢀ1
3
carboxylate groups in the region 1542–1614 cm for the
ꢀ
ꢀ1
ꢀ
m (COO ) and 1350–1378 cm for the m (COO ) vibra-
as
s
tions. IR spectra of complexes containing Schiff bases
ꢀ1
(
3–6) exhibit bands at 1614–1618 cm , which can be
assigned to the m(C@N) vibrations. In the IR spectra of
copper complexes 7 and 8 bands were found at 1096,
2
.2.8. [Cu (mdpta) (btc)](ClO ) Æ 4H O (8)
3 3 4 3 2
Mdpta (0.32 cm , 2 mmol) was added to a solution of
3
ꢀ1
ꢀ1
618 cm and 1091, 624 cm for 7 and 8, which can be
assigned to the m (ClO ) and m (ClO ) vibrations, typical
3
Cu(ClO ) Æ 6H O (0.74 g, 2 mmol) in ethanol (50 cm )
After addition of a solution of Na btc (0.1 mol/dm ,
3
4
4
4
4
2
2
3
for a non-coordinated perchlorate anion [26].
3
3
3
.3 cm ), a dark blue solution was obtained. Dark blue
The nickel complexes have effective magnetic moments in
the 2.73–3.72 B.M. range (per one Ni atom). For these com-
plexes we can assume octahedral (1, 4, 5) or penta-
coordinated (2, 3) arrangements of donor atoms around
crystals were obtained in one week. The crystals were col-
lected on a frit, washed with water and dried at room tem-
perature. Yield: 48%.
Table 1
Analytical data
Complex
Found/calc. (%)
C
H
N
Cl
Ni, Cu
(
(
(
(
(
(
(
(
1) Ni
2) Ni
3) Ni
4) Ni
5) Ni
6) Cu
7) [Cu
8) [Cu
3
3
2
3
2
(bimz)
(btz) (btc)
)(btc) Æ 7H
6
(btc)
2
Æ 12H
2
O
47.4/47.6
46.3/46.0
40.5/40.9
46.9/46.6
41.9/41.4
40.2/40.2
32.9/32.7
29.9/29.9
4.2/4.4
3.7/4.0
4.9/4.2
5.4/4.9
3.9/32
4.7/4.3
5.9/6.4
5.5/5.7
11.0/11.1
19.7/20.1
2.9/2.2
5.7/5.1
4.9/4.4
2.5/2.0
9.4/9.5
10.5/10.5
11.7/11.6
9.5/9.4
9
2
Æ 12H
2
O
(L
(L
(L
1
2
3
2
O
18.1/18.1
15.7/15.9
18.9/18.4
18.3/18.5
14.7/14.3
16.2/15.8
)
2
(Hbtc) Æ 9H
2
O
)(btc) Æ 4H
)(btc) Æ 7H
(pmdien) (btc)](ClO
(mdpta) (btc)](ClO
2
O
2
(L
4
2
O
3
3
4
)
3
Æ 6H
Æ 4H
2
O
O
7.0/8.0
10.1/8.8
3
3
4
)
3
2
Table 2
Results of physico-chemical study
ꢀ
1
Complex
leff (B.M.)
UV–Vis
IR (cm )
3
ꢀ1
ꢀ
ꢀ
(
per Ni, Cu)
·10 (cm
)
m
as(COO )
m
s
(COO )
m(C@N)
(
(
(
(
(
(
(
(
1) Ni
2) Ni
3) Ni
4) Ni
5) Ni
6) Cu
7) [Cu
8) [Cu
3
3
2
3
2
(bimz)
(btz) (btc)
)(btc) Æ 7H
6
(btc)
2
Æ 12H
2
O
3.29
3.60
3.72
2.73
2.89
2.07
1.94
1.90
17.5; 28.0
17.5; 27.1
15.5; 27.4
24.6; 27.5
21.4; 27.7
24.3; 28.1
15.5; 29.4
16.2; 33.7
1610
1612
1542
1546
1567
1552
1600
1614
1366
1371
1369
1365
1378
1358
1350
1372
9
2
Æ 12H
2
O
(L
(L
(L
1
2
3
2
O
O
1614
1614
1614
1618
)
2
(Hbtc) Æ 9H
2
O
)(btc) Æ 4H
)(btc) Æ 7H
(pmdien) (btc)](ClO
(mdpta) (btc)](ClO
2
2
(L
4
2
O
3
3
4
)
3
Æ 6H
Æ 4H
2
O
O
3
3
4
)
3
2

P. Kopel et al. / Polyhedron 26 (2007) 535–542
539
the central nickel atom. The large magnetic moments can be
due to large orbital contributions expected for trigonal
bipyramidal Ni(II) complexes with orbitally degenerate
states [27]. If we assume a distorted octahedral arrangement
for complexes 1, 4 and 5, the bands found in UV–Vis spec-
contribution also occurs [30]. The UV–Vis absorption spec-
tra of the copper complexes contain bands in the region
ꢀ
1
ꢀ1
15500–24300 cm
and 28100–33700 cm , belonging
probably to d–d and CT transitions. Complex 6 could be
polymeric and we can assume an octahedral or penta-
coordinated arrangement of the chromophore. In complex
7 we can assume a similar arrangement of donor atoms
around the central copper atom as in complex 8 (confirmed
by single crystal X-ray analysis).
ꢀ
1
ꢀ1
tra in the 17500–21400 cm
and 22900–28000 cm
3
3
region can be assigned to the A (F) ! T (F) and
2
g
1g
3
3
A (F) ! T (P) transitions, respectively [28]. The UV–
2
g
1g
ꢀ1
Vis bands of complexes 2 (at 15500, 27400 cm ) and 3
ꢀ1
3
0
3
00
(
at 17500, 27100 cm ), can be assigned to the E ! E
The complexes are insoluble in most common organic
solvents except for complex 7, which is soluble in dimethyl-
formamide and water. The molar conductivity of complex
3
0
3
0
and E ! A transitions, respectively, when a trigonal-
2
bipyramidal geometry is suggested [29].
ꢀ
3
ꢀ3
2
TG curves of the complexes 3–5 (not shown) exhibit no
plateau that could be assigned to thermally stable interme-
diates. The thermal decomposition is complete between 425
and 480 ꢁC and the final product is NiO, which was con-
firmed by powder X-ray diffraction analysis.
The copper complexes exhibit effective magnetic
moments in the 1.90–2.07 B.M. range (per one Cu atom).
These values are in good agreement with the assumption
of one unpaired electron of Cu(II) ion where an orbital
7 in dimethylformamide (10 mol dm ) is 218.1 S cm
ꢀ
1
mol , which is a value typical for 3:1 electrolytes [31].
The perchlorate anions are situated outside the coordina-
tion sphere of the central copper atom.
The antimicrobial activities of the complexes were esti-
mated and it was found that only complex 5 exhibits a very
small activity against S. aureus CCM 3953, S. epidermidis
and S. aureus MRSA for the maximum concentration used
ꢀ
1
(100 lg mL ). The remaining complexes do not signifi-
cantly inhibit the growth of the test organisms.
Table 3
Crystal data and structure refinement of [Cu
3
(mdpta)
Cu
M = 1203.90)
107(2)
3
(btc)](ClO
4 3 2
) Æ 4H O
3
.2. Crystal structure of
Chemical formula
3
C
30
H
70
N
3
O23Cl
3
[Cu (mdpta) (btc)](ClO ) Æ 4H O (8)
3
3
4 3
2
(
Temperature (K)
The structure was solved by standard SHELX programs
32,33]. Crystal data and structure refinement is given in
Cell setting; space group
monoclinic; P21=n
[
Unit cell dimensions
˚
Table 3; selected bond and angles are listed in Table 4. It
is apparent that the molecule (see Fig. 1) forms a trinuclear
a (A)
18.5892(3)
9.7725(3)
26.5520(3)
92.315(4)
˚
b (A)
˚
c (A)
b (ꢁ)
Table 4
Selected bond lengths (A) and angles (ꢁ) of [Cu
4H
˚
3
˚
V (A )
4819.578
4; 1.659
3 3 4 3
(mdpta) (btc)](ClO ) Æ
ꢀ
3
Formula units; D
x
(Mg m
)
2
O
Crystal form; color
Crystal size (mm)
prismatic; blue
0.4 · 0.4 · 0.2
Bond lengths
Cu1–O1
Cu2–O3
Cu3–O5
Cu1–N1
Cu1–N2
Cu1–N3
Cu2–N4
Cu2–N5
Cu2–N6
Cu3–N7
Cu3–N8
Cu3–N9
2.058(2)
2.009(2)
2.012(2)
1.971(3)
2.046(3)
1.957(2)
2.010(3)
2.037(3)
1.989(3)
1.987(3)
2.024(3)
1.960(3)
Data collection
Diffractometer
Radiation type
Oxford diffraction CCD
Mo Ka
0.71069
none
1.565
˚
Wavelength (A)
Absorption correction type
ꢀ1
Absorption coefficient l (mm
Range of h, k, l
)
ꢀ27 6 h 6 27;
ꢀ
13 6 k 6 11;
39 6 l 6 36
ꢀ
h Range (ꢁ)
Reflections measured/unique/observed
Criterion for observed reflections
2.73–32.17
47612/15453/10361
I > 3r(I)
Bond angles
O1–Cu1–N3
O1–Cu1–N1
N1–Cu1–N2
N2–Cu1–N3
O3–Cu2–N4
O3–Cu2–N6
N5–Cu2–N6
N4–Cu2–N5
O5–Cu3–N7
O5–Cu3–N9
N7–Cu3–N8
N8–Cu3–N9
R
int
0.0466
85.22(9)
84.69(9)
97.41(10)
94.13(10)
87.48(9)
88.08(9)
98.09(10)
92.86(10)
91.68(10)
93.42(12)
95.90(11)
93.86(13)
Refinement
Refinement on
R, wR
F
0.0509, 0.0654
1.85
S
Number of parameters
Weighting scheme
620
2
2 ꢀ1
w = [r (F) + (0.02F) ]
0.0069
(
D/s.u.)max
˚
ꢀ3
˚
ꢀ3
)
Dqmax (e A )/Dqmin (e A
Extinction correction
Source of atomic scattering
factors
1.58/ꢀ1.25
none
international tables for X-ray
crystallography (1992, Vol. C)

540
P. Kopel et al. / Polyhedron 26 (2007) 535–542
condition. The occupancy of the new position was refined
to 0.235(2).
As the next step we have localized five possible positions
for water molecules. Three of them were regularly distrib-
uted over the available space. Two remaining peaks,
ꢀ
located in the vicinity of the disordered ClO4 , were not
fully occupied and the refined occupancies were in a close
ꢀ
relationship with those for the two positions of ClO4 . A
more detailed analysis of O–O distances showed that the
more occupied position of the water molecule makes too
short a distances with oxygen atoms from the less occupied
ꢀ
ClO4 position and vice versa.
Finally, the structure has been completed with the
hydrogen atoms except for those belonging to water mole-
cules. The H positions were restrained to keep an ideal
geometry during the refinement.
3
[
.3. EPR spectra and magnetic properties of
Cu (mdpta) (btc)](ClO ) Æ 4H O (8)
3
3
4 3
2
3 3 4 3 2
Fig. 1. Molecule of [Cu (mdpta) (btc)](ClO ) Æ 4H O. Thermal ellipsoids
are drawn at 50% probability level. Perchlorate ions and solvating water
molecules are omitted for clarity.
The magnetic properties of the trimer were determined
over the temperature range 1.8–300 K. Plots of the mag-
netic susceptibility and reciprocal magnetic susceptibility
are given in Fig. 2. The magnetic dependence of the exper-
imental and calculated vCuT in the field (0.5 T) for the
trimer (vCu is the susceptibility value per one copper center)
is shown in Fig. 3.
copper complex, containing three CuN O chromophores
3
connected via a benzene-1,3,5-tricarboxylate bridge. The
perchlorate anions and water molecules are out of the
coordination sphere. The geometry of the chromophores
is square planar (see Table 4), but with a significant tetra-
The Curie–Weiss behavior indicates a linear relation of
the reciprocal magnetic susceptibility curve at higher
temperatures (100–300 K) with a Curie constant C =
hedral distortion. The deviations from ideal CuN O planes
3
˚
(
in A) are for O-atoms: from 0.239(2) to ꢀ0.375(2); for
3
ꢀ1
N-atoms: from 0.081(2) to 0.582(3) and from ꢀ0.383(2)
to ꢀ0.734(2). The dihedral angles between Cu(1)O(1)
N(1)N(2)N(3) (A), Cu(2)O(3)N(4)N(5)N(6) (B) and
Cu(3)O(5)N(7)N(8)N(9) (C) are: A–B 106.5(2)ꢁ; A–C
0.426 cm mol K and Weiss-constant, h = ꢀ1.74 K and
a small anomaly is observed only at the lowest tempera-
tures. The compound reveals a magnetic behavior which
is characteristic of antiferromagnetic spin coupling. The
vCuT values decreases gradually with lowering of the tem-
9
6.5(2)ꢁ and B–C 9.9(3)ꢁ.
3
ꢀ1
3
The subsequent anisotropic refinement converged to
perature, from 0.425 cm mol K at 300 K to 0.256 cm
ꢀ
1
a reasonable fit R = 0.0757 for observed reflections
mol K at 1.8 K, and the effective magnetic moment from
1.85 B.M. at 300 K to 1.43 B.M. at 1.8 K.
1
I > 3r(I). However, Fourier maps in the vicinity of one of
ꢀ
the ClO4 anions revealed a clear indication of some disor-
The powdered sample of the complex indicates a
rhombic deformed square-pyramidal EPR spectrum in
der. Even more convincing was the difference Fourier map
in the same area. Another Cl position slightly shifted from
the original one has been located. Moreover we could also
localize a separate peak having a reasonable distance from
that new Cl position. The vector between these two new
atoms had the opposite direction with respect to one of ori-
ginal Cl–O bonds. This made it possible to deduce that the
ꢀ
second position of ClO4 is related to the basic position by
a rotation about 180ꢁ perpendicular to the original Cl–O
bond. The remaining three new oxygen positions could
not be localized so clearly because the rotation brings them
too close the original ones.
The rigid body option of Jana 2000 has been used to
make a final refinement [34]. One molecule with adjustable
shape in the two above mentioned positions has been used.
Together with the average geometry of ClO we refined
4
also translation and rotation parameters for each position
and the site occupancies restricted by the complementary
Fig. 2. Plots of the magnetic data vCu (s) and 1/vCu (d) versus
temperature for [Cu (mdpta) (btc)](ClO ) Æ 4H O.
3 3 4 3 2

P. Kopel et al. / Polyhedron 26 (2007) 535–542
541
the higher temperature region (Fig. 4) with spectroscopic
splitting factors g = 2.17 , g = 2.11 , g = 2.07 at
1
8
2
8
3
0
2
93 K and g = 2.17 , g = 2.11 , g = 2.06 at 77 K.
1 4 2 9 3 8
At liquid helium temperature (4.2 K), an isotropic EPR
signal with a single symmetric line only at g = 2.06(1) with
dHpp = 180 G is observed.
X-ray analysis indicated that the Cu(II) centers form a
regular triangle. An isotropic exchange model Hamiltonian
of the trimer can be written as follows:
b
b b
b b
b b
H ¼ ꢀ2JðS
1
S
2
þ S
2
S
3
þ S
1
S
3
Þ
where S = 1/2, J is an exchange parameter.
i
A closed-form solution of the magnetic susceptibility
derived from the susceptibility takes the form [35–39]:
Fig. 3. Plots of the magnetic data
temperature for [Cu (mdpta) (btc)](ClO
the calculated curve (see text).
v
Cu
T
experimental (s) versus
)
3
Æ 4H O. Full line represents
2
2
2
B
3J=kT
J=kT
3
3
4
Ng l 1 þ 5e
v ¼
3
4
kT 1 þ e
where N, g, b, k and T have their usual meanings and both
J and g factors were calculated in the fitting processes. The
best least-squares fit (solid lines in Fig. 3) was obtained
ꢀ
1
for the following values: J = ꢀ0.56 cm , g = 2.13 and
9
ꢀ5
R = 4.79 · 10
.
vffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
(
),
,
u
n
.
n
u X Â
t
Ã
X
exp
M
calc:
M
2
exp
M
2
exp
M
2
R ¼
ðv Þ ꢀ ðv
Þ
ðv
Þ
1
ðv
Þ
i
i
i
i
i¼1
i¼1
Acknowledgements
This work was supported by the Polish Ministry of
Education and Science, Grant No. 1 T09A 124 30. Authors
thank Mgr. Ji rˇ ´ı Mikul ´ı k for collection and reduction of
ˇ
X-ray data, Assoc. Prof. Zden eˇ k Sindel a´ rˇ for magneto-
chemical measurements at room temperature, Drs. M.
Kol a´ rˇ and K. Dole zˇ al for antimicrobial testing and Mr.
Jan Wala for powder X-ray data collection.
Appendix A. Supplementary data
Crystallographic data are deposited in Cambridge Crys-
tallographic Data Centre, No. CCDC 601336. Copies of
the data can be obtained free of charge on application to
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK; fax
+
44 1223 336 033; e-mail: deposit@ccdc.cam.ac.uk or
http://www.ccdc.cam.ac.uk. Supplementary data associ-
ated with this article can be found, in the online version,
at doi:10.1016/j.poly.2006.08.010.
References
[1] M.O. Keeffe, M. Eddaoudi, H. Li, T. Reineke, O.M. Yaghi, J. Solid
State Chem. 3 (2000) 2000.
[
[
[
2] S. Feng, R. Xu, Acc. Chem. Res. 34 (2001) 239.
3] G. Ferey, Chem. Mater. 13 (2001) 3084.
4] X.-J. Yang, B. Wu, W.H. Sun, C. Janiak, Inorg. Chim. Acta 343
(
2003) 366.
Fig. 4. X-band EPR spectra of a powdered sample of [Cu
ClO Æ 4H O at different temperatures.
3
(mdpta)
3
(btc)]-
[5] D. Braga, A. Angeloni, E. Tagliavini, F. Grepioni, J. Chem. Soc.,
Dalton Trans. (1998) 1961.
(
4
)
3
2

542
P. Kopel et al. / Polyhedron 26 (2007) 535–542
[
6] M.J. Plater, M.R.J. Foreman, R.A. Howie, J.M.S. Skakle, E. [24] P. Comba, Y.D. Lampeka, A.Y. Nazarenko, A.I. Prikhodko, H.
Coronado, C.J. Gomez-Garcia, T. Gelbrich, M.B. Hursthouse, Inorg.
Chim. Acta 319 (2001) 159.
7] G. Wu, X. Shi, Q. Fang, G. Tian, L. Wang, G. Zhu, A.W. Addison,
Y. Wei, S. Qiu, Inorg. Chem. Commun. 6 (2003) 402.
8] X. Li, D. Sun, R. Cao, Y. Sun, Y. Wang, W. Bi, S. Gao, M. Hong,
Inorg. Chem. Commun. 6 (2003) 908.
Pritzkow, Eur. J. Inorg. Chem. (2002) 1464.
[25] National Committee for Clinical Laboratory Standards. Performance
Standards for Antimicrobial Susceptibility Testing. Approved stan-
dard–eighth ed., NCCLS document, M2-A8. Wayne, PA, USA, 2003,
pp. 1–70.
[26] P. Scholer, A.E. Merbach, Inorg. Chim. Acta 15 (1975) 15.
[27] G. Wilkinson, Comprehensive Coordination Chemistry, Pergamon,
Oxford, 1987.
[
[
[
9] O.M. Yaghi, C.E. Davis, G. Li, H. Li, J. Am. Chem. Soc. 119 (1997)
2861.
[
[
10] O.M. Yaghi, H. Li, T.L. Groy, J. Am. Chem. Soc. 118 (1996) 9096.
11] M.R.J. Foreman, T. Gelbrich, M.B. Hursthouse, M.J. Plater, Inorg.
Chem. Commun. 3 (2000) 234.
[28] A.B.P. Lever, Inorganic Electronic Spectroscopy, Elsevier, Amster-
dam, 1984.
[29] M. Ciampolini, Inorg. Chem. 5 (1966) 35.
[
12] C. Daiguebonne, Y. G e´ rault, F. Le Dret, O. Guillou, K. Boubekeur,
J. Alloys Compd. 344 (2002) 179.
[30] E. K o¨ nig, Magnetic Properties of Coordination and Organo-
metallic Transition Metal Compounds, Springer-Verlag, Berlin,
1966.
[
[
[
13] M.J. Plater, R.A. Howie, A.J. Roberts, Chem. Commun. (1997) 893.
14] K.Y. Choi, K.M. Chun, I.H. Suh, Polyhedron 20 (2001) 57.
15] T.B. Lu, H. Xiang, R.L. Luck, L. Jiang, Z.W. Mao, L.N. Ji, New J.
Chem. 26 (2002) 969.
[31] W.J. Geary, Coord. Chem. Rev. 7 (1971) 81.
[32] G.M. Sheldrick, Acta Crystallogr., Sect. A 46 (1990) 467.
[33] G.M. Sheldrick, SHELXL-97: Program for Crystal Structure Refine-
ment, University of G o¨ ttingen, Germany, 1997.
[34] V. Pet rˇ ´ı cˇ ek, M. Du sˇ ek, Z. Kristallogr. 219 (2004) 692.
[35] B.S. Tsukerblat, B.Y. Kuyarskaya, M.I. Belinski, A.V. Ablov, V.M.
Novotvortsev, V.T. Kalinnikov, Theor. Chim. Acta (Berlin) 38 (1975)
131.
[36] M. Inoue, M. Kubo, J. Coord. Chem. 6 (1977) 157.
[37] R.J. Butcher, C.J. O’Connor, E. Sinn, Inorg. Chem. 20 (1981)
537.
[38] J.P. Costes, F. Dahan, J.P. Laurent, Inorg. Chem. 25 (1986) 413.
[39] Y. Nakao, H. Nakamura, W. Mori, T. Sakurai, S. Suzuki, A.
Nakahara, Bull. Chem. Soc. Jpn. 59 (1987) 2755.
[
[
16] H.J. Choi, M.P. Suh, J. Am. Chem. Soc. 120 (1998) 10622.
17] C.J. Kepert, T.J. Prior, M.J. Rosseinsky, J. Am. Chem. Soc. 122
(2000) 5158.
[
[
[
18] T.J. Prior, M.J. Rosseinsky, Inorg. Chem. 42 (2003) 1564.
19] C.J. Kepert, M.J. Rousseinsky, Chem. Commun. (1998) 31.
20] M.J. Plater, M.R.S. Foreman, E. Coronado, C.J. Gomez-Garcia,
A.M.Z. Slawin, J. Chem. Soc., Dalton. Trans. (1999) 4209.
[
[
[
21] D. Cheng, M.A. Khan, R.P. Houser, Inorg. Chem. 40 (2001) 6858.
22] H. Oshio, H. Ichida, J. Phys. Chem. 99 (1995) 3294.
23] H.S. Huh, D. Min, Y.K. Lee, S.W. Lee, Bull. Korean Chem. Soc. 23
(2002) 619.