To understand the effects of the terminal substituent at the diimine ligand on the photophysics of heteroleptic cationic Ir(III) complexes and to obtain Ir(III) complexes with extended ground-state absorption to the 0.8near-IR region while retaining the long-lived and broadly absorbing triplet excited state, we synthesized three heteroleptic cationic iridium (III) complexes bearing cyclometalating 1-phenylisoquinoline ((CN)-N-boolean AND) ligands and substituted 6,6 '-bis(7-R-fluoren-2-yl)-2,2 '-biquinoline ((NN)-N-boolean AND) ligand (R = H, NO2, or NPh2). The photophysics of these complexes was systematically investigated via spectroscopic methods and time-dependent density functional theory. All complexes possess strong ligand-localized (1)pi,pi* transitions mixed with ligandto-ligand charge transfer ((LLCT)-L-1)/metal-to-ligand charge transfer ((MLCT)-M-1) transitions below 400 nm, and a broad and featureless absorption band above 400 nm that arises from the N<^>N ligand-localized (1)pi,pi*/(ILCT)-I-1 (intraligand charge transfer) transitions as well as the very weak (LLCT)-L-1,3/(MLCT)-M-1,3 transitions at longer wavelengths. The electron withdrawing NO2 substituent on the (NN)-N-boolean AND ligand leads to a blue-shift of the (1)pi,pi*/(ILCT)-I-1 absorption band, while the electron donating NPh2 substituent causes a pronounced red-shift of this band. The unsubstituted and NO2-substituted complexes (complexes 1 and 2, respectively) are moderately emissive at room temperature (RT) in solution as well as at 77 K in the glassy matrix, while the NPh2-substituted complex (3) is weakly emissive at RT, but the emission becomes much brighter at 77 K. Complexes 1 and 2 show very broad and strong triplet excited-state absorption from 460 to 800 nm with moderately long lifetimes, while complex 3 exhibits weak but broad absorption bands from 384 to 800 nm with a longer lifetime than those of 1 and 2. The nonlinear transmission experiment manifests that complexes 1 and 2 are strong reverse saturable absorbers (RSA) at 532 nm, while 3 shows weaker RSA at this wavelength. These results clearly demonstrate that it is feasible to tune the ground state and excited-state properties of the Ir(III) complexes via the terminal substituents at the diimine ligand. By introducing the fluoren-2-yl groups to the 2,2 '-biquinoline ligand to extend the diimine ligand pi-conjugation, we can obtain Ir(III) complexes with reasonably long-lived and strongly absorbing triplet excited state while red-shifting their (LLCT)-L-1,3/(MLCT)-M-1,3 absorption band into the near-IR region. These features are critical in developing visible to near-IR broadband reverse saturable absorbers.