N‐Annulated Perylene Diimide Emitters for High‐Performance Peroxyoxalate/H 2 O 2 Chemiluminescence
Xiaoli Qin, Ziying Zhan, Edward Cieplechowicz, Liuqing Yang, Congyang Zhang, Kenneth Chu, Sara Jahanghiri, Gregory C. Welch, Zhifeng DingABSTRACT
Perylene diimides (PDIs), as one type of the most promising luminescent materials, have been attracted much attention. Herein, chemiluminescent (CL) properties of two N ‐annulated PDI dimers with hexyl linear alkyl chains (PDI‐1) and 2,4,6‐trimethylbenzyl sidechains (PDI‐2) at the pyrrolic N ‐positions were investigated. CL emissions are explored in chemical reactions with bis(2‐carbopentyloxy‐3,5,6‐trichlorophenyl) oxalate (CPPO) and hydrogen peroxide (H 2 O 2 ). Spooling CL spectroscopy was utilized for investigating their CL reaction mechanism, illuminant decay and absolute efficiencies. CL emission peak wavelength of PDI‐1 or PDI‐2 is similar to their photoluminescence (PL) one, demonstrating emissions mainly from the monomeric excited state in the absence of surface states. Moreover, absolute irradiance measurements on a set of a spectrograph and CCD camera or an Ocean Insight spectrometer along with a 6‐inch integrating sphere were calibrated using a standardized light source for further quantum efficiency determinations. The absolute CL efficiency of PDI‐1 (3.57% ± 0.03%) was discovered to be 6 times higher than that of PDI‐2 (0.603% ± 0.001%). The absolute CL efficiencies of PDI‐1 and PDI‐2 are superior to those of many other organic molecules and graphene quantum dots. This work provides a novel pathway for the exploration of these PDI materials to improve their CL performance.