Geometric and Electronic Structure of Papaverine and Its Acid Strength
V. A. Babkin *
Volgograd State University of Architecture and Civil Engineering, Sebryakovskiy Branch, Mikhailovka, Volgograd Region, Russia
V. Yu Dmitriev
Volgograd State University of Architecture and Civil Engineering, Sebryakovskiy Branch, Mikhailovka, Volgograd Region, Russia
D. S. Andreev
Volgograd State University of Architecture and Civil Engineering, Sebryakovskiy Branch, Mikhailovka, Volgograd Region, Russia
L. M. Lisina
Volgograd State University of Architecture and Civil Engineering, Sebryakovskiy Branch, Mikhailovka, Volgograd Region, Russia
A. I. Rakhimov
Volgograd State Technical University, Volgograd, Russia
N. A. Rakhimova
Volgograd State Technical University, Volgograd, Russia
V. S. Belousova
I.M. Sechenov First Moscow State Medical University, Moscow, Russia
O. A. Ponomarev
Institute of Mathematical Problems of Biology, Russian Academy of Sciences, Puschino, Russia
G. E. Zaikov
N.M. Emmanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
O. V. Stoyanov
Kazan State Technological University, Kazan, Russia
*Author to whom correspondence should be addressed.
Abstract
For the first time ever, the quantum-chemical calculation of papaverine molecule was performed within the framework of molecular model by methods RHF/6-311G** and DFT-PBE0/6-311G**. Optimized geometric and electronic structure of this compound was obtained. Its acid strength was also theoretically estimated. It was proved that papaverine molecule belongs to the class of very weak acids (pKa>14). It was shown that 3.4-di(methoxy)benzyl group is the electron-donating substituent. It is revealed, that dimethoxy-group and 3.4-di(methoxy)benzyl group influence on the distribution of electronic density and pKa value.
Keywords: Quantum-chemical calculation, RHF/6-311G** and DFT-PBE0/6-311g** methods, papaverine, dimethoxy-group, 3.4-di(methoxy)benzyl group, acid strength