New architecture of organo electronic chalcones derivatives: Synthesis, crystal structures and optical properties

Abstract A series of four organics conjugate chalcone derivatives [1: (E)-2-(1-(3-oxo-1,3-diphenylprop-1-en-2-yl)pyridin-2(1H)-ylidene)malononitrile, 2: (E)-2-(1-(3-oxo-3-phenyl-1-(p-tolyl)prop-1-en-2-yl)pyridin-2(1H)-ylidene)malononitrile, 3: (E)-2-(1-(1-(4-methoxyphenyl)-3-oxo-3-phenylprop-1-en-2-yl)pyridin-2(1H)-ylidene)malononitrile, 4: (E)-2-(1-(1-(4-chlorophenyl)-3-oxo-3-phenylprop-1-en-2-yl)pyridin-2(1H)-ylidene)malononitrile] were synthesized and structurally characterized by single-crystal X-ray diffraction, 1H and 13C NMR, FTIR and UV–Visible spectral analysis. The four studied compounds have the same molecular skeleton and the main difference corresponds to the substitution on the C13 carbon atom of the phenyl ring by a methyl, methoxy and chloride groups for 2, 3 and 4 respectively. Third harmonic generation (THG) measurements have been performed on thin films at 1064 nm. To perform induced second harmonic generation measurements, the four molecular compounds were reoriented by using the corona poling technique on the films. These measurements highlight that compound 1 exhibits a significant NLO signature compared to the three other compounds. The effects of the substitution on the structural organizations and the optical properties is investigated and discussed.