Monomere Kupfer(I)-Alkyle mit β-Wasserstoffatomen und Kupfer(I)-Aryle mit kondensierten Aromaten; die Festkörperstruktur von [(η5-C5H4SiMe3)2Ti(CCSiMe3)2]CunC4H9

The synthesis of heterobimetallic titanium(IV)–copper(I) complexes of type {[Ti](CCSiMe3)2}CuR {3a, R=iC3H7; 3b, R=nC4H9; 3c, R=cC5H9; 3d, R=9-C13H9; 5a, R=1-C10H7; 5b, R=9-C14H9; [Ti]=(η5-C5H4SiMe3)2Ti} in which monomeric low-valent copper(I) organyls (CuR) are stabilised by the chelating effect of the organometallic π-tweezer [Ti](CCSiMe3)2 are accessible by the reaction of {[Ti](CCSiMe3)2}CuSC6H4CH2NMe2-2 (1) with equimolar amounts of ER (E=Li, BrMg). These species feature monomeric copper alkyls or aryls, bearing β-hydrogen atoms (complexes 3a–3c) or condensed aromatic π-systems (complexes 5a and 5b). While 3a–3d, 5a and 5b are stable at low temperature in the solid-state, it appeared that in solution 3a–3c undergo β-hydride elimination, affording propene (3a), 1-butene (3b) or cyclopentene (3c). Next to these species, HSiMe3 (8) along with the dimeric titaniumcopper acetylide {[Ti](CCSiMe3)(CuCC)}2 (6) is also formed. In contrast, 5b decomposes on heating (30 °C) to afford the tweezer molecule [Ti](CCSiMe3)2 (9) and (C14H9)2 (10). Possible reaction mechanism for the latter reactions will be discussed. The solid-state structure of 3b is reported. Complex 3b crystallizes in the triclinic space group with cell parameters a=13.659(2), b=17.270(3), c=18.106(4) Å, α=107.64(3), β=100.11(3), γ=108.51(3)°, Z=4 and V=3681(1) Å3. The most striking structural feature of 3b, which will be discussed, is that the nC4H9 moiety is orientated out of the Ti(CCSi)2Cu plane.