Reactions of a phosphinito bridged diplatinum(I) complex with coinage metal electrophiles

We have recently described the synthesis of the complex [(PHCy2)Pt1(m-PCy2){k2P,O-m-P(O)Cy2}Pt2(PHCy2)] (Pt-Pt) (1), the first unsymmetrical phosphinito bridged Pt(I) species.[1] The phosphinito bridge differentiates the charge distributions on the two platinum atoms as confirmed by NMR spectroscopy (dPt(1) = -4798 ppm, dPt(2) = -5207 ppm) and DFT studies. Complex 1 shows a rich chemistry as it reacts with nucleophiles [PHCy2, PCy3, P(S)HCy2],[2] protic species HX [P(OH)Cy2, PhSH, HF, HCl, HBr, HI, HBF4],[3, 4] and small molecules such as H2.[5] Recently, we started investigations on the reactivity of complex 1 towards Au and Ag based electrophiles. In this communication, it will be shown that, differently from the isolobal H+ (which attacks the phosphinito oxygen and migrates onto the Pt-Pt bond),3 the [Ag(PPh3)]+ electrophile attacks complex 1 selectively to the Pt2-mP bond to afford the cationic cluster [(PHCy2)Pt1(m-PCy2){k2P,O-m-P(O)Cy2}Pt2{m- -Ag(PPh3)}(PHCy2)]+ (Pt–Pt) (2+) in which the [Ag(PPh3)]+ moiety bridges the mP-Pt2 bond. Analogous reactivity is observed also when phosphane free electrophiles such as AgOTf, AgBF4, AgClO4 and AgCl are used. Moreover, the reactivity of 1 towards Au(I) electrophiles such as AuCl and [Au(PPh3)Cl] was dependent on the reagent and on the experimental conditions. references: 1. Gallo, V.; Latronico, M.; Mastrorilli, P.; Nobile, C. F.; Suranna, G. P.; Ciccarella, G.; Englert, U.; Eur. J. Inorg. Chem., 2005, 4607–4616. 2. Gallo, V.; Latronico, M.; Mastrorilli, P.; Nobile, C. F.; Polini, F.; Re, N.; Englert, U.; Inorg. Chem., 2008, 47, 4785–4795. 3. Latronico, M.; Polini, F.; Gallo, V.; Mastrorilli, P; Calmuschi-Cula B.; Englert, U.; Re, N.; Repo T., Raisanen M.; Inorg. Chem., 2008, 47, 9979-9796. 4. M. Latronico, P. Mastrorilli, V. Gallo, M.M.Dell’Anna, F. Creati, N. Re, U. Englert, Inorg. Chem. 2011, 50, 3539–3558 5. Mastrorilli P., Latronico M., Gallo V., Polini F., Re N., Marrone A., Gobetto R., Ellena S.. J. Am. Chem. Soc. 2010, 132, 4752–4765