Abstract: New compounds of (E-(1, 3-bis)3-bromophenyl)prop-2-en-1-one], [E-(1-(3-Nitrophenyl-(3-(1H-pyrrol- 2-yl)prop-2-en-1-one], [E-(1-(3-Nitrophenyl-(3-(1-H-pyrrol-2-yl)prop-2-en-1-one],( E-(1-(3-Nitrophenyl-(3-(1-hpyrrol- 2-yl)prop-2-en-1-one] and [(E)-N, N-1, 3-bis)3-Nitrophenyl)propan-3-yl-1-ylidene) dimethan amine] were synthesized. These prepared compounds were synthesized from chalcone and characterized through using FT-IR, ultraviolet/visible and H-NMR spectroscopy. The newly prepared compounds were studied theatrically in gas phase through using HyperChem.8 program for the molecular mechanics, semi-empirical calculations. Binding Energy (ΔEb) the Heat formation (ΔH°f) and Total Energy (ΔET) for chalcones were calculated measured by the semi-empirical (PM3). Semi-empirical method was used to assess the infrared spectra and ultraviolet/visible spectra for the chalcones and the wave numbers which were theoretically calculated, then were was a comparison with the experimented values. There was an agreement between theoretically obtained frequencies and with frequencies found experimentally, furthermore, calculations assisted in assigning unambiguously the most diagnostic bands.