DFT modelling of the infrared spectra for isolated and aqueous forms of adenine

S. Thicoipe , Philippe Carbonnière (1) , Claude Pouchan (1)

1 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux

This theoretical study provides the anharmonic vibrational spectra of isolated and aqueous forms of adenine. The calculations were performed at the DFT B3LYP/6-31+G(d,p) level of theory using two different ways for the treatment of the anharmonicity: time-independent (VPT2) and time-dependent (molecular dynamics) methods. The wavenumbers obtained from both treatments are compared to experimental data for the two forms. Globally, the VPT2 method appears slightly better to describe the mid-IR spectra in the fingerprint region between 600 and 1700 cm−1 for the isolated form, the two approaches leading similar results for the aqueous adenine. Finally, the structural model of solvation used for aqueous adenine that combines an explicit solvent model with a polarizable continuum model gives, as in the case of cytosine, thymine and guanine, previously studied, excellent results. © 2017, Springer-Verlag Berlin Heidelberg.

Mots clés: Density functional theory; IR spectroscopy; Solvation model; Vibrational anharmonic calculations

Domaines: Chimie

S. Thicoipe, Philippe Carbonnière, Claude Pouchan. DFT modelling of the infrared spectra for isolated and aqueous forms of adenine. Theoretical Chemistry Accounts: Theory, Computation, and Modeling, 2017, 136 (4), ⟨10.1007/s00214-017-2076-0⟩. ⟨hal-01499132⟩