Four useful polypyridine iridium(III) complexes in the form of [IrCl
2L
2]
+ were prepared and their spectroscopic and electrochemical properties as well as X-ray crystallography were investigated. The ligands used were L = 2,2′-bipyridine, 4,4′-dimethyl-2,2′-bipyridine, 4,4′-diphenyl-2,2′-bipyridine, 1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline, and 2,2′-biquinoline. Synthetic methods were developed by a sequential ligand-replacement, which occurred in the reaction vessel using a microwave oven. All complexes showed that LUMOs are based on the π-system contribution of the polypyridine ligand for [IrCl
2(bpy)
2]
+, [IrCl
2(dmbpy)
2]
+, [IrCl
2(dpbpy)
2]
+, [IrCl
2(phen)
2]
+, [IrCl
2(dpphen)
2]
+ and [IrCl
2(bqn)
2]
+. The HOMOs are also localized on the polypyridine ligand in the iridium complexes. It was found that [IrCl
2L
2]
+ emits intense phosphorescence at room temperature. In particular, the use of dpbpy as ancillary ligands extends the lifetime (660 ns) of the
3(π-π
*) excited states of Ir(III) polypyridine complexes. The complex [IrCl
2(bqn)
2]
+ with electron acceptor substituents shows a large red-shift to 622 nm. It is noticed that iridium polypyridine complexes show intense emissions at various colors, such as yellow for [IrCl
2(dmbpy)
2]
+ and red for [IrCl
2(bqn)
2]
+, which can be applied to photosensitizers. The spectroscopic and electrochemical details are also reported herein.
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