Crystalline hydrogen-bonded organic framework for air-tolerant triplet-triplet annihilation upconversion.

A hydrogen-bonded organic framework (HOF) consisting of a 9,10-diphenylanthracene carboxylic derivative, DPACOOH, was developed for solid state triplet-triplet annihilation upconversion (TTA-UC). The HOF sample shows a 70% increase in upconversion quantum yield and a lower threshold value of 126.0 mW cm -2 compared to those of the disordered powder sample, due to a 43% longer triplet diffusion length in HOF than that in the powder sample.