Photo-physical effects of the chemical insertion of the dimethyl-amine moiety on the newly synthesized oligophenylene (OMPA)

The synthesized oligo [4-(methoxyphenyl) acetonitrile] (OMPA) was chemically modified by Knoevenagel condensation of OMPA with dimethylformamide dimethyl acetal (DMF-DMA). obtained oligomer is composed short chains poly [3-(dimethylamino)-2-(4-methoxyphenyl)acrylonitrile] and denoted OMFA. Experimental measurements: ultraviolet-visible (UV-vis), steady-state time-resolved photoluminescence spectroscopies, infrared spectroscopy, thermogravimetric analysis (TGA), were combined theoretical calculations, based on density functional theory (DFT) methodologies, to highlight the effect grafting dimethyl-amine group photo-physical electronic properties as-synthesized oligomer. Thus, a redshift absorption spectra observed upon chemical group. Added that, decrease optical bandgap (Egopt) energy gap EH-L=EHOMO-ELUMO occurs modification. DFT computations show that insertion into monomer induces drastic change their frontier orbitals HOMO LUMO.