title: Methylaluminium 8-quinolinolates: synthesis, characterization and use in ring-opening polymerization (ROP) of ε-caprolactone.
abstract: The stoichiometric reactions of 2-(2,6-R-phenylimino)quinolin-8-ol (L1-L5, L1: R = Me, L2: R = Et, L3: R = (i)Pr, L4: R = Cl, L5: R = F) with Me(3)Al afforded the dimeric aluminium complexes [Me(2)AlL](2) (1-5) in good yields. By contrast, stoichiometric reactions of 2-(1-(2,6-R-phenylimino)propyl) quinolin-8-ol (L6-L10, L6: R = Me, L7: R = Et, L8: R = (i)Pr, L9: R = Cl, L10: R = F)) with Me(3)Al gave the mononuclear aluminium complexes Me(2)AlL (6-10) accompanied with by-products of the form Me(2)AlL·Me(3)Al (11-15). All methylaluminium complexes were characterized by NMR spectroscopy, elemental analysis, and the molecular structures of complexes 3, 6 and 8 were determined by single-crystal X-ray diffraction. Aluminium compounds 1-5 possessed negligible activity towards the ring-opening polymerization of ε-caprolactone either in the presence or absence of BnOH. In contrast, in the presence of BnOH, the mononuclear aluminium compounds 6-10 could efficiently initiate the ring-opening polymerization of ε-caprolactone; the polymerization proceeded in a living manner.
authors.affiliation: Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China. whsun@iccas.ac.cn
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Sun
authors.forename: Miao
authors.initials: M
authors.lastname: Shen
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Shaofeng
authors.initials: S
authors.lastname: Liu
authors.forename: Carl
authors.initials: C
authors.lastname: Redshaw
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D002208:Caproates / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007783:Lactones / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D011804:Quinolines / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D002208:Caproates; D007783:Lactones; D009942:Organometallic Compounds; D011804:Quinolines; C121056:caprolactone; D000535:Aluminum