Computational Investigation on Naphthoquinone Derivatives :Nuclear Magnetic Resonance (NMR) and Quantum mechanic

Abstract

Naphthoquinones are natural aromatic compounds that can be discovered in various plant families. In recent times a diversity of biological activities of these compounds has been reported. In most cases, these pharmacological activities are related to redox and acid-base properties, which can be modulated synthetically by modifying the substituents attached to the 1, 4- naphthoquinone ring, in order to enhance their therapeutic actions. In the current study we used dipole moment and nuclear magnetic resonance (NMR) to depict these molecules properties. The density functional theory (DFT) calculations at the level of B3LYP/6-31G* have been applied to analyze the substituent effect on the electronic structural properties including thermochemical parameters of Naphtoquinone Derivatives in gas phase using Gaussian 98. Dipole moment (Debye), energy of structure formation (HF/Kcal/mol) and point group, NMR parameters such as isotropic shielding (σiso) and anisotropic shielding (σaniso), σ11, σ22, σ33 obtained. Also thermodynamic properties and natural bond orbitals (NBO) were calculated. It dovetails our recent work of electron transfer pathways on Naphtoquinone Derivatives in different replacement is a fundamental step in constructing a knowledge base which will ultimately be of use in many cases.