Premium
DFT investigation of sites of protonation of antitumor of 2‐(4‐aminophenyl)benzazoles in the gas phase and in solution
Author(s) -
Hilal Rifaat,
Elroby Shabaan A. K.
Publication year - 2005
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.20500
Subject(s) - protonation , polarizable continuum model , chemistry , density functional theory , gas phase , computational chemistry , proton affinity , polarizability , solvent effects , solvent , ring (chemistry) , potential energy surface , organic chemistry , molecule , ion
The proton affinity on each of the possible sites in the antitumor 2‐(4‐aminophenyl)benzazoles has been calculated at the B3LYP/6‐311G** level of theory in the gas phase and in solution. The N 3 ‐site of protonation is found to be strongly favored over the NH 2 ‐site for the studied compounds both in gas phase and in solution. The stability of N 3 ‐protonated species is explained by the resonance interaction of the NH 2 ‐group with the heterocyclic ring. The potential energy surface (PES) for the protonation process was studied at the density functional theory (DFT)/B3LYP/6‐311++G** level of theory. Solvent effects on the PES were also examined using two models: Onsager self‐consistent field and polarizable continuum model (PCM). © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005