Electron-deficient (pentamethylcyclopentadienyl)titanium trialkyls: evidence of [cyclic] Ti.cntdot..cntdot..cntdot.H-C and [cyclic] Ti.cntdot..cntdot..cntdot.C-C interactions. Crystal and molecular structure of .mu.-[o-(CH2)2C6H4]{(.eta.5-C5Me5)Ti[o-(CH2)2C6H4]}2

Synthesis and reactivity of new silyl substituted monocyclopentadienyl zirconium complexes. X-ray molecular structure of [Zrη5-C5H4 (SiMe2CH2Ph)(CH2Ph)3]

“…These NMR data would suggest that l•here is somehow, a non classical benzyl interaction in solution for the benzyl ligands bonded to zirconium [28] with no significant interactions in the side chain benzyl group attached to silicon. Similar spectroscopic belhaviour has been reported for related d o electronically unsaturated benzyl complexes of the early transition metals [13,[28][29][30][31][32].…”

“…Two of the phenyl rings are pointing downwards toward the metal, and their planes are almost perpendicular to the Cp ring plane. However, the phenyl group attached to C41 is pointing upwards and makes an angle of 38. where all the benzyl groups point down and are symmetrically placed, and to Cp * Ti(CH2Ph) 3 [29,30] where the phenyl groups are symmetrically located with one of the phenyl rings pointing up, but with its plane parallel to the Cp plane.…”

Synthesis of Ethylene-co-Norbornene Polymers Promoted by MAO Free Catalysts Based on Group 4 Dicarbollide Complexes

“…Polymerization grade ethylene, purchased from Società Ossigeno Napoli (S. O. N.) was dried by passing over activated 3A molecular sieves. Ethylene-bis(1-indenyl)ZrCl 2 , [39] (g 5 -C 2 B 9 H 11 )Ti(NEt 2 ) 2 (NHEt 2 ), [40] (g 5 -C 2 -B 9 H 11 )Zr(NEt 2 ) 2 (NHEt 2 ), [40] (g 5 -C 5 H 5 )TiCl 3 , [41] Ti(NEt 2 ) 4 , [42] Zr(NEt 2 ) 4 , [42,43] (g 5 -C 5 Me 5 )TiCl 3 , [44] (g 5 -C 5 H 5 )ZrCl 3 , [44] (g 5 -C 5 Me 5 )Ti(CH 3 ) 3 , [45] B(C 6 F 5 ) 3 [46] were synthesized according to the literature procedures. MAO, purchased from Witco as 10 wt.-% solution in toluene, was dried in vacuo at 50 8C to remove toluene and "free" AlMe 3 and used as solid.…”

“…Polymerization results by 1-TIBA, 2-TIBA, 1-MAO and 2-MAO catalysts have been preliminary compared with those of cyclopentadienyl derivatives of the group 4 metals, (g 5 -C 5 R 5 )TiX 3 [R = H, X = Cl (3); R = Me, X = Cl (4), Me(5)], (g 5 -C 5 H 5 )ZrCl 3 (6), ethylenebis(1-indenyl) zirconium dichloride (7) and "Cp-free" compounds M(NEt 2 ) 4 [M = Ti (8), Zr (9)] precursors of the dicarbollide compounds 1-2, under the same conditions (T p = 50 8C, [M] = 1 610 -3 m; P E = 1 atm; [N] = 1.75 m). The 1-TIBA and 2-TIBA catalysts exhibit productivity values greater than the corresponding MAO activated system and incorporate high concentration of the cyclic monomer in the copolymer products (N mol-% = [38][39][40][41][42][43][44][45]. Crystalline blocks of isotactic alternating NENE sequences were identified in the P(E-co-N)s copolymers produced by these catalysts by means of 13 C NMR and DSC analysis.…”

High molecular weight atactic polypropene synthesized with (?5-pentamethylcyclopentadienyl)tribenzyl titanium activated with MAO

“…Cp*TiBz 3 was synthesized by the reaction of freshly prepared PhCH 2 MgBr with Cp*TiCl 3 in Et 2 O at Ϫ10°C as previously described. 17 MAO was prepared in accordance with a recent report written by our laboratory. 16 The residual trimethylalumium (TMA) content in the MAO was 16.8 mol % by pyridine titration.…”