Chromium ethylene polymerisation catalysts bearing reduced Schiff-base N,O-chelate ligands
Abstract
Treatment of CrCl3(THF)3 with the lithium and sodium salts of the reduced Schiff-base ligand 3,5-(tBu)2-2-(OH)C6-H2CH2NH(2,6-Me2C6H3) affords bis-helate chromium(II) and mono-chelate chromium(III complexes respectively; both give active ethylene polymerisation catalysts upon treatment with alkylaluminium activators.