Synthesis of titanium(IV) complexes containing 2,6-dimethylaniline substituted amino alcohols and their utilization in ethylene polymerizations

Two new Ti(IV) complexes of the type [(OCHRCH2N-2,6-Me2Ph)Ti(NMe2)(2)](2) ( where R = H, or 'butyl) have been synthesized by protonolysis of Ti(NMe2)(4 ) with the corresponding N-substituted amino alcohol ligand. The two comple xes were studied as Ziegler-Natta type polymerization catalysts in the pres ence of an excess of methylaluminoxane (MAO). It was found that ethylene po lymerization activity for both catalysts increased by increasing the polyme rization temperature from 25 to 70 degreesC. If the catalysts were pretreat ed with trimethylaluminum, the activities increased at 25 degreesC, but sli ghtly decreased at 70 degreesC. Both complexes were found to be ineffective for the polymerization of propylene. An X-ray crystal structure of [(OCH2C H2N-2,6Me(2)Ph)Ti(NMe2)(2)](2) shows the complex to be dimeric in the solid state, with bridging through the amino alcohol oxygen atoms. This complex crystallizes in the monoclinic system space group, P2(1)/n with a = 9.181(6 ), b = 13.766(3), c = 13.002(3), beta = 93.08(3) and Z = 4. (C) 2001 Elsevi er Science B.V. All rights reserved.