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Synthesis and Characterization of Multi-Alkali-Metal Tetraphenolates and Application in Ring-Opening Polymerization of Lactide.
- Source :
-
Inorganic Chemistry . 12/17/2012, Vol. 51 Issue 24, p13380-13389. 10p. - Publication Year :
- 2012
-
Abstract
- A series of alkali metal complexes supported by two bulky tetraphenols were synthesized and characterized. The reactions of ɑ,ɑ,ɑ',ɑ'-tetra(3,5-di-ferf-butyl-2-hydroxyphenyl)-p-xylene(para-tetraphenol) with "BuLi, sodium, and KSi(NMe₂)₃ gave bimetallic complexes 1, 2, and 3, respectively. Treatments of the ɑ,ɑ,ɑ',ɑ'-tetra(3,5-di-ierf-butyl-2-hydroxyphenyl)-m-xylene(meta-tetraphenol) with 2 or 4 equiv of "BuLi 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--π interaction. Complexes 1--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. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00201669
- Volume :
- 51
- Issue :
- 24
- Database :
- Academic Search Index
- Journal :
- Inorganic Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 84608953
- Full Text :
- https://doi.org/10.1021/ic302193y