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The Effect of Ultraviolet Radiation on the Chemical Bath Deposition of Bis(thiourea) Cadmium Chloride Crystals and the Subsequent CdS Obtention
Published on: August 30, 2018
Geometric correlations and infrared spectrum of adenine-uracil hydrogen bonds in CDCl(3) solution
1Institut für Physik, Universität Rostock, D-18051 Rostock, Germany.
Abstract:
Hybrid QM/MM molecular dynamics simulations have been carried out for the Watson-Crick base pair of 9-ethyl-8-phenyladenine and 1-cyclohexyluracil in deuterochloroform solution at room temperature. Trajectories are analyzed paying special attention to the geometric correlations within the N-HN and N-HO hydrogen bonds in the base pair. Even though the two hydrogen bonds are only approximately linear and the heterocycles are tilted with respect to each other, hydrogen bond and N-H lengths follow a simple empirical correlation based on Pauling's valence bond order model. In order to describe the IR line shape of the two NH-stretching vibrations, the correlation between their fundamental transition frequencies and the hydrogen bond lengths is exploited. This facilitates efficient evaluation of the fluctuating transition frequencies along the QM/MM trajectory which allows the determination of the line shape function.
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