A series of charge-neutral bis-tridentate Ir(III) complexes (1, 3, and 4) were prepared via employing three distinctive tridentate prochelates, that is, (pzp^tBph^FO)H₂, [(phpyim)H₂·(PF₆)], and [(pimb)H₃·(PF₆)₂], which possess one dianionic pzp^tBph^FO, together with a second monoanionic tridentate chelate, namely, (pzp^tBph^FO)H, phpyim, and pimb, respectively. Moreover, a homoleptic, charge-neutral complex 2 was obtained by methylation of chelating (pzp^tBph^FO)H of 1 in basic media, while closely related cationic complexes 5-7 were obtained by further methylation of the remaining pyrazolate unit of previously mentioned neutral complexes 2-4, followed by anion metatheses. All of these Ir(III) metal complexes showed a broadened emission profile with an onset at ∼450 nm, a result of an enlarged ligand-centered ππ* transition gap, but with distinct efficiencies ranging from 0.8% to nearly unity. Comprehensive spectroscopic and computational approaches were executed, providing a correlation for the emission efficiencies versus energy gaps and between the metal-to-ligand charge transfer/ππ* emitting excited state and upper-lying metal-centered dd quenching state. Furthermore, Ir(III) complexes 3 and 4 were selected as dopant emitters in the fabrication of sky-blue phosphorescent organic light-emitting diodes, affording maximum external quantum efficiencies of 16.7 and 14.6% with CIE_x,y coordinates of (0.214, 0.454) and (0.191, 0.404) at a current density of 10² cd/m², respectively. Hence, this research highlights an inherent character of bis-tridentate Ir(III) complexes in achieving high phosphorescence quantum yield at the molecular level.

#	Concept	H-Index	Publications	Citations
1	Engineering	1	1	30
2	Chemical Engineering	1	1	30
3	Chemistry	1	1	30
4	Optoelectronics	1	1	30
5	Organic Chemistry	1	1	30

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