Synthesis and characterisation of polymeric metal-ion carboxylates from benzene-1,3,5-tricarboxylic acid with Mn(II), Co(II) or Zn(II) and 2,2-bipyridyl, phenanthroline or a pyridyl-2-(1-methyl-1H-pyrazol-3-yl) derivative

Article abstract of DOI:10.1016/S0020-1693(01)00449-2

A total of 13 new co-ordination solids have been prepared of composition [Co(HBTC)(PHEN)(H₂O)] (12), [Mn₃(BTC)₂(PHEN)₃] (13), [Mn(HBTC)(6)(H₂O)] (14), [Mn(HBTC)(7)(H₂O)] (15), [Zn₃(BTC)₂(6)₃(H₂O)₃] ·4H₂O (16), [Zn(HBTC)(6)(H₂O)] (17), [Zn(H₂BTC)₂(6)] (18), [Zn(HBTC)(7)(H₂O)] (19), [Zn(HBTC)(8)(H₂O)] (20), [Zn₂(HBTC)₂(9)₂]·2H₂O (21), [Zn(HBTC)(10)(H₂O)]·H₂O (22), [Co(HBTC)(10)(H₂O)]·H₂O (23) and [Co(HBTC)(11)(H₂O)] (24) (6 = pyridine-2-(1-methyl-1H-pyrazol-3-yl); 7 = pyridine-2-(1-methyl-4-bromo-1H-pyrazol-3-yl); 8 = pyridine-2-(1-methyl-4-nitro-1H-pyrazol-3-yl); 9 = pyridine-2-(1-methyl-5-trifluoromethyl-1H-pyrazol-3-yl); 10 = pyridine-2-(1-methyl-5-tert-butyl-1H-pyrazol-3-yl); 11 = pyridine-2-(1-methyl-4-nitro-5-tert-butyl-1H-pyrazol-3-yl). Compounds 12, 14, 15 and 24 have similar structures which contain metal atoms in M₂O₂ rings. Compounds 17, 19 and 20 all contain single stranded coordinative chains. At low temperatures compounds 14 and 15 both have high spin S = 5 ground states.

Full text of DOI:10.1016/S0020-1693(01)00449-2

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Inorganica Chimica Acta 319 (2001) 159–175
Synthesis and characterisation of polymeric metal-ion carboxylates
from benzene-1,3,5-tricarboxylic acid with Mn(II), Co(II) or Zn(II)
and 2,2-bipyridyl, phenanthroline or a
pyridyl-2-(1-methyl-1H-pyrazol-3-yl) derivative
M. John Plater a,*, Mark R. St J. Foreman a, R. Alan Howie a, Janet M.S. Skakle a,
Eugenio Coronado b,1, Carlos J. Go´mez-Garc´ıa b, Thomas Gelbrich c,2,
Michael B. Hursthouse c
a Department of Chemistry, Uni6ersity of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland, UK
b Instituto de Ciencia Molecular, Uni6ersidad de Valencia, Dr. Moliner 50, 46100 Burjassot, Spain
c Department of Chemistry, Uni6ersity of Southampton, Highfield, Southampton SO17 1BJ, UK
Received 8 February 2001; accepted 2 April 2001
Abstract
A
total of 13 new co-ordination solids have been prepared of composition [Co(HBTC)(PHEN)(H2O)] (12),
[Mn3(BTC)2(PHEN)3] (13), [Mn(HBTC)(6)(H2O)] (14), [Mn(HBTC)(7)(H2O)] (15), [Zn3(BTC)2(6)3(H2O)3]·4H2O (16), [Zn-
(HBTC)(6)(H2O)] (17), [Zn(H2BTC)2(6)] (18), [Zn(HBTC)(7)(H2O)] (19), [Zn(HBTC)(8)(H2O)] (20), [Zn2(HBTC)2(9)2]·2H2O (21),
[Zn(HBTC)(10)(H2O)]·H2O (22), [Co(HBTC)(10)(H2O)]·H2O (23) and [Co(HBTC)(11)(H2O)] (24) (6=pyridine-2-(1-methyl-1H-
pyrazol-3-yl); 7=pyridine-2-(1-methyl-4-bromo-1H-pyrazol-3-yl); 8=pyridine-2-(1-methyl-4-nitro-1H-pyrazol-3-yl); 9=pyridine-
2-(1-methyl-5-trifluoromethyl-1H-pyrazol-3-yl); 10=pyridine-2-(1-methyl-5-tert-butyl-1H-pyrazol-3-yl); 11=pyridine-2-(1-
methyl-4-nitro-5-tert-butyl-1H-pyrazol-3-yl). Compounds 12, 14, 15 and 24 have similar structures which contain metal atoms in
M2O2 rings. Compounds 17, 19 and 20 all contain single stranded coordinative chains. At low temperatures compounds 14 and
15 both have high spin S=5 ground states. © 2001 Elsevier Science B.V. All rights reserved.
Keywords: Crystal structures; Manganese complexes; Copper complexes; Zinc complexes; Carboxylate complexes
1. Introduction
with manganese(II) or cobalt(II) acetate and 2,2%-
bipyridyl in a 1:1:1 ratio to give polymers of composi-
tion [M(HBTC)(BIPY)(H2O)] (M=Co, 1; M=Mn, 2;
M=Zn, 3) [1] Compounds 1 and 2 possess similar
square shaped chains of M2O2 rings whereas compound
3 consisted of single stranded chains. Compound 2 was
shown to exhibit ferromagnetic properties at low tem-
peratures [1]. In order to examine the effects of alter-
ations to the co-ordination environment of the
metal-ion on the structural and magnetic properties a
series of polymers are now reported in which 2,2-
bipyridyl (BIPY) (4) is replaced with either phenanthro-
line (PHEN) (5) or a pyridyl-2-(1-methyl-1H-pyra-
zol-3-yl) derivative (6–11). The ligand syntheses are
described in Section 6.
The hydrothermal synthesis of metal salts of aro-
matic polycarboxylic acids is attracting attention in the
field of crystal engineering as a consequence of their
novel structures and properties such as porosity and
magnetic interactions between paramagnetic metal-ions
[1–5]. In our recent work we reported the hydrothermal
reaction of benzene-1,3,5-tricarboxylic acid (H3BTC)
* Corresponding authors. Tel.: +44-1224-272943; fax: +44-1224-
272921; e-mail: m.j.plater@abdn.ac.uk.
1 Tel./fax: +34-96-3864 859; e-mail: eugenio.coronado@uv.es [E.
Coronado].
2 Fax: +44-1703-596 723; e-mail: gelbrich@soton.ac.uk [T. Gel-
brich].
0020-1693/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0020-1693(01)00449-2

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M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
2. Results and discussion
The product from the hydrothermal reaction of
H3BTC, manganese acetate and phenanthroline is an
anhydrous solid of composition [Mn3(BTC)2(PHEN)3]
(13) (Fig. 2). By infrared spectroscopy it was clear that
all the carboxylic acid groups are deprotonated. The
structure consists of layers containing both BTC and
phenanthroline ligands binding to manganese carboxy-
lates. The manganese has a distorted octahedral co-or-
dination environment consisting of carboxylate oxygens
in axial sites, two other carboxylate oxygens and two
nitrogen atoms. The carboxylate oxygens which are in
the equatorial sites are part of carboxylate groups in
which the plane formed by the three carboxylate atoms
is in the same plane as the aromatic systems of both the
BTC trianion and the phenanthroline ligands. The
plane formed by the three atoms in the axial carboxy-
lates are approximately 90° away from the planes
formed by the aromatic systems. All of the chains of
manganese atoms and carboxylate groups have the
same orientation. Each chain has six nearest neighbour-
2.1. Structure of [Co(HBTC)(PHEN)(H2O)] (12) and
[Mn3(BTC)2(PHEN)3] (13)
A close analogue of 2,2-bipyridyl (BIPY) (4) is 1,10-
phenanthroline (PHEN) (5) which has similar steric
demands at the nitrogen atoms. However, phenanthro-
line is less flexible and has a larger p system than
2,2-bipyridyl. The hydrothermal reaction of cobalt ace-
tate, H3BTC and phenanthroline produced a red solid
of composition [Co(HBTC)(PHEN)(H2O)] (12) (Fig. 1).
The crystal structure of 12 is similar to that of [Co-
(HBTC)(BIPY)(H2O)] (1) reported previously. It con-
tains hydrogen-bonded mats of cobalt carboxylate units
which bear phenanthroline ligands forming a layered
structure. The cobalt has a distorted octahedral co-or-
dination environment. A water oxygen and a nitrogen
atom are in axial sites while the equatorial sites are
occupied by two bridging carboxylate oxygens, a non-
bridging carboxylate oxygen and the other nitrogen
atom. The nitrogen atoms and the water oxygen are all
cis to the non-bridging carboxylate. In common with
structure 1 the cobalt atoms in 12 are in Co2O2 rings.
This solid contains 1D double chains of carboxylates
which are linked into sheets by hydrogen bonding
shown in Fig. 1. These sheets are separated by layers of
phenanthroline ligands.
,
ing chains. The intrachain Mn–Mn distance is 6.517 A,
while the shortest interchain Mn–Mn distance is 8.162
,
A. The benzene rings of the BTC trianions are parallel
to the phenanthroline ligands which maximises p or-
bital overlap.
2.2. Structure of [Mn(HBTC)(6)(H2O)] (14) and
[Mn(HBTC)(7)(H2O)] (15)
It was decided to investigate the effects of substitut-
ing one pyridine ring in the nitrogen ligand for a
pyrazole ring. The hydrothermal reaction of manganese
acetate, H3BTC and pyridine-2-(1-methyl-1H-pyrazol-
3-yl) (6) or pyridine-2-(1-methyl-4-bromo-1H-pyrazol-
3-yl) (7) gave polymers of composition [Mn(HBTC)-
(6)(H2O)] (14) (Fig. 3) and [Mn(HBTC)(7)(H2O)] (15)
(Fig. 4) which are similar in structure to [Mn-
(HBTC)(BIPY)(H2O)] (2). Chains of HBTC ligands
bridge between manganese atoms. Each chain is linked
by hydrogen bonding to the next forming sheets. Above
and below each sheet is a layer of pyridyl pyrazole
ligands. In the structures of compounds 14 and 15
layers of manganese carboxylates and nitrogen hetero-
cycles are present. The layers of manganese carboxy-
lates consist of 1D double chains of manganese
carboxylates linked together at the manganese atoms by
bridging carboxylates. Hydrogen bonds involving water
and carboxylic acid protons fix each chain to it’s neigh-
bours so forming sheets.
In both 14 and 15 the manganese has a distorted
octahedral co-ordination geometry. The manganese
atoms are in pairs with two bridging carboxylate oxy-
gen atoms linking them in common with 2. One oxygen
from a non-bridging carboxylate group is binding to
the metal. At a site cis to all the carboxylate oxygens
and the pyrazole nitrogen a water is co-ordinating. At
Fig. 1. Top: drawing of the metal-ion co-ordination environment in
12. Bottom: drawing of the double stranded hydrogen bonded chains.

M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
161
Fig. 2. Top: drawing of the metal-ion co-ordination environment in 13. Middle and bottom: drawings of the chains.
,
104.39°. The next nearest manganese atom is 9.212 A
away.
the remaining site trans to the water is the pyridine
nitrogen atom. A hydrogen bond between a water
hydrogen and the non-bridging carboxylate is present.
The other water hydrogen is hydrogen bonding to a
carboxylic acid group which is in a different chain of
carboxylates while the carboxylic acid proton is hydro-
gen bonding to a non-manganese bound oxygen in the
bridging carboxylate.
2.3. Structure of [Zn3(BTC)2(6)3(H2O)3]·4H2O (16),
[Zn(HBTC)(6)(H2O)] (17) and [Zn(H2BTC)2(6)] (18)
Treatment of H3BTC and compound 6 with zinc
acetate under hydrothermal conditions in a 1:1:1 ratio
gave a mixture of compounds 16 and 17. Compound 16
contains a BTC trianion in contrast with many of the
other compounds reported here while compound 17
contains the HBTC dianion. By the addition of either
sodium acetate or acetic acid to the reaction mixture 16
and 17 can be obtained as pure solids respectively. It
The manganese atoms in compound 14 are in planar
,
Mn2O2 rings with a Mn–Mn distance of 3.489 A. The
Mn–O–Mn angle in the ring is 104.23°. Outside the
Mn2O2 unit the nearest neighbouring manganese atoms
,
is 7.739 A away. In compound 15 the Mn–Mn distance
,
in the dimer is 3.482 A and the Mn–O–Mn angle is

162
M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
Fig. 3. Top: drawing of the metal-ion co-ordination environment in 14. Bottom: drawing of the double stranded chains.
was found that by increasing the concentration of acetic
acid a third solid 18 could be obtained. Compound 18
contains H2BTC anions which are crosslinked by a
hydrogen bonding network.
torted tetrahedral co-ordination environment consisting
of two carboxylate oxygens and two nitrogens. Within
the solid there are corrugated layers formed by the
hydrogen bonds between different molecules. The hy-
drogen bonds are between carboxylic acid groups.
Compound 16 has three different zinc atoms in the
asymmetric unit (Fig. 5). All three zincs have similar
co-ordination environments. The zinc has a distorted
trigonal bipyrimidal geometry. At the axial sites are a
water oxygen and a pyrazole nitrogen. The equatorial
sites are occupied by the pyridine nitrogen and oxygen
atoms from two non-bridging carboxylate groups. The
solid contains layers of carboxylates and is extensively
hydrogen bonded. The hydrogen bond donors are wa-
ter molecules while the acceptors are water and car-
boxylate oxygens.
2.4. Structures of [Zn(HBTC)(7)(H2O)] (19) and
[Zn(HBTC)(8)(H2O)] (20) and [Zn2(HBTC)2(9)2]·2H2O
(21)
Treatment of H3BTC and pyridine-2-(1-methyl-4-
bromo-1H-pyrazol-3-yl) (7) or pyridine-2-(1-methyl-4-
The zinc in compound 17 has a distorted square
based pyramidal geometry. At the axial site is a car-
boxylate oxygen. The equatorial sites are occupied by a
water, a carboxylate oxygen and two nitrogen atoms
from a molecule of 6. The water is cis to the pyrazole
nitrogen and carboxylate oxygen, while in the trans site
is the pyridine nitrogen. The solid has a layered struc-
ture. Both within and between the two sheets which
make up the layers are hydrogen bonds.
In contrast to the other structures compound 18 is a
molecular solid (Fig. 6). The zinc atoms have a dis-
Fig. 4. Drawing of the metal-ion co-ordination environment in struc-
ture 15.

M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
163
Fig. 5. Top: drawing of the metal-ion co-ordination environment in 16. Bottom: drawing of a sheet in 16 omitting the bidentate ligand.
is the pyridine nitrogen and carboxylate oxygens from
two different HBTC dianions. Of the two oxygen atoms
linked to a zinc which are in the eight membered ring,
one is in an axial site and the other in the equatorial
site. One of the two oxygens in the bridging carboxylate
is at the axial site on a zinc while the other is at an
equatorial site.
The solid consists of alternate layers of zinc carboxy-
lates and nitrogen heterocycles. The mats of zinc car-
boxylates are structurally different to the others
reported in this paper. The hydrogen bonding network
does not involve the carboxylates which are binding to
the metal atoms.
nitro-1H-pyrazol-3-yl) (8) with zinc acetate in a 1:1:1
ratio under hydrothermal conditions gave solids 19 and
20, respectively (Fig. 7). Both 19 and 20 have similar
single stranded chain structures to compound 17. It is
clear that the presence of the bromine atom or the nitro
group at the four position on the pyrazolyl group
favours the formation of solids which are similar in
structure to 17. It is not known if this is due to an
electronic effect or a steric effect. In order to investigate
the effect of electron withdrawing groups on the pyra-
zole ring pyridine-2-(1-methyl-5-trifluoromethyl-1H-
pyrazol-3-yl) (9) was prepared. Treatment of H3BTC
and compound 9 with zinc acetate under hydrothermal
conditions formed
a solid of composition [Zn2-
(HBTC)2(9)2]·2H2O (21) which contains Zn2C2O4 rings
(Fig. 8).
2.5. Structures of [Zn(HBTC)(10)(H2O)]·H2O (22) and
[Co(HBTC)(10)(H2O)]·H2O (23)
The co-ordination environment of Zn1 is distorted
trigonal bipyrimidal. In the axial sites are a carboxylate
oxygen and a pyrazole nitrogen. In the equatorial sites
As the presence of the trifluoromethyl group caused
such a great change in structure of 21 when compared

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M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
with 17, 19 and 20, it was decided to substitute the
trifluoromethyl group for a tert-butyl group. The hy-
drothermal reactions of zinc and cobalt acetates with
H3BTC and pyridine-2-(1-methyl-5-tert-butyl-1H-pyra-
zol-3-yl) (10) formed isostructural solids 22 and 23 (Fig.
9). The metal atom is in a distorted octahedral environ-
ment which consists of a water and a pyridine nitrogen
in the axial sites. The equatorial sites are occupied by
the pyrazole nitrogen and three carboxylate oxygens.
The structure is not layered but instead the metal
carboxylate units form a network of distorted rectangu-
lar tubes which are filled by molecules of 10. The
HBTC dianions are alternately in different planes pro-
ducing a complex hydrogen bonded structure.
sulfuric acids formed pyridine-2-(1-methyl-5-tert-butyl-
4-nitro-1H-pyrazol-3-yl) (11) in high yield. While steric
inhibition of resonance prevents the nitro group from
expressing its full electron withdrawing effect, it has an
inductive pull on the electrons in the pyrazole ring. We
found that the reaction of 11 with H3BTC and cobalt
acetate formed a co-ordination polymer of composition
[Co(HBTC)(11)(H2O)] (24) (Fig. 10). The cobalt atoms
in 24 have a distorted octahedral co-ordination envi-
ronment. The axial sites are occupied by a water oxy-
gen and the pyridine nitrogen. Two of the cis equatorial
sites are occupied by bridging carboxylate oxygen
atoms. The remaining two sites are occupied by the
pyrazole nitrogen and a non-bridging carboxylate oxy-
gen. The metal atoms are arranged in pairs like those
found in 1, 2, 12, 14 and 15. The X-ray crystallography
confirms that the nitro group in 24 is not conjugated to
the pyrazole ring. The extended structure is similar to
that of 1 (Tables 1–12).
2.6. Structure of [Co(HBTC)(11)(H2O)] (24)
Although the tert-butyl group in 10 has a great steric
bulk treatment of 10 with a mixture of nitric and
Fig. 6. Top: drawing of the metal-ion co-ordination environment in 18. Bottom: Drawing of a section of 18.

M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
165
(proportional to the square of the magnetic moment)
versus temperature. At room temperature the mT
value is 4.3 emu K mol−1 per manganese, which is very
close to the value expected for magnetically isolated
manganese(II) centers with a spin sextuplet (S=5/2).
When cooling, mT reveals a continuous increase with a
tendency of levelling below approximately 3 K, reach-
ing a value of 7.0 emu K mol−1 at 2 K. Such a
behaviour is characteristic of a ferromagnetic coupling
between two spin sextuplets, whereby the plateau at
lower temperatures corresponds to the exclusive ther-
mal population of the S=5 ground spin state. There-
fore, the magnetic data were conveniently analysed with
the appropriate van Vleck equation for the magnetic
susceptibility of a high spin manganese(II) dimer with
the isotropic Heisenberg hamiltonian Hex= −2JSA·SB,
where J is the magnetic coupling parameter. A fitting of
the data to this model leads to g=2.0 and J=0.72
cm−1. An 8% of monomeric impurity had to be intro-
duced. The agreement is excellent in the whole tempera-
ture range (Fig. 1).
An additional proof of this picture comes from the
low temperature magnetisation data. Thus, the isother-
mal variation of the magnetisation at 2 and 5 K versus
the applied magnetic field closely follows the expected
behaviour expected for a total spin S=5 with g=2.0,
indicating that the ground spin state of the system is the
ferromagnetic one (Fig. 12).
These results indicate that although the structure of
compound 14 consists of chains of manganese dimers,
the exchange interaction seems to be restricted to the
Mn(II)–Mn(II) pairs which are magnetically coupled
through two bridging oxygens from two carboxylate
groups. The spin coupling through the benzene-1,3,5-
tricarboxylate anion is negligible.
Fig. 7. Top: drawing of the metal-ion co-ordination environment in
19. Middle and bottom: drawing of the single stranded chains.
3.2. [Mn(HBTC)(C9H8N3Br)H2O] (15)
The magnetic properties of compound 15 are very
similar to those of compound 14. Fig. 13 shows a plot
of the product of mT (proportional to the square of
the magnetic moment) versus temperature. At room
temperature the mT value is 4.3 emu K mol−1 per
manganese, which is very close to the value expected
for magnetically isolated manganese(II) centers with a
spin sextuplet (S=5/2). When cooling, mT reveals a
continuous increase with a tendency of levelling below
approximately 5 K and even showing a soft maximum
at approximately 3.5 K with a mT value of 6.97 emu K
mol−1. As for compound 14, we have analysed these
data with the appropriate van Vleck equation for the
magnetic susceptibility of a high spin manganese(II)
dimer with the isotropic Heisenberg hamiltonian Hex=
−2JSA·SB. A fitting of the data to this model leads to
g=2.0 and J=0.73 cm−1, which are, within experi-
Fig. 8. Top: drawing of the metal-ion co-ordination environment in
21.
3. Magnetic measurements
3.1. [Mn(HBTC)(C9H9N3)H2O] (14)
The magnetic properties of compound 14 are de-
picted in Fig. 11 with a plot of the product of mT

166
M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
Fig. 9. Top: drawing of the metal-ion co-ordination environment in 22. Bottom: drawing of a section of the network.
mental error, the same values that those obtained for
compound 14. The agreement is excellent in the whole
temperature range (Fig. 3). The only difference with
compound 14 is that in 15 there is no need to introduce
a monomeric impurity in the fitting procedure al-
though, in order to satisfactorily reproduce the soft
decrease in the mT plot at very low temperatures, it is
Fig. 11. Thermal dependence of the product susceptibility times the
temperature (mT) for complex 14 and the theoretical behaviour of a
ferromagnetic manganese(II) dimer (solid line). The inset shows the
plateau of mT in the low temperature region.
Fig. 10. Drawing of the metal-ion co-ordination environment in 24.

M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
167
Table 1
,
Hydrogen bonds (A and °) for compound 12
D–H···A
d(D–H) d(H···A) d(D···A) Ú(DHA)
O(3)–HCA···O(2)c4 0.81(4)
O(7)–HWA···O(4)c5 0.82(3)
O(7)–HWB···O(6)c1 0.94(4)
1.84(4)
1.94(3)
1.73(4)
2.619(2) 160(4)
2.757(3) 170(3)
2.611(3) 155(3)
Symmetry transformations used to generate equivalent atoms: c1 x,
y–1, z; c2 −x, −y, −z; c3 x, y+1, z; c4 x−1, y, z; c5 x+1,
y, z.
Table 2
,
Hydrogen bonds (A and °) for compound 14
D–H···A
d(D–H)
d(H···A)
d(D···A)
Ú(DHA)
Fig. 12. Plot of the isothermal magnetisation M (per pair of man-
ganese(II) ions) vs. H/T at 2 and 5 K for compound 14. The Brillouin
function for a spin S=5 with g=2 is plotted as a solid line and
compared to the behaviour calculated for two non-interacting local
spins SA=SB=5/2 (dashed line).
O4–H3O···O2c5 0.87(7)
O7–H2O···O3c4 0.84
O7–H1O···O5c1 0.86
1.78(7)
1.93
1.85
2.615(4)
2.764(4)
2.640(4)
159(7)
173.8
151.4
Symmetry transformations used to generate equivalent atoms: c1 x,
y, z+1; c2 −x+1, −y+1; c3 x, y, z−1; c4 x−1, y, z; c5
x+1, y, z.
Table 3
,
Hydrogen bonds (A and °) for compound 15
D–H···A
d(D–H) d(H···A) d(D···A) Ú(DHA)
O(5)–H(5)···O(3)c4
0.82
2.05
2.00(8)
1.92(8)
2.657(4)
2.716(4)
2.623(5)
130.3
143(7)
162(7)
O(7)–H(7A)···O(6)c5 0.84(8)
O(7)–H(7B)···O(2)
0.73(8)
Symmetry transformations used to generate equivalent atoms: c1 x,
y+1, z; c2 −x+1, −y, −z; c3 x, y−1, z; c4 x−1/2, −y−1/2,
z−1/2; c5 x+1/2, −y+1/2, z+1/2.
Fig. 13. Thermal dependence of the product susceptibility times the
temperature (mT) for complex 15 and the theoretical behaviour of a
ferromagnetic manganese(II) dimer (solid line). The inset shows the
plateau of mT in the low temperature region.
Table 4
,
Hydrogen bonds (A and °) for compound 16
D–H···A
d(D–H) d(H···A) d(D···A) Ú(DHA)
O(13)–H(3WA)···O(17)
0.900(2) 1.750(3)
2.633(4) 166.18(17)
2.843(3) 170.68(18)
3.155(4) 153.03(19)
2.767(3) 167.69(19)
2.688(3) 163.9(3)
2.651(3) 170.1(2)
O(13)–H(3WB)···O(3)c5 0.837(2) 2.014(2)
O(14)–H(4WA)···O(9)c3 0.802(3) 2.418(3)
O(14)–H(4WB)···O(2)c5 0.899(2) 1.882(2)
O(15)–H(5WA)···O(16)
0.810(2) 1.901(3)
O(15)–H(5WB)···O(12)c5 0.843(2) 1.817(2)
O(16)–H(6WA)···O(7)c5 0.967(3) 1.9985(18) 2.876(3) 149.85(19)
O(16)–H(6WB)···O(1)c5 0.960(3) 2.000(2)
O(17)–H(7WA)···O(8)c6 0.945(3) 1.895(3)
2.811(3) 140.95(18)
2.720(4) 144.4(2)
3.374(3) 179.8(2)
2.888(4) 177.2(3)
3.533(4) 167.8(2)
2.927(6) 110.7(2)
3.247(6) 148.5(3)
O(17)–H(7WB)···O(7)
O(18)–H(8WA)···O(4)
0.856(3) 2.518(2)
0.856(3) 2.033(2)
O(18)–H(8WB)···O(11)c7 0.939(3) 2.610(2)
O(19)–H(9WA)···O(17)
O(19)–H(9WB)···O(7)
0.990(6) 2.426(4)
0.990(5) 2.362(2)
Fig. 14. Plot of the isothermal magnetisation
M (per pair of
manganese(II) ions) vs. H/T at 2 K for compound 15. The Brillouin
function for a spin S=5 with g=2 is plotted as a solid line and
compared to the behaviour calculated for two non-interacting local
spins SA=SB=5/2 (dashed line).
Symmetry transformations used to generate equivalent atoms: c1 x,
y−1, z+1; c2 x, y−1, z; c3 x, y+1, z−1; c4 x, y+1, z; c5
−x+1, −y, −z+1; c6 −x+1, −y−1, −z+2; c7 −x+1,
−y−1, −z+1.

168
M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
Table 5
Table 9
,
,
Hydrogen bonds (A and °) for compound 17
Hydrogen bonds (A and °) for compound 21
D–H···A
d(D–H) d(H···A) d(D···A) Ú(DHA)
D–H···A
d(D–H) d(H···A) d(D···A) Ú(DHA)
O(5)–H(5A)···O(2)c3 0.82(6)
1.79(6)
2.02(5)
2.15(6)
2.592(4) 168(6)
2.798(4) 159(5)
2.802(4) 140(6)
O(5)–H(5)···O(4W)
0.82
1.90
1.85
1.81
2.13
2.664(7) 154.8
2.661(5) 173.1
2.624(5) 172.3
2.759(8) 133.1
O(7)–HWA···O(1)c4
O(7)–HWB···O(6)c5
0.81(4)
0.80(7)
O(10)–H(10)···O(15)c2 0.82
O(16)–H(16A)···O(9)c5 0.82
O(23)–H(23)···O(2W)c5 0.82
Symmetry transformations used to generate equivalent atoms: c1
x−1, y, z; c2 x+1, y, z; c3 x, y+1, z; c4 −x, −y+1, −z+1;
c5 x, y−1, z.
Symmetry transformations used to generate equivalent atoms: c1
−x+1/2, y−1/2, −z+3/2; c2 −x+1/2, y+1/2, −z+5/2; c3 x,
y, z−1; c4 −x+1/2, y+1/2, −z+3/2; c5 −x+1/2, y−1/2,
−z+5/2; c6 x, y, z+1.
Table 6
,
Hydrogen bonds (A and °) for compound 18
Table 10
D–H···A
d(D–H) d(H···A) d(D···A) Ú(DHA)
,
Hydrogen bonds (A and °) for compound 22
O(3)–H(3A)···O(2)c1
O(6)–H(6A)···O(5)c2
O(9)–H(9A)···O(8)c3
0.88(4) 1.84(4)
0.82 1.83
0.99(5) 1.69(5)
1.84
2.672(4) 158(4)
2.631(4) 166.8
2.653(4) 164(5)
2.656(4) 175.8
D–H···A
d(D–H) d(H···A) d(D···A) Ú(DHA)
O(4)–H(4O)···O(6)c3
0.89(6) 1.82(6)
2.712(3) 174(5)
2.704(4) 169(5)
2.891(4) 168(4)
2.751(4) 161(5)
2.937(5) 152(6)
O(11)–H(11)···O(12)c4 0.82
O(7)–H(7WA)···O(8)c4 0.78(5) 1.94(5)
O(7)–H(7WB)···O(6)c5 0.85(5) 2.06(5)
O(8)–H(8WA)···O(1)c1 0.94(6) 1.84(6)
O(8)–H(8WB)···O(3)c6 0.75(6) 2.26(6)
Symmetry transformations used to generate equivalent atoms: c1−
x+1, −y, −z; c2 −x−1, −y−1, −z; c3 −x, −y, −z+1; c4
−x+2, −y+1, −z+1.
Symmetry transformations used to generate equivalent atoms: c1
x+1, y, z; c2 x−1, y, z; c3 x, −y+1/2, z−1/2; c4 −x+1,
−y+1, −z; c5 −x, −y+1, −z; c6 x+1, −y+1/2, z+1/2.
Table 7
,
Hydrogen bonds (A and °) for compound 19
D–H···A
d(H···A)
d(D–H)
d(D···A)
Ú(DHA)
Table 11
,
Hydrogen bonds (A and °) for compound 23
O6–H6···O2c3
1.798
0.840
0.860
0.839
2.603(6)
2.846(6)
2.758(6)
160.18
144.45
151.95
O7–H7A···O1c4 2.102
O7–H7B···O5c6 1.989
D–H···A
d(D–H) d(H···A) d(D···A) Ú(DHA)
O(4)–H(4O)···O(6)c3
0.84(4) 1.88(4)
2.707(3) 171(4)
2.707(3) 167(3)
2.891(3) 163(3)
2.746(3) 165(5)
2.945(4) 158(4)
Symmetry transformations used to generate equivalent atoms: c1
x+1, y, z; c2 x −1, y, z; c3 x, y+1, z; c4 −x−1, −y, −z+1;
c5 −x, −y, −z+1; c6 x+1, y−1, z.
O(7)–H(7WA)···O(8)c4 0.94(4) 1.78(4)
O(7)–H(7WB)···O(6)c5 0.79(3) 2.13(3)
O(8)–H(8WA)···O(1)c1 0.88(5) 1.88(5)
O(8)–H(8WB)···O(3)c6 0.79(5) 2.19(5)
Table 8
,
Hydrogen bonds (A and °) for compound 20
Symmetry transformations used to generate equivalent atoms: c1
x+1, y, z; c2 x−1, y, z; c3 x, −y+1/2, z−1/2; c4 −x+1,
−y+1, −z; c5 −x, −y+1, −z; c6 x+1, −y+1/2, z+1/2.
D–H···A
d(D–H) d(H···A) d(D···A)
Ú(DHA)
O(8)–H(8)···O(4)c3
0.82
1.82
2.17
2.32
1.89
2.6213(17) 165.8
2.8942(17) 147.1
2.882(2) 126.2
2.7657(18) 161.0
Table 12
O(12)–H(12A)···O(3)c4 0.82
O(12)–H(12A)···O(6)c5 0.82
O(12)–H(12B)···O(7)c6 0.91
,
Hydrogen bonds (A and °) for compound 24
D–H···A
d(D–H) d(H···A) d(D···A) Ú(DHA)
Symmetry transformations used to generate equivalent atoms: c1
x+1, y, z; c2 x−1, y, z; c3 x, y−1, z; c4 −x+1, −y+1, −z;
c5 −x, −y+1, −z; c6 x, y+1, z.
O(7)–H(7A)···O(5)c4 0.74(3)
O(9)–HW9A···O(8)c5 0.73(3)
1.95(3)
2.10(3)
1.82(4)
2.685(2) 174(4)
2.798(2) 160(3)
2.627(2) 164(4)
O(9)–HW9B···O(4)
0.83(4)
Symmetry transformations used to generate equivalent atoms: c1 x,
y−1, z; c2 −x+1, −y+1, −z; c3 x, y+1, z; c4 x+1/2,
−y+3/2, z+1/2; c5 x−1/2, −y+1/2, z−1/2.
necessary to add a molecular field term, zJ%, that
accounts for the interdimer and interchain magnetic
interactions. The obtained molecular field parameter
zJ% is very small (−0.003 cm−1) and indicates the
presence of very weak antiferromagnetic interdimer and
interchains interactions, as already reported for the
magnetisation at 2 K versus the applied magnetic field
in compound 15 closely follows the expected behaviour
expected for a total spin S=5 with g=2.0, indicating
that the ground spin state of the system is also the
ferromagnetic one (Fig. 14).
related isophthalate (−0.03 cm−1
)
[6] and
terephthalate bridges (−0.04 and −0.065 cm−1) [7,8].
As for compound 14, the isothermal variation of the

M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
169
These results indicate that compounds 14 and 15
present very similar magnetic behaviours, as could be
anticiped from the similarities existing in the structure
of the central Mn(II) dimer of both compounds. The
only difference deals with the presence of a very weak
antiferromagnetic interdimers and interchains inter-
action that seems to be present only in compound 15.
Nevertheless, the presence of 8% of monomeric Mn(II)
impurity in compound 14 significantly modifies the low
temperature region of the plot precluding the determi-
nation of any interdimers or interchains interaction, as
they are only effective in the low temperature region.
The ferromagnetic coupling between the manganese(II)
ions connected through the oxygen bridges has only
been observed in a very similar Mn(II) dimer also
connected through two oxygen bridges, where a J value
of 0.90 cm−1 was found [1].
using a Bruker SMART 1000 diffractometer [9], with
graphite-monochromated Mo Ka radiation (u=
,
0.71073 A). Intensity data were collected using ꢀ-steps
of width 0.3° accumulating area detector frames span-
ning at least a hemisphere of reciprocal space for all
structures and were integrated using the program SAINT
[9]. All data were corrected for Lorentz, polarisation
and long-term intensity fluctuations. Absorption effects
were corrected on the basis of multiple equivalent
reflections using SADABS [9]. Structures 12, 13, 15, 16
and 20–23 were solved by direct methods using
SHELXS-86 [10]; 17, 18 and 24 were solved by Patterson
methods using SHELXS-97 [10]. All were refined by
full-matrix least-squares against F2 using SHELXL-97
[10]. For structures 12, 15–18, 20, 23 and 24, hydrogen
atoms attached to water and/or hydroxyl oxygen atoms
were located objectively from the difference Fourier
map and refined freely. In the case of 16, the water
hydrogen atoms were then refined subject to distance/
angle constraints using the FRAG and FEND commands
of SHELXL-97 [10]. For structure 21, water hydrogen
atoms could not be located satisfactorily and were thus
not included in the refinement. All other hydrogen
atoms in all structures were placed in ideal geometric
positions and refined using a riding model. Refinements
converged to the values given in Tables 13 and 14. For
structures 14 and 19 intensity data were recorded at 150
K, using a Nonius Kappa CCD area-detector diffrac-
tometer mounted at the window of a rotating anode
FR591 generator with a molybdenum anode (0.71073
4. Magnetic measurements
Variable temperature susceptibility measurements
were carried out in the temperature range 2–300 K at a
magnetic field of 0.1 T for sample 14 and 0.04 T for
sample 15 on polycrystalline samples with a SQUID
magnetometer (Quantum Design MPMS-XL-5). The
susceptibility data were corrected from the diamagnetic
contributions as deduced by using Pascal’s constant
tables and were fitted with the van Vleck equation for a
S=5/2 dimer with a monomeric paramagnetic impurity
(c):
,
A). The crystal-to-detector distance was 30 mm and €
and ꢀ scans were carried out to fill the Ewald sphere.
m=(1−c)
Data collection and processing were carried out using
NAg2i2 2e2x+10e6x+28e12x+60e20x+110e30x
kBT 1+3e2x+5e6x+7e12x+9e20x+11e30x
35g2
32
the programs DIRAX, COLLECT and DENZO and MAXUS
+c
and an empirical absorption correction was applied
using SORTAV [11–15]. The structure was solved by
direct methods [10] and refined by full-matrix least-
squares on F2 [10]. Non-hydrogen atoms were refined
anisotropically and hydrogen positions were placed in
geometrical positions using a riding model.
where x=J/kBT.
With the molecular field approach the expression for
the susceptibility becomes:

m
% =
m
2zj %
NAg2i2
m
1−
6. Experimental
The theoretical curve of the magnetisation has been
calculated with the Brillouin function:
Pyridine-2-(1H-pyrazol-3-yl) was prepared by the
treatment of 2-acetylpyridine with dimethylformamide
dimethyl acetal followed by cyclisation with hydrazine
[16,17]. Pyridine-2-(1-methyl-1H-pyrazol-3-yl) (6) was
prepared by the reaction of pyridine-2-(1H-pyrazol-3-
yl) with sodium hydride and methyl iodide in THF
2S+1
2S
(2S+1)y
2S
1
2S
y
ꢀ
n
M(vB)=gS
coth
−
coth
2S
where y=(gSiH/kBT).
[18,19].
Pyridine-2-(1-methyl-5-trifluoromethyl-1H-
5. X-ray crystallographic studies
pyrazol-3-yl) (9) was prepared by the base catalysed
reaction of 2-acetylpyridine with ethyl trifluoroacetate
followed by condensation with hydrazine then alkyla-
tion with methyl iodide. Pyridine-2-(1-methyl-5-tert-bu-
Details of the structure determinations are given in
Tables 13 and 14. X-ray diffraction data were collected)

Table 13
Summary of key crystallographic data for compounds 12–18
12
13
14
15
16
17
18
Formula
M
T (K)
Crystal system
Space group
Unit cell dimensions
C21H14CoN2O7
465.27
303(2)
C21H11MnN2O6
442.26
301(2)
monoclinic
P21/c
C18H15MnN3O7
440.27
150(2)
C18H14BrMnN3O7
519.17
301(2)
monoclinic
P21/n
C
45H47N9O19Zn3
C18H15N3O7Zn
450.70
300(2)
C27H19N3O12Zn
642.82
305(2)
1214.03
303(2)
triclinic
triclinic
triclinic
triclinic
triclinic
/
(
(
(
(
(
P1
P1
P1
P1
P1
,
a (A)
9.5706(6)
10.8684(6)
11.2064(7)
96.6030(10)
111.3840(10)
111.5420(10)
967.02(10)
2
6.5174(4)
16.9817(10)
15.8145(9)
9.6017(7)
10.2445(7)
10.9171(5)
99.034(3)
111.469(3)
107.413(3)
909.58(10)
2
11.2361(5)
10.7196(5)
16.0005(7)
10.2993(4)
17.0138(6)
17.1149(6)
60.2420(10)
88.9900(10)
83.1820(10)
2582.18(16)
2
9.4079(8)
9.4247(8)
11.7321(9)
66.756(2)
80.184(2)
79.824(2)
934.92(13)
2
8.2264(7)
8.3315(7)
19.8883(16)
100.103(2)
92.595(2)
101.369(2)
1311.13(19)
2
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
V (A )
92.9810(10)
100.4040(10)
3
,
1747.93(18)
4
0.802
1895.52(15)
4
2.853
319
Z
v (mm−1
)
0.936
0.775
1.465
1.361
1.012
)
Reflections collected
8602
16840
9790
17408
25163
8343
13057
Independent reflections/Rint
Data/restraints/parameters
R1/wR2 [F2\2|(F2)]; (all data)
5485/0.0349
5485/0/292
0.045/0.090;
0.095/0.104
5797/0.1435
5797/0/271
0.074/0.165;
0.142/0.190
1.357/−0.900
3640/0.0447
3640/0/296
0.061/0.162;
0.075/0.168
1.948/−0.686
6045/0.0518
6045/0/281
0.065/0.198;
0.101/0.214
3.009/−1.525
16580/0.0206
16580/0/688
0.045/0.123;
0.087/0.138
1.736/−0.510
5341/0.0715
5341/0/275
0.059/0.120;
0.134/0.142
0.479/−0.711
9148/0.0672
9148/0/399
0.057/0.079;
0.233/0.111
0.378/−0.412
159
175
Largest difference peak and hole (e 0.403/−0.588
−3
,
A
)

M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
171
Table 14
Summary of key crystallographic data for compounds 19–24
19
20
21
22
23
24
Formula
M
T (K)
Crystal system
Space group
Unit cell dimensions
C18H14BrN3O7Zn
529.60
150(2)
C18H14N4O9Zn C38H28F6N6O14Zn2 C22H25N3O8Zn C22H25CoN3O8 C22H22CoN4O9
991.40
301(2)
triclinic
1037.40
305(2)
monoclinic
P21/n
524.82
303(2)
monoclinic
P21/c
518.38
303(2)
monoclinic
P21/c
545.37
305(2)
monoclinic
P21/n
triclinic
(
(
P1
P1
,
a (A)
9.4355(4)
9.4615(4)
11.3350(5)
70.514(2)
79.874(2)
81.082(2)
934.02(7)
2
9.4599(4)
9.5514(4)
11.5650(5)
69.9570(10)
77.8540(10)
80.6310(10)
955.01(7)
1
29.906(2)
11.1569(8)
27.756(2)
9.9726(4)
15.0501(6)
15.6492(7)
10.0113(7)
15.0119(7)
15.6030(7)
15.1118(7)
10.8511(5)
15.2521(7)
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
V (A )
62.2390(10)
94.7300(10)
95.3080(10)
108.6160(10)
3
,
8195.0(10)
8
1.275
2340.77(17)
4
1.102
2334.9(2)
4
0.788
2370.18(19)
4
0.784
Z
v (mm−1
)
3.504
1.350
Reflections collected
Independent reflections/
Rint
7341
2865/0.0563
9022
5416/0.0139
36733
11730/0.0870
20537
7022/0.0409
11939
3343/0.0405
18498
8401/0.0450
Data/restraints/parameters 2865/1/283
5416/0/296
11730/0/1197
0.045/0.068;
0.118/0.080
7022/0/331
3343/0/331
8401/0/338
R1/wR2 [F2\2|(F2)];
0.058/0.126;
0.072/0.132
1.207/−1.332
0.031/0.084;
0.038/0.087
0.482/−0.312
0.047/0.143;
0.083/0.153
0.678/−0.420
0.032/0.082;
0.044/0.088
0.302/−0.263
0.046/0.103;
0.097/0.118
0.607/−0.355
(all data)
Largest difference peak
0.320/−0.257
−3
,
and hole (e A
)
tyl-1H-pyrazol-3-yl) (10) [20] was prepared by the se-
quential reaction of 2,2-dimethylbutan-3-one with ex-
cess potassium-tert-butoxide and ethyl pyridine-2-
carboxylate, condensation with hydrazine, then alkyla-
tion with methyl iodide. All organic chemicals were
purchased from Lancaster while metal salts were pur-
chased from Aldrich. Hydrothermal reactions were per-
formed using previously described equipment [1].
Infra-red spectra and thermal gravimetric analyses were
performed using previously described equipment [1].
618m and 476w (cm−1); lH (250 MHz; CDCl3) 8.62 m
(1H), 7.89 m (1H), 7.64 m (1H), 7.39 m (1H), 7.14 m
(1H), 3.85 s (3H). lC (62.9 MHz; CDCl3) 150.9, 149.6,
147.6, 136.3, 132.4, 122.7, 122.1 92.0 and 39.7; MS
(EI+) 237, 239; (CI+) 240, 238, 160; (ES+) molecu-
lar ion observed at 237.9973 amu (12C91H914N379Br re-
quires 237.9980).
6.2. Pyridine-2-(1-methyl-4-nitro-1H-pyrazol-3-yl) (8)
Compound 6 (1.7 g, 10.7 mmol) was added to a
mixture of water (2 ml) and sulphuric acid (9 ml) and
cooled to below 5°C. A mixture of nitric (6 ml) and
sulfuric (5 ml) acids was added dropwise maintaining
the temperature below 5°C. The mixture was heated
over 1 h at 90°C. After maintaining at this temperature
for 4 h the mixture was poured onto ice. The ice was
allowed to melt before the mixture was made alkaline
with sodium hydroxide. A white solid formed. The
mixture was extracted with CH2Cl2, dried with sodium
sulphate, filtered and evaporated to yield a white solid
(2.13 g, 98%). Anal. Found: C, 51.9; H, 3.7; N, 27.1.
C9H8N4O2 requires C, 52.9; H, 4.0; N, 27.4%. IR (KBr)
1638s, 1617s, 1540m, 1513w, 1492s, 1440w, 1428w,
1384w, 1369w, 1349s, 1340s, 1241w, 1220m, 1145w,
1100m, 1060w, 1037w, 988w, 843m, 833s, 795s, 759s,
624m and 607m (cm−1); lH (250 MHz; CDCl3) 8.71
(1H), 8.23 s (1H), 7.78 m (2H) and 7.34 m (1H); lC
(62.9 MHz; CDCl3) 149.8, 149.0, 146.5, 136.3, 131.5,
6.1. Pyridine-2-(1-methyl-4-bromo-1H-pyrazol-3-yl)
(7) [18,19]
Pyridine-2-(1-methyl-1H-pyrazol-3-yl) 6 was added
to 20% acetic acid (50 ml) followed by the dropwise
addition of bromine (0.5 ml, 1.5 g) in acetic acid (10 ml)
over 5 min to form a pale yellow solution. After stirring
for 20 min the mixture was cooled in an ice bath and
sodium hydroxide (15.0 g) in water (50 ml) was added
slowly keeping the temperature below 12°C. The pH
was now 13. The mixture was extracted with CH2Cl2,
dried with sodium sulphate, filtered and evaporated to
give compound 7 in quantitative yield. Anal. Found: C,
45.2; H, 3.3; N, 17.5. C9H8N3Br requires C, 45.4; H,
3.4; N, 17.7%. IR (neat) 1637s, 1620s, 1592m, 1568w,
1543w, 1500w, 1474w, 1452w, 1420sh, 1401w, 1385w,
1342w, 1308w, 1274w, 1247w, 1202m, 1151w, 1094w,
1052w, 1013w, 1000w, 982w, 793m, 743w, 699w, 688w,

172
M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
125.0, 124.0 and 40.3; MS (EI+) 204 (M+), 174, 105;
(CI+) 175 (MH+); (ES+) molecular ion found at
205.0732 amu (12C91H914N416O2 requires 205.0725).
1638w, 1619w, 1597s, 1592s, 1567m, 1541m, 1494s,
1466s, 1413m, 1392w, 1379m, 1366m, 1361m, 1282m,
1271w, 1253m, 1218s, 1206sh, 1186w, 1151w, 1111w,
1096w, 1047w, 1033w, 1024w, 993m, 969w, 930w, 899w,
793s, 746m, 686m, 624w, 588w, 566w, 519w and 403m
(cm−1); lH(250 MHz; CDCl3) 8.56 m (1H), 7.86 m
(1m), 7.64 m (1H), 7.11 m (1H), 6.45 s (1H), 4.00 s (3H)
and 1.38 s (9H); lC (62.9 MHz; CDCl3) 152.8, 152.5,
149.3, 136.5, 122.1, 119.7, 102.3, 39.7, 31.3 and 29.6;
1H–1H COSY cross peaks seen at 8.56 (7.11), 8.56
(7.64) weak, 7.86 (7.64), 7.86(7.11) weak, 7.64 (7.11);
1H–13C HMQC cross peaks seen at 7.86(1525),
7.86(119.7), 7.64(136.5), 7.11(122.1) and 6.45(102.3);
MS (EI+) 216, 215, 201, 200; (CI+) 217, 216; (ES+)
6.3. Pyridine-2-(1-methyl-5-trifluoromethyl-1H-
pyrazol-3-yl) (9)
Pyridine-2-(5-trifluoromethyl-1H-pyrazol-3-yl) (1.28
g, 6.0 mmol) was placed in a 250 ml flask with benzene
(80 ml). Any trace of water was removed under
Dean–Stark conditions before the benzene was
removed in vacuum. THF (40 ml) was added followed
by sodium hydride (60% oil dispersion 1.3 g, 33 mmol).
After the production of hydrogen gas stopped, methyl
iodide (0.4 ml, 6.4 mmol) was added. After allowing the
mixture to stand for 48 h, water (2 ml) was added.
After a further 4 days all solvent was removed in vacuo.
Water (20 ml) and concentrated hydrochloric acid (5
ml) was added. The aqueous mixture was washed with
CH2Cl2 (2×10 ml) before excess sodium hydroxide was
added. The aqueous mixture was now extracted with
CH2Cl2 (5×10 ml). The organic extract was now dried
with Na2SO4, filtered and evaporated to give a brown
oil (774 mg, 57%) which was used without further
purification. lH (250 MHz; CDCl3) 8.58 m (1H), 7.86 m
(1H), 7.69 m (1H), 7.20 m (2H), 4.01 s (3H); MS (EI+)
227; (CI+) 228, 214, 174; (ES+) molecular ion
observed at 228.0743 amu (12C110H914N319F3 requires
228.0748).
molecular ion observed at 216.1504 amu (12C113H N3
14
18
requires 216.1500).
6.5. Pyridine-2-(1-methyl-4-nitro-5-tert-butyl-1H-
pyrazol-3-yl) (11)
A solution of 10 (2.20 g, 10.23 mmol) in 80% sulfuric
acid (10 ml) was treated with a mixture of 69% nitric
acid (5 ml) and 99% sulfuric acid (5 ml) at 0°C. After
25 min the mixture was heated up to 82°C. After 4.5 h
at approximately 90°C the reaction mixture was poured
onto iced water (300 ml). The reaction flask was washed
out with water (50 ml) and the washings were added to
the iced water. After allowing to stand overnight at
room temperature the pH was adjusted to 14 with
sodium hydroxide. After cooling the mixture was ex-
tracted with CH2Cl2 (5×50 ml). After drying over
MgSO4 and filtering the dichloromethane extract was
concentrated in vacuo to give compound 11 as an off
white solid (2.45 g, 92%). Anal. Found: C, 59.8; H, 6.1;
N, 21.3. C13H16N4O2 requires C, 60.0; H, 6.2; N, 21.5%.
lH (250 MHz; CDCl3) 8.54 m (1H), 7.78 m (1H), 7.77
m (1H), 7.69 m (1H), 7.20 m (1H), 4.05 s (3H) and 1.47
(9H); lC (62.9 MHz; CDCl3) 149.7, 149.6, 143.6, 141.2,
136.5, 123.2, 120.7, 41.6, 33.1 and 28.6; MS (EI+) 260,
245, 230, 215, 198, 188, 187; (CI+) 261, 231; (ES+)
6.4. Pyridine-2-(1-methyl-5-tert-butyl-1H-pyrazol-3-yl)
(10)
Pyridine-2-(5-tert-butyl-1H-pyrazol-3-yl) [20] (20 g,
0.099 mmol) was added to a suspension of sodium
hydride (60% in mineral oil 6.33 g, 99.4 mmol) in THF
(500 ml) followed by the addition of pyridine. The
mixture was cooled in an ice bath before the addition of
methyl iodide (6.2 ml). After stirring for 30 min the
mixture was allowed to stand overnight before the
addition of water (20 ml). The THF was removed in
vacuo before the addition of water (80 ml), concen-
trated hydrochloric acid (25 ml) and CH2Cl2 (100 ml).
The mixture was shaken, and the solid which formed
was collected by filtration, and washed with CH2Cl2 (25
ml). The aqueous layer was separated and washed twice
with CH2Cl2 (2×50 ml). The organic extract was dis-
carded. The solid and water (100 ml) was added to the
aqueous layer followed by the addition of excess
sodium hydroxide. After allowing the mixture to cool
the aqueous layer was extracted with CH2Cl2 (4×50
ml). The organic extract was dried with sodium sul-
phate before being concentrated down to an oil which
solidified on standing (11.7 g, 55%). Anal. Found: C,
72.7; H, 8.2; N, 18.9. C13H17N3 requires 72.5; H, 8.0; N,
19.5%. IR 3068w, 3017w, 2963s, 2943m, 2908m, 2871w,
molecular
17
ion
observed
at
261.1352
amu
(12C113H N146O2 requires 261.1351).
14
6.6. [Co(C9H4O6)(C12H8N2)(H2O)] (12)
H3BTC (52 mg, 0.248 mmol), cobalt acetate (62 mg,
0.249 mmol) and phenanthroline (46 mg, 0.255 mmol)
were placed in a bomb with water (10 ml). The resulting
mixture was heated at 100°C h−1 to 230°C. After 2 h
the bomb was cooled to 180°C at 5°C h−1, after 6 h the
bomb was cooled at 4°C h−1 to room temperature. The
solid was collected by filtration then washed with water
and dried in air (98 mg, 85%). Anal. Found: C, 53.6; H,
2.6; N, 5.8. [Co(C9H4O6)(C12H8N2)(H2O)] requires C,
56.4; H, 2.7; N, 6.3%. IR (KBr) 3413br, 3294s, 1698m,
1631s, 1570sh, 1550m, 1523w, 1499w, 1481w, 1459w,

M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
173
1430m, 1413sh, 1371m, 1343w, 1319w, 1245w, 1230m,
1214w, 1176m, 11446w, 1103w, 1074w, 1054w, 1030w,
1007w, 883w, 869w, 847m, 799w, 762m, 728w, 715w,
699w, 673m and 618w (cm−1).
collected, washed with water and air-dried. Anal.
Found: C, 42.0; H, 2.7; N, 7.8. [Mn(C9H4O6)-
(C9H8N3Br)(H2O)] requires C, 41.6; H, 2.7; N, 8.1%).
IR (KBr) 1698s, 1615s, 1582m, 1558m, 1546sh, 1520w,
1476w, 1434m, 1408w, 1373s, 1331s, 1317sh, 1289w,
1236m, 1204w, 1182m, 1157sh, 1099m, 1061w, 1035w,
989w, 880m br, 801m, 791m, 760m, 689m and 668m
(cm−1); TGA: Above 220°C decomposition occurred.
6.7. [Mn3(C9H3O6)2(C12H8N2)3] (13)
H3BTC (105.6 mg, 0.503 mmol), manganese acetate
(187 mg, 0.764 mmol), phenanthroline (138 mg, 1.15
mmol), sodium acetate trihydrate (200 mg, 1.47 mmol)
and water (20 ml) were placed in a 45 ml bomb. After
sealing this was heated at 100°C h−1 to 240°C. After 2
h the bomb was cooled at 5°C h−1 to 180°C. After a
further 6 h the bomb was cooled at 4°C h−1 to 20°C.
The yellow solid (215 mg, 76%) was collected by filtra-
tion, washed with water and dried in air. Anal. Found:
C, 56.6; H, 2.5; N, 6.2. [Mn3(C9H3O6)2(C12H8N2)3] re-
quires C, 57.9; H, 2.7; N, 7.5%. IR (KBr) 1655s, 1638s,
1618s, 1590w, 1561m, 1515w, 1497w, 1447m, 1429w,
1410w, 1385m, 1343w, 1102w, 968w, 928w, 903w, 865w,
842m, 766m, 749w, 725m, 714m, 688w, 669w and 635w
cm−1. TGA: Between 240 and 350°C a mass loss of 8%
occurred.
6.10. [Zn3(C9H3O6)2(C9H9N3)3(H2O)3]·4H2O (16)
H3BTC (104 mg, 0.495 mmol), zinc acetate (165 mg,
0.752), compound 6 (120 mg, 0.754) and sodium acetate
trihydrate (130 mg, 0.955 mmol) were placed in a bomb
with water (10 ml). The resulting mixture was heated at
100°C h−1 to 230°C. After 2 h the bomb was cooled to
180°C at 5°C h−1 then after 6 h the bomb was cooled
at 4°C h−1 to room temperature. The pH of the mother
liquor was 4.6 and the solid was collected by filtration.
The product (265 mg, 50%) was washed with water and
dried in air. Anal. Found: C, 44.3; H, 3.7; N, 9.5.
[Zn3(C9H3O6)2(C9H9N3)3(H2O)3]. 4H2O requires C,
44.5; H, 3.8; N, 10.4%. IR (KBr) 3477s br, 1632sh,
1616s, 1569m, 1508w, 1439s, 1409w, 1356br, 1291w,
1245m, 1159w, 1124w, 1101w, 1079w, 1055w, 1019w,
780m, 768m, 731m, 693w, 669w, 640w, 619w, 587w,
570w, 551w, 496w, 477w and 411w (cm−1); TGA: an
endothermic mass loss of 9.5% occurs between room
temperature and 170°C (for the dehydration of the
heptahydrate a mass loss of 10.3% is required).
6.8. [Mn(C9H4O6)(C9H9N3)(H2O)] (14)
H3BTC (101 mg, 0.481 mmol), manganese(II) acetate
tetrahydrate (119 mg, 0.489 mmol), compound 6 (77
mg, 0.484 mmol) and water (10 ml) were placed in a 45
ml Parr bomb. The resulting mixture was heated at
100°C h−1 to 240°C. After 2 h the bomb was cooled to
180°C at 5°C h−1, after 6 h the bomb was cooled at
4°C h−1 to room temperature. The bomb was opened
and the nearly colourless product (155 mg, 73%) was
collected by filtration before being washed with water
and air-dried. Anal. Found: C, 48.4; H, 3.2; N 9.3.
[Mn(C9H4O6)(C9H9N3)(H2O)] requires C, 49.1; H, 3.4;
N 9.5%. IR (KBr) 3553sh, 3465sh, 3238m, 3416br s,
2922m, 2853w, 1742w, 1701s, 1677w, 1637s, 1617vs,
1571m, 1561m, 1550sh, 1524w, 1509w, 1501w, 1438m,
1409w, 1383w, 1367m, 1339m, 1321sh, 1293w, 1243w,
1227m, 1173m, 1160w, 1140sh, 1101w, 1077w, 1017w,
961w, 945w, 882w, 803w, 776w, 761m, 672s, 658w,
641w, 627w, 614w, 599w, 584w, 554w, 538w, 527w,
509w, 494w, 479w, 465w and 410w (cm−1); TGA:
Above 220°C decomposition occurred.
6.11. [Zn(C9H4O6)(C9H9N3)(H2O)] (17)
H3BTC (106 mg, 0.505 mmol), zinc acetate (112 mg,
0.510 mmol), compound 6 (120 mg, 0.754 mmol), acetic
acid (0.1 ml) and water (9.9 ml) were placed in a bomb.
The resulting mixture was heated at 100°C h−1 to
230°C. After 2 h the bomb was cooled to 180°C at 5°C
h−1 then after 6 h the bomb was cooled at 4°C h−1 to
room temperature. The pH of the mother liquor was
3.4 and the solid (135 mg, 59%) was collected by
filtration. Anal. Found: C, 48.1; H, 3.2; N, 8.4.
[Zn(C9H4O6)(C9H9N3)(H2O)] requires C, 48.0; H, 3.3;
N, 9.3%. IR (KBr) 3450br, 1710m, 1619s, 1579m,
1559sh, 1508w, 1441s, 1369s, 1332sh, 1245m, 1187w,
1159w, 1099w, 1085w, 1053w, 1024w, 1004w, 964w,
935w, 909w, 878w, 784m, 768w, 754m, 724w, 694m,
678m, 646w, 639w, 620w, 593w, 578w, 554w and 416w
(cm−1).
6.9. [Mn(C9H4O6)(C9H8N3Br)(H2O)] (15)
H3BTC (95 mg, 0.452 mmol), manganese acetate (111
mg, 0.453 mmol) and compound 7 (108 mg, 0.451
mmol) were placed in a bomb with water (10 ml). The
resulting mixture was heated at 100°C h−1 to 240°C.
After 2 h the bomb was cooled to 180°C at 5°C h−1
then after 6 h the bomb was cooled at 4°C h−1 to room
temperature. The brown crystals (168 mg, 72%) were
6.12. [Zn(C9H5O6)2(C9H9N3)] (18)
H3BTC (104 mg, 0.495 mmol), zinc acetate (104 mg,
0.474), compound 6 (109 mg, 0.685 mmol), acetic acid
(1.0 ml) and water (9.0 ml) were placed in a bomb. The
resulting mixture was heated at 100°C h−1 to 230°C.

174
M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
After 2 h the bomb was cooled to 180°C at 5°C h−1
then after 6 h the bomb was cooled at 4°C h−1 to room
temperature. The pH of the mother liquor was 3.1 and
the solid (190 mg, 60%) was collected by filtration.
Anal. Found: C, 50.4; H, 3.0; N, 6.4. [Zn(C9H5O6)2-
(C9H9N3)] requires C. 50.5; H, 3.0; N, 6.5%. IR (KBr)
3460br, 3117m, 1719s, 1698s, 1655w, 1637sh, 1618s,
1577m, 1563sh, 1544sh, 1509w, 1442m, 1430sh, 1383w,
1362w, 1336w, 1323w, 1288m, 1258w, 1243w, 1213m,
1173w, 1160sh, 1114w, 1100w, 1056w, 1027w, 965w,
936w, 912w, 846w, 799w, 774m, 745m, 705w, 692w,
675m, 649w, 618w, 557w, 444w and 417w (cm−1).
After sealing the bomb was heated at 100°C h−1 to
230°C. After 2 h the bomb was cooled at 5°C h−1 to
180°C then after a further 6 h the bomb was cooled at
4°C h−1 to 20°C. The solid (52 mg, 47%) was collected
by filtration, washed with water and dried in air. Anal.
Found: C, 44.3; H, 2.9; N, 7.7. [Zn2(C9H4O6)2-
(C10H9N3F3)2]·2H2O requires C, 43.9; H, 2.9; N, 8.1%.
IR (KBr) 3553sh, 3463sh, 3412br, 3296m, 3238sh,
3133m, 3097m, 1707sh, 1697s, 1635s, 1561s, 1439s,
1386sh, 1372s, 1332sh, 1278s, 1219m, 1180s, 1161m,
1131s, 1102w, 1062s, 1024w, 976w, 935w, 915w, 858w,
843w, 796m, 755s, 730m, 697m, 646w, 621w, 605w,
575w, 541w, 521w, 459w and 414w (cm−1); TGA: an
endothermic mass loss of 3.4% occurs between 60 and
180°C (Dehydration of the tetrahydrate would require
a mass loss of 3.5%. Above 280°C decomposition
occurred.
6.13. [Zn(C9H4O6)(C9H8N3Br)(H2O)] (19)
H3BTC (116 mg, 0.552 mmol), zinc acetate dihydrate
(122 mg, 0.556 mmol), compound 7 (140 mg, 0.587)
and water (10 ml) were placed in a bomb. After sealing
this bomb was heated to 220°C. After 2 h the bomb
was cooled at 5°C h−1 to 180°C then after 6 h the
bomb was cooled at 5°C h−1 to 20°C. The colourless
solid (229 mg, 78%) was collected by filtration, washed
with water and air dried. Anal. Found: C, 41.6; H, 2.4;
N, 7.9. [Zn(C9H4O6)(C9H8N3Br)(H2O)] requires C,
41.5; H, 2.5; N, 8.1%. IR (KBr) 3418br, 3099m, 1708s,
1625s, 1580s, 1520sh, 1510w, 1439s, 1375sh, 1354s,
1323w, 1251s, 1232w, 1209w, 1188m, 1158w, 1099m,
1051w, 990m, 947w, 934w, 881m, 863w, 788m, 755m,
723m, 680s, 638w, 623w, 558w and 419w (cm−1).
6.16. [Zn(C9H4O6)(C13H17N3)(H2O)]·H2O (22)
H3BTC (52 mg, 0.248 mmol), zinc acetate (54 mg,
0.246 mmol), compound 10 (53 mg, 0.246 mmol) and
water (10 ml) were placed in a 23 ml bomb. After
sealing this was heated at 100°C h−1 to 220°C. After 2
h the bomb was cooled at 5°C h−1 to 180°C then after
a further 6 h the bomb was cooled at 4°C h−1 to 20°C.
The white solid (110 mg, 85%) was collected by filtra-
tion, washed with water and dried in air. Anal. Found:
C, 49.5; H, 4.5; N, 7.6. [Zn(C9H4O6)(C13H17N3)(H2O)]·
H2O requires C, 50.4; H, 4.8; N, 8.0%. IR (KBr)
3553m, 3413br, 1708, 1655w, 1637m, 1617s, 1575sh,
1561m, 1507w, 1475w, 1457w, 1436m, 1376m, 1366m,
1316w, 1291w, 1250m, 1231m, 1181w, 1156w, 1111w,
1054w, 1021w, 1005w, 980w, 964w, 955w, 939w, 902w,
885w, 854w, 838w, 788w, 760w, 732w, 689w and 670w
(cm−1).
6.14. [Zn(C9H4O6)(C9H8N4O2)(H2O)] (20)
H3BTC (98 mg,), zinc acetate dihydrate (103 mg,
0.468 mmol), compound 8 (95 mg, 0.463 mmol) and
water (10 ml) were placed in a 23 ml bomb. After
sealing the bomb was heated to 220°C. After 2 h the
bomb was cooled at 5°C h−1 to 180°C then after 6 h
the bomb was cooled at 5°C h−1 to 20°C. The colour-
less solid (179 mg, 78%) was collected by filtration,
washed with water and air dried. Anal. Found: C, 43.4;
H, 2.5; N, 10.7. [Zn(C9H4O6)(C9H8N4O2)(H2O)] re-
quires C, 43.6; H, 2.9; N, 11.3%. IR (KBr) 1697s,
1625s, 1580m, 1541m, 1529sh, 1503m, 1444s, 1411w,
1372sh, 1348vs, 1248s, 1232m, 1187m, 1162w, 1099m,
1068w, 1053w, 1033w, 961w, 946w, 882m, 836m, 794m,
755m, 740sh, 720m and 680 cm−1; TGA: a mass loss of
4.0% occurs between 140 and 220°C (For the dehydra-
tion of the monohydrate a mass loss of 3.6% is re-
quired). Above 250°C decomposition occurred.
6.17. [Co(C9H4O6)(C13H17N3)(H2O)]·H2O (23)
H3BTC (50 mg, 0.238 mmol), cobalt acetate (60 mg,
0.241 mmol), compound 10 (51 mg, 0.237 mmol) and
water (10 ml) were placed in a 23 ml bomb. After
sealing this was heated at 100°C h−1 to 220°C. After 2
h the bomb was cooled at 5°C h−1 to 180°C then after
a further 6 h the bomb was cooled at 4°C h−1 to 20°C.
A pink solid (101 mg, 82%) was collected by filtration,
washed with water and dried in air. Anal. Found: C,
50.5; H, 4.7; N, 7.5. [Co(C9H4O6)(C13H17N3)(H2O)]·
H2O requires C, 51.0; H, 4.9; N, 8.1%. IR (KBr) 3549s,
3478br, 3420br, 3131m, 3073w, 2969m, 1709m, 1686w,
1655w, 1637w, 1613s, 1561m, 1553m, 1501w, 1459m,
1436m, 1384m, 1365m, 1311w, 1289w, 1250m, 1231m,
1181m, 1156w, 1112w, 1102w, 1069w, 1054w, 1019w,
1001w, 980w, 962w, 939w, 898w, 848w, 809w, 787m,
760m, 730m, 690w and 669m (cm−1).
6.15. [Zn2(C9H4O6)2(C10H8N3F3)2]·2H2O (21)
H3BTC (45.3 mg, 0.216 mmol), zinc acetate dihydrate
(47.3 mg, 0.215 mmol), compound 9 (49 mg, 0.216
mmol) and water (10 ml) were placed in a 23 ml bomb.

M.J. Plater et al. / Inorganica Chimica Acta 319 (2001) 159–175
175
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Inorg. Chem. Commun. 3 (2000) 234.
6.18. [Co(C9H4O6)(C13H17N4O2)(H2O)] (24)
[3] O.M. Yaghi, H. Li, T.L. Groy, J. Am. Chem. Soc. 118 (1996)
9096.
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1915.
H3BTC (54 mg, 0.257 mmol), cobalt acetate (64.4
mg, 0.259 mmol), compound 11 (67 mg, mmol) and
water (10 ml) were placed in a 23 ml bomb. After
sealing this was heated at 100°C h−1 to 220°C. After 2
h the bomb was cooled at 5°C h−1 to 180°C then after
a further 6 h the bomb was cooled at 4°C h−1 to 20°C.
The red solid (115 mg, 81%) was collected by filtration,
washed with water and dried in air. The solid formed is
a mixture of red crystals and a fine red solid Anal.
Found: C, 48.65; H, 3.91; N, 10.29. [Co(C9H4O6)-
(C13H17N4O2)(H2O)] requires C, 48.4; H, 4.2; N,
10.3%); Red crystals: IR (KBr) 3430s, 3017br, 1695s,
1633sh, 1610m, 1578m, 1571m, 1542w, 1524m, 1474w,
1465w, 1442m, 1399w, 1374s, 1335s, 1320sh, 1293w,
1237m, 1183m, 1158w, 1103m, 1066w, 1051w, 1029w,
1017w, 953w, 941w, 881m, 860w, 839m, 817w, 793m,
760m, 696w, 669m, 644w and 613w (cm−1); Fine red
solid IR (KBr) 3010w, 2971s, 2932w, 2922w, 2892w,
1638w, 1619w, 1594m, 1572w, 1541s, 1524s, 1511sh,
1468s, 1427m, 1397w, 1367s, 1288m, 1272w, 1250m,
1213s, 1156w, 1101w, 1058w, 1044w, 1017m, 992w,
970w, 936w, 902w, 862m, 836m, 801s, 753m, 725w,
692m, 679m, 623w, 600w, 543w, 463w and 409w
(cm−1).
[9] Bruker, SMART, SAINT and SADABS, Bruker AXS Inc., Madison,
WI, 1999.
[10] G.M. Sheldrick, Acta Crystallogr., Sect. A 46 (1990) 467.
[11] A.M. Duisenberg, J. Appl. Crystallogr. 25 (1992) 92.
[12] R. Hooft, B.V. Nonius, COLLECT: data collection software,
1998.
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