Theoretical study on hydration of two particular diazanaphthalenes

CÉSAR A. SPEDALETTI; MARIO R. ESTRADA; GRACIELA N. ZAMARBIDE; JUAN C. GARRO; CARLOS A. PONCE; FRANCISCO TOMÁS VERT

JOURNAL OF MOLECULAR STRUCTURE THEOCHEM

Año: 2005 p. 211 - 216

0166-1280

Abstract Quinazoline (symmetrical) and quinoxaline (unsymmetrical), diazanaphthalenes involved in certain biological reactions, have been studied computational with the purpose of comparing their protonation and covalent hydration mechanisms. Geometry optimizations of neutral, mono and diprotonated cations and hydrated products have been carried out at three levels of theory. Geometry optimizations were performed at HF, DFT/B3LYP levels of theory using 6-311G* basis set and single point energies were calculated at the MP2 level of theory using the same basis set. In agreement with experimental results, calculations predict a two steps mechanism resulting in a hydrated cation in which the OH of the water is located depending on the symmetry of the diazanaphthalene molecule. q 2004 Elsevier B.V. All rights reserved.2004 Elsevier B.V. All rights reserved.