Theoretical study on the proton chemical shifts of hydrogen bonded nucleic acid bases.

The variation of the proton chemical shifts due to the formation intermolecular hydrogen bonds is computed for a number of complexes which can be formed between the bases of the nucleic acids. The shifts expected for the isolated base pairs, in particular for the G-N1 H, T(or U)-N3H protons and the protons of the amino groups of A, G c, when combined with previous computations on the shifts to be expected upon base stacking, may enable a refined analysis of the high resolution NMR spectra of self complementary polynucleotides or tRNAs. Two examples are presented of a direct computation of proton shits associated with helix-coil transitions, helpful for deducing the helical structure in solution

Potential energy surface diabatisation: application to the study of excited atom deactivation by small molecules

Quasi-diabatic potential energy surfaces arc calculated within the two- state approximation, according to a method developped by Lorquet, for Li+N2 and Mg+C2H2 C2V systems. This way, the exciplex formation can be interpreted as resulting from crossings between charge transfer surfaces and low-lying excited states

Theoretical Investigations of the Influence of Pressure on the Selectivity of the Michael Addition of Diphenylmethaneamine to Stereogenic Crotonates

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