167110-00-1Relevant articles and documents
Steric effects in the chemistry of platinum cluster complexes
Hao, Leijun,Jobe, Ian R.,Vittal, Jagadese J.,Puddephatt, Richard J.
, p. 2781 - 2789 (2008/10/09)
A study of steric effects of the ligands R2PCH2PR2, R = aryl, on the formation and chemistry of the clusters [Pt3(μ3-CO)(μ-R2PCH2PR 2)3(O2CCF3)]+, 4, and [Pt3(μ3-CO)(μ-R2PCH2PR 2)3]2+, 8, is reported. When R = 2-MeC6H4, reduction of [Pt(O2CCF3)2(R2PCH 2PR2)] by CO/H2O gave only the binuclear complex [Pt2H(CO)(μ-R2PCH2PR2) 2]+, but with smaller groups R, further reduction to 4 (R = 4-MeC6H4, 3-MeC6H4, 3,5-Me2C6H3, 3,5-F2C6H3, 3,5-Cl2C6H3) or to [Pt4(μ-CO)2(μ-H)(μ-R2PCH2PR 2)3(R2PCH2PR2)] + (R = 4-MeC6H4, 3,5-F2C6H3) occurred. The complexes were characterized spectroscopically and for 4(CF3CO2), R = 3,5-Cl2C6H3, crystallographically [C80H42Cl24F6O5P 6Pt3·0.5CH2Cl 2·L5H2O, monoclinic, P21/n, a = 23.365(4) A, b = 24.599(4) A?, c = 19.141(7) A?, β = 102.44(2)°, Z = 4, R = 0.0727]. The complexes 8 can all form adducts with I-, SCN-, and CF3CO2- though evidence is presented that coordination of CF3CO2- is reversible in solution when R = 3,5-Cl2C6H3. Reactions of 8 with the ligands L = PPh3, PMePh2, P(OPh)3, and P(OMe)3 to form the adducts [Pt3(μ3-CO)(μ-R2PCH2PR 2)3L]2+ are reversible, and the position of equilibrium depends on the steric effects of R, indicating the steric sequence R = 4-MeC6H4, 3-MeC6H4 2C6H3 2C6H3 2C6H3.
