3.3.5.5- tetrakis pentamethylcyclopentadienyl

Tetrakis(pentamethylcyclopentadienyl)-1,2,4,3,5-tritel]uradisilolane2 1.2 g (4.0 mmol) of decamcthyl-silicocene are dissolved at room temperature in 15 ml of toluene. To this solution is added dropwisc a solution of 1.32 g (4.0 mmol) tributylphosphane telluride in 10 mlo( toluene during 1 h. The resulting dark-red solution is evaporated to dryness under vacuum. The residue is washed with pentane and recrystallized from boiling toluene yield 76% m.p. 227° (dec.). 

C72H48CI2N6RU, Ruthenium(II), tris(4,7-diphe-nyl-l,10-phenantroline)-, chloride, 34 66 C72H8oCo4F24Ni2P4Rh4, Rhodium(III), dodeca-cyanotetrakis cyclopentadienylcobalt(III) tetrakis pentamethylcyclopentadienyl-, tetrakis hexafluorophosphate, 34 170 C72H96C09M05N48O24 xMeOH XH2O,... 

CojUCmHjo, Cobalt(lII), di-p-iodo-bisliodoCo5-pentamethylcyclopentadienyl)-, 23 17 Co2N,O6C 0H24, Cobalt(IU), tris(l,2-ethanedi-amine)-, cir-bis(carbonato)-dicyanocobaltate(lll), 23 66 Co4C16N12O32C2H40 4H2Ot Cobalt(III), tctra-p-hydroxo-(pui-oxalato)-tetrakis[triam-mine-, hexaperchlorate, tetrahydrate, 23 114... 

ThCl4, Thorium tetrachloride, 28 322 TiClC oH,o, Titanium(IlI), chlorobis(ii -cyclopentadienyl)-, 28 261 TiCljCjoHj, Titanium, dichlorobis(Ti -chlorocyclopentadienyl)-, 29-.200 TiN404oSiV3W,Cg,H,49,1,2,3-Trivanado-nonatungstosilicate(4—), pj-KV-cyclo-pentadienyl)trioxotitanate(rV)]-, A-fl-, tetrakis(tetrabutylammonium), 27 132 Ti02C,2H,o, Titanium, dicarbonylbis(ii -cyclopentadienyl)-, 28 250 TiOjC22H3o, Titanium, dicarbonylbis(ti -pentamethylcyclopentadienyl)-,... 

In case of borate as cocatalyst, the catalytic activity of the titanium complex with a pentamethylcyclopentadienyl hgand is high, but a titanium complex with a cyclopentadienyl ligand without any substituents is not active for the syndiospecific styrene polymerization. The reason is that the reaction product of the borate and the cycopentadienyltitanium compound is unstable. The stability of the active site with the borate compound is lower in comparison to that with MAO. The reaction of CH2(Cp)2Ti(Me)2 with dimethylanilinium tetrakis(pentafiuorophenyl)borate or tris(pentafluorophenyl)borane in an equimolar mixture has been examined by Miyashita, Nabika, and Suzuki [11]. Two types of methylene bis(cyclopentadienyl)titanium ion complexes were isolated (see Fig. 3.6). These complexes were active in the polymerization of styrene, but only atactic polystyrene was formed. 

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