372195-27-2Relevant academic research and scientific papers
B(C6F5)3 as C6F5 transfer agent in zirconium chemistry: Borole sandwich and borole-bridged triple-decker complexes
Woodman, Timothy J.,Thornton-Pett, Mark,Hughes, David L.,Bochmann, Manfred
, p. 4080 - 4091 (2001)
Treatment of Cp″Zr(C6F5)(OEt2) {η5-(3-RC4H3BC6F5)} (1H, R = H; 1Me, R = Me; Cp″ = 1,3-C5H3 (SiMe3)2) in toluene with nitriles R′CN gives rise to the adducts Cp″Zr(C6F5)-(NCR′) {η5-(3-RC4H3BC6F5)} (2H, R = H, R′ = Me; 3H, R = H, R′ = tBu; 3Me, R = Me, R′ = tBu) in high yields. The reaction of 1H and 1Me with a 4-fold excess of tert-butylisocyanide in toluene at -20°C leads to the formation of Cp″Zr(C6F5)(CNtBu)2 {η5-(3-RC4H3BC6F5)} (4H, R = H; 4Me, R = Me), while warming to room temperature results in the insertion of one molecule of isocyanide into the zirconium-C6F5 bond to give the η2-iminoacyl complexes Cp″Zr{η2-(C6F5CNtBu)}(CNtBu) {η5-(3-RC4H3 BC6F5)} (5H, R = H; 5Me, R = Me). The structures of 3H and 5H were confirmed by X-ray diffraction. The reaction of the diene complexes CpRZr(η3-crotyl)(η4-butadiene) (6a, CpR = C5H4SiMe3; 6b, C5H4Me; 6c, Cp; 6d, Cp″) with B(C6F5)3 in toluene solution at room temperature proceeds quantitatively with C-H activation, butene elimination, and C6F5 transfer to generate CpRZr(C6F5){η4-CH2CHC HCHB(C6F5)2} (7a-d). These boryldiene complexes are thermally unstable and smoothly rearrange to give the triple-decker complexes Zr2(CpR)2(C6 F5)2 {μ-η5:η5- C4H4BCH2-η3,κF-CHCHCHB (C6F5)3} (8a-d). The formation of these complexes involves the complete transfer of all three C6F5 substituents of one B(C6F5)3 molecule, as well as C-H activation and the loss of one C6F5 group as pentafluorobenzene. The triple-decker complexes feature a Zr2 C4B core, a zwitterionic structure, and an unusually strong Zr-F donor interaction. On activation with methylalumoxane (MAO), 8a-d polymerize ethene.
