Adduct Studies and Reactivity of <i>trans</i>-[(C₂F₅)₂MeP]₂Pt(Me)X (X = O₂CCF₃, OTF, OSO₂F)

Abstract

The comparative reactivity properties of previously reported trans -(dfmp) 2 Pt(Me)X (dfmp = (C 2 F 5 ) 2 MeP; X = O 2 CCF 3, OTf, OSO 2 F) with small molecules are presented. Anionic ligand displacement by CO depends upon X and the corresponding acid solvent. In trifluoroacetic acid, treatment of trans -(dfmp) 2 Pt(Me)(O 2 CCF 3 ) with CO results in loss of dfmp to form the mixed phosphine/carbonyl product (dfmp)(CO)Pt(Me)(O 2 CCF 3 ). However, in triflic and fluorosulfonic acids trans -(dfmp) 2 Pt(Me)(X) compounds react with CO to form trans -(dfmp) 2 Pt(Me)(CO) + (X) - . trans -(dfmp) 2 Pt(Me)(X) systems react with H 2 under both acidic and aprotic conditions to form trans -(dfmp) 2 Pt(H)(X); trans -(dfmp) 2 Pt(H)(OTf) has been crystallographically characterized. Treatment of trans -(dfmp) 2 Pt(H)(OTf) with CO or dfmp gives trans -(dfmp) 2 Pt(H)(CO) + or (dfmp) 3 Pt(H) +, respectively. In contrast to trans -(dfmp) 2 Pt(Me)(OTf), which releases methane in HOTf, trans -(dfmp) 2 Pt(Me)(OSO 2 F) in FSO 3 H at 80 °C cleanly produces the reductive elimination product MeOSO 2 F. Carbonylation of trans -[(dfmp) 2 PtMe(CO)] + X - under 1000 psi CO in turn cleanly produces MeC(O)X at ambient temperatures. The mechanism of reductive elimination from these Pt(II) precursors is discussed.