Color Tuning of Cyclometalated Iridium Complexes through Modification of Phenylpyrazole Derivatives and Ancillary Ligand Based on ab Initio Calculations

Various iridium complexes consisting of phenylpyrazole (ppz) ligands and isoquinolinecarboxylic acids (iq) as ancillary ligands were designed by energy band-gap calculations
via ab initio calculations and synthesized to give rise to various emission wavelengths as
expected. Fine color tuning was achieved through varying the position of the methyl
substituent on the phenylpyrazole moiety with HOMO electron densities. Additional color
tuning was made possible by altering the LUMO through the use of different ancillary ligands
such as 1-isoquinolinecarboxylic acid (1iq) and 3-isoquinolinecarboxylic acid (3iq).