hydrogenchloride in toluene soln. of Cp2ZrCl(CHCH2C(CH3)3)Al(i-Bu)2 in toluene treated with HCl at -40 °C;

hydrogenchloride; N,N,N',N',N'',N''-hexamethylphosphoric triamide in toluene soln. of Cp2ZrCl(CHCH2C(CH3)3)Al(i-Bu)2 in toluene treated with HMPA at-40 °C, added of 1 equiv HCl;