Synthesis and Characterization of Magnesium Alkoxides Incorporated into Bulky Aluminium Tetraphenolate Helices and Application in the Ring‐Opening Polymerization of Lactides. Issue 20 (4th June 2013)

• Record Type: Journal Article
• Authors: Jian, Chunli; Zhang, Jinjin; Dai, Zhongran; Gao, Yuan; Tang, Ning; Wu, Jincai
• Is Part Of: European journal of inorganic chemistry. Issue 20(2013)
• Page Start: 3533
• Page End: 3541
• Publication Date: 2013-06-04
• Subjects: Ring‐opening polymerization -- Kinetics -- Heterobimetallic complexes -- Magnesium -- Aluminium -- Lactides; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201300284
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: Two aluminium and magnesium heterobimetallic complexes of [(LAl)MgOBn]2 (2 ) and [(LAl)Mg(OC2 H4 OCH3 )]2 (3 ), in which L = N 1, N 1, N 2, N 2 ‐tetrakis(2‐hydroxy‐3, 5‐dimethylbenzyl)‐1, 2‐ethanediamine, have been synthesized and characterized by NMR spectroscopy, X‐ray crystallography, and elemental analysis. The magnesium alkoxide of complex 2 supported by the bulky aluminium tetraphenolates, as a rare helical heterobimetallic initiator, can effectively initiate the ring‐opening polymerization (ROP) of L ‐lactide (L ‐LA) leading to polymers with good molecular weight control and narrow molecular weight distributions. Kinetic studies have shown the overall rate expression is –d[lactide]/d t = k [lactide][complex] for the ROP of L ‐LA. Furthermore, complex 2 shows modest isotactic selectivity in the ROP of rac ‐lactide. Abstract : Two active Mg alkoxides have been incorporated into two bulky Al tetraphenolates and the helical complex 2 used to initiate the ring‐opening polymerization (ROP) of L ‐ and rac ‐lactide, leading to polymers with good molecular weight control and narrow molecular weight distributions. An overall rate expression of –d[lactide]/d t = k [lactide][complex] for the ROP of L ‐lactide was deduced.