Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 23, 2016
Previous Article Next Article

Structures of potassium calix[4]arene crown ether inclusion complexes and application in polymerization of rac-lactide

Author affiliations

Abstract

Reaction of 1,3-dipropoxy-p-tert-butyl-calix[4]arene (L1H2) with KN(SiMe3)2 afforded a one-dimensional (1D) chain complex [K2L1]n (1). Upon reaction with 1 equivalent 18-crown-6, complex 1 can convert to complex [K2(18-crown-6)L1] (2) which possesses a sandwich structure. Treatment of two calix[4]arene-crown ligands of 1,3-dihydroxy-p-tert-butyl-calix[4]arene-crown-5 (L2H2) and 1,2-dihydroxy-p-tert-butyl-calix[4]arene-crown-5 (L3H2) with KN(SiMe3)2 gave the dinuclear complex [K2L2] (3) and the mononuclear complex [K(THF)L3H] (4), respectively. Complexes 1–4 were all characterized by single-crystal X-ray diffraction techniques. The variable temperature 1H NMR spectrum indicates there is a quick rotation equilibrium of the two phenoxy groups in complex 3. In addition, complexes 1–4 have been tested for the ring-opening polymerization (ROP) of rac-lactide and the results showed that complexes 2 and 3 are highly active for the ROP of rac-lactide. The obtained polymers displayed low dispersity values (Đ) and the molecular weights are close to the calculated ones. Furthermore, complexes 2 and 3 show moderate isoselectivities of Pm = 0.67 and Pm = 0.73, respectively.

Graphical abstract: Structures of potassium calix[4]arene crown ether inclusion complexes and application in polymerization of rac-lactide

Back to tab navigation

Supplementary files

Article information


Submitted
13 Apr 2016
Accepted
16 May 2016
First published
16 May 2016

Dalton Trans., 2016,45, 9636-9645
Article type
Paper

Structures of potassium calix[4]arene crown ether inclusion complexes and application in polymerization of rac-lactide

Y. Li, H. Zhao, X. Mao, X. Pan and J. Wu, Dalton Trans., 2016, 45, 9636
DOI: 10.1039/C6DT01417H

Social activity

Search articles by author

Spotlight

Advertisements