Trindane−Ruthenium Sandwich Complexes:  An NMR and X-ray Crystallographic Study of [(trindane)RuCl<sub>2</sub>]<sub>2</sub>, (trindane)RuCl<sub>2</sub>[P(OMe)<sub>3</sub>], and [(trindane)<sub>2</sub>Ru][BF<sub>4</sub>]<sub>2</sub>

Trindane and [(<i>p</i>-cymene)RuCl<sub>2</sub>]<sub>2</sub> react in the melt to yield [(trindane)RuCl<sub>2</sub>]<sub>2</sub> (<b>4</b>), the NMR spectra of which reveal the presence of [{(trindane)Ru}<sub>2</sub>(μ-Cl)<sub>3</sub>]Cl (<b>6</b>) in solution. The X-ray crystal structure of <b>4</b> reveals that two of the cyclopentene rings adopt <i>endo</i> envelope conformations, while the third five-membered ring is folded in an <i>exo</i> fashion to avoid a terminal chlorine in the other half of the dimer. Bridge cleavage with trimethyl phosphite gives (trindane)RuCl<sub>2</sub>[P(OMe)<sub>3</sub>] (<b>8</b>), 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 <b>4</b> with excess trindane in the presence of AgBF<sub>4</sub> yields the dicationic sandwich compound [(trindane)<sub>2</sub>Ru]<sup>2+</sup> 2BF<sub>4</sub><sup>-</sup> (<b>3</b>).