Author:

Keywords:

density-functional theory, pi-pi interactions, potential-energy surface, molecular electrostatic potentials, distributed multipole analysis, ab-initio calculations, intermolecular interactions, aromatic-molecules, hsab principle, local hardness, Science & Technology, Physical Sciences, Chemistry, Physical, Physics, Atomic, Molecular & Chemical, Chemistry, Physics, DENSITY-FUNCTIONAL THEORY, PI-PI INTERACTIONS, POTENTIAL-ENERGY SURFACE, MOLECULAR ELECTROSTATIC POTENTIALS, DISTRIBUTED MULTIPOLE ANALYSIS, AB-INITIO CALCULATIONS, INTERMOLECULAR INTERACTIONS, AROMATIC-MOLECULES, HSAB PRINCIPLE, LOCAL HARDNESS, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, 0306 Physical Chemistry (incl. Structural), 0307 Theoretical and Computational Chemistry, 3406 Physical chemistry, 3407 Theoretical and computational chemistry, 5102 Atomic, molecular and optical physics

Abstract:

The present work focuses on the influence of aromatic stacking on the ability of an aromatic nitrogen base to accept a hydrogen bond. Substituent effects were studied at the MP2 level for 10 complexes of a substituted benzene stacked with pyridine in a parallel offset conformation. The interaction energies between each substituted benzene and pyridine were analyzed in terms of Hartree-Fock, correlation, and electrostatic contributions. It appears that the basicity of pyridine is directly related to the electrostatic interaction between the cycles. It increases with increasing electron donating character of the benzene substituents. Also, density functional theory based descriptors such as global and local hardnesses and the benzene ring polarizability are found to adequately predict the interaction energy. These findings may be important in the study of DNA/ RNA chains.