Physicochemical Properties of Derivatives of N,N-Dimethylamino–cyclic–chalcones: Experimental and Theoretical Study

Abstract

A series of three N,N-dimethyl-amino-cyclic-chalcones chromophores of the D-π-A type (1-3) where, (Donor= N,N-dimethyl-aniline) and Acceptor= indan-1-one (1), 3,4-dihydro-2H-naphthalen-1-one (2) and 3,4,5-tetrahydro-benzocyclohepten-1-one (3), were synthesized and their structural, optical and electronic properties were studied. The influence of fused cycling ring size on their properties was investigated using cyclic voltammetry, steady-state absorption, steady-state fluorescence and DFT theoretical calculations. Both experimental and theoretical calculations have been used to explain the observed structural, energetic and spectral differences in these compounds. These compounds have almost similar E1/2 (OX) . However, the measured E1/2 (Red) vary. The fused cyclic ring has more impact on the HOMO energies than LUMO's. Protonation could be facilitated on two sites. However, our DFT and TD-DFT calculations reveal that carbonyl oxygen has the most–negative-surface electrostatic potential, thus the highest affinity toward accepting H+.