Crystal and molecular structures of benzo[4,5]imidazo[1,2-c]quinazolin-6- one and 10-carboxybenzo[4,5]imidazo[1,2-c]quinazolin-6-one: A quantum-chemical study of their tautomerism

Benzo[4,5]imidazo[1,2-c]quinazolin-6-one and 10-carboxybenzo[4,5]imidazo[1, 2-c]quinazolin-6-one were isolated in the crystalline state and studied by X-ray diffraction. The crystal and molecular structures of these compounds were determined by X-ray diffraction. The energy characteristics of the tautomeric and ionic forms were calculated by the quantum-chemical PM3 method. © Pleiades Publishing, Inc., 2011.