Theoretical studies of engertics, structures and chemical reactions on carbon and BN surfaces and related molecules

Abstract

This thesis focuses on the energetics, structure and reactivity of wide band gap materials such as diamond and cubic boron nitride. The surface atomic structures were studied using periodic density functional theory (DFT). The chemisorption of hydrogen, oxygen, C2 biradical and C2H2 on the bulk-truncated as well as reconstructed surface is investigated. Layered resolved density-of-states (DOS) as well as band structure calculations were performed to derive insights into the surface electronic structure.To understand the problems of aromaticity in ringed carbon and borazine systems, we consider the cyclacene structures, which can be the molecular analogs of carbon and boron nitride nanotubes Unrestricted Density Functional Theory (UDFT) calculations were also performed for the borazine and benzene cyclacenes system to obtain insights into the structural and electronic properties as a function of number of rings presented in cyclacenes. In addition, the fluoro-substituted cyclancenes were also investigated to examine the relationships between the frontier molecular orbitals gap, structure and ring size.