Theoretical study of frequencies modes, energy gap and HOMO –LUMO energies in solvents combinations for monomer urea

Abstract

Molecular structure determination for monomer urea as well as theirvibrational frequencies have been theoretically investigated by molecular orbitalby Ab Initio calculation based on DFT theory level using 6-311G basis setperformed by B3LYP method. Assignments for vibrational frequencies weremade, and solvent effect on the IR frequencies using eleven solvents: water,Dimethylsulfoxied, Ethanol, Acetone, Aniline, Chlorobenzene, Chloroform,Toluene, Benzene ,Cyclohexane and Heptane. The vibration mode of carbonylis shifted to lower frequencies while the NH2 bending increased in polar solvent.The correlation between the dielectric constant and parameters[C=O freq.,Energy gap, HOMO and LUMO] in eleven solvents obtained values r2 withrange 0.890-0.973