A DFT/TD-DFT Study on the Molecular Structure Absorption and Fluorescence Spectra of Gas/Solution Phases Adenosine 5′-triphosphate Molecule

In this study, the conformational structure of the tetra-protonated Adenosine 5'triphosphate molecule has been investigated using Spartan 08 package program with the molecular dynamics method. Following the conformational analysis; geometry optimization, excited states, absorption and fluorescence (emission) spectra, molecular orbitals, chemical hardness, electronic chemical potential, electronegativity and electrophilicity indexes of the molecule were calculated by using density functional theory and time-dependent density functional theory method with B3LYP functional with 6-311+G (d, p) basis set. All calculations for the tetra-protonated ATP molecule have also been carried out both in the gas phase and in the aqueous solution and then results were compared with the experimental data reported in the literature.