Abstract
•Tricyclic π-conjugated architectures were developed through a photochemical route.•Absorption properties of these compounds were experimentally investigated.•An emission in the blue region of the visible spectrum was underlined.•Electrochemical gap of the compounds was found to be 2.34 eV to 2.80 eV.
A variety of novel functional phenanthrene and phenanthrene‒like derivatives have been synthesized, in 46%‒67% overall yields, through a short and practical photochemical pathway involving soft conditions and very low-cost starting materials. The target π‒conjugated systems have been characterized by 1H, 13C and COZY NMR and FT−IR spectroscopies. The absorption properties of these compounds have been explored experimentally in various solvents showing a strong absorption wholly in the UV spectrum (λmax = 281−285 nm), while little variations of the shape of the absorption bands are ascertained. These compounds exhibited blue or red-shifted emissions resulting in quantum yields of 0.07 to 0.21. Their electrochemical properties have been also investigated by cyclic voltammetry to underline an irreversible redox-active process towards such species and to assess the HOMO and LUMO energy levels which allow an electrochemical band gap (Eg–el) raging between 2.34 eV to 2.80 eV.
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