10.1021/ic5013044.s001 Yifei Liu Yifei Liu Cheikh Mbacké Ndiaye Cheikh Mbacké Ndiaye Corinne Lagrost Corinne Lagrost Karine Costuas Karine Costuas Sylvie Choua Sylvie Choua Philippe Turek Philippe Turek Lucie Norel Lucie Norel Stéphane Rigaut Stéphane Rigaut Diarylethene-Containing Carbon-Rich Ruthenium Organometallics: Tuning of Electrochromism American Chemical Society 2014 EPR UV DTE ligand oxidation quantum chemical calculations electrochemical cyclization electrochemical ring closure EEC 2014-08-04 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Diarylethene_Containing_Carbon_Rich_Ruthenium_Organometallics_Tuning_of_Electrochromism/2268772 The association of a dithienylethene (DTE) system with ruthenium carbon-rich systems allows reaching sophisticated and efficient light- and electro-triggered multifunctional switches R-[Ru]-CC-DTE-CC-[Ru]-R, featuring multicolor electrochromism and electrochemical cyclization at remarkably low voltage. The spin density on the DTE ligand and the energetic stabilization of the system upon oxidation could be manipulated to influence the closing event, owing to the noninnocent behavior of carbon-rich ligands in the redox processes. A combination of spectroscopic (UV–vis–NIR–IR and EPR) and electrochemical studies, with the help of quantum chemical calculations, demonstrates that one can control and get a deeper understanding of the electrochemical ring closure with a slight modification of ligands remote from the DTE unit. This electrochemical cyclization was established to occur in the second oxidized state (EEC mechanism), and the kinetic rate constant in solution was measured. Importantly, these complexes provide an unprecedented experimental means to directly probe the remarkable efficiency of electronic (spin) delocalization between two <i>trans</i> carbon-rich ligands through a metal atom, in full agreement with the theoretical predictions. In addition, when no cyclization occurs upon oxidation, we could achieve a redox-triggered magnetic switch.