Rhenium complexes with weakly coordinating solvent ligands, cis-[Re(PR3)(CO)4-(L)][BArF], L = CH2Cl2, Et2O, NC5F5:: Decomposition to chloride-bridged dimers in CH2Cl2 solution

The solvent-coordinated complexes [cis-Re(CO)(4)(PR3)(S)][BArF] (R = Ph, Pr-i, Cy BArF = [B(3,5-(CF3)(2)C6H3)(4)](-)) for S = Et2O. CH(2)Chl(2) and NC5F5 have been prepared from reaction of the neutral methyl precursors, cis-Re-(CO)(4)(PR3)(Me), with either [H(OEt2)(2)][BArF] or [Ph3C][BArF] in the appropriate solvent. A crystal structure of the complex [cis-Re(CO)(4)((PPr3)-Pr-i)(ClCH2Cl)][BArF] shows that the dichloromethane ligand is coordinated through one chlorine, with an Re-Cl distance of 2.554(2) Angstrom. The first example of a structurally characterized pentafluoropyridine complex of rhenium was also determined, [cis-Re(CO)(4)((PPr3)-Pr-i)(NC5F5)][BArF], with an Re-N distance of 2.319(5) Angstrom. Activation of C-CI bonds in the dichloromethane complexes result in the formation of the chloride-bridged dimers, {[Cis-Re(CO)(4)(PR3)](2)(mu-Cl)}{BArF}, and the X-ray structures of the Ph and Cy derivatives were determined.