Synthesis and Characterization of Multi-Alkali-Metal Tetraphenolates and Application in Ring-Opening Polymerization of Lactide

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• 作者：Jinjin Zhang ; Chunli Jian ; Yuan Gao ; Lei Wang ; Ning Tang ; Jincai Wu
• 刊名：Inorganic Chemistry
• 出版年：2012
• 出版时间：December 17, 2012
• 年：2012
• 卷：51
• 期：24
• 页码：13380-13389
• 全文大小：618K
• 年卷期：v.51,no.24(December 17, 2012)
• ISSN：1520-510X

文摘

A series of alkali metal complexes supported by two bulky tetraphenols were synthesized and characterized. The reactions of 伪,伪,伪鈥?伪鈥?tetra(3,5-di-tert-butyl-2-hydroxyphenyl)-p-xylene(para-tetraphenol) with ⁿBuLi, sodium, and KSi(NMe₂)₃ gave bimetallic complexes 1, 2, and 3, respectively. Treatments of the 伪,伪,伪鈥?伪鈥?tetra(3,5-di-tert-butyl-2-hydroxyphenyl)-m-xylene(meta-tetraphenol) with 2 or 4 equiv of ⁿBuLi afforded complexes 4 or 5, while the reactions of meta-tetraphenol with sodium and KSi(NMe₂)₃ gave only trimetallic complexes 6 and 7 for the additional p鈭捪€ interaction. Complexes 1鈥?b>7 were all characterized by single-crystal X-ray diffraction techniques. In the presence of benzyl alcohol, all complexes are active catalysts for the ring-opening polymerization of l-lactide. Comparatively, bimetallic complexes 1, 2, and 3 are more efficient catalysts because of their symmetric structures, in which complex 3 presents as a rare highly active potassium catalyst for the ring-opening polymerization of lactide, leading to polymers with good molecular weight control and narrow molecular weight distributions.