A Selective Chromium Catalyst System for the Trimerization of Ethene and Its Coordination Chemistry

Abstract In this paper a novel ligand of the type [PNPNH] is presented for the application in a new homogeneous highly selective ethene trimerization system for the formation of 1‐hexene, which consists of the chromium source CrCl 3 (thf) 3 , the ligand Ph 2 PN( i Pr)P(Ph)N( i Pr)H ( 1 ), and Et 3 Al as an activator in toluene. The excellent characteristics of this new system, e.g. very high selectivity to C 6 with highest purity of the C 6 fraction (>99 % 1‐hexene), activity on a constant level on a long timescale, use of small amounts of Et 3 Al as a cheap activator, and only very low production of PE, make it to a hot candidate for industrial application. Its organometallic background gives an indication of the nature of the active catalyst species.