Hydrocarbyl complexes preparation

Hydrocarbonyl compounds, lanthanide complexes, 4, 4 ( -Hydrocarbyl)bis(zirconocene), preparation, 4, 906 Hydrocarbyl-bridged cyclopentadienyl-amido complexes, with Zr(IV), 4, 864 Hydrocarbyl complexes bis-Cp Ti hydrocarbyls reactions, 4, 551 structure and properties, 4, 551 synthesis, 4, 542 cobalt with rf-ligands, 7, 51 cobalt with rf-ligands, 7, 56 cobalt with ]4-ligands, 7, 59 cobalt with rf-ligands, 7, 71 heteroleptic types, 4, 192 homoleptic types, 4, 192 into magnetic metal nanoparticles via ligand stabilization, 12, 87 via polymer stabilization, 12, 87 into noble metal nanoparticles... 

Two factors are important for the success of this preparation Due to the high steric demand of the CH(SiMe3)2 ligand the intermediate hydrocarbyl complex can be isolated completely free of donor solvents and alkali halides. 

Metallacyclobutene complexes of both early and late transition metals can, in some cases, be prepared by intramolecular 7-hydrogen elimination, although the intimate mechanism of the reaction varies across the transition series. For low-valent late metals, the reaction is generally assumed to proceed via the oxidative addition of an accessible 7-C-H bond (Scheme 28, path A), but for early metals and, presumably, any metal in a relatively high oxidation state, a concerted cr-bond metathesis is considered most probable (path B). In this process, the 7-C-H bond interacts directly with an M-X fragment (typically a second hydrocarbyl residue) to produce the metallacycle with the extrusion of H-X (i.e., a hydrocarbon). Either sp3- or spz-hybridized C-H bonds can participate in the 7-hydrogen elimination. 

Instead of the free acid it is sometimes advantageous to use a metal salt (e. g., of Cu of Ni") to introduce the anions. Preformed complexes of the type L2 dX2 [18] and L2Pd(R)X [19] where L2 represents a chelating ligand, X a weakly coordinating anion, and R a hydrocarbyl group (e. g., methyl) have also been tested as catalysts. The results are, generally, very similar to those obtained with catalysts prepared in situ. 

Amine or hydrocarbyl elimination was also employed to prepare the following t -mono-Cp-silylamido derivatives (Scheme 106), including zirconium bis(diethylamido) complexes 469 with variations on the ring and amido substitutions,330 zirconium dibenzyl complex 4 70,331 t -mono-Ind-silylamido zirconium complex 471, 0 isodicy-clopentadienyl zirconium complexes 472,332 and enantiomerically pure zirconium bis(dimethylamido) and dichloro complexes 473333 with the R or S -CH(Me)Ph group attached to the amido nitrogen the last two complexes of this... 

D. Jeremic, D.W. Stephan, Hydrocarbyl phosphinimine/ cyclopentadienyl complexes of group IV metals and preparation thereof, CA 2282070 of 09 Dec 2008 (filed 10 Sept 1999) ... 

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