Polyamine-Stabilized Sodium Aryloxides: Simple Initiators for the Ring-Opening Polymerization of rac-Lactide

详细信息    查看全文

• 作者：Beatriz Calvo ; Matthew G. Davidson ; Daniel Garci虂a-Vivo虂
• 刊名：Inorganic Chemistry
• 出版年：2011
• 出版时间：April 18, 2011
• 年：2011
• 卷：50
• 期：8
• 页码：3589-3595
• 全文大小：904K
• 年卷期：v.50,no.8(April 18, 2011)
• ISSN：1520-510X

文摘

Metalation of 2,4,6-tri(methyl)phenol (^MeArOH) and 2,6-di(tert-butyl)-4-methylphenol (^BuArOH) with NaN(SiMe₃)₂ in toluene and in the presence of stoichiometric amounts of the polydentate amines N,N,N鈥?N鈥?/i>-tetramethylethylenediamine (TMEDA) and N,N,N鈥?N鈥测€?N鈥测€?/i>-pentamethyldiethylenetriamine (PMDETA) affords three new sodium aryloxide complexes [Na(渭-OAr^Bu)(TMEDA)]₂ (3), [Na(渭-OAr^Me)(PMDETA)]₂ (4), and [Na(OAr^Bu)(PMDETA)] (5). Complexes 3 to 5 have been isolated as crystalline materials in reasonable yields and characterized in the solid state by X-ray crystallography and in solution by NMR spectroscopy. Complexes 3 to 5 and the related [tris(2-dimethylaminoethyl)amine] (Me₆TREN) derivatives [Na(OAr^Me)(HOAr^Me)(Me₆TREN)] (1) and [Na(OAr^Bu)(Me₆TREN)] (2), recently prepared in our group, are shown to be active as initiators for the ring-opening polymerization (ROP) of rac-lactide with benzyl alcohol as a co-initiator. However, during the course of the polymerization reactions intrachain and stereorandom transesterification side-reactions were observed under some of the experimental conditions tested.