Suja, Krishnan; Dr.Prathapachandra Kurup,M R(Cochin University of Science and Technology, June , 2008)
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Abstract:
Coordination chemistry of pentadentate 2,6-diacetylpyridine
bis(thiosemicarbazone) Schiff base ligands has been intensively studied due to the versatility of the molecular chain in order to obtain very different
geometries as well as their broad therapeutic activity. Metal complexes of
thiosemicarbazone with aldehydes and ketones have been widely reported.
But there have been fewer reports on potential pentadentate
bis(thiosemicarbazones) formed from 2,6-diacetylpyridine. Keeping these in
view, we have synthesized four bis(thiosemicarbazone) systems with
2,6-diacetylpyridine. In the present work, the chelating behavior of
bis(thiosemicarbazones) are studied, with the aim of investigating the
influence of coordination exerts on their conformation and or configuration, in
connection with the nature of the metal and of the counter ion. The selection
of the 2,6-diacetylpyridine as the ketonic part was based on its capability to
form polynuclear complexes with different coordination number. The doubled
armed bis(thiosemicarbazones) can coordinate to a metal centre as dianionic
ligand by losing its amide protons or it can coordinate as monoanionic ligand
by losing its amide proton from one of the thiosemicarbazone moiety or it can
also be coordinate as neutral ligand. Hence it is interesting to explore the
coordinating capabilities of these ligands whether in neutral form or anionic
form and to study the structural variations occurring in the ligands during
complexation such as change in conformation.
Description:
Department of Applied Chemistry,
Cochin university of Science and Technology
Laly, K; Dr.Prathapachandra Kurup,M R(Cochin University of Science and Technology, July , 2011)
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Abstract:
In the present work,the chelating behaviour of thiosemicarbazones of a heterocyclic diketone, 2,6-diacetylpyridine is studied,with the aim of investigating the influence coordination exerts on their conformation and /or configuration, in connection with the nature of the metal and of the counter ion.The various possibilities like unsubstitution,ring incorporation at terminal nitrogen and condensation of one of the ketone group alone have been tried for ligand selection.Mainly first row transition metals like manganese,iron,nickel,copper,zinc and cadmium are studied.Metals like cobalt also were studied but could not result in fruitful isolation of the compound due to solubility problems.Different spectroscopic and characterization techniques have been utilized to reveal the nature of the metal and the ligands in coordinated metal complex.
Description:
Department of Applied Chemistry,Cochin University of Science and Technology