Majid Saghi - Department of chemistry, Arak Branch, Islamic Azad University, Arak, Iran
Ali Lotfi - Department of chemistry, Quchan Branch, Islamic Azad University,Quchan, Iran
Mohammad Hosein Bigtan - Department of chemistry, Arak Branch, Islamic Azad University, Arak, Iran
Reza Zare - Department of chemistry, Quchan Branch, Islamic Azad University,Quchan, Iran

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, B۳LYP, B۳P۸۶, B۳PW۹۱ and two basis set ۶-۳۱۱G**, ۶-۳۱۱++G** were used in order to making calculation. The results of calculations in geometry parameters indicated that in our parameters, B۳P۸۶ method and ۶-۳۱۱++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 B۳P۸۶/۶-۳۱۱++G** basis set was investigated.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, B۳LYP, B۳P۸۶, B۳PW۹۱ and two basis set ۶-۳۱۱G**, ۶-۳۱۱++G** were used in order to making calculation. The results of calculations in geometry parameters indicated that in our parameters, B۳P۸۶ method and ۶-۳۱۱++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 B۳P۸۶/۶-۳۱۱++G** basis set was investigated.

Enaminone; Isomer; Geometric parameters; HF; DFT