Synthesis, structural characterization and ethylene polymerization behavior of complex [Ph4P][CrCl3{HB(pz)3}] [HB(pz)3 = hydrotris(1-pyrazolyl)borate]

Reaction of CrCl3(THF)3 with K[HB(pz)3] in THF leads to the formation of the complex K[CrCl3{HB(pz)3}] (1). The salt metathesis of complex 1 with [Ph4P]Br in CH2Cl2 yields the complex [Ph4P][CrCl3{HB(pz)3}](2). The structure of complex 2 · CHCl3 has been determined by single crystal X-ray diffraction. In the anion the metal centre shows a distorted octahedral geometry with the hydrotris(1-pyrazolyl)borate bonded as N,N′,N″-donor tripod ligand and three chloride atoms completing the co-ordination sphere. Complex 2 in the presence of MAO leads to the formation of an active catalyst for the polymerization of ethylene.