Spectra, Electronic Structure of 2-Vinyl Naphthalene and Their Oligomeric Scaffold Models: A Quantum Chemical Investigation

Abstract

This investigation comprises with the spectral, electronic and oligomeric scaffold modelling of 2-vinyl naphthalene (1[2VN]). The normal mode vibrational characteristic nature of the system has been studied using experimental FT-IR and FT-Raman spectra along with simulated vibrational compliments using B3LYP/6-31 + G(d,p). The FT-IR and FT-Raman spectrums have been recorded in the range of 4000–400 cm⁻¹ and 4000–50 cm⁻¹ respectively. The Potential energy distribution (PED) of 1[2VN] deepen the understanding on different modes of vibrations promoted by individual wavenumber. The experimental UV–Visible spectra was recorded within the region of 400–200 nm and correlated with calculated spectra by solvated TD-DFT B3LYP/6-31 + G(d,p) model. The calculated equilibrium structure has been compared with experimentally available structure and the chemical bonding nature was characterized using natural bond orbital (NBO) analysis. Thermodynamic properties such as heat capacities, entropies, enthalpies and their associations with temperature rise have been investigated. The frontier molecular orbital analysis (FMO), molecular electrostatic potential (MEP) and hyperpolarizability were investigated. In addition, the oligomer forms of 1[2VN] were constructed and around 19 scaffold candidates designed by substituting several donor acceptor moieties at different position to get a candidate with minimized the band gap. The geometry, FMO, MEP, NBO and selected NLO properties has been explored to identify the high efficient donor-pi-acceptor system.