Molecular structure, spectroscopic (FT-IR, FT-Raman), NBO analysis of N,N'-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine

Abstract

In the present work, we have synthesized and reported a combined experimental and theoretical study on the molecular structure, vibrational spectra and HOMO-LUMO analysis of N,N'-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine (C20N6H22). The FT-IR and FT-Raman spectra of N,N'-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine were recorded. The molecular geometry, harmonic vibrational wavenumbers and bonding features of the title molecule in the ground-state have been calculated by using the density functional B3LYP method with 6-31G(d) as basis set. Non-linear optical (NLO) behavior of the N,N'-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine was investigated by determining the electric dipole moment μ, polarizability α, and hyperpolarizability β using the above mentioned basis set. The molecular properties such as ionization potential, electro-negativity, chemical potential, electrophilicity have been deduced from HOMO-LUMO analysis employing the same basis set. The calculated HOMO and LUMO energies showed that charge transfer occurs within the molecule. Stability of the molecule arising from hyper conjugative interaction and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Finally, the calculation results were applied to simulate infrared and Raman spectra of the title compound which showed good agreement with the observed spectra.

Keywords: Density functional theory; HOMO–LUMO analysis; N,N′-diphenyl-6-piperidin-1-yl-[1,3,5]-triazine-2,4-diamine; Vibrational spectra.