image: Image of TTA-UC with Δ-［Ir（Bzq）2（phen）］2 （donor）and DPA （acceptor）in R-limonene solvent in organically modified synthetic hectorite
Credit: Jun Yoshida
The topic of “triplet–triplet annihilation photon up-conversion（TTA-UC）involving iridium（III） complexes” is attracting an extensive attention. More recently the investigation has been extended to the systems hybridizing iridium（III）complexes with organic or inorganic polymers. Only few attempts, however, have been reported to use clay minerals as a host material. In this paper, the iridium（III）complexes were used as a donor due to their highly emitting properties. As an example, a cationic iridium（III）complex, ［Ir（bzq）2（phen）］+ （bzqH = benzo［h］quinoline； phen = 1,10-phenanthroline）, was hybridized with synthetic saponite and used as a donor to realize the TTA-UC stored in 9,10-diphenylanthracene as an acceptor.It is emphasized that the efficiency of TTA-UC was enhanced in colloidal clay systems. Extending the work, the hybridization was also performed with organically modified synthetic hectorite. The TTA-UC was achieved even in an aprotic medium of 1:1 （v/v） toluene/R-limonene under air. Notably R-limonene is a natural product belonging to a green solvent. The present finding may have demonstrated the utility of clay minerals for energy up-conversion in green solvents.
Journal
Applied Clay Science
Article Title
Triplet-triplet annihilation up-conversion of cationic iridium(III) complex solubilized by organically-modified hectorite in a green solvent