Self-assembled Transition Metal Coordination Frameworks of ...

Chapter I _,
assemblies to generate sufficient ion abundance without fragmentation. Also, the
assignments of square structures based on mass signals need caution, since triangle or
unspecific aggregates may generate during ionization processes [32]. So several
complimentary analysis methods are necessary for the unequivocal characterization of
these assemblies.
1.3. A preface on carbohydrazones and thiocarbohydrazones
Carbohydrazones and thiocarbohydrazones are condensation products of
carbohydrazide and its thio analogue thiocarbohydrazide respectively with carbonyl
compounds. Carbohydrazide and thiocarbohydrazide are next symmetric homologue
of urea, the compound most directly associated with the foundation of organic
chemistry, and thiourea respectively. Curtius and Heidenreich have described in 1894
and more fully in 1895 [33] the synthesis and characterization, by its conversion into
suitable derivatives, of carbohydrazide by the hydrazinolysis of diethyl carbonate. ln
1908 Stolle, formerly Curtius’ assistant, discovered thiocarbohydrazide by continuing
the work [34]. In between and in the next decades the mono and di condensation
derivatives of carbohydrazide and thiocarbohydrazide with aldehydes and ketones,
carbohydrazones and thiocarbohydrazones, were reported by various research groups
[34-36]. A comprehensive and critical account of the chemistry of carbohydrazide and
thiocarbohydrazide and their relevant derivatives have been provided by Frederick
Kurzer and Michael Wilkinson in 1970 [36]. The systematic review covers historical
works and all subsequent corrected works of previous studies to the end of that period
with then state of knowledge. Conversely, the crystal and molecular structure of
thiocarbohydrazide was reported by Braibanti er al. [37]. The crystal structure of
carbohydrazide was reported by Domiano et al. [38] and later along with electron
deformation density distribution [39] and ab initio molecular orbital studies [40].
Carbohydrazide and thiocarbohydrazide possess a number of synonyms. The
various names of carbohydrazide include 1,3-diaminourea, N,N'-diaminourea,
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