title: Zwitterionic bis(phenolate)amine lanthanide complexes for the ring-opening polymerisation of cyclic esters.
abstract: The reaction of Sm{N(SiMe3)2}3 with the bis(phenol)amines H2O2N(R) (H2O2N(R) = RCH2CH2N(2-HO-3,5-C6H2(t)Bu2)2; R = OMe, NMe2 or Me) gave exclusively zwitterions Sm(O2N(R))(HO2N(R)). For R = OMe or NMe2 these were efficient catalysts for the ring-opening polymerisation of epsilon-caprolactone and D,L-lactide with a tendency to form cyclic esters; in contrast, no polymerisation was observed for R = Me.
authors.affiliation: Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, UK.
authors.forename: Hellen E
authors.initials: HE
authors.lastname: Dyer
authors.forename: Saskia
authors.initials: S
authors.lastname: Huijser
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Schwarz
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Robbert
authors.initials: R
authors.lastname: Duchateau
authors.forename: Philip
authors.initials: P
authors.lastname: Mountford
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D003500:Cyclization; D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008024:Ligands; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D010636:Phenols / Q000737:chemistry*
chemical_list: D004952:Esters; D028581:Lanthanoid Series Elements; D008024:Ligands; D009942:Organometallic Compounds; D010636:Phenols