Theoretical Study of the Relationship Between Wiener, Padmakar-Ivan, and Szeged Topological Indices in Contrast to Energy, Electric Moments and Partition Coefficient of Armchair Polyhex Carbon Nanotubes with Various Circumference and Fixed Lengths

Abstract

The use of theoretical tools for the molecular modeling of physicochemical processes and chemical reaction is one of the main distinctive characteristics of modern chemistry. Topological indices have attracted more attention from theoretical chemists and others and have become the focus of computational chemistry. Chemical graph theory is a branch of mathematics which combines graph theory and chemistry and has been extensively applied to predicting the physical properties of small molecules through Quantitative Structure Property Relationship (QSPR). Quantum chemical calculations are thus an attractive source of new molecular descriptors, which can, in principle, express all of the electronic and geometric properties of molecules and their intractions. Electric moments and energies of molecules are examples of quantum chemical descriptors used in QSPR studies. In this study, the relationship between some of the topological indices such as Wiener, Padmakar-Ivan, Szeged indices and partition coefficient (Log P) in contrast to the electric moments and energy (kJmol⁻¹) of some armchair polyhex carbon nanotubes TUVC₆[2p,q] with various circumference and fixed lengths are represented. Each nanotube is optimized at the level of the Becke3, Lee-Yang-Parr (B3LYP) method, using the 3–21G standard basis set. The relationship between topological and quantum chemical descriptors are discussed in this study.

Keywords:

• Nanotubes
• topological indices
• electric moment
• Log P

Acknowledgments

The authors gratefully acknowledge Dr. Steffan Weber for providing us the Nanotube Modeler Software.