The reaction of titanocene bis(ferrocenylacetylide) and bis(ruthenocenylacetylide) with silver cation: formation of bis(Ti-tweezers) silver complexes
摘要:
Titanocene bis(acetylide) where the acetylide has ferrocenyl or ruthenocenyl terminal group (C5H4R)(2)Ti{(C=C)(n)-Mc}(2), reacted with 0.5 equivalent amount of AgPF6 giving cationic heptanuclear complexes of the form [(C5H4R)(4)Ti-2{(C=C)(n)-Mc}(4)Ag](PF6) (la: R = SiMe3, n = 1, Me = ferrocenyl, 2a: R = H, n = 2, Me = ferrocenyl, 3a: R = SiMe3, n = 2, Me = ferrocenyl, 4a: R = SiMe3, n = 1, Me = ruthenocenyl) in good yields. Likewise, complex [(C5H4SiMe3)(4)Ti-2(C=CPh)(4)Ag](PF6) (5a) was isolated. The Ti(IV)-Fe(II)-Ag(I) complex 3a was structurally characterized to confirm the solid-state geometry of the first bis(Ti-tweezers) type chelate complex with silver cation in which the silver was coordinated by four triple bonds of the two titanocene bis(acetylide) moieties. The similar Ti(IV)-Ru(IH)-Ag(I) complex 4a was also characterized by single-crystal X-ray analysis. Complex 3a reacted with 1.5 equivalents (with respect to Ti) of AgPF6 to liberate Fc-(C=C)(4)-Fe (Fc = ferrocenyl) quantitatively. (C) 1998 Elsevier Science S.A. All rights reserved.
Reductive coupling reaction induced by remote-site oxidation in titanocene bis(metallocenylacetylide), where metallocenyl = ferrocenyl or ruthenocenyl: a novel route to Cn (n = 4, 6, and 8) wire with the metallocenyl groups at both terminals
摘要:
The titanocene bis(acetylide) complexes (eta(5)-C5H4R)(2)Ti[(C=C)(m)-Mc][(C=C)(n)-Mc'] (R = H, SiMe3; m, n = 1 or 2; Mc, Mc' = ferrocenyl or ruthenocenyl) have been prepared and found to be easily oxidized with 2 equiv. amount of AgPF6 liberating a neutral product, Mc-(C=C)(m)(C=C)(n)-Mc'. Electrochemical studies indicate that the reaction is induced by initial oxidation of Mc and Mc' followed by unprecedented reductive coupling of the two alkynyl carbons bound to titanocene. (C) 1997 Elsevier Science S.A.