title: Synthesis, characterization, and catalysis of mixed-ligand lithium aggregates, excellent initiators for the ring-opening polymerization of L-lactide.
abstract: Three novel mixed-ligand lithium aggregates, [(mu(3)-EDBP)Li(2)](2)[(mu(3)-(n)Bu)Li(0.5Et(2)O)](2) (1), [(mu(3)-EDBP)Li(2)](2)[(mu(3)-OBn)Li](2) (2), and [(mu(3)-EDBP)Li(2)](2)[(mu(3)-OCH(2)CH(2)OCH(2)CH(3))Li](2) (3), have been synthesized and structurally characterized. The reaction of 2,2'-ethylidene-bis(4,6-di-tert-butylphenol) (EDBP-H(2)) with 3.6 molar equiv of (n)BuLi gives 1 in high yield. 1 further reacts with benzyl alcohol and 2-ethoxyethanol respectively to yield the corresponding products 2 and 3. Experimental results show that 2 and 3 efficiently initiate the ring-opening polymerization of L-lactide in a controlled fashion, yielding polymers with very narrow polydispersity indexes in a wide range of monomer-to-initiator ratios.
authors.affiliation: Department of Chemistry, National Chung-Hsing University, Taichung 402, Taiwan, ROC.
authors.forename: B T
authors.initials: BT
authors.lastname: Ko
authors.forename: C C
authors.initials: CC
authors.lastname: Lin
mesh_terms: D019905:Benzyl Alcohol / Q000737:chemistry; D003500:Cyclization; D005026:Ethylene Glycols / Q000737:chemistry; D019344:Lactic Acid / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D011091:Polyesters / Q000138:chemical synthesis* / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: C434085:((mu(3)-EDBP)Li(2))(2)((mu(3)-(n)Bu)Li(0.5Et(2)O))2; C434086:((mu(3)-EDBP)Li(2))(2)((mu(3)-OBn)Li)(2); C434084:((mu(3)-EDBP)Li(2))(2)((mu(3)-OCH(2)CH(2)OCH(2)CH(3))Li)(2); D005026:Ethylene Glycols; D009942:Organometallic Compounds; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D008094:Lithium; C021296:2-ethoxyethanol; D019905:Benzyl Alcohol