Chromocene–Cyclopentadienyltitanium Trichloride Ion Pairs and Their Rearrangement to Titanocene Chloride–Cyclopentadienylchromium Dichlorides – Ethylene Polymerization Tests

Abstract

Reactions of chromocene [CrCp 2 ] (Cp = η 5 -C 5 H 5 ) with cyclopentadienyltitanium trichlorides [Ti(η 5 -C 5 H 5-n Me n )Cl 3 ] (n = 0-5) and [Ti(C 5 Me 4 Et)TiCl 3 ] in toluene resulted in precipitation of ion pairs of [CrCp 2 ] + [Ti(η 5 -C 5 H 5-n Me n )Cl 3 ] -(1-6) and [CrCp 2 ] + [Ti(η 5 -C 5 Me 4 Et)Cl 3 ] -(7). Heating their toluene solutions to 100°C yielded the titanocene chloride -cyclopentadienylchromium dichloride complexes with the metals linked by bridging chloride ligands. For n = 0-3, the purple-violet complexes [CpCp′Ti(μ-Cl) 2 Cr(Cp)Cl] (Cp′ -cyclopentadienyl ligand of the titanium component) (8-11) were stable at 100°C, and the single-crystal structure of [Cp 2 Ti(μ-Cl) 2 Cr(Cp)Cl] (8) was determined. The bridging complexes of the same type for n = 4, 5 and the C 5 Me 4 Et ligand (12-14) were contaminated with titano-[a] J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v.v.i., 2637 1 H NMR broad-range spectra of [D 8 ]toluene solutions of 5-7 did not consistently yield reliable data. Even though solid-state Eur.

Multilayer 3D Chirality and Its Synthetic Assembly

“…In recent years, several other groups have made great progress on planar chiral and achiral Lewis acids of Ti, Zr, and Dy which showed effectiveness on polymerization processes P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P and for achieving molecular magnetic hysteresis [35][36][37][38].…”

Preparation of silyl-terminated branched polyethylenes catalyzed by Brookhart's nickel diimine complex activated with hydrosilane/B(C6F5)3

“…18 In recent years, we have investigated the hydrosilane/B (C 6 F 5 ) 3 (SiHB) system for the activation of early transition (Ti, Zr) metal halide complexes to generate catalytic systems for catalytic (co)polymerization of olefins and hydrodehalogenation reactions. [19][20][21][22] We proposed that the hydride transfer from hydrosilane to B(C 6 F 5 ) 3 and finally to the transition metal is the key activation step (Scheme 1).…”