Synthesis of a novel triple-site diphosphinoamine （PNP） ligand and its applications in ethylene tetramerization

A novel triple-site diphosphinoamine （PNP） ligand was synthesized and characterized. In combination with Cr（Ⅲ） and methylaluminoxane （MAO）, it generated active catalytic systems for ethylene tetramerization toward 1-octene with high catalytic activity and long lifetime. The effects of reaction temperature, molar ratio of AI/Cr and molar ratio of ligand/Cr on catalytic activity and selectivity to 1-octene were studied with reaction kinetics of the catalytic system for ethylene tetramerization described. At the AI/Cr molar ratio of 100, the catalytic activity is up to 2.29×10^6 g· mol^-1 （Cr）· h^-1 and the selectivity to 1-octene is 49.65 wt%.

Synthesis of a novel triple-site diphosphinoamine (PNP) ligand and its applications in ethylene tetramerization

A novel triple-site diphosphinoamine (PNP) ligand was synthesized and characterized. In combination with Cr(III) and methylaluminoxane (MAO), it generated active catalytic systems for ethylene tetramerization toward 1-octene with high catalytic activity and long lifetime. The effects of reaction temperature, molar ratio of Al/Cr and molar ratio of ligand/Cr on catalytic activity and selectivity to 1-octene were studied with reaction kinetics of the catalytic system for ethylene tetramerization described. At the Al/Cr molar ratio of 100, the catalytic activity is up to 2.29x10⁶ g·mol⁻¹ (Cr)·h⁻¹ and the selectivity to 1-octene is 49.65 wt%. Supported by the Program for New Century Excellent Talents in University (NCET) and the Program for New Century Excellent Talents in Heilongjiang Provincial Universities (Grant No. NCET-06-010)