Recent advances in versatile pyridazine-cored materials: principles, applications, and challenges

Searching for adaptable, versatile, and highly performing substances or building blocks is the goal of materials science. Owing to their exceptional structural modifiability, capability for supramolecular assembly, distinctive optoelectronic specialty, and superior device performance, various pyridazine-based (PD-based) heteroaromatic hydrocarbons (HAHs), which are embedded with the adjacent sp(2)-N pair (-N=N-/=N-N=), have attracted increasing attention in the field of organic optoelectronic materials. In particular, organic field-effect transistors (OFETs), organic photovoltaic devices (OPVs), organic light-emitting diodes (OLEDs), fluorescence probes, luminescence, chromism, catalysis, and supramolecular assembly have witnessed notable advancements in recent years. This review categorized different molecular species, outlined structural traits, personality traits, and device performance and analyzed connections between those elements, including PD-based polymers, pure organic small molecules, pure organic complexes, and ligand-metal complexes as host materials, thermally active delayed fluorescence materials, electrode materials, chromism materials, fluorescence probes, organic catalysts, and energy materials. The aza-quantity, substituent, regioisomerism, dihydrogen bond, and dual-coordination effect were all summarized and expanded. In addition, the trends, challenges, and future aspects of PD-based HAHs were discussed and prospected.