Electronic properties of neuroleptics: ionization energies of benzodiazepines

Salvatore Millefiori (1) , Andrea Alparone (1)

1 Dipartimento di Scienze Chimiche

Vertical ionization energies (VIEs) of medazepam, nordazepam and their molecular subunits have been calculated using the electron propagator method in the P3/CEP-31G* approximation. Vertical electron affinities (VEAs) have been obtained with a ∆SCF procedure at the DFT-B3LYP/6-31+G* level of theory. Excellent correlations have been achieved between IE and IE, allowing reliable assignment of the ionization processes. Our proposed assignment differs in many instances from that previously reported in the literature. The electronic structure of the frontier Dyson orbitals shows that the IE and EA values of the benzodiazepines can be modulated by substitution at the benzene rings. Hardness values, evaluated as (IE − EA)/2, follow the trend of the experimental singlet transition energies. Medazepam is a less hard (i.e., less stable) compound than nordazepam.

Mots clés: Benzodiazepines; Vertical ionization energies; Vertical electron affinities; DFT calculations; Electron propagator theory calculations

Salvatore Millefiori, Andrea Alparone. Electronic properties of neuroleptics: ionization energies of benzodiazepines. Journal of Molecular Modeling, 2010, 17 (2), pp.281-287. ⟨10.1007/s00894-010-0723-7⟩. ⟨hal-00590996⟩