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Two reactions of [Re2Cl8]2− with diphosphines that lead to ReRe bond cleavage

1988; Elsevier BV; Volume: 142; Issue: 2 Linguagem: Inglês

10.1016/s0020-1693(00)81569-8

1873-3255

F. Albert Cotton, L.M. Daniels,

Asymmetric Hydrogenation and Catalysis

Reactions of (n-Bu4N)2Re2Cl8 with the diphosphines Et2PCH2CH2PEt2 (depe) and (p-MeC6H4)2- PCH2CH2P(p-C6H4Me)2 (dtpe) were carried out under mild conditions with the hope of obtaining Re2Cl6(diphos)2 type products. On the contrary, in both cases the only isolated products contained mononuclear ReIII cations of the type [trans-ReCl2- (diphos)2]+. The following two compounds and their crystallographic characterizations are described: 1: [ReCl2(dtpe)2]Cl·-3CH2Cl2, yellow, space group P1, a = 17.326(2),b = 18.002(2), c=11.1931(9) Å,α= 102.861(7), β=105.345(7), γ=81.111(8)γ, Z=2. 2: [ReCl2(depe)2]2 [Re2Cl8], olive green, space group Pbca,a = 23.069(3), b= 24.036(3), c = 14.818(2) Å, Z = 4. The cations in each case have trans structures and bond lengths within the expected ranges. The [Re2Cl8]2− ion has the expected structure and shows the typical form of disorder, with 74% major and 26% minor orientations of the Re2 unit.