Efficient Enhancement of the Visible-Light Absorption of Cyclometalated Ir(III) Complexes Triplet Photosensitizers with Bodipy and Applications in Photooxidation and Triplet–Triplet Annihilation Upconversion

Red-light-absorbing diimine Pt(II) bisacetylide complexes showing near-IR phosphorescence and long-lived 3IL excited state of Bodipy for application in triplet-triplet annihilation upconversion

Bodipy is used for the preparation of Pt(II) bisacetylide complexes which show strong absorption of visible light and long-lived triplet state. Room temperature (RT) near-IR phosphorescence of Bodipy was observed. The π-conjugation framework of visible light-harvesting Bodipy ligand was connected to the Pt(II) center by the C≡C bond. The complexes were used as triplet photosensitizers for triplet-triplet annihilation (TTA) upconversion.

Singlet oxygen generation by cyclometalated complexes and applications

While cyclometalated complexes have been extensively studied for optoelectronic applications, these compounds also represent a relatively new class of photosensitizers for the production of singlet oxygen. Thus far, singlet oxygen generation from cyclometalated Ir and Pt complexes has been studied in detail. In this review, photophysical data for singlet oxygen generation from these complexes are presented, and the mechanism of (1) O2 generation is discussed, including evidence for singlet oxygen generation via an electron-transfer mechanism for some of cyclometalated Ir complexes. The period from the first report of singlet oxygen generation by a cyclometalated Ir complex in 2002 through August 2013 is covered in this review. This new class of singlet oxygen photosensitizers may prove to be rather versatile due to the ease of substitution of ancillary ligands without loss of activity. Several cyclometalated complexes have been tethered to zeolites, polystyrene, or quantum dots. Applications for photooxygenation of organic molecules, including "traditional" singlet oxygen reactions (ene reaction, [4 + 2] and [2 + 2] cycloadditions) as well as oxidative coupling of amines are presented. Potential biomedical applications are also reviewed.

Cyclometalated Ir(iii) complexes with styryl-BODIPY ligands showing near IR absorption/emission: preparation, study of photophysical properties and application as photodynamic/luminescence imaging materials

Heteroleptic C^N cyclometalated iridium(iii) complexes showing strong NIR absorption were prepared.