Three novel phosphorescent 2-phenylpyridine-based iridium(III) complexes, $[(ppy)_2Ir(P^{}N)]PF6;(1),;[(dfppy)_2Ir(P^{}N)]PF_6$ (2), and $[(dfmppy)_2 Ir(P^{}N)]PF6$ (3), where $P^{}N$ = 2-[(diphenylphosphino)methyl]pyridine (dppmp), were synthesized and characterized. The absorption, photoluminescence, cyclic voltammetry and thermal stability of the complexes were investigated. The complexes showed bright blue luminescences at wavelengths of 448 $sim$ 500 nm at room temperature in $CHCl_3$ and revealed that the $pi$-acceptor ability of the phosphorous atom in the ancillary dppmp ligand plays an important role in tuning emission color resulting in a blue-shift emission. The single crystal structure of $[(dfmppy))_2Ir(P^N)]PF_6$ was determined using X-ray crystallography. The iridium metal center adopts a distorted octahedral structure coordinated to two dfmppy and one dppmp ligand, showing cis C-C and trans N-N chelate dispositions. There is a $pi-pi$ overlap between π electrons delocalized in the difluorophenyl rings.