| Abstract
| - Reaction of 2,5-di-tert-butyl-3,4-dimethylphospholide potassium [K(Dtp)] with YCl3 or SmI3(THF)3.5 in THF followed by reaction with o-dimethylaminobenzylpotassium [K(CH2C6H4NMe2-o)] afforded the solvent-free mono(phospholyl)lanthanoid bis(benzyl) complexes 3-Ln [(Dtp)Ln(CH2C6H4NMe2-o)2] (Ln = Y, Sm). While the reaction between K(Dtp) and ScCl3 in THF led to the THF-ring-opened product [{Sc[μ-O(CH2)4(Dtp)]Cl2(THF)2}2], 3-Sc could be obtained by reaction of the 1-H phosphole Dtp-H with [Sc(CH2C6H4NMe2-o)3] in toluene. Complexes 3-Y and 3-Sc when activated with [Ph3C][B(C6F5)4] gave good to excellent results in the syndiospecific polymerization of styrene.
- Reaction of 2,5-di-tert-butyl-3,4-dimethylphospholide potassium [K(Dtp)] with YCl3 or SmI3(THF)3.5in THF followed by reaction with o-dimethylaminobenzylpotassium [K(CH2C6H4NMe2-o)] afforded thesolvent-free mono(phospholyl)lanthanoid bis(benzyl) complexes [(Dtp)Ln(CH2C6H4NMe2-o)] (Ln = Y(3-Y), Sm (3-Sm)). The Sc analogue could not be obtained under these conditions, as the reaction betweenK(Dtp) and ScCl3 in THF led to the THF-ring-opened product [{Sc[μ-O(CH2)4(Dtp)]Cl2(THF)2}2] (5).Replacing THF by a mixture of toluene/pyridine gave [(Dtp)ScCl2(pyridine)] (6), which on further reactionwith [K(CH2C6H4NMe2-o)] in toluene afforded [(Dtp)Sc(CH2C6H4NMe2-o)2] (3-Sc). Protonation of[K(Dtp)] with p-toluenesulfonic acid gave the 1H phosphole Dtp-H (7), which could not be isolated purebut is stable in solution at room temperature. 3-Sc could also be obtained from the reaction between thein-situ-prepared 7 and [Sc(CH2C6H4NMe2-o)3] in toluene. Complexes 3-Ln were activated with [Ph3C][B(C6F5)4] and tested in the syndiospecific polymerization of styrene. Whereas 3-Sm did not show anyactivity, 3-Y and 3-Sc gave good to excellent results.
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