Vibrational assignment and crystal structure of 3-amino-1-phenyl-2-buten-1-one

3-Amino-1-phenyl-2-buten-1-one (APBO) was synthesized by amination of benzoylacetone (BA) and its structure was studied by X-ray crystallographic method. The geometry of APBO was also optimized by means of density functional theory (DFT) and ab initio calculations and the results were compared with the X-ray crystallographic data. The vibrational fundamentals predicted within harmonic model, calculated at the B3LYP/6-311++G**, and by anharmonic model, calculated at the B3LYP/6-31G** level, display excellent agreement with the measured data. The proposed assignments are further confirmed by observing the deuterium isotopic shifts of different bands through predictions by the same theoretical method. The theoretical results obtained for APBO were compared with those of 4-amino-3-penten-2-one (APO).