A single Ti O C linkage induces interfacial charge-transfer transitions between TiO2 and a π-conjugated molecule

Interfacial charge-transfer (ICT) transitions between wide-band-gap semiconductors such as titanium dioxide (TiO 2 ) and π-conjugated molecules enable the absorption of visible light with colorless organic compounds and also direct photoinduced electron transfers across the interfaces. ICT transitions have been reported to be induced by a double Ti O C linkage of enediol compounds with two hydroxy groups to TiO 2 . In this Letter, we demonstrate that a single Ti O C linkage of phenol with one hydroxy group can induce ICT transitions in the visible region. Our result widely opens up the range of organic compounds available for ICT transitions from diol compounds to mono-hydroxy compounds.