Self-assembled Transition Metal Coordination Frameworks of ...

,____ p _p C0pper(H) complexes
from 10 pM to 100 t1M. The above complexes attain a LD50 at a higher concentration,
which was found to be above 100 uM. But complexes such as 11, 15 and 18 not
showed a promising anti cancer effect. This makes us to suggest 13, 16 and 17 as
superior anticancer gadgets against breast cancer.
4.5. Concluding remarks
This chapter presents syntheses and physico-chemical characterizations of
twelve novel di/polynuclear Cu(ll) coordination compounds. Nine of these complexes
are assigned as dicopper(II) complexes of carbohydrazones or thiocarbohydrazones,
two are assigned as trinuclear while one is assigned as a tetranuclear complex of
copper(II). All the Cu(ll) complexes were organized by mono or dideprotonated
carbohydrazone or thiocarbohydrazone ligands under neutral reaction conditions. The
Cu(ll) compounds are found very reluctant to form molecular grids by self-assembly
with present series of carbohydrazone and thiocarbohydrazone ligands possessing
mainly two coordination pockets, consistent with their reluctance to take up a regular
octahedral geometry. The structures of the complexes were assigned tentatively, in the
absence of single crystal X-ray studies, and are consistent with other spectral and
magnetic studies.
In the literature survey, it is found that coordination studies of
carbohydrazone and thiocarbohydrazone are more with copper compared to other
transition metals. The EPR and magnetic features of all copper complexes are
discussed. The spectra are generally found to exhibit two uncoupled Cu(ll) species in
DMF solutions recorded at 77 K. Spectral simulations of all these species, under the
investigation conditions, are obtained well and the EPR parameters are reported.
Variable temperature magnetic studies of all the Cu(ll) complexes are found to exhibit
strong antiferromagnetic coupling between metal centers. It is found that EPR solution
behaviour of most of the Cu(ll) complexes contradicts with the solid powder form
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