Theoretical Vibrational Mode Analysis of Schiff Bases using Semi Empirical Methods-I

摘要

Two new Schiff bases viz., 2N-[(3,4,5-trimethoxybenzalidene)aminopyridine] and 2N-[(4-methoxybenzalidene)aminopyridrne] were synthesized by condensation of 3,4,5-trimethoxybenzaldehyde or 4-methoxybenzaldehyde with 2-amino pyridine in separate procedures, Their IR spectra was obtained experimentally by KBr method and was analyzed for significant peaks. Semi empirical methods AMI, PM3, MNDO, ZINDO methods were used to compare the experimentally obtained IR spectra with the computer simulated IR spectra using transmittance vs. frequency plots given by four methods. Apart from the comparison of the significant part of the spectra, the statistical correlation was also calculated for the theoretical spectra and methods; to establish use of these methods as alternative and supportive tool in analytical chemistry and to establish purity of the synthesized compounds.