名称:
Syntheses and Structures of the Crystalline, Highly Crowded 1,3-Bis(trimethylsilyl)cyclopentadienyls [MCp″3] (M = Y, Er, Yb), [PbCp″2], [{YCp″2(μ-OH)}2], [(ScCp″2)2(μ-η2:η2-C2H4)], [YbCp″2Cl(μ-Cl)K(18-crown-6)], and [{KCp″}∞]
摘要:
Yttrium and the smaller group 3 and 4f metal homoleptic M(III) cyclopentadienyls [MCp ''(3)] (Cp '' = [eta(5)-C5H3(SiMe3)(2)-1,3](-) and M = Y (1Y), Er (1Er), or Yb (1Yb)) were prepared from YCp '' I-2 (2Y) or the appropriate [LnCp '' I-2(thf)] and KCp '' in satisfactory (1Y), very low (1Er), or low (1Yb) yield. Attempted reaction of [ScCp '' I-2(thf)] with KCp '' failed to produce the homoleptic Sc(III) cyclopentadienyl. Compound 1Yb was synthesized in better yield by the redox reaction between [YbCp ''(2)(thf)] and either [PbCp ''(2)] (3) or the in situ prepared HgCp ''(2) (4) analogue. Complexes 3 and 4 were obtained by a salt metathesis route, 3 was isolated as a crystalline solid, while 4 was used only as a hexane solution. The structures of crystalline 1Y, 1Yb, 3, [{YCp ''(2)(mu-OH)}(2)] (5Y) [prepared by hydrolysis of 1Y], [(ScCp ''(2))(2)-(mu-eta(2):eta(2)-C2H4)] (6) {isolated in low yield from the reaction of ScCp '' I-2 (2Sc) with [K(18-crown-6)](2)[C6H2(SiMe3)(4)-1,2,4,5]}, [LaCp '' Cl-2(mu-Cl)K(18-crown-6)] (7La) {obtained from the foregoing potassium reagent and [{LaCp ''(2)(mu-Cl)}(2)]}, [YbCp '' Cl-2(mu-Cl)K(18-crown-6)] (7Yb), and [{KCp ''}(infinity)] (8) were determined by X-ray diffraction.