Comparative study of quantum mechanical methods related to nucleic acid bases: Electronic spectra, excited state structures and interations

Abstract

This review is devoted to the comprehensive analysis of theoretical and experimental investigations of excited state properties of nucleic acid bases (NAB), base pairs, and their interactions with water molecules. The ground state geometries of these molecules were determined long ago using X-ray crystallographic and neutron diffraction techniques. However, the geometries of such complex molecules cannot be determined experimentally in the excited state. Fortunately, some limited information can be obtained in this context experimentally. Experimental methods, which have been also validated in recent theoretical studies, in some cases have suggested the nonplanar geometries of NABs in the excited state. The mode of interaction of water molecules with NABs has been found to be significantly different in the nπ* excited state compared to those in the ground state. Though, in this review article some attention pertains to the ground state properties of these molecules; however, the primary emphasis is on electronic singlet excited state properties, such as electronic transition energies, excited state geometries and interaction with water molecules in electronic singlet excited states. © 2006 Springer.