| Investigations of (dfepe)Pt(II) (dfepe = (C2F5) 2PCH2CH2P(C2F5)2) coordination chemistry in superacidic media are reported. Reaction with HX and SbF5 or SbF5:SO2 afforded both (dfepe)Pt(Me)X where X = OTf (1&barbelow;), FSO3 (2&barbelow; ) and Sb2F11 (3&barbelow;), and (dfepe)PtX2 complexes (where X = OTf (4&barbelow;), FSO3 (5&barbelow;) and Sb2F11 (6&barbelow;)). The reactivity of these compounds in their respective superacids with the CO, H2 and Benzene led to the formation of new weakly-coordinated adducts, which were characterized in solution by NMR and IR spectroscopy. Treatment of (dfepe)Pt(X)2 and (dfepe)Pt(Me)(X) (X = OTf, FSO3) in their neat respective acids with 1 atm CO cleanly afforded the monocarbonyl cations (dfepe)Pt(X)(CO)+ (X = OTf, FSO3) (7&barbelow;) and (dfepe)Pt(Me)(CO)+ (8&barbelow; ). In the case of X = FSO3, exposure to CO at pressures above 100 psi led to the reversible formation of [(dfepe)Pt(CO)2] 2+(9&barbelow;). Hydrogenation of 4–6 with 1 atm of H2 initially forms [(dfepe)Pt(μ-H)]2 and subsequently protonates to form [(dfepe)2Pt2(H)3] + (10&barbelow;). Reaction of 4 and 5 with benzene yielded a rare square planar diphosphine Pt(II) η6-arene complex, (dfepe)Pt(C6H6)2+ ( 11). Preliminary findings of the catalytic hydrogenation of (11) under ambient temperature and 1 atm H2 are reported. Initial high-pressure experiments with small molecules N2, Xe, CO2 and CH4 employing a high pressure sapphire NMR cell are also presented. |
