Self-assembled Transition Metal Coordination Frameworks of ...

Chapter I _ ,_
of mono or dinuclear dioxomolybdenum [51,53]. tin [54] and niobium [55] complexes
of different thiocarbohydrazones are reported. Similarly, oxovanadium(IV) [56].
La(Ill) and Pr(lll) [57] complexes of some carbohydrazones and other complexes of
related substituted carbohydrazides [58.59] are reported. Also, many reports of
substituted carbohydrazides and thiocarbohydrazides are in patent literature [60-64].
The (thio)carbohydrazones are next higher homologue of
(thio)semicarbazones with a possible extra metal binding domain. Their coordination
chemistry towards transition metal ions are found least studied compared to lower
homologues. Reports of some interesting compounds of suitably substituted
thiocarbohydrazones in the last decade [28-31, 65-68] provided a new dimension to
the chemistry of thiocarbohydrazones and carbohydrazones, and is mainly behind our
interest. We designed some flexible ligands. suitably substituted carbohydrazones and
thiocarbohydrazones, mainly having two potential coordination pockets (ditopic).
Coordination frameworks of these ligands towards selected metal ions and their
important features are the subjects of our study.
1.3.1. Applications of carbohydrazones and thiocarbohydrazones
Carbohydrazones and thiocarbohydrazones are an important class of
compounds and has been achieved the attention of various fields of biology and
different branches of chemistry. The attention of applications of carbohydrazones and
thiocarbohydrazones were arrived, ever since their discovery, as an extension of the
application studies of their precursors carbohydrazide and thiocarbohydrazide. In
short, carbohydrazide and thiocarbohydrazide are found useful in biochemical [69],
pharmacological and related properties like convulsant, anticarcinogenic,
antibacterial, fungicidel, etc [36]. Carbohydrazide and thiocarbohydrazide are used for
the formation of industrially important various polymers, in photography, and for
various miscellaneous uses [36]. Carbohydrazones and thiocarbohydrazones have also
been reported with most of these applications [36]. They have been found a variety of
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