Polynaphthalene-Based Oxazaborinine Complexes Formulated as Red Light Emitters and High-Performance Asymmetric Supercapacitors

Abstract

Developinga solid organic emitter based on an oxazaborinine complexwith improved photophysical characteristics has become essential tofulfilling the rising need for optical and electrochemical technology.Two oxazaborinine complexes (TNB (a tri-naphthalene boroncomplex) and DNB (a di-naphthalene boron complex)) decoratedwith naphthalene and triphenylamine have been developed, which showemission in the red light region in the solid phase. Their effectivenessas asymmetric supercapacitor electrodes in aqueous electrolytes isalso being studied. Polynapthaldimine-substituted DNI (di-naphthalene imine) and TNI (tri-naphthalene imine)have been initially synthesized and converted to a N,O-linked boroncomplex. TNB in solids (lambda(em) 660 nm)and the polydimethylsiloxane (PDMS) composite (lambda(em) 632 nm) emit pure red light. The optimized structure has been generated,and the HOMO-LUMO energy was calculated with the help of densityfunctional theory (DFT). Due to the higher conjugation effect andlower HOMO-LUMO energy difference, TNB could beused as a supercapacitor electrode. In a three-electrode configuration, TNB has a maximum specific capacitance of 896.25 F/g. Furthermore,an asymmetric supercapacitor device (ASC) was fabricated in an aqueouselectrolyte using TNB as a positive electrode havinga high specific capacitance of 155 F/g. Even in an aqueous electrolyte,the ASC device reached the operating potential window of 0 to 1.4V with an enhanced energy density of 42.19 W h/kg and similar to 96%cyclic stability after 10 000 cycles. The reported oxazaborininecomplex and its electrochemical efficiency in aqueous electrolytesmake it ideal for supercapacitor applications and directly impactthe development of advanced electrodes for next-generation supercapacitors.