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The synthesis and characterisation of coordination and hydrogen-bonded networks based on 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoic acidElectronic supplementary information (ESI) available: Synthetic details for the preparation of H2L. PXRD patterns of 1-6, 8. Further TG-DTA traces for H2L, 1-6, 8. Infrared spectra of 1, 1-desolv, 2, 4, 5, 6-dry, and air- and TGA-dried 8. CCDC 1040598-1040606. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/C5DT00011D
The synthesis, structural and thermal characterisation of a number of coordination complexes featuring the N , O -heteroditopic ligand 4-(3,5-dimethyl-1 H -pyrazol-4-yl)benzoate, H L are reported. The reaction of H 2 L with cobalt( ii ) and nickel( ii ) nitrates at room temperature in basic DMF/H 2...
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| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Online Access: | Get full text |
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| Summary: | The synthesis, structural and thermal characterisation of a number of coordination complexes featuring the
N
,
O
-heteroditopic ligand 4-(3,5-dimethyl-1
H
-pyrazol-4-yl)benzoate, H
L
are reported. The reaction of H
2
L
with cobalt(
ii
) and nickel(
ii
) nitrates at room temperature in basic DMF/H
2
O solution gave discrete mononuclear coordination complexes with the general formula {[M(H
L
)
2
(H
2
O)
4
]·2DMF} (M = Co (
1
), Ni (
2
)), whereas the reaction with zinc(
ii
) nitrate gave [Zn(H
L
)
2
]
∞
,
3
, a coordination polymer with distorted diamondoid topology and fourfold interpenetration. Coordination about the tetrahedral Zn(
ii
) nodes in
3
are furnished by two pyrazolyl nitrogen atoms and two carboxylate oxygen atoms to give a mixed N
2
O
2
donor set. Isotopological coordination polymers of zinc(
ii
), {[Zn(H
L
)
2
]·2CH
3
OH·H
2
O}
∞
,
4
, and cobalt(
ii
), [Co(H
L
)
2
]
∞
,
5
, are formed when the reactions are carried out under solvothermal conditions in methanol (80 °C) and water (180 °C), respectively. The reaction of H
2
L
with cadmium(
ii
) nitrate at room temperature in methanol gives {[Cd(H
L
)
2
(MeOH)
2
]·1.8MeOH}
∞
6
, a 2-D (4,4)-connected coordination polymer, whereas with copper(
ii
) the formation of green crystals that transform into purple crystals is observed. The metastable green phase [Cu
3
(H
L
)
4
(μ
2
-SO
4
)(H
2
O)
3
]
∞
,
7
, crystallises with conserved binding domains of the heteroditopic ligand and contains two different metal nodes: a dicopper carboxylate paddle wheel motif, and, a dicopper unit bridged by sulfate ions and coordinated by ligand pyrazolyl nitrogen atoms. The resultant purple phase {[Cu(H
L
)
2
]·4CH
3
OH·H
2
O}
∞
,
8
, however, has single copper ion nodes coordinated by mixed N
2
O
2
donor sets with
trans
-square planar geometry and is threefold interpenetrated. The desolvation of
8
was followed by powder X-ray diffraction and single crystal X-ray diffraction which show desolvation induces the transition to a more closely packed structure while the coordination geometry about the copper ions and the network topology is retained. Powder X-ray diffraction and microanalysis were used to characterise the bulk purity of the coordination materials
1-6
and
8
. The thermal characteristics of
1-2
,
4-6
and
8
were studied by TG-DTA. This led to the curious observation of small exothermic events in networks
4
,
6
, and
8
that appear to be linked to their decomposition. In addition, the solid state structures of H |
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| ISSN: | 1477-9226 1477-9234 |
| DOI: | 10.1039/c5dt00011d |