Study of the Optoelectronic, Nonlinear Properties and Spectroscopic analysis of the molecule fulminene using ab initio and DFT methods

Fulminene is a crystalline polycyclic aromatic hydrocarbon (PAH) and is one of the most promising materials for organic optoelectronics. The molecular geometries of fulminene in the gas phase were studied using ab-initio quantum mechanical calculation at the restricted Hartree-Fock theory (RHF) level and density functional theory (DFT) calculations with B3LYP, B3PW91 and CAM-B3LYP functional were performed using a 6-311 + G (d, p) basis set. The spectroscopic properties (IR, NMR chemical shifts, and UV-Vis), electronic structure were evaluated. Good agreement with the experimental results was obtained for IR intensities, 1 H NMR spectrum and visible absorption maxima (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\lambda }_{max})$$\end{document}. Reactivity descriptors, thermodynamic properties at different temperatures, HOMO-LUMO orbital analysis, optoelectronic, and nonlinear optical properties have been evaluated. The calculated HOMO-LUMO energies show that the charge transfer occurs inside the molecule. The HOMO-LUMO energy gap was found to be in good agreement with the experimental results reported in the literature and this allowed us to conclude that our molecule is a good insulator as the gap is greater than 4 eV. Our results also show that this molecule has potential applications in optoelectronics and as a linear and nonlinear optical material, therefore it can be used as an insulator in many electronic devices.