Magnesium butadiene as a reagent for the preparation of transition-metal butadiene complexes: molecular structure of bis(.eta.-butadiene)[1,2-bis(dimethylphosphino)ethane]hafnium

Transition metal complexes of triphosphorus macrocycles: A new class of homogeneous olefin polymerisation catalysts

“…Addition of a co-catalyst to a solution of [12]aneP 3 Et 3 MCl 3 (M = Ti, V, Cr) gives rise to low to moderately active polymerisation catalysts. The relevant polymerisation data is shown in Tables 1 and 2.…”

“…The addition of MAO (methylaluminoxane) to a solution of [12]aneP 3 Et 3 TiCl 3 (1) in CH 2 Cl 2 gives rise to a colour change from pale blue to light yellow. On addition of monomer, the system shows some catalytic activity.…”

“…Of particular interest is the potential for stabilisation of relatively robust reaction intermediates, by exploiting the advantages arising from the macrocyclic ligand structure, which may support or enhance reactivity for which tertiary phosphine complexes are not commonly noted. With this in mind, we have investigated the coordination chemistry of the title ligand ( [12]aneP 3 R 3 ) with the early transition metals. 10 In this paper, we report the catalytic activity of these compounds with respect to the polymerisation of ethene and α-alkenes.…”

“…Substitution of the P-borne alkyl group with a pendant ether function was found to switch the catalytic activity of chromium() complexes from polymerisation to oligomerisation. A nickel halide complex of [12]aneP 3 Et 3 was also found to be active in alkene polymerisation. …”

“…28 We have tested the activity of the methoxypropyl pendant ether [12] Fig. 3) in ethene polymerisation in order to compare possible influences of hemi-labile donors.…”