Pentamethylcyclopentadienyl-rhodium and-iridium complexes XIV. The solvolysis of coordinated acetone solvent species to tris(μ-difluorophosphato)bis[η5-pentamethylcyclopentadienylrhodium(III)] hexafluorophosphate, to the η5-(2,4-dimethyl-1-oxapenta-1,3-dienyl)(pentamethylcyclopentadienyl)iridium cat