The photoproperties of main group metal complexes with the electron configurations s2 (e.g. Tl+, Sb3+, Te4+) and so (e.g. T13+, Pb4+) were studied on the basis of a general concept which relates characteristic excited states to typical photophysical and photochemical processes. The photochemistry is dominated by metal- centered sp (s2) and ligand to metal charge transfer (so) excited states which are capable of inducing inter- and intramolecular redox reactions.