One of the activation procedures most frequently used in late transition metal chemistry consists in generating cationic metal complexes by halide abstraction from the metal center in the presence of a weakly coordinating anion. We report here on the major effect of replacing Ag(I) with Tl(I) salts, although they are often used indiscriminately as halide abstractors. The Pt(II) complex [Pt(CH2Ph)Cl(PCH2-ox)] (1) (PCH2-ox = κ2-P,N-(oxazolinylmethyl)diphenylphosphine) yielded the expected metathesis product [Pt(CH2Ph)(OTf)(PCH2-ox)] (2) when treated with 1 equiv of AgOTf (OTf = SO3CF3) in CH2Cl2. In a coordinating solvent such as acetonitrile, chloride displacement readily afforded [Pt(CH2Ph)(NCCH3)(PCH2-ox)]X (3), irrespective of the nature of the halide abstractor (M+ = Ag+ or Tl+) and counterion (X- = OTf-, BF4-, PF6-) used. Reaction of 1 in CH2Cl2 with only half an equivalent of AgBF4 afforded the new, chloride-bridged dinuclear complex [{Pt(CH2Ph)(PCH2-ox)}2(μ-Cl)]BF4 (5·BF4), which results from trapping of the cation [Pt(η3-CH2Ph)(PCH2-ox)]+ (4) by unreacted 1. Similarly, the Pt/Pd heterometallic, single-chloride bridged complex [{Pt(CH2Ph)(PCH2-ox)}(μ-Cl){PdMe(PCH2-ox)}]BF4 (6·BF4) was obtained by reaction of 4 with [PdClMe(PCH2-ox)] in a 1:1 ratio. When 1 was reacted in CH2Cl2 with Tl+ instead of Ag+, formation of 4 was not observed and the main product was an unexpected adduct of Tl+ to 1 whose X-ray analysis established the formation of both a Pt−Tl bond and a η6-benzyl−Tl interaction. This bimetallic complex, [(PCH2-ox)ClPtTl{μ-(η1-CH2;η6-C6H5)CH2Ph}(Pt−Tl)]PF6 (7·PF6), is to our knowledge the first metal−metal bonded Tl−Pt−Cl complex to be fully characterized. The coordination geometry around Pt(II) is square-pyramidal, with Tl(I) in the apical position. The Pt−Tl distance of 3.0942(9) Å corresponds to a metal−metal bond that results mainly from donation of electron density from the Pt(II) 5dz2 orbital to the vacant Tl(I) 6pz orbital. The Pt−Tl bond is not exactly orthogonal to the Pt(II) square-plane (angle of 70(3)°), but parallel to the C(1)−C(2) bond, thus allowing better π-donation from the benzyl ligand to Tl+. When the corresponding benzoyl complex [Pt{C(O)Ph}Cl(PCH2-ox)] (9) was reacted with MX (M+ = Ag+, Tl+) in CH2Cl2, only chloride abstraction and CO deinsertion occurred. Our findings explain why halide abstraction to generate a cationic metal complex with enhanced (catalytic) reactivity may not come to full completion or fail owing to trapping of the cationic complex or “capture” of Tl+ by the neutral precursor acting, in our case, as an unprecedented chelate through metal−metal bond formation and benzyl coordination. The crystal structures of 1, 5·BF4·0.5CH2Cl2, 7·PF6, 9·0.5CH2Cl2, and 10·PF6·0.75C4H8O have been determined by X-ray diffraction.