engleski

Formamide as the model compound for photodissociation of the peptide bond

Knowledge of how the small molecules incorporating peptide bond interact with the ultraviolet light is of considerable importance for understanding the effect of light irradiation on biological systems. Most of these studies have been focused on formamide as the simplest prototype of the peptide bond. In this talk an overview of our recent computational studies of deactivation processes for formamide and its methyl substituted derivatives, acetamide and N, Ndimethylformamide, in their lowest singlet excited states using an on-the-fly surface hopping method will be presented. Special attention will be put on exploring the effect of embedding formamide in the argon matrix. For this purpose recently developed hybrid nonadiabatic photodynamics QM/MM approach was used. Comparison of the gas phase results with those obtained in the argon matrix indicates that embedding of ormamide in the argon matrix has strong impact on the outcome of the process. This is illustrated by an increase of the lifetime of the S1 state with respect to the gas phase and prevention of full separation of the fragments resulting from the central C-N bond dissociation.

formamide; photodissociation; dynamics calculations

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