A Theoretical Study on Vibration Frequencies of Some Aniline Derivatives and Correlations with Experimental Data

Abstract

In this work, a theoretical study on the vibrational frequencies of all possible isomers of some aniline derivatives with general formula C₆H₅-nXnNH₂ (n = 1-5; X = F, Cl, Br) is reported. Calculations have been done at B3LYP employing the 6-31G(d), 6-31G(d,p), 6-31++G(d,p) and 6-311++G(d,p) levels of theory. The optimized structures were used for calculation of vibrational frequencies at B3LYP/6-311++G(d,p) level of theory. The resulting data were scaled by 0.952 for N-H stretching bond and 0.981 for C-N, C-X (X = F, Cl, Br), C=C, N-H (bending) bonds. The results showed that, there is a good agreement between the scaled theoretical frequencies and experimental data for this type of compounds.