The bulky titanium monoamido complex Cl 3 TiNCy 2 (1) was synthesized from TiCl 4 and dicyclohexylamine (Cy 2 NH). The solid-state structure of 1 demonstrates a close intramolecular contact between the metal centre and one ipso carbon atom of the amido ligand. This contact may indicate an agostic interaction analogous to those of transition metal alkyl compounds. The alteration of the coordination sphere of 1 with neutral ligands [pyridine (2), 2,2Ј-bipyridyl (3), N,N,NЈ,NЈtetramethylethane-1,2-diamine (tmeda, 4), and 1,2-bis(dimethylphosphanyl)ethane (dmpe, 5)] results in octahedral compounds with a meridional arrangement of the ligands. The solid-state structure of 5 reveals a significantly closer contact between the titanium atom and one ipso carbon atom of the ligand. The magnesium reduction of 1 in the presence of adamantylidenepentafulvene yields the dark green com-

The synthesis and crystal structures of two dinuclear titanocene hydride complexes are reported. Both complexes, namely bis(η 5 -(di-para-tolylmethyl)cyclopentadienyl)titanium hydride dimer, [(η 5 -C 20 H 19 ) 2 Ti(μ-H)] 2 (2a), and bis(η 5 -2-adamantylcyclopentadienyl)-titanium hydride dimer, [(η 5 -C 15 H 19 ) 2 Ti(μ-H)] 2 (2b), are formed via activation of molecular hydrogen by the corresponding bis(η

The reactions of organic azides (RN 3 ; R = 2,6-dimesitylphenyl, SiMe 3 ) with bis(η 5 :η 1 -pentafulvene)titanium complexes 1 and titanium monopentafulvene complexes [Cp # Ti(η 5 :η 1 -pentafulvene)Cl] (5; #: R 5 = H, Me) were investigated. For complexes 1, insertion of the γ-N atom of the azide into the Ti-C exo bond results in the formation of titanium triazenido complexes 2 in good yields. Complexes 2 undergo subsequent rearrangements in solution to titanium imido com- [a] [a]

The reaction of η(5),η(1)-pentafulvene titanium complexes with the strong N-heterocyclic carbene (NHC) donor 1,3,4,5-tetramethylimidazole-2-ylidene, leads to the formation of isolable NHC titanium adducts, featuring a haptotropic shift of the pentafulvene ligand, proved by single crystal X-ray diffraction as well as NMR spectroscopy studies.

The syntheses of alkyl titanium and zirconium dicyclohexylamido complexes from (Cy2N)3MCl (Cy: cyclohexyl, M: Ti 1a, M: Zr 1b) are presented. Particularly the β-H-containing n-butyl derivatives (Cy2N)3M n Bu (M: Ti 3a, M: Zr 3b) become available as isolable, thermally stable complexes by reactions of 1 with n-BuLi. The solid-state structures of 3a and 3b are presented. No hints for C–H agostic interactions are found. The behavior of 3 is discussed in comparison to the corresponding methyl complexes (Cy2N)3MMe (M: Ti 2a, M: Zr 2b) in the solid state, as well as in solution.