9-9′-Bifluorenylidene (BFD) complexes of ruthenium [{(η5-C5Me5)Ru}n(BFD)]x (x = 0, n = 1' x = 1+, n = 2): EPR and spectroelectrochemical studies. X-ray structure of [{(η5-C5Me5Ru}(BFD)](OSO2CF3)

[(η5-C5Me5Ru]+ coordinates to the six-membered aromatic rings of the bifluorenylidene (BFD) chromophore to afford mononuclear [(η5-C5Me5)Ru(BFD)]+ and dinuclear {[(η5-C5Me5)Ru]29BFD)}2+ compounds which could be isolated as trifluoromethane sulfonate salts, 1(OTf) and 2(OTf)2, respectively. The X-ray structure of 1 was determined and both compounds were studied by spectroelectrochemical methods and their reduced species by EPR.