Self-assembled Transition Metal Coordination Frameworks of ...

_g C0pper(II) complexes
complex of bis(pyridine-2-aldehyde) thiocarbohydrazone, along with its crystal
structure. The dinuclear symmetric dicopper(ll) complex of bis(phenyl(2­
pyridyl)methanone) thiocarbohydrazone (HZLZ) [16] describes the X-ray structure and
lacks EPR and magnetic studies. For carbohydrazones, similarly, there is only single
report [l7] of magnetic and EPR features discussed along with its dinuclear X-ray
crystal structure. The EPR characteristic of this complex is described with only a
powder spectrum broad single g value and magnetochemistry is confirmed with
antiferromagnetic coupling between Cu(H) electrons. Therefore, an investigation
including temperature dependence of magnetic susceptibility and EPR characteristics
appeared interesting, which prompted this study and is the initial step towards this
spectrum of wide scope.
4.2. Experimental
4.2.1. Materials
Cu(OAc)2- H20 (Qualigens), CuSO4- SHZO (Merck), CuBr2 (Merck), CuCl2­
ZHZO (Merck), Cu(ClO4)2- 6H2O (Aldrich), NaN3 (Reidel-De Haen) were used as
received and solvents methanol (Rankem), chloroform (S.D. Fine), DMF (S.iD. Fine),
etc were used as received.
Caution! Perchlorate and azide complexes of metals with organic ligands are
potentially explosive and should be handled with care.
4.2.2. Synthesis of copper(II) complexes
[cu3(HL’)L’cz.]- 3H;O (8)
To a hot methanolic solution of I~I2L' (0.330 g, 0.75 mmol) was added an
equimolar amount of CuCl2- 2H;O (0.132 g) dissolved in l0 ml hot methanol. The
brown colored mixture was refluxed for 10 minutes and allowed to stand at room
temperature to get brown solid product. The compound precipitated was filtered,
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