Vibration modes studies of 3,4,5-trimethoxy benzaldehyde, 4-hydroxy-3-methoxy benzaldehyde and 4-chloro benzaldehyde Schiff base of 2-amino pyridine- A quantum chemical study

摘要

The vibration modes of the title compounds are examined by experimentically and theoretically using the Semi-empirical AM1 and PM3 computational methods. Vibration modes for 2N-(3, 4, 5-trimethoxy benzalidine) aminopyridine (TMBAPy), the correlation coefficients obtained for AM1 and PM3 methods are 0.999587and 0.999712, respectively. However, vibration modes for 2N-(4-hydroxy-3-methoxy benzalidine) aminopyridine (HMBAPy), the correlation coefficients for AM1 and PM3 methods are 0.986742 and 0.98184, respectively. As well as correlation coefficient for 2N-(4-chlorobenzalidine) aminopyridine (p-CIBAPy) Schiff base compound are 0.999646 and 0.999714 by AM1 and PM3 Semi-empirical methods, respectively. PM3 method provides most satisfactory correlations between experimental and calculated fundamental vibration modes of 2N-(3, 4, 5-trimethoxy benzalidine) aminopyridine (TMBAPy) and 2N-(4-chlorobenzalidine) aminopyridine (p-CIBAPy) compounds (CC = 0.999712_and 0.999714, respectively). AM1 Semi-empirical method yields highest correlation (0.986742) for 2N-(4-hydroxy-3-methoxy benzalidine) aminopyridine (HMBAPy) Schiff base compound.