Ligand recognition processes in the formation of homochiral C3-symmetric LnL3 complexes of a chiral alkoxide

Arnold, P. L., Buffet, J.-C., Blaudeck, R., Sujecki, S. and Wilson, C. (2009) Ligand recognition processes in the formation of homochiral C3-symmetric LnL3 complexes of a chiral alkoxide. Chemistry: A European Journal, 15(33), pp. 8241-8250. (doi: 10.1002/chem.200900522) (PMID:19609985)

Abstract

The reaction of a chiral racemic bidentate ligand HL1 (tBu2P(O)CH2CH(tBu)OH) with mid to late trivalent lanthanide cations affords predominantly homochiral lanthanide complexes (RRR)‐[Ln(L1)3] and (SSS)‐[Ln(L1)3]. A series of reactions are reported that demonstrate that the syntheses are under thermodynamic control, and driven by a ligand ‘self‐recognition’ process, in which the large asymmetric bidentate L1 ligands pack most favourably in a C3 geometry around the lanthanide cation. The synthesis of bis(L1) adducts [Ln(L1)2X] (X=N(SiMe3)2, OC6H3tBu‐2,6) is also reported. Analysis of the diastereomer mixtures shows that homochiral (L1)2 complexes are favoured but to a lesser extent. The complexes Ln(L1)3 and [Ln(L1)2(OC6H3tBu‐2,6)] have been studied as initiators for the polymerization of ε‐caprolactone and its copolymer with lactide, glycolide and its copolymer with lactide, and ε‐caprolactam.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Wilson, Dr Claire
• Authors: Arnold, P. L., Buffet, J.-C., Blaudeck, R., Sujecki, S., and Wilson, C.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Chemistry: A European Journal
• Publisher: Wiley
• ISSN: 0947-6539
• ISSN (Online): 1521-3765
• Published Online: 16 July 2009