An achiral photochromic dithionite (micro-O(2)SSO(2)) complex with n-propyl moieties forms chiral crystals and undergoes an enantioselective photoisomerization (ee > 90%) to an oxysulfur (micro-O(2)SOS*O) complex, containing an asymmetric S atom, with essentially 100% interconversion of the chiral crystals.
