Branched Polyynes: Synthesis, Properties, and Application in Dopamine Detection

ABSTRACT Herein, we report the synthesis and characterization of four homological branched polyynes ( 3a–3d ). X‐ray diffraction revealed that a propeller‐shaped configuration was adopted by those polyynes. Subsequently, their ultraviolet‐visible absorption and fluorescence spectra were studied in dichloromethane solutions. Interestingly, compared to its several analogues (peripheral methyl, phenyl, and pyridinyl substituted), the thiophene‐substituted homologue 3d exhibited enhanced absorption and redshifted emission. Besides, strong and stable electrochemiluminescence signals were observed for all the above polyynes. Surprisingly, unlike the aforesaid photoluminescence, compound 3a with methyl substituted periphery exhibited the strongest electrochemiluminescence emission. Finally, 3a was selected as an electrode material to construct an ultrasensitive and stable dopamine sensor, validating the practical potential of those polyynes. This work provided new design concepts for regulating the photoelectric properties of branched polyynes.