Mono-, di- and trinuclear complexes of bis(terpyridine) ligand: Synthesis, crystal structures and magnetic properties

Article abstract of DOI:10.1016/j.poly.2013.02.054

Application of Stille-coupling protocol allowed for synthesis of new bis(terpyridine) ligand L (6′,6″-(2-phenylpyrimidine-4,6-diyl)bis(6- methyl-2,2′-bipyridine)) which comprises two tridentate N-donor subunits, designed so as to exploit the formation of

Full text of DOI:10.1016/j.poly.2013.02.054

Polyhedron 54 (2013) 260–271
Contents lists available at SciVerse ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
Mono-, di- and trinuclear complexes of bis(terpyridine) ligand: Synthesis,
crystal structures and magnetic properties
a
a
a
b
a,
⇑
´
Monika Wałe˛sa-Chorab , Adam Gorczynski , Maciej Kubicki , Maria Korabik , Violetta Patroniak
a Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60780 Poznan´, Poland
b Faculty of Chemistry, University of Wrocław, 14 Joliot-Curie, 50383 Wrocław, Poland
a r t i c l e i n f o
a b s t r a c t
Application of Stille-coupling protocol allowed for synthesis of new bis(terpyridine) ligand L (60,600-(2-phe-
nylpyrimidine-4,6-diyl)bis(6-methyl-2,20-bipyridine)) which comprises two tridentate N-donor subunits,
designed so as to exploit the formation of supramolecular architectures of different nuclearity. Further
complexation, while maintaining reaction parameters unaltered, with the following salts: CoCl2 (1),
Co(NO3)2 (2), Cu(NO3)2 (3) and Mn(ClO4)2 (4) led to three different classes of compounds: mono-, di- and
trinuclear species, the result of self-assembly being contingent on the choice of the metal ion as well as
to its corresponding counterion. Single crystal structures of [Co(L)Cl2] (1), [Co2(L)(NO3)4](CH3CN)2 (2),
[Cu2(L)(NO3)4](CH3CN)2 (3) and [Mn3(L)2(H2O)2(CH3CN)4](ClO4)6ꢀ2H2O (4) are presented, together with
description of their magnetic behavior. Delusively simple coordination compounds were found to self-
assemble into interesting supramolecular architectures in the solid state: 1D pillar-like constituent
arranged in the helical manner (1), sheets of isostructural 2 and 3, hydrogen bonded zig-zag shaped chains
(4). Magnetic susceptibility measurements made the determination of both antiferromagnetic interactions
and metal ions0 multiplicity possible.
Article history:
Received 17 December 2012
Accepted 25 February 2013
Available online 6 March 2013
Keywords:
Cobal
Copper
Manganese
Magnetic properties
Self-assembly
Ó 2013 Elsevier Ltd. All rights reserved.
1. Introduction
polymers, with emphasis being put on silver [16], which is the
inherent domain of crystal engineering.
Concepts such as molecular recognition and self-organisation
introduced by J.M. Lehn and embedded within the domain of
supramolecular chemistry have granted additional attention to
reversible, directional interactions, the most important being
hydrogen [1] and dative bonds [2]. If one anticipates to conduct
preprogrammed self-assembly, among variety of factors to
consider, it is careful design of ligand that is especially important
as far as formation of multicomponent structures such as grids
[3–6] or helicates [7–9] is concerned. One of the most spectacular
recent examples shows how a slight change in the ligands bend an-
gle critically switches the outcome of self-assembly between
Ligands bearing terpyridine and parent-like moieties have been
found to be particularly appealing what is, in connection with var-
ious modes of coordination to metal ions, reflected by their utiliza-
tion in numerous fields such as nanotechnology [17], catalysis [18],
bioassays [19] and polymer science [2].
When it comes to cobalt and manganese ions, variety of oxida-
tion states they may adopt – especially in the case of the latter one
– makes the assumption of catalytic and magnetic properties logi-
cal and obvious in connection with rigid, multidentate, properly
designed N-donor ligand. Cobalt compounds, although well known
for their catalytic activities in fields such as organometallic chem-
istry [20] have been recently highlighted for both oxidative and
reductive reactions in terms of the water splitting process [21].
When magnetic properties are under evaluation such as spin-cant-
ing [22], spin-frustration [23], spin-flop transitions [24], or meta-
magnetism [25] manganese(II) is the metal of choice, provided,
thesis being above all supported by work of Zhao and co-workers,
where Kagomé layer-based 3D Mn(II) framework showed coexis-
tence of all four aforementioned phenomena [26].
M24L48 and M12L24 coordination spheres [10].
It is unwise to forget about counterions which are very often
chosen so as not to disrupt favorable molecular recognition out-
comes, albeit their misleadingly insignificant role is usually under-
rated, not to say overlooked [11]. They may be per se responsible
for a variety of factors ranging from surfactants [12] and vessel for-
mation [13], stability of mesogenic materials [14], morphology and
size of nanocrystals [15] to finish on the structure of coordination
Herein we report the synthesis of new N-heterocyclic ligand L
(Fig. 1) bearing two tridentate, terpyridine-like moieties capable
of forming transition metal complexes of various nuclearity,
namely: mono- [Co(L)Cl2] (1), di- [M2(L)(NO3)4] (where M – Co(II)
⇑
Corresponding author. Fax: +48 618291508.
E-mail address: violapat@amu.edu.pl (V. Patroniak).
0277-5387/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.poly.2013.02.054

M. Wałe˛sa-Chorab et al. / Polyhedron 54 (2013) 260–271
261
subsequently the solvent was removed under reduced pressure
on rotary evaporator. Purification by means of chromatography
on alumina with CH2Cl2: n-hexane (3:2 v:v) as an eluent yielded
0.561 g (64.1%) of white powder. mp 242–245 °C, FABMS:
m/z = 493.7 (M+H+, 100), IR (KBr):
(CH3) 2962; s(CH3) 2852;
(C@N)py 1444, 1438, 1384, 1371, 1365;
(C–H)py 995, 826, 787, 756, 695, 643 cmꢂ1
m
=
m
(C–H)ar 3056, 3002; mas
(C@C)py 1601, 1566, 1540, 1471;
(C–H)py 1087, 1072;
1H NMR (CDCl3,
m
m
m
c
q
.
300 MHz): d = 9.72 (s, 1H, Hg), 8.77 (dd, 4H, J = 2.1 Hz, Hd, Hf),
8.65 (d, 2H, J = 7.8 Hz, Hc), 8.62 (d, 2H, J = 8.0 Hz, Hh), 8.05 (t, 2H,
J = 7.7 Hz, He), 7.82 (t, 2H, J = 7.7 Hz, Hb), 7.58 (m, 3H, J = 1.8 Hz,
Hi, Hj), 7.26 (d, 2H, J = 6.9 Hz, Ha), 1.65 (s, 6H, CH3) ppm. 13C
NMR (CDCl3, 300 MHz): d = 164.28, 164.07, 158.00, 155.93,
155.42, 153.84, 137.95, 136.89, 130.67, 128.54, 128.39, 123.49,
Fig. 1. Schematic representation of bis(terpyridine) ligand L and its labeling for 1H
NMR spectroscopic assignements.
122.49, 121.56, 118.26, 111.71, 24.70 ppm. Anal.
32H24N6 (492.57): C, 78.03; H, 4.91; N, 17.06. Found: C, 78.05;
H, 4.87; N, 17.04%.
Calc. for
C
– 2 or Cu(II) – 3) and trinuclear [Mn3(L)2(H2O)2(MeCN)4](ClO4)6 (4)
species, which may be altered and controlled by the choice of the
metal ion and its corresponding counterion. Complexes have been
characterized in terms of crystal structure, spectroscopic and mag-
netic properties.
2.2. Synthesis of transition metal ion complexes: general procedure
Complexes have been synthesized in identical manner i.e. by
maintaining the same conditions to exclude other factors that
could affect the self-assembly phenomena than metal ion and its
corresponding counterion.
2. Experimental
To the solution of ligand L (20.7 mg, 42.07
solved in 10 mL of CH2Cl2/MeCN (9:1 v:v) mixture, appropriate
amount of metal salt (84.14 mol) was added, what resulted in
the change in color. After 48 h of stirring in ambient conditions sol-
vents were removed under reduced pressure on rotary evaporator,
the residue was consecutively redissolved in minute quantity of
acetonitrile that afforded clear solution and precipitated by grad-
ual addition of diethyl ether. Colored complex was filtered, washed
well with Et2O and air dried.
lmol) previously dis-
2.1. General
l
The metal salts and reagents were used without further purifi-
cation as supplied from Aldrich or Acros Organics. 2-(6-Methyl-
pyridin-2-yl)-6-(trimethylstannyl)pyridine A was prepared by the
substitution of 2-methyl-6-(trimethylstannyl)pyridine with 2,6-
dibromopyridine via Stille coupling that resulted in acquisition of
6-bromo-60-methyl-2,20-bipyridine in 60% yield, which was conse-
quently converted to A by bromium exchange quenching protocol
with Sn2Me6 as previously reported by us [27]. 4,6-Dichloro-2-
phenylpyrimidine b was synthesized according to the literature
[28]. NMR spectra were run on a Varian Gemini 300 MHz spec-
trometer and were calibrated against the residual protonated sol-
vent signals (CDCl3: d = 7.24) and are given in ppm. Electrospray
Ionisation mass spectra for acetonitrile solutions (ꢁ10ꢂ4 M) were
determined using a Waters Micromass ZQ spectrometer. Sample
solutions were introduced into the mass spectrometer source with
2.2.1. [Co(L)Cl2] 1
Green solid was isolated with 68% yield. Crystals suitable for
structure determination were grown by vapor diffusion of diiso-
propyl ether into an acetonitrile solution of the complex at lowered
temperature. ESI-MS: m/z (%) = 586 (10) [Co(L)Cl]+, 515 (20)
[Na(L)]+, 284 (10) [Co(L)(H2O)]2+. IR (KBr):
(CH3) 2970; s(CH3) 2924;
1470; (C@N) 1447, 1427, 1387, 1357, 1295, 1251; d(CH3) 1325;
m
=
m
(C–H)ar 3064; mas
m
m(C@C) 1598, 1590, 1569, 1535, 1483,
m
a syringe pump at a flow rate of 40 l
L/minꢂ1 with a capillary volt-
q
(C–H) 1183, 1172, 1075, 1028; c(C–H) 1012, 920, 895, 834, 810,
798, 696, 657 cmꢂ1. Anal. Calc. for [Co(C32H24N6)Cl2] (622.41): C,
age of +3 kV and a desolvation temperature of 300 °C. The source
temperature was 120 °C. The cone voltage (Vc) was set to 30 V to
allow transmission of ions without fragmentation processes. Scan-
ning was performed from m/z = 100–2000 for 6 s, and 10 scans
were summed to obtain the final spectrum. Microanalyses were
obtained using a Perkin–Elmer 2400 CHN microanalyzer. Fast
Atom Bombardment spectra were determined by FAB+ using a
ZAB-HF VG apparatus in an m-nitrobenzyl alcohol matrix. IR spec-
tra were obtained with a Perkin–Elmer 580 spectrophotometer and
are reported in cmꢂ1. The metal salts and reagents were used with-
out further purification as supplied from Aldrich or Across.
Caution! Perchlorate complexes of metal ions in the presence of
organic ligands are potentially explosive. Only a small amount of
material should be used and handled with care.
61.75; H, 3.89; N, 13.50. Found: C, 61.74; H, 3.93; N, 13.52%.
2.2.2. [Co2(L)(NO3)4](CH3CN)2
2
Yellow solid was isolated with 65% yield. Crystals suitable for
structure determination were grown by vapor diffusion of toluene
into an acetonitrile solution of the complex at lowered tempera-
ture. ESI-MS: m/z (%) = 881 (5) [Co2(L)(NO3)3(CH3CN)2]+, 796 (10)
[Co2(L)(NO3)3]+, 515 (20) [Na(L)]+, 368 (10) [Co2(L)(NO3)2]2+, 311
(25) [Co(L)(H2O)4]2+
(C–H)ar 3093; as(CH3) 2978;
1572, 1537, 1511, 1485, 1473;
as(NO2) 1445, s(NO2) 1297; d(CH3) 1325;
1076, 1028;
(C–H) 1011, 922, 835, 811, 796, 768, 699, 659 cmꢂ1
,
224 (5) [Co2(L)(NO3)]3+
.
IR (KBr):
(C@C) 1602,
m
=
m
m
ms(CH3) 2930;
m
m(C@N) 1384, 1362, 1300, 1250;
m
m
q
(C–H) 1184, 1143,
c
.
Anal. Calc. for [Co2(C32H24N6)(NO3)4] (858.02): C, 44.77; H, 2.82;
N, 16.32. Found: C, 44.83; H, 2.78; N, 16.35%.
2.1.1. 60,60-(2-phenylpyrimidine-4,6-diyl)bis(6-methyl-2,20bypiridine)
L
To a mixture of crude 2-(6-methylpyridin-2-yl)-6-(trimethyl-
stannyl)pyridine A (1.414 g, 4.25 mmol), 4,6-dichloro-2-phenyl-
pyrimidine B (0.382 g, 1.70 mmol), Pd(PPh3)4 (0.246 g, 0.2 mmol)
and LiCl (0.305 g, 6.61 mmol), 100 mL of degassed toluene was
added gradually via syringe, constantly maintaining argon atmo-
sphere. Reaction was stirred under reflux for 24 h at 120 °C and
2.2.3. [Cu2(L)(NO3)4](CH3CN)2 3
Green complex was isolated with 68% yield. Single crystal suit-
able for XRD analysis was found via vapor diffusion of diethyl ether
to the acetonitrile solution of the complex at lowered temperature.
ESI-MS: m/z (%) = 804 (10) [Cu2(L)(NO3)3]+, 617 (20) [Cu(L)(NO3)]+,
493 (50) [L+H]+, 278 (50) [Cu(L)]2+. IR (KBr):
m = m(C–H)ar 3086;

262
M. Wałe˛sa-Chorab et al. / Polyhedron 54 (2013) 260–271
pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
leff ¼ 2:83 vcmorr ꢀ TðB:M:Þ
ð1Þ
m
s(CH3) 2933;
m
(C@C) 1607, 1575, 1541, 1469, 1466;
m(C@N) 1418,
1384, 1251;
m
(NO3-) 1433, 1289;
q(C–H) 1187, 1141, 1046, 1015;
The best exchange parameters were obtained by fitting with a
c
(C–H) 920, 885, 833, 811, 796, 767, 703, 664, 624 cmꢂ1. Anal. Calc.
good agreement factor R defined as follows:
for [Cu2(C32H24N6)(NO3)4] (867.68): C, 44.30; H, 2.79; N, 16.14.
Found: C, 44.33; H, 2.82; N, 16.15%.
2
vei xpT ꢂ vci alcTÞ
n
X
ð
R ¼
ð2Þ
2
ð
vei xpTÞ
i¼1
2.2.4. [Mn3(L)2(H2O)2(CH3CN)4](ClO4)6ꢀ2H2O 4
Yellow solid was isolated with 69% field. Single crystal suitable
for XRD analysis was acquired via vapor diffusion of tert-butyl-
methyl ether to the acetonitrile solution of the complex at lowered
temperature. ESI-MS: m/z (%) = 646 (5) [Mn(L)(ClO4)]+, 523 (10)
3. Results and discussion
[Mn3(L)2(ClO4)3(CH3CN)3]3+
,
520 (10) [Mn(L)2]2+
,
515 (25)
We have extensively studied systems that could be applied to
variety of dative-bonded supramolecular architectures, deriving
from polypyridine ligands that are capable of forming complexes
in bis(bidentate) (N2)2 manner, C22H18N4 (4,6-Bis(6-methylpyri-
din-2-yl)-2-phenylpyrimidine) for instance [34]. Further experi-
ence has been gained, owing to studies on ligands bearing two
tridentate metal ion ‘pockets’, as exemplified on 6,60-(pyrimidine-
4,6-diyl)bis(N,N-diethylpicolinamide) ligand, with N2O(carbonyl)
binding subunits [35,36,9]. Noted research was the starting point
to synthesize ligand L, where meridional donor moieties would
contain exclusively nitrogen donor atoms – by expansion of
bis(bidentate) (N2)2 system through addition of pyridine units,
thus forming (N3)2 structural arrangement. Similar bis(terpyridine)
systems can be found in the literature, nevertheless investigation
upon their self-assembling capacities was mainly restrained to
the formation of grid-type architectures [3,4,37].
[Na(L)]+, 495 (10) [Mn3(L)2(ClO4)3(CH3CN)]3+, 481 (5) [Mn3(L)2
(ClO4)3]3+, 400 (10) [Mn2(L)(ClO4)2]2+, 356 (5) [Mn3(L)2(ClO4)2
(CH3CN)2]4+, 273 (10) [Mn(L)]2+, 282 (10) [Mn(L)(H2O)]2+, 211 (5)
[Mn3(L)2(CH3CN)3]6+, 191 (10) [Mn3(L)2]6+. IR (KBr):
m
=
m
(C–H)ar
(C@C) 1600, 1572, 1538,
(C@N) 1396, 1385, 1360, 1292, 1247; d(CH3) 1325;
(C–H) 1183, 1143, 1130, 1020; as(Cl–O) 1088; das(O–Cl–O) 626;
(C–H) 1019, 923, 827, 792, 772, 704, 659 cmꢂ1. Anal. Calc. for
(1982.93): C,
3107;
1486, 1471;
q
c
mas(CH3) 2971; ms(CH3) 2930; m
m
m
[Mn3(C32H24N6)2(H2O)2(CH3CN)4](ClO4)6ꢀ2H2O
43.61; H, 3.46; N, 11.30. Found: C, 43.70; H, 3.40; N, 11.35%.
2.3. Crystallographic studies
Diffraction data were collected at room temperature by the
x
-scan technique, for 1 on a SuperNova diffractometer with
mirror-monochromatized Cu K radiation (k = 1.54178 Å) and for
2–4 on an Xcalibur diffractometer (Eos detector) with graphite-
Our previous attempts to synthesize bis(terpyridine) ligand L
ended with monosubstitution of chlorine in 4,6-dichloro-2-phe-
nylpyrimidine and formation of C21H15ClN4 (6-(6-chloro-2-phenyl-
pyrimidin-4-yl)-60-methyl-2,20-bipyridine). The latter molecule
was further complexated with CoCl2 to afford mononuclear com-
pound as proved by single crystal X-ray analysis and DFT geometry
optimization [38]. Interestingly, there is a striking resemblance
between mononuclear cobalt(II) chloride complexes of mono(ter-
pyridine) ligand C21H15ClN4 and bis(terpyridine) ligand L (1) (cf.
crystal structures section) in terms of geometrical surrounding
what, based on calculations performed for the former one, allows
us to assume that Co(II) ion exists in its quadruplet state. This
has been further corroborated by magnetic susceptibility measure-
ments (cf. magnetic properties). The difference in bulkiness of
methyl and phenyl substituents together with distorted trigonal
bypiramid geometry Co(II) ion exhibits is characteristic for catalyt-
ically active species, particularly in terms of asymmetric catalysis,
thus such determination is especially important [39].
Hexadentate ligand L was eventually prepared by palladium
catalyzed cross-coupling reaction (Fig. 2) and subsequently mixed
with the following transition metal salts: CoCl2 1, Co(NO3)2 2,
Cu(NO3)2 3 or Mn(ClO4)2 4 in 1:2 (L: metal salt) molar ratio.
Scheme 1 shows that ligand L forms a variety of coordination
architectures, depending on the choice of the metal ion, further
aided by the presence of specific counterions.
We have very recently highlighted that bis(terpyridine) ligand L
forms dinuclear helicate architecture with Ag(CF3SO3) salt, what
was followed by the finding that silver(I) complexes noted above
exhibit unusual catalytic properties in reduction of organic pollu-
tants upon UV–Vis irradiation [40].
a
monochromatized Mo K radiation (k = 0.71073 Å). The data were
a
corrected for Lorentz-polarization and absorption effects [29].
Accurate unit-cell parameters were determined by a least-squares
fit of 2700 (1), 2377 (2), 8175 (3) and 3886 (4) reflections of high-
est intensity, chosen from the whole experiment. The structures
were solved with SIR92 [30] and refined with the full-matrix
least-squares procedure on F2 by SHELXL97 [31]. Scattering factors
incorporated in SHELXL97 were used. All non-hydrogen atoms were
refined anisotropically, hydrogen atoms were placed in the calcu-
lated positions, and refined as ‘riding model’ with the isotropic dis-
placement parameters set at 1.2 (1.5 for methyl groups) times the
Ueq value for appropriate non-hydrogen atom. Relevant crystal
data are listed in Table 1, together with refinement details. The
crystals of 1 decompose during the data collection and therefore
the dataset is incomplete; also in 1 there are huge voids in the crys-
tal structure, apparently without any interpretable electron
density. In the structure of 2 and 3, two molecules of solvent – ace-
tonitrile fill the voids in the asymmetric part of the crystal struc-
ture. In 4 some components of the structure (the cation and two
perchlorate anions) occupy the special positions of the space group
Pccn, they have C2 internal symmetry. In this structure the residual
electron density was interpreted as the water molecule, weakly
bound to the rest of the structure. The positions of hydrogen atoms
from this water molecule have not been found.
2.4. Magnetic measurement studies
Magnetization measurements in the temperature range of
1.8–300 K were carried out on powdered samples of complexes,
at the magnetic field 0.5 T, using a Quantum Design SQUID Magne-
tometer (type MPMS-XL5). Polycrystalline sample for magnetic
measurements was obtained from pure crystals. Corrections for
diamagnetism of the constituting atoms were calculated using Pas-
cal’s constants [32,33], the value of 60 ꢃ 10ꢂ6 cm3 mol–1 being
used as the temperature-independent paramagnetism of copper(II)
ion. The effective magnetic moments were calculated from the
expression:
Even though the complexation reactions were performed under
identical conditions, different architectures were obtained in terms
of nuclearity variations. From single-crystal X-ray analyses it was
possible to determine ‘model’ coordinative tendencies of the
systems under study i.e. nitrogen donor ligand and metal ions
self-assemble to form molecules of different stoichiometries,
depending on metal ion chosen and its counterion. During the
course of investigation it was found that both the nuclearity and
degree of coordination of the complexes are a result of an interplay

M. Wałe˛sa-Chorab et al. / Polyhedron 54 (2013) 260–271
263
Table 1
Experimental crystal data, data collection and structure refinement details.
Compound
1
2
3
4
Formula
Formula weight
Crystal system
Space group
a (Å)
C
32H24Cl2CoN6
C36H30Co2N12O12
940.58
monoclinic
P21/c
11.6996(8)
28.4396(17)
12.1052(8)
100.917(6)
3954.9(6)
4
C36H30Cu2N12O12
949.80
monoclinic
P21/c
11.7108(9)
28.468(2)
12.1216(9)
100.920(7)
3967.9(5)
4
C72H68Cl6Mn3N16O28
1982.94
orthorhombic
Pccn
23.6769(5)
14.8424(3)
23.2580(4)
90
8173.4(3)
4
1.61
4052
622.40
tetragonal
I41/a
33.0623(8)
33.0623(8)
13.1825(4)
90
14410.0(7)
16
1.15
5104
b (Å)
c (Å)
b (°)
V (Å3)
Z
dx(g cmꢂ3
F(000)
)
1.58
1920
0.92
1.59
1936
1.15
l
(mmꢂ1
)
5.31
0.75
h Range (°)
hkl range
2.67–73.80
2.75–25.00
ꢂ13 6 h 6 13, ꢂ33 6 k 6 33,
ꢂ14 6 l 6 14
2.75–25.00
ꢂ13 6 h 6 13, ꢂ33 6 k 6 33,
ꢂ14 6 l 6 14
2.81–25.00
ꢂ25 6 h 6 26, ꢂ40 6 k 6 28,
ꢂ28 6 h 6 27, ꢂ17 6 k 6 17,
ꢂ15 6 l 6 11
ꢂ27 6 l 6 27
Reflections
Collected
Unique (Rint
6808
4393 (0.020)
2592
37072
6958 (0.181)
3183
56927
6981 (0.149)
3466
83866
7194 (0.039)
5826
)
With [I > 2r(I)]
Number of parameters
370
563
563
7194
Weighting scheme
A
B
0.0488
0
0.03
0
0.05
0
0.1243
56.5492
0.096
0.252
0.114
0.263
1.04
2.14/ꢂ2.00
R(F) [I > 2
r
(I)]c
0.034
0.075
0.067
0.084
0.87
0.080
0.113
0.196
0.142
0.99
0.063
0.118
0.138
0.130
0.98
wR(F2) [I > 2
r(I)]
R(F) [all data]
wR(F2) [all data]
Goodness of fit (GOF)
Maximum/minimum
D
q
0.14/ꢂ0.19
0.43/ꢂ0.43
0.68/ꢂ0.37
(e Åꢂ3
)
cernible, since they take part in the formation of zig-zag chains via
hydrogen bonding with non-coordinating water molecules present
in the crystal lattice. Anions which exhibit stronger capability to
coordinate namely Clꢂ (1) or NO3ꢂ (2 and 3) prevent second L mol-
ecule from full saturation of metal ion in bis(tridentate) manner,
which results in formation of respectively mono- [Co(L)Cl2] (1)
and dinuclear [M2(L)(NO3)4](CH3CN)2 (2,3) species. Surprisingly,
halides are the salts of choice when mononuclear compounds are
to be acquired, rendering ligands remaining tridentate donor pock-
et unaltered, in specificity and resemblance to the aforementioned
[Co(C21H15ClN4)Cl2](CH3CN) [38].
Mass spectrometry was used to determine equilibrium present
in solution and to further establish the nature of supramolecular
architectures in terms of nuclearity. For instance: when studying
[Cu2(L)(NO3)4](CH3CN)2 (3) in solution, [Cu2(L)(NO3)3]+ and
[Cu(L)(NO3)]+ are easily recognizable, more predominant being
the latter one what is however obvious, at the same time demon-
strating the subtle equilibrium present in solution under given
conditions. This is in contrast to the solid state studies, where from
magnetic susceptibility measurements it was possible to directly
determine the amount of mono- and dinuclear species present (cf.
magnetic properties). Similar species are found for [Co2(L)(NO3)4]
(2) complexes, proving simultaneously the existence of dinuclear
complexes in acetonitrile solution, which are, as magnetic proper-
ties further indicate, exclusive in the solid state. Data consistency
was additionally displayed in such a manner that the highest
nuclearity found for any compound never exceeded the one estab-
lished by X-ray studies (which means solely 1:1 (Co:L) species
were found for mononuclear complex [CoLCl2].
Fig. 2. Synthesis and schematic representation of bis(terpyridine) ligand L.
between electronic states of metal and the corresponding anions’
binding capabilities. In the presence of manganese(II) perchlorates,
trinuclear species [Mn3(L)2(H2O)2(MeCN)4] (ClO4)6ꢀ2H2O 4 form
with two ligand molecules L employed, native counterions being
absent in the first coordination sphere, what is consistent with
poor coordinating properties of ClO4-. Nevertheless when we focus
on molecular packing of complex 4, their role becomes readily dis-
3.1. Crystal structures
Despite carrying reaction in 2:1 M ratio (CoCl2:L) X-ray analysis
of crystals acquired by slow diffusion methods revealed the follow-
ing structural formula: [Co(L)Cl2] – 1 (Fig. 3).

264
M. Wałe˛sa-Chorab et al. / Polyhedron 54 (2013) 260–271
Scheme 1. Schematic representation of different supramolecular architectures formed by ligand L.
The Co(II) ion is five-coordinated by three ring nitrogen atoms
nal bipyramidal geometry) [41]. For Co(II) ion in 1 t = 0.34. Surpris-
ingly, when multiplying [Co(L)Cl2] in three dimensions to form
crystal lattice, one finds that the base constructive unit is one-
dimensional pillar structure, its constituents arranged in a helical
manner (Fig. 4) by 41 screw axis, what means that full 360o turn
encompasses four molecules of the complex.
Overall, unit cell comprises Z = 16 molecules, thus four pillar-like
structures may be singled out, each in relation to others by symme-
try elements that is distinctive for I41/a space group. When viewing
pillars along y axis (Fig. 5), one may perceive two short contacts that
of one half of the L molecule and two chlorine atoms. Interestingly
in this case two halves of L have different disposition of nitrogen
atoms: while the N atoms are all-cis in the coordinated part (NCCN
torsion angles close to 0°), in the uncoordinated part all nitrogen
atoms are trans with respect to each other, NCCN torsion angles
are close to 180° (as expected for the uncoordinated molecule
due to the Hꢀ ꢀ ꢀH repulsion). The five heterocyclic rings are not
far from coplanarity, the dihedral angle between the planes of ter-
minal rings is 22.48°; the phenyl ring attached to the central ring is
however significantly twisted, its plane makes the dihedral angle
of 40.62(10)° to the plane of the pyrimidine ring. Geometry around
the metal ion may be evaluated by means of structural index
contribute to their stability: Cl1ꢀ ꢀ ꢀH–C11 (2.851(x) Å) and
p–p
(3.341(x) Å) stacking between central coordinating pyridine ring
and the methyl substituted ring from transoidal conformation.
Furthermore, (cf. magnetic data) such an arrangement is respon-
sible for the weak intermolecular antiferromagnetic interactions
parameter
s proposed by Addison (s = (b–a/60), where s ranges
from 0 (undistorted square pyramidal geometry) to 1.0 (ideal trigo-
Fig. 3. Perspective view of the complex 1; ellipsoids are drawn at 50% probability level, hydrogen atoms are shown as spheres of arbitrary radii. Relevant distances (Å):
Co1–N1 2.201(3), Co1–N9 2.025(2), Co1–N15 2.268(3), Co1–Cl1 2.2923(9), Co1–Cl2 2.2579(9).

M. Wałe˛sa-Chorab et al. / Polyhedron 54 (2013) 260–271
265
2 and the data for 3 will be given in parentheses. The coordination
modes of both Co(II) are very similar; the cations are five-coordi-
nated by three N ring atoms as well and two oxygen atoms from
two different nitrate anions (Figs. 7 and 8).
Due to the fact that both halves of the ligand molecule are en-
gaged in coordination, all nitrogen atoms are in subsequent cis dis-
position, NCCN torsion angles being close to 0°. The five-ring
skeleton of the ligand molecule itself is even closer to planarity
than in 1, the dihedral angle between terminal rings being only
11.3(3)° [11.2(2)°]; on the other hand, the phenyl ring is almost
perpendicular to this plane, it makes the dihedral angle of
77.8(2)° [77.6(2)°] with the pyrimidine-ring plane, the latter being
responsible for antiferromagnetic interactions (cf. magnetic data).
Tau parameters equals 0.16 and 0.195 for Co1 and Co2 respec-
tively, whereas direct distance between them is 6.264 Å
[6.268 Å]. Such high degree of planarity, in relation to N-heterocy-
clic scaffolding, finds reflection in crystal packing which consists of
sheets of dinuclear complexes alternated by voids which are occu-
pied by acetonitrile molecules (Fig. 9).
When perchlorate ions are introduced, initial substrates self-
organize into the trinuclear complex [Mn3(L)2(H2O)2(MeCN)4](-
ClO4)6ꢀ2H2O (4) which exhibits entirely different architecture
(Fig. 10).
The structural units scaffolding involves two molecules of li-
gand L and three, unequal in binding mode, Mn(II) ions, the non-
central cations’ coordination spheres being further filled by two
acetonitrile and one water molecules each. The complex has C2
symmetry, the twofold axis parallel to z runs through the central
Mn(II) ion. All metal ions are six-coordinated and the coordination
polyhedra are distorted octahedra, however the ligands are in dif-
ferent disposition. Central manganese(II) ion Mn2 is coordinated
by six nitrogen atoms from two different – but related by 2 axis
– ligand molecules. The three nitrogen atoms from other halves
of the ligands are involved in coordination of two other Mn(II) ions
(distance between Mn2-Mn1(3) is 6.724 Å), coordination of these
centers are completed by two acetonitrile and one water mole-
cules. Two additional water molecules and six perchlorate anions
occupy second coordination sphere, having direct impact on the
compounds crystal packing (Fig. 11).
Two types of hydrogen bonding patterns direct trinuclear
complex molecules into zig-zag chains: O–Hꢀ ꢀ ꢀOH2 (2.734 (8) Å)
resulting from interactions between water molecules – one di-
rectly bound to Mn(II) ion and the non-coordinated one;
dash;Hꢀ ꢀ ꢀOClO3 (2.795 (8) Å) bonds being the manifestation of
immediate vicinity of the coordination-free water molecule and
the oxygen atom of perchlorate group (Fig. 12).
Fig. 4. 1D pillar-like constituent as seen along fourfold screw axis (z-direction).
between Co(II) ions in 1. It should be however noted that non-coor-
dinating bypyridine arm of the ligand L greatly contributes to the
overall crystal packing of 1, what results in large voids – Fig. 6 – with
diameter of over 5 Å, where no interpretable electron density is
present (cf. experimental section).
Its elusive role is particularly noticeable when comparing the
degree of symmetry crystal structures of following compounds
show: [Co(C21H15ClN4)Cl2](CH3CN) – crystal system being triclinic
[38], [Co(L)Cl2] (1) – crystal system being tetragonal. Bipyridine
moiety is major distinctive factor which tunes and eventually
determines the outcome of self-assembly phenomena, thus it is
probable that highly symmetrical crystal packing of mononuclear
(1) system is the thermodynamically most favorable outcome of
self-assembly, therefore it prevents formation of dinuclear com-
pounds when applying halides as counterions.
In [Co2(L)(NO3)4](CH3CN)2 (2) and [Cu2(L)(NO3)4] (CH3CN)2 (3)
one molecule of L coordinates two cations in the baguette manner,
just as it was anticipated in the experimental procedure. Since the
molecules are almost identical we would discuss only the complex
Fig. 5. 1D pillar like constituent as seen along y axis. Short contacts are depicted as dashed, light-blue lines. (Color online.)

266
M. Wałe˛sa-Chorab et al. / Polyhedron 54 (2013) 260–271
Fig. 6. The crystal packing of 1 as seen along fourfold screw axis (z-direction). The view shows relatively large, apparently empty voids in the crystal structure.
Fig. 7. ORTEP representation of the cation 2; ellipsoids are drawn at 50% probability level, hydrogen atoms are shown as spheres of arbitrary radii. Relevant distances (Å):
Co1–N1 2.038(6), Co1–N8 1.917(6), Co1–N14 2.119(5), Co1–O53 1.964(5), Co1–O43 2.137(5); Co2–N16 2.076(5), Co2–N26 1.922(5), Co2–N32 2.042(5), Co2–O63 1.962(5),
Co2–O73 2.178(6).
Poor coordinative properties of ClO4ꢂ are responsible for exclu-
sive synthesis of complexes that incorporate two ligand molecules
L, being at the same time consonant with counterion dependent
self-assembly process preserved in the solid state.
configurations are known in four-, five- and six-coordinate com-
plexes [32,33,42–49,47,50–51]. For each of these coordination
numbers, systems are known where the two spin states may be
thermally interconverted. The magnetic moments generally being
4
in the range 4.7–5.2 B.M. for high spin (quartet state T1g) and
3.2. Magnetic properties
1.8–2.2 B.M. for low spin (doublet state 2Eg) complexes. The mag-
netic properties of molecules depend on the local geometry and
the chemical links between them. In cobalt(II) complexes the
Magnetic properties of complexes 1, 2, 3 and 4 are illustrated in
form of
vm and
vmT, plotted as a function of temperature (
vm being
decrease in the vmT product at low temperatures is generated by
the molar magnetic susceptibility per one paramagnetic ion).
the combined effect of intramolecular antiferromagnetic interac-
tions between the metal centers, zero-field splitting (ZFS) and
the intrinsic spin–orbit coupling of the high-spin CoII metal ions
in octahedral surrounding. The spin–orbit coupling results in the
splitting of the energy levels arising from the T1g ground term
[43]. This orbital degeneracy leads to highly anisotropic interac-
3.3. Cobalt complexes (1 and 2)
4
Cobalt(II), a d7 ion in coordination compounds, can exist in a
low spin doublet state or a high spin quartet state. Both spin-state

M. Wałe˛sa-Chorab et al. / Polyhedron 54 (2013) 260–271
267
Fig. 8. Perspective view of the cation 3; ellipsoids are drawn at 50% probability level, hydrogen atoms are shown as spheres of arbitrary radii. Relevant distances (Å): Cu1–N1
2.056(5), Cu1–N8 1.932(5), Cu1–N14 2.134(4), Cu1–O53 1.967(4), Cu1–O43 2.137(4); Cu2–N16 2.092(4), Cu2–N26 1.937(4), Cu2–N32 2.047(5), Cu2–O63 1.960(4), Cu2–O73
2.177(5).
Fig. 9. Crystal packing of [Co2(L)(NO3)4](CH3CN)2 (2), red arrows indicate non-coordinated acetonitrile molecules. (Color online.)
tions, the effective exchange Hamiltonian containing not only spin
operators but orbital ones as well, what makes the magnetism of
cobalt complexes extremely difficult to analyze [44]. In these cases
the value of magnetic coupling J should be significantly reduced by
taking into account the orbital reduction factor x and the spin–
orbit coupling parameter k (the Lines theory [43a]). However, if
distortion from the octahedral surroundings is strong enough, then
the orbital momentum is completely or partially quenched in a
ligand field of a certain symmetry [45,46]. The magnetic properties
of CoII in the low, trigonal–bipyramidal (TBP) or square-pyramidal
(SP) symmetries can be treated in a simple manner, as the ground
term does not have first-order orbital angular momentum [32,
46–49,47,50,51] and a spin-only treatment is valid. The com-
pounds Co(terpy)X2ꢀnH20 (terpy – terpyridine) were analysed by
magnetic susceptibility measurements, in particular to study the
high-spin-low-spin behavior [33,42].
0.16, 0,195 of 2, respectively. For that reason orbital momentum
effects were neglected in magnetic interpretation. The 300 K mT
(T) value of 1 is 4.34 cm3 Kmolꢂ1
eff = 5.89 B.M.) and is higher
than the spin – only value 3.87 B.M. for S = 3/2. mT (T) remains
v
(l
v
nearly constant in a wide range of temperatures and smoothly de-
creases below 50 K to the value 1.33 cm3 K molꢂ1
at 1.8 K (Fig. 13).
(leff = 3.26 B.M.)
The slight decrease of
vmT at low temperatures could be inter-
preted on the basis of zero-field splitting (ZFS) effects originated
and spin–orbit coupling of CoII d7 ion and/or intermolecular anti-
ferromagnetic interactions [32]. Taking into account magnetic
anisotropy of cobalt(II) ion, the expressions of magnetic suscepti-
bility can be derived from the spin Hamiltonian:
H ¼ D½S2 ꢂ 1=3SðS þ 1Þꢄ þ g bHzSz þ g bðHxSx þ HySyÞ
ð3Þ
k
?
z
Our investigations show two types of cobalt(II) bis(terpyridine)
ligand complexes, mononuclear 1 and dinuclear 2 ones. The single-
crystal X-ray structures of these compounds reveal a distorted
square-pyramidal ligand field at each CoII ion in both 1 and 2 com-
where DS2z represents the splitting into two Kramers doublets in the
absence of a magnetic field, (|D| being the energy gap between the
Kramers doublets | 3/2> and | 1/2>).
The
vmT data were well fit by the Curie–Weiss expression
plexes, characterized by distortion parameters
s
= 0.34 of 1 and
[32,51]:

268
M. Wałe˛sa-Chorab et al. / Polyhedron 54 (2013) 260–271
Fig. 10. Perspective view of the cation 4; ellipsoids are drawn at 33% probability level, hydrogen atoms are omitted for clarity. Relevant distances (Å): Mn1–N1 2.298(6),
Mn1–N8 2.196(6), Mn1–N14 2.360(6), Mn1–N41 2.112(9), Mn1–N51 2.263(8), Mn1–O1W 2.155(6), Mn2–N16 2.407(5), Mn2–N26 2.196(5), Mn2–N32 2.261(5). The letter A
denotes the symmetry code 3/2 ꢂ x, 1/2 ꢂ y,z.
Fig. 11. Zig-zag chains of [Mn3(L)2(H2O)2(MeCN)4] (ClO4)6ꢀ2H2O (4) as seen along y axis.
ꢀ
ꢁ
Nb2g2SðS þ 1Þ
where g|| and g\ are the spectroscopic splitting factors, N-the Avo-
gadro number, b the Bohr magneton, k the Boltzman constant and
T is the absolute temperature.
1
3
1 þ 9eꢂ2D=kT
2
3
k
v
¼
þ
kðT ꢂ hÞ
4 þ ð1 þ eꢂ2D=kT
Þ
ꢀ
ꢁ
Nb2g2?SðS þ 1Þ
kðT ꢂ hÞ
3T
1 þ 4D ð1 ꢂ eꢂ2D=KT
1 þ eꢂ2D=kT
Þ
Least-squares fitting of the data of 1 leads to D = 13 cmꢂ1
,
ꢃ
ð4Þ
g\ = 2.08, g|| = 2.45 h = ꢂ0.7 cmꢂ1 R = 2.73 ꢃ 10ꢂ5
.

M. Wałe˛sa-Chorab et al. / Polyhedron 54 (2013) 260–271
269
Fig. 12. Crystal packing of [Mn3(L)2(H2O)2(MeCN)4](ClO4)6ꢀ2H2O (4) directed by hydrogen bonds; O–Hꢀ ꢀ ꢀOH2 and O–Hꢀ ꢀ ꢀOClO3 contacts are represented by red and light-blue
lines respectively. (Color online.)
Fig. 14. Temperature dependences of experimental vm and vmT vs. T for complex 2.
The solid lines are the calculated curves, with parameters presented in the text. The
inset shows the vm curve in the low temperature range.
Fig. 13. Temperature dependences of experimental vm and vmT vs. T for complex 1.
The solid lines are the calculated curves, with parameters presented in the text.
The negative h = ꢂ0.7 cmꢂ1value informs about weak intermo-
lecular antiferromagnetic interactions as a results of short inter-
molecular contacts along y axis of 1D pillar-like constituent of 1
ceptibility maximum indicates an antiferromagnetic exchange
interactions between two copper(II) centers, defined by spin
Hamiltonian H = ꢂJ
RS1S2 where J is the coupling constant. The
(Cl1ꢀ ꢀ ꢀH–C11 and
p
2
–
p
stacking).
compound obeys Curie–Weiss law above 100 K, with Curie
C = 0.431 cm3 K molꢂ1 and Weiss h = ꢂ17 K constants. Negative
value of Weiss constant confirms antiferromagnetic interactions
between copper(II) ions.
In complex
maximum of magnetic susceptibility was
observed at 4 K (Fig. 14), which indicated antiferromagnetic cou-
pling within the dinuclear species.
The same model was used for dinuclear cobalt complex 2, com-
parable D = 13 cmꢂ1, g\ = 2.08, g|| = 2.55 (gav = 2.40) fitting param-
eters were obtained and negative Weiss constant h = ꢂ4.2 cmꢂ1
(R = 1.07 ꢃ 10ꢂ4). The magnetic data of 2 were also approximately
modeled by using an isotropic Heisenberg spin Hamiltonian:
H = ꢂ4J(SCo1SCo2), where J is the exchange interactions within the
[Co2] complex [46,47,51], D = 13 cmꢂ1 was used as constant and
the van Vleck expression of the magnetic susceptibility as:
The magnetic data of the complex 3 were fitted using modified
Bleaney–Bower’s equation [32]:
Nb2g2 2e2J=kT þ 10e6J=kT þ 28e12J=kT
vT
¼
ð5Þ
k
1 þ 3e2J=kT þ 5e6J=kT þ 7e12J=kT
Good approximation (cf. red solid line Fig. 14) was obtained
with the parameters: g = 2.33, J = ꢂ1.70 cmꢂ1, R = 1.80 ꢃ 10ꢂ4
.
3.4. Copper complex
In the case of copper 3 complex, the existence of dinuclear as
well as mononuclear form is observed in temperature dependence
of magnetic susceptibility (Fig. 15).
The magnetic susceptibility reaches a maximum at about 40 K,
then decreases with temperature lowering to a minimum value at
15 K. Further temperature decreasing results in an increase of vm
suggesting the presence of monomeric form in this sample. Sus-
Fig. 15. Temperature dependences of experimental
The solid lines are the calculated curves, with parameters presented in the text.
vm and vmT vs. T for complex 3.

270
M. Wałe˛sa-Chorab et al. / Polyhedron 54 (2013) 260–271
constant J, thus the isotropic spin Hamiltonian is described as fol-
lows: H = 2 J(S1S2 + S2S3), neglecting interactions between S1S3.
The equation of molar susceptibility of trinuclear cluster [52]:
Ng2b2
4kT
vtri
¼
1 þ 20e3J=kT þ 105e8J=kT þ 210e15J=kT þ 330e24J=kT þ 429e35J=kT þ 455e48J=kT þ 340e63J=kT
ꢃ
1 þ 4e3J=kT þ 9e8J=kT þ 10e15J=kT þ 10e24J=kT þ 9e35J=kT þ 7e48J=kT þ 4e63J=kT
ð7Þ
and molecular field model of magnetic interactions were used:
vtri
vcmorr
¼
ð8Þ
2zJ0
1 ꢂ
ꢀ
vtri
Nb2g2
where N – the Avogadro’s number, g – the spectroscopic splitting
factor, b – the Bohr magneton, k – the Boltzmann constant and T
is the absolute temperature, J – intramolecular exchange within
tri-MnII cluster, zJ0 – intermolecular magnetic exchange parameter,
z is number of interacting moleculꢂe1s. The best fit parameters:
g = 2.0, J = ꢂ0.10 cmꢂ1, zJ0 = ꢂ0.02 cm confirm very weak antifer-
romagnetic interactions between MnII ions.
Fig. 16. Temperature dependence of experimental
solid lines are the calculated curves, with parameters presented in the text.
vmT vs. T for complex 4. The
(
)
!
ꢂ
ꢃꢂ1
Ng2dimb2
3kT
1
3
Ng2monb2
4kT
vm
¼
1 þ ðeꢂj=kT
Þ
ð1 ꢂ xÞ þ
x
ð6Þ
Similar very weak antiferromagnetic interactions between MnII
ions through 1,3-diazine (pyrimidine) and 1,4-diazine (pyrazine)
were observed by Ishida et al. [47] and by us, recently [53,56]. In
comparison of the magnitude of magnetic interactions between
CoII, CuII and MnII compounds (2, 3 and 4) with other pyrimidine
and pyrazine bridged systems, the net antiferromagnetic interac-
tions, defined by n2 J instead of J, is more appropriate, were n being
the number of magnetic orbitals (the number of unpaired electrons
of the metal center) [32,54,55].
where x is the mole fraction of the monomeric form, and gmon and
gdim are spectroscopic splitting factors of the monomer and dimer
forms, respectively, the other symbols have the usual meaning.
Magnetic parameters: gdim = 2.12, gmon = 2.12, 2J = ꢂ40 cm–1 and
monomeric form at level 7.5% were obtained, R = 3.5 ꢃ 10ꢂ4
.
Magnetic methods are very sensitive to identify monomeric
impurity existing very often in dimeric copper complexes and use-
ful to characterize amount of noncoupled species in the sample
[32]. The resulted singlet–triplet energy gap 2J is in good agree-
ment with the temperature of magnetic susceptibility maximum.
The temperature Tmax is related to 2J according to: |2J|/
kTmax = 1.599 [32] and observed values follow this relation.
In the Table 2 we collected exchange parameters, expressed as J,
n2 J, as well as 2J/kB.
Collected experimental data present weak antiferromagnetic
interactions and suggest that the metal(II) sites communicate
through the planar, p-delocalized diazine rings in the coupled sub-
units. Comparable values of magnetic coupling parameters were
obtained for complexes with the same metal ions. Analyzed by
us complexes 2, 3 and 4 confirm that he highest magnitude of
interactions was observed for CuII coupled dimers, however, simi-
lar metal to metal separation across the bridging diazine rings
(from 6.495 to 6.725 Å) for all presented complexes were observed.
Because of planarity of diazine ring the dx2 ꢂy2 type magnetic orbi-
tal of copper(II) ion (in a square pyramidal geometry in 3 and in
[57]) is mainly located in the basal xy plane. The significant
3.5. Manganese complex
Magnetic data of six coordinated manganese(II) complex 4 were
calculated per tri-MnII clusters according to the crystal structure.
High spin S = 5/2 with
l
eff = 5.98 B.M. (
v
mT = 4.46 cm3 K molꢂ1) is
observed at 300 K. The
vmT is practically constant in the whole
experimental temperature range (Fig. 16). Only a slight decrease,
observed at the lowest temperatures, below 10 K may suggest weak
antiferromagnetic interactions between MnII ions. The magnetic
exchange interactions within the tri-MnII clusters are mediated
through pyrimidine bridge and there exists only one exchange
r
-overlap between two magnetic orbitals through bridging ring
would account for the antiferromagnetic coupling observed in this
family.
Table 2
Exchange parameters for pyrimidine and pyrazine bridged compounds.
a
MII
J(cmꢂ1
)
n2
J
2J/kB (K)b
Model of interactions (bridge)
Ref.
Co 2
Cu 3
Mn 4
Mn
Mn
Mn
Mn
Co
ꢂ1.7
ꢂ40
ꢂ15.3
ꢂ40
ꢂ2.44
dimer (pyrimidine)
dimer + monomer (pyrimidine)
trimer (pyrimidine)
dimer (pyrazine)
tetramer (pyrazine)
dimer (pyrazinedicarboxylate)
dimer (pyrimidinedicarboxylate)
dimer (pyrimidinedicarboxylate)
dimer (pyrimidinedicarboxylate)
dimer (pyrazine)
this work
this work
this work
[56]
[56]
[47]
[47]
[47]
[47]
[57]
ꢂ57.6
ꢂ0.1
ꢂ0.22
ꢂ0.29
ꢂ2.5
ꢂ0.28
ꢂ5.50
ꢂ7.25
ꢂ7.0
ꢂ0.32c
ꢂ0.42c
ꢂ0.40
ꢂ0.28c
ꢂ0.26c
ꢂ6.5
ꢂ0.38
ꢂ2.15
ꢂ19.4
ꢂ3.1
Cu
Cu
Cu
ꢂ32c
ꢂ32c
ꢂ46
ꢂ40.9
ꢂ40.9c
ꢂ17.2 to ꢂ21.2c
ꢂ58.8c
ꢂ24.7 to ꢂ30.5
ꢂ17.2 to ꢂ21.2c
dimer (2-pyridylpyrazine)
[58]
a
b
c
J = singlet–triplet energy gap.
2J = singlet–triplet energy gap.
Calculated from the value presented in the literature.

M. Wałe˛sa-Chorab et al. / Polyhedron 54 (2013) 260–271
271
[14] M. Kaller, C. Deck, A. Meister, G. Hause, A. Baro, S. Laschat, Chem. Eur. J. 16
(2010) 6326.
4. Conclusions
[15] M. Distaso, R.N.K. Taylor, N. Taccardi, P. Wasserscheid, W. Peukert, Chem. Eur.
J. 17 (2011) 2923.
[16] C. Desmarets, I. Azcarate, G. Gontard, H. Amouri, Eur. J. Inorg. Chem. (2011)
4558.
[17] A. Winter, S. Hoeppener, G.R. Newkome, U.S. Schubert, Adv. Mater. 23 (2011)
3484.
[18] G.R. Winter, U.S. Newkome, ChemCatChem 3 (2011) 1384.
[19] S. Roy, S. Saha, R. Majumdar, R.R. Dighe, A.R. Chakravarty, Polyhedron 29
(2010) 3251.
[20] D. Zabel, A. Schubert, G. Wolmershäuser, Eur. J. Inorg. Chem. 23 (2008) 3648.
[21] V. Artero, M. Chavarot-Kerlidou, M. Fontecave, Angew. Chem., Int. Ed. 50
(2011) 7238.
[22] J. Boonmak, M. Nakano, N. Chaichit, C. Pakawatchai, S. Youngme, Inorg. Chem.
5 (2011) 7324.
[23] D.G. Nocera, B.M. Bartlett, D. Grohol, D. Papoutsakis, M.P. Shores, Chem. Eur. J.
10 (2004) 3850.
[24] W. Li, P.T. Barton, R.P. Burwood, A.K. Cheetham, Dalton Trans. 40 (2011) 7147.
[25] M.-H. Zeng, W.-X. Zhang, X.-Z. Sun, X.-M. Chen, Angew. Chem., Int. Ed. 44
(2005) 3079.
[26] E.-C. Yang, Z.-Y. Liu, Y.-L. Li, J.-Y. Wang, X.-J. Zhao, Dalton Trans. 40 (2011)
8513.
[27] V. Patroniak, M. Kubicki, A.R. Stefankiewicz, A.M. Grochowska, Tetrahedron 61
(2005) 5475.
[28] K. Burdeska, H. Fuhrer, G. Kabas, A.E. Siegriest, Helv. Chim. Acta 64 (1981) 113.
[29] Agilent Technologies, CrysAlis PRO (Version 1.171.33.36d). Agilent
Technologies Ltd., 2011.
[30] A. Altomare, G. Cascarano, C. Giacovazzo, A. Gualardi, J. Appl. Crystallogr. 26
(1993) 343.
[31] G.M. Sheldrick, Acta Crystallogr., Sect. A 64 (2008) 112.
[32] O. Kahn, Molecular Magnetism, Willey-VCH, 1993.
[33] H.A. Goodwin, Top. Curr. Chem. 234 (2004) 23.
[34] V. Patroniak, A.R. Stefankiewicz, J.-M. Lehn, M. Kubicki, Eur. J. Inorg. Chem.
(2005) 4168.
The ability of new bis(terpyridine) ligand L to stabilize mono-
and polynuclear metal species enables the facile synthesis of novel
supramolecular architectures. X-ray crystal structures have
revealed that depending on the counterions applied, one may ob-
tain mono- [Co(L)Cl2] (1), di- [M2(L)(NO3)4](CH3CN)2 (2 or 3) or tri-
nuclear [Mn3(L)2(H2O)2(MeCN)4] (ClO4)6ꢀ2H2O (4) species, self-
assembly being as well determined by the appropriate choice of
the metal ion. In particular it is revealed upon insight into com-
plexes’ crystal structures: non-coordinating terpyridine subunit
of mononuclear 1 accounts for organization into one-dimensional
pillar-like helical constituents; strongly coordinating nitrate
anions of isostructural 2 and 3 renders solely the formation of
irregular molecular sheets possible; poorly coordinating ClO4ꢂ spe-
cies, together with water molecules are responsible for the exis-
tence of zig-zag shaped chains present in 4. Metal ions have been
found to exhibit both high-spin multiplicity and antiferromagnetic
coupling, as indicated by magnetic susceptibility measurements.
Our contribution provides not only an avenue for preparing new
potential functional materials [59] but is also an essential input
of work which considers taming the complexity. Further studies
will involve exploitation of potential applicative interest of newly
synthesized compounds such as for instance determination of
porosity for 1 which may act as potential ‘molecular sieve’ (cf. its
relatively low density, Table 1) [60].
[35] V. Patroniak, P.N.W. Baxter, J.-M. Lehn, M. Kubicki, M. Nissinen, K. Rissanen,
Eur. J. Inorg. Chem. (2003) 4001.
Acknowledgements
[36] V. Patroniak, P.N.W. Baxter, J.-M. Lehn, Z. Hnatejko, M. Kubicki, Eur. J. Inorg.
Chem. (2004) 2379.
[37] M. Ruben, E. Breuning, M. Barboiu, J.-P. Gisselbrecht, J.-M. Lehn, Chem. Eur. J. 9
(2003) 291.
We would like to express our deep gratitude to Prof. Jean-Marie
Lehn for the opportunity to carry out a part of these studies in his
laboratory and for his precious advice. This research was carried
out as a part of the National Science Center project (Grant No.
2011/03/B/ST5/01036).
[38] A. Ciesielski, A. Gorczyn´ ski, P. Jankowski, M. Kubicki, V. Patroniak, J. Mol.
Struct. 973 (2010) 130.
[39] I. Iwakura, T. Ikeno, T. Yamada, Angew. Chem., Int. Ed. 44 (2005) 2524.
[40] M. Wałe˛sa-Chorab, V. Patroniak, M. Kubicki, G. Ka˛dziołka, J. Przepiórski, B.
Michalkiewicz, J. Catal. 291 (2012) 1.
[41] A.W. Addison, T.N. Rao, J. Reedijk, J. VanRijn, G.C. Verschoor, J. Chem. Soc.,
Dalton Trans. (1984) 1349.
Appendix A
[42] S. Kremer, W. Henke, D. Reinen, Inorg. Chem. 21 (1982) 3013.
[43] a M.E. Lines, J. Chem. Phys. 55 (1971) 2977;
Crystallographic data (excluding structure factors) for the
structural analysis has been deposited with the Cambridge Crystal-
lographic Data Centre, Nos. CCDC – 852516 (1), CCDC - 852517 (2),
CCDC – 853865 (3) and CCDC – 852518 (4). Copies of this
information may be obtained free of charge from: The Director,
CCDC, 12 Union Road, Cambridge, CB2 1EZ, UK. Fax:+44 1223 336
033, e-mail:deposit@ccdc.cam.ac.uk, or www: www.ccdc.cam.ac.uk.
b F. Lloret, M. Julve, J. Cano, R. Ruiz-Garcia, E. Pardo, Inorg. Chim. Acta 361
(2008) 3432;
c G. De Munno, T. Poerio, M. Julve, F. Lloret, G. Viau, New J. Chem. (1998) 299.
[44] J. Olguín, M. Kalisz, R. Clérac, S. Brooker, Inorg. Chem. 51 (2012) 5058.
[45] S.M. Ostrovsky, K. Falk, J. Pelikan, D.A. Brown, Z. Tomkowicz, W. Haase, Inorg.
Chem. 45 (2006) 688.
[46] M. Sarkaz, R. Clérac, C. Mathonière, N.G.R. Hearns, V. Bertolasi, D. Ray, Eur. J.
Chem. (2009) 4675.
[47] T. Ishida, T. Kawakami, S. Mitsubori, T. Nogami, K. Yamaguchi, H. Iwamura, J.
Chem. Soc., Dalton Trans. (2002) 3177.
[48] M.-H. Zeng, S. Gao, X.-M. Chen, Inorg. Chem. Commun. 7 (2004) 864.
[49] J.S. Maass, M. Zeller, T.M. Breault, B.M. Bartlett, H. Sakiyama, R.L. Luck, Inorg.
Chem. 51 (2012) 4903.
[50] S.M. Ostrovsky, R. Werner, D.A. Brown, W. Haase, Chem. Phys. Lett. 353 (2002)
290.
[51] E. Shurdha, C.E. Moore, A.L. Rheingold, J.S. Miller, Inorg. Chem. 50 (2011)
10546.
[52] L. Chen, D. Shi, J. Zhao, Y. Wang, P. Ma, J. Wang, J. Niu, Cryst. Growth Des. 11
(2011) 1913.
References
[1] J.-M. Lehn, Supramolecular Chemistry: Concepts and Perspectives, Wiley-VCH,
Weinheim, 1995.
[2] A. Wild, A. Winter, F. Schlütter, U.S. Schubert, Chem. Soc. Rev. 40 (2011) 1459.
[3] M. Ruben, J. Rojo, F.J. Romero-Salguero, L.H. Uppadine, J.-M. Lehn, Angew.
Chem., Int. Ed. 43 (2004) 3644.
[4] J.R. Price, N.G. White, A. Perez-Velasco, G.B. Jameson, C.A. Hunter, S. Brooker,
Inorg. Chem. 47 (2008) 10729.
[5] L.K. Thompson, Coord. Chem. Rev. 233–234 (2002) 193.
[6] L.N. Dave, K.V. Shuavev, L.K. Thompson, Inorg. Chem. 48 (2009) 3323.
[7] E.C. Constable, S. Decurtins, C.E. Housecroft, T.D. Keene, C.G. Palivan, J.R. Price,
J.A. Zampese, Dalton Trans. 39 (2010) 2337.
[53] M. Wałe˛sa-Chorab, A.R. Stefankiewicz, D. Ciesielski, Z. Hnatejko, M. Kubicki, J.
Kłak, M. Korabik, V. Patroniak, Polyhedron 30 (2011) 730.
[54] G. Beobide, O. Castillo, A. Luque, U. García-Couceiro, J.P. García-Terán, P.
Román, Inorg. Chem. 45 (2006) 5367.
[8] A.R.K. Glasson, L.F. Lindoy, G.V. Meehan, Coord. Chem. Rev. 252 (2008) 940.
[9] A.R. Stefankiewicz, M. Wałe˛sa, P. Jankowski, A. Ciesielski, V. Patroniak, M.
Kubicki, Z. Hnatejko, J.M. Harrowfield, J.-M. Lehn, Eur. J. Inorg. Chem. (2008)
2910.
[10] Q.-F. Sun, J. Iwasa, D. Ogawa, Y. Ishido, S. Sato, T. Ozeki, Y. Sei, K. Yamaguchi, M.
Fujita, Science 328 (2011) 1144.
[11] T.B. Gasa, C. Valente, J.F. Stoddart, Chem. Soc. Rev. 40 (2011) 57.
[12] C. Oelschlaeger, P. Suwita, N. Willenbacher, Langmuir 26 (2010) 7045.
[13] D. Li, J. Song, P. Yin, S. Simotwo, A.J. Bassler, Y.Y. Aung, J.E. Roberts, K.I.
Hardcastle, C.L. Hill, T. Liu, J. Am. Chem. Soc. 133 (2011) 14010.
[55] L. Rodrigez, E. Labisbal, A. Sousa-Pedrares, J.A. Garcia-Vázquez, J. Romero, M.L.
Duran, J.A. Real, A. Sousa, Inorg. Chem. 45 (2006) 7903.
[56] M. Wałe˛sa-Chorab, M. Kubicki, M. Korabik, Violetta Patroniak, submitted.
[57] J. Carranza, J. Sletten, C. Brennan, F. Lloret, J. Cano, Dalton Trans. (2004) 3997.
[58] E. Burkholder, V. Golub, Ch.J. O’Connor, J. Zubieta, Inorg. Chem. 42 (2003) 6729.
[59] M.D. Allendorf, A. Schwartzberg, V. Stavila, A.A. Talin, Chem. Eur. J. 17 (2011)
11372.
[60] S.D. Burd, S. Ma, J.A. Perman, B.J. Sikora, R.Q. Snurr, P.K. Thallapally, J. Tian, L.
Wojtas, M.J. Zaworotko, J. Am. Chem. Soc. 134 (2012) 3663.