Synergetic experimental and theoretical investigation of molecular structure – Optical properties relationships of anthrazoline-based polymeric chains

The photoluminescence and UV–Vis absorption spectra of copolyamides containing 1,9-anthrazoline with para- and meta-[(substituted carbonyl)amino]phenyl-1-ene moieties in a polymer backbone were studied by a combination of experimental and theoretical approaches. The investigation was accomplished through time-dependent density functional theory electronic structure calculations of small-molecule models mimicking a polymer chain. Theoretical absorption and luminescence spectra of ten atomistic models were compared with corresponding experimental data, and the optical properties of two new luminescent molecules with bromine auxochrome were predicted. An analysis of the optical properties demonstrate an identical effect of the type and position of a substituent on the spectra for para- and meta-[(substituted carbonyl)amino]phenyl-1-ene moieties. It was found that the absorption and luminescence spectra of theoretical para-models demonstrate red shifts relative to the corresponding meta-ones. The same phenomenon was observed in experimental spectra of low-molecular-mass compounds and corresponding copolyamides in solution and bulk. Unique optical properties allow anthrazoline-based polymer compounds to be used in numerous advanced optoelectronic applications with desired optical and electronic characteristics. • A synthesis was conducted of copolyamides with anthrazoline in a main chain. • The para- and meta-orientation of phenylene is present in the anthrazoline fragments. • Absorption and luminescence spectra of atomistic models were calculated using TD-DFT. • Optical properties of luminophore polymers with a bromine auxochrome were predicted. • Optical spectra of para-moieties with anthrazoline show red shift against meta-ones.