The reaction of compound cis-[Pt(C₆F₅)₂(SEt₂)₂] with the imine ligands ArCH?NCH₂CH₂NMe₂ (Ar = 2-BrC₆H₄ (1a) or 2,6-Cl₂C₆H₃ (1b)) in toluene produces coordination compounds cis-[Pt(C₆F₅)₂(ArCH?NCH₂CH₂NMe₂)] (2a, 2b) containing a bidentate [N,N′] ligand. No further reactivity has been observed from this point. Compound 2b has been characterized by single-crystal XRD. Under analogous conditions, imine ligand 2-BrC₆H₄CH?NCH₂(4′-ClC₆H₄) (1c) produced the Pt^II-metalated compound [PtBr{6-(C₆F₅)(2-C)C₅H₃CHNCH₂(4′-ClC₆H₄)SEt₂] (2c), which contains a five-membered metallacycle with a biaryl linkage involving a C₆F₅ group. The derivative compounds [PtBr{6-(C₆F₅)(2-C)C₅H₃CHNCH₂(4′-ClC₆H₄)L] (L = SMe₂ (3c), L = PPh₃ (4c)) were also prepared, and compound 4c has also been characterized by XRD. The kinetico-mechanistic study of the formation of compound 2c has also been pursued in view of the previously published data, leading to seven-membered metallacycles. The time monitoring via UV-vis of the full process allowed the detection and NMR characterization of two intermediate species. An initial Pt^IV complex is present in steady-state low-concentration conditions, and formation of a non-cyclometalated intermediate Pt^II compound is also detected during the process. The latter already contains the C-C coupled ligand arising from a reductive elimination of the former. Intramolecular C-H activation from the latter produces the final characterized compound 2c along with C₆F₅H. The full process has been studied as a function of temperature and pressure as well as at varying nonstoichiometric concentrations of SEt₂ and free imine ligand. The results agree with the quenching of the process at important excesses of SEt₂ (for stoichiometric reasons) or free imine (avoiding the formation of the final complex from the C-C reductively coupled intermediate). The thermal and pressure activation parameters measured indicate that the mechanism operating in this case lies out of the continuum existing for the series of C-H bond activations studied so far. The more than probable associative shift of the reactivity of the PtII complex containing the electron-withdrawing C₆F₅ ligands is held responsible for this fact.