Studying the geometric parameters, stability of isomer and IR frequencies in enaminone compounds with the DFT and HF methods: A theoretical study

Enaminones are the large category of chemical compounds that their numerous applications caused to be interested by researchers and scientists in two important experimental and theoretical forms. Calculating chemistry as one of the vital field for the chemistry can help us to investigate of enaminone structures. Our three isomers of the compounds are enaminone. In this research, Sustainability and inter-molecular hydrogen bond strength of each isomer is investigated. Four methods HF, B3LYP, B3P86, B3PW91 and two basis set 6-311G**, 6-311++G** were used in order to making calculation. The results of calculations in geometry parameters indicated that in our parameters, B3P86 method and 6-311++G** basis set have considerable preference than other methods and basis sets. In regarding to this method and basis set, hydrogen bonding was investigated and the third isomer (III) showed the strongest hydrogen bond achieved. Finally theoretical vibrational frequencies, in B3P86/6-311++G** basis set was investigated.