Ling‐Jiun Wang, Dongtao Liu, Dongmei Cui
Aug 16, 2012
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Influential Citations
53
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Journal
Organometallics
Abstract
The acid–base reactions of NNN-tridentate pyrrolyl ligands (HL1: 2,5-bis((pyrrolidin-1-yl)methylene)-1H-pyrrole; HL2: 2,5-bis((piperidino)methylene)-1H-pyrrole) with rare-earth metal tris(alkyl)s, Ln(CH2SiMe3)3(THF)2, afforded the corresponding bis(alkyl) complexes L1Ln(CH2SiMe3)2(THF)x (Ln = Sc, x = 0 (1a); Ln = Y, x = 1 (1b); Ln = Lu, x = 1 (1c)), L2Sc(CH2SiMe3)2 (2a), and L22Ln2(CH2SiMe3)4 (Ln = Y (2b); Lu (2c)) in moderate to high yields. X-ray diffraction analysis revealed that the scandium complexes 1a and 2a are THF solvent-free monomers where the ligands coordinate to the Sc3+ ion in a κ1:κ2 mode, while the yttrium and lutetium complexes 1b and 1c have the same ligand coordination geometry to that of the scandium complex but are one-THF solvates; complex 2b, however, is a dimer bridged by two anionic L2 fragments that coordinate to the two yttrium ions in mixed η5:η5/κ1:κ1 coordination modes. Upon activation with an organoborate, all these complexes initiated the controlled polymerization of isopr...