A new aza-15-crown-5 ether-appended iridium complex was synthesized and showed promising on-off selective emission-triggering by inhibition of photoinduced electron transfer (PET) upon binding of Mg(2+).

Photochemical primary processes of benzoyltriphenylgermane and benzoylphenyldimethylgermane were studied at room temperature in cyclohexane and chloroform. The germyl radicals generated were observed directly with the aid of a laser-photolysis technique.

Cyclic voltammetry of seven substituted benzoylsilanes (1) and three benzoylgermanes (2) were investigated. The effects of substituents of 1 and 2 on both cathodic reduction and anodic oxidation potentials were discussed. The cathodic reduction products of 1 were also examined.