Trindane−Ruthenium Sandwich Complexes:  An NMR and X-ray Crystallographic Study of [(trindane)RuCl₂]₂, (trindane)RuCl₂[P(OMe)₃], and [(trindane)₂Ru][BF₄]₂

Trindane and [(p-cymene)RuCl₂]₂ react in the melt to yield [(trindane)RuCl₂]₂ (4), the NMR spectra of which reveal the presence of [{(trindane)Ru}₂(μ-Cl)₃]Cl (6) in solution. The X-ray crystal structure of 4 reveals that two of the cyclopentene rings adopt endo envelope conformations, while the third five-membered ring is folded in an exo fashion to avoid a terminal chlorine in the other half of the dimer. Bridge cleavage with trimethyl phosphite gives (trindane)RuCl₂[P(OMe)₃] (8), and the X-ray crystal structure shows that all three peripheral rings are folded such that the wingtip methylene groups are oriented toward the metal. Finally, treatment of 4 with excess trindane in the presence of AgBF₄ yields the dicationic sandwich compound [(trindane)₂Ru]²⁺ 2BF₄^- (3).