Reactions of Ruthenium(II)-co-ordinated Phenyl Phosphines: Synthesis and X-Ray Crystal Structures of the Orthometallated Complexes [Ru(C6H4PR1R2)(CH2SiMe3)(eta-6-C6Me6)] (R1=R2=Ph; R1=Ph, R2=Me; R1=R2=Me) and of [{Ru(CH2SiMe3)2(mu-sigma,eta-6-PMe2Ph)}2] containing Bridging Dimethylphenylphosphine Ligands