Molecular Structure, Vibrational Spectroscopic (FT-IR, FT-Raman), UV and NLO Analysis of N-Methylurea by Density Functional Method

The theoretical investigations on the molecular structure and electronic and vibrational characteristics of n-methylurea are presented. DFT/B3LYP calculations obtained the vibration frequencies using a 6–31++G (d, p) basis set. The molecular equilibrium geometry of the title compound was fully optimized. Quantum chemical calculations of the equilibrium geometry were calculated with scaled quantum mechanics. Theoretically, the identification of atoms in molecular structure using IR spectrum in Gaussian software with 6-31++ (d, p) basis set. HOMO–LUMO energies, energy gap (ΔE), electro negativity (χ), chemical potential (μ), global hardness (η), and softness (S) were calculated for the title molecule. The title compound has a low softness value (0.15517), and the calculated value of the electrophilicity index (2.29723) describes the biological activity. The stability and charge delocalization of the title molecule were studied by NLO behaviour in terms of first order polarizability; dipole moment and anisotropy of polarizability were accounted for the computed values of μ, α, and β for the title molecule are 3.9248D, 6.745026×10-24 esu, and 5.09515×10-31 esu, respectively, which are greater than those of urea. High and non-zero μ values suggest the chemical could be a promising NLO material. The title molecule's thermodynamic properties were examined at various temperatures, demonstrating relationships between heat capacity (Cp), entropy (S), and enthalpy changes (∆H). The charges and variety are altered to reflect the different Mulliken charges for each case. We determine and assess adjacent reactivity descriptors based on electronic density.