Half-sandwich cyclopentadienyl rhodium complexes bearing pendant sulfur or oxygen ligands and their catalytic behaviors in ethylene polymerization

Abstract

Two half-sandwich rhodium complexes with sulfur or oxygen functionalized cyclopentadienyl ligands [η 5-C 5H 4(CH 2) 2SCH 2CH 3]RhI 2 3, {[η 5-C 5H 4(CH 2) 2OCH 3]RhI 2} 2 4 have been synthesized and characterized by IR, 1H-NMR spectra and Elemental analyses. The molecular structures of complexes 3 and 4 have been determined by X-ray crystallographic analysis. Complexes 3, 4 with a pendent arm on cyclopentadienyl ligand have been tested as catalysts for ethylene and norbornene polymerization in the presence of MAO. Complexes 3 and 4 kept high activities of ca. 10 6 g PE mol −1 Rh h −1 with morderate molecular weight ( M w ≈ 10 5 g mol −1) of polyethylene in the ethylene polymerization. Catalytic activities, molecular weights of polyethylene have been investigated under the various reaction conditions.