Water thiouracil interaction with

The present work discusses some properties of thiouracil nucleobases calculated at the B3LYP/6-31+G(d,p) computational level, namely, their structures, most stable tautomers, proton affinities and deprotonation enthalpies, hydrogenation, interaction with water, and base pairing, in order to shed a certain light on the problem of why their functioning in RNA and modified DNA base pairs is so unusual. 

Thiouracils Structures, Tautomerism, Interaction with Water... 

What makes the thiated nucleobases so markedly different from the normal ones Put in the other words, what is a key effect of the thio substitution which, in turn, causes a variety of bizarre effects in the interaction of thiouracils with water, in proton migration, recognition patterns, biological and pharmacological activities, etc., etc. There are actually two key effects underlying the thio substitution and certainly inter-related. One is that such substitution dramatically changes the structural features of nucleic acids whereas the other is due to the drastic change of their functional ones expressed in terms of intermolecular interactions. 

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