A　series　of　Ir(III)　complexes　(N)2Ir(N　N)　(N　N　are　4,4′-dihydroxy-2,2′-bipyridine　and　4,4′-diamino-2,2′-bipyridine,　and　N　are　phenylpyridine,　benzo[h]quinolone,　and　2-phenylquinoline)　were　synthesized　and　characterized.　Two　of　the　complexes　were　structurally　characterized　via　X-ray　crystallography.　The　photophysical　and　photochemical　properties　of　these　complexes　were　studied.　Preliminary　studies　of　their　applications　on　pH　sensing,　and　cell　imaging　were　also　performed.　©　2015　Elsevier　B.V.　All　rights　reserved.