Synthese von [(η5-C5H5)2Ti(Cl)(CCSiMe3)]Ni(CO) und dessen Reaktionsverhalten gegenüber Phosphiten: die Festkörperstruktur von (CO)2Ni[P(OC6H4CH3-2)3]2

Treatment of [Ti](Cl)(CCSiMe3) (1) {[Ti]=(η5-C5H5)2Ti} with Ni(CO)4 (2) in a 1:1 molar ratio produces the heterobimetallic early–late transition metal complex {[Ti](Cl)(CCSiMe3)}Ni(CO) (3), which features a low-valent Ni(CO) entity stabilized by a datively bonded Cl and a η2-coordinated Me3SiCC ligand. As side-products [Ti]Cl2 (8) and {[Ti](CCSiMe3)2}Ni(CO) (5) are formed. The latter complex can also be synthesized by the reaction of [Ti](CCSiMe3)2 (4) with equimolar amounts of 2. If 3 is reacted with stoichiometric amounts of P(OR)3 (6a, R=C6H5; 6b, R=C6H4CH3-2; 6c, R=C6H4tBu-2) the bis(alkynyl) titanocene 4, (CO)2Ni[P(OR)3]2 (7a, R=C6H5; 7b, R=C6H4CH3-2; 7c, R=C6H4tBu-2), complex 8, {[Ti](μ,η1:η2-CCSiMe3)}2 (9) along with Me3SiCCCCSiMe3 (10) is produced. A possible mechanism for the formation of these species is presented. The solid-state structure of 7b is reported. Complex 7b crystallizes in the tetragonalic space group P-421c with the following parameters: a=14.852(2), b=14.852(2), c=19.410(4) Å, V=4281.5(12) Å3, Z=4 and ρ=1.271 g cm−3. Mononuclear 7b features a Ni(0) centre in a pseudo-tetrahedral environment, caused by the CO and P(OC6H4CH3-2)3 ligands.