Several iridium complexes {iridium (III) bis [2-(3-methoxyphenyl)-1, 3-benzothiozolato-N, C2′] acetylacetonate (MeO-BT) 2Ir (acac), iridium (III) bis [2-(2, 4-difluorophenyl)-1, 3- benzothiozolato-N, C2′] acetylacetonate (2F-BT) 2Ir (acac), and iridium (III) bis [2-(2, 4- difluorophenyl)-6-fluoro-1, 3-benzothiozolato-N, C2′] acetylacetonate (3F-BT) 2Ir (acac)} having different substituents on 2-phenylbenzothiazole have been synthesized. The ...