Designed prototype molecules for making a three-terminal single-molecule device, star-shaped Fe-II, Co-II, and Ru-II trisbipyridine complexes containing three dithienylcyclopentenes, have been synthesized and characterized. All complexes displayed reversible photochromic behavior when irradiated with UV or visible light. The open form of these complexes could be cyclized electrochemically as revealed by cyclic voltammetric studies and bulk electrolysis experiments.