Medhat Ibrahima and Eckhard Koglinb
a Spectroscopy Department,   National  Research  Center  , Dokki,   Cairo , Egypt
b Institute of  Physical Chemistry Juelich Research Center , D52425,  Germany


Density functional theory (DFT) was used to investigate both the structure and vibrational frequencies of acetate group. A model of B3LYP with four basis set is used to optimize and locate the energy minimum of the acetic acid molecule. The results obtained of both bond lengths and bond angles showed that B3LYP/6-31G(d,p) gave the optimal structure of acetate in acetic acid molecule. Vibrational frequencies of acetic acid at the same level of theory are calculated with assignment of each band frequency. The model B3LYP/6-31G(d,p) was used to calculate the characteristic C=O stretching of acetate group in case of acetic acid dimer, aceto-benzoic acid and aceto-polyacrylic acid respectively.


Key words: molecular modeling, DFT, vibrational spectra, ِِِِacetate group