Organometallic compounds

摘要

Organometallic cpds. of formula (I) are claimed, in which M = Cr, Mo or W; L = a pi-ligand; T = a bridging gp.; A = a pi- ligand or another electron donor; R<1> = H or 1-20C hydrocarbyl. Also claimed are (i) catalyst components contg. (I) and cocatalysts; (ii) a process for the prodn. of (I) by reacting a cpd. of formula HL-T-AH (II) with a cpd. of formula M(NR<1>2)4 (III), in which M = a tetravalent metal; (iii) a process for the prodn. of polyolefins by polymerisation of olefins in presence of a catalyst contg. (I) and a cocatalyst.