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Chromatographic separation and 13C NMR characterization of aromatic diester-diacids isomers

✍ Scribed by Wenxi Huang; Lianxun Gao; Xin Zhang; Jiping Xu; Mengxian Ding

Publisher
John Wiley and Sons
Year
1996
Tongue
English
Weight
478 KB
Volume
197
Category
Article
ISSN
1022-1352

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✦ Synopsis

Abstract

Reverse phase high performance liquid chromatography (HPLC) was used to separate and quantify aromatic diester‐diacids isomers which arise from the opening selectivity of anhydride rings towards methanol. ^13^C NMR spectroscopy was a supplementary tool to characterize the isomer structure. It was found that a meta‐position attack is slightly preferred in pyromellitic dianhydride (PMDA), while the preferred position of an attack in bridged dianhydrides is determined by the chemical nature (donors or acceptors) of the bridged group. The stronger its electron‐withdrawing abilities, the lower the probability of a meta‐position attack.

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