Nitrile grafted thia[5]Helicenes through a photocyclization pathway of styrylnaphtho[2,1-b]thiophenes: Synthesis and photophysical properties

•A photochemical pathway was developed for novel thia[5]Helicenes.•Six helical architectures were obtained with good overall yields.•Absorption properties of new Helicenes were experimentally investigated.•An emission in the blue region of the visible spectrum was noted.•Electrochemical gap values of thia[5]Helicenes were found less than 3.01 eV.