1H and 13C NMR study of proton transfer in azoles. Mechanism of proton transfer in pyrazole in solutions containing bis-(acetylacetonato) nickel (II).

Proton transfer in pyrazole systems involving interaction with a paramagnetic transition metal complex has been studied with 1H and 13C NMR techniques. Kinetics of the ligand exchange in the pyrazole complex of bis-(acetylacetonato)nickel (II) has been investigated, and hyperfine coupling constants for the interaction of the nickel unpaired electron with the ligand nuclei in the complex have been determined. Catalytic admixtures of bis-(acetylacetonato)nickel (II) are shown to modify the mechanism of the proton transfer in pyrazole. The spectral data are discussed in terms of outer-sphere coordination and cooperative proton transfer effects.

[Significance of chiral purity of biomolecules for self-reproduction of organisms]. / O znachenii kiral'noi chistoty biomolekul dlia samovosproizvedeniia organizmov

Living systems mainly syntesise and utilise chiral pure polimers which have only one form of enantiomers (l, l,..., l-proteins, d, d, d,..., d-sugars). The biologycal meaning of chiral purity of molecules in organisms is discussed. It is shown that chiral purity of biomolecules is necessary to ensure ordering of organisms during selfreproduction. Even when formation of chiral pure form does not have any advantages over formation of a set of other stereoisomers, only chiral pure molecules may act as regulators of further syntheses. Molecules with distorded chiral purity are not able to maintain the initial order during selfreproduction.