Thiophene fused indenocorannulenes: synthesis, variable emission, and exceptional chiral configurational stability

Abstract

A set of thiophene fused indenocorannulenes (TFICs) was synthesized and characterized by X-ray crystallography, electrochemical, and photophysical methods. Two chiral derivatives were resolved and their absolute configurations defined by Flack analysis (12a) and by comparison of experimental VCD/ECD spectra with hybrid DFT methods (12b and 3a). The emission wavelengths of 13 compounds were compared and varied over 220 nm (emission colors from violet to red). The bowl-inversion activation barrier of 12 was determined to be 192.7 kJ mol⁻¹, corresponding to a configurational stability of weeks at 200 °C; on par with the highest helicene and phosphine values.