A DFT Study on Effectiveness of Position of Carbonyl Group in Chalcone Derivatives.

In the present paper effect of carbonyl group positionon the NLO response of selected chalcone derivatives has been discussed. The position of carbonyl group in chalcone chromophores plays a vital role in enhancing the NLO behavior of chalcones. To provide a strategy to enhance NLO response the theoretical calculations were carried out using density functional theory by employing B3LYP/6-31G(d) level of theory. The DFT calculations were carried out on eight chalcones with carbonyl group at different location in combination with donorgroup. The DFT results suggest that depending on the position of carbonyl group one can possibly use thiophene and benzene as electron donor/acceptor in NLO chromophores design. Also the donor group placed on phenyl ring is more effective to enhance NLO property in comparison with donor group substituted at thiophene ring. We also demonstrate that position of carbonyl group in chalcones can alter the nature of charge transfer from D-Ï€-A-Ï€-D toD-Ï€-Asystem. The flexibility to change the nature of charge transfer gives great opportunity to tune the NLO and physical properties of chalcone derivatives. [ABSTRACT FROM AUTHOR]