Skip to main content

Research Repository

Advanced Search

Co-polymerization of propylene oxide and CO2 using early transition metal (groups IV and V) metallocalix[n]arenes (n = 4, 6, 8)

Sun, Yong Chang; Wang, Zhong Yu; He, Zhen Hong; Xing, Tian; Wang, Zhong?Yu; Sun, Yong?Chang; He, Zhen?Hong; Wang, Kuan; Liu, Zhao Tie; Elsegood, Mark R.J.; Bedwell, Elizabeth V.; Redshaw, Carl


Yong Chang Sun

Zhong Yu Wang

Zhen Hong He

Tian Xing

Zhong?Yu Wang

Yong?Chang Sun

Zhen?Hong He

Kuan Wang

Zhao Tie Liu

Mark R.J. Elsegood

Elizabeth V. Bedwell

Profile Image

Professor Carl Redshaw
Professor of Inorganic Materials Chemistry and REF Lead for Chemistry


A number of metallocalix[n]arenes, where n = 4, 6, or 8, of titanium and vanadium have been screened for their ability to act as catalysts for the co‐polymerization of propylene oxide and CO2 to form cyclic/polycarbonates. The vanadium‐containing catalysts, namely [VO(L1Me)] (1), [(VO2)L2H6] (2), [Na(NCMe)6]2[(Na[VO]4L2)(Na(NCMe))3]2 (3), [VO(μ‐OH)L3/H2]2∙6CH2Cl2 (4), {[VO]2(μ‐O)L4[Na(NCMe)2]2} (5), {[V(Np‐tolyl)]2L4} (6) and [V(Np‐RC6H4)Cl3] (R = Cl (7), OMe (8), CF3 (9)), where L1H3 = methylether‐p‐tert‐butylcalix[4]areneH3, L2H8 = p‐tert‐butylcalix[8]areneH8, L3H4 = p‐tert‐butylthiacalix[4]areneH4, L4H6 = p‐tert‐butyltetrahomodioxacalix[6]areneH6, performed poorly, affording, in the majority of cases, TONs less than 1 at 90°C over 6 h and low molecular weight oligomeric products (Mn ≤ 1665). In the case of the titanocalix[8]arenes, {(TiX)2[TiX(NCMe)]2(μ3‐O)2(L2)} (X = Cl (10), Br (11), I (12)), which all adopt a similar, ladder‐type structure, the activity under the same conditions is somewhat higher (TONs >6) and follows the trend Cl > Br > I; by comparison the non‐calixarene species [TiCl4(THF)2] was virtually inactive. In the case of 10, it was observed that the use of PPNCl (bis[triphenylphosphine]iminium chloride) as co‐catalyst significantly improved both the polymer yield and molecular weight (Mn 3515). The molecular structures of the complexes [HNEt3]2[VO(μ‐O)L3H2]2∙3CH2Cl2 (4∙3CH2Cl2), [VO(μ‐OH)L3/H2]2∙6CH2Cl2 (4/) (where L3/H2 is a partially oxidized form of L3H4) and {(TiCl)2[TiCl(NCMe)]2(μ3‐O)2(L2)}·6.5MeCN (10·6.5MeCN) are reported.


Sun, Y. C., He, Z. H., Wang, Z. Y., Xing, T., Wang, Z., Sun, Y., …Redshaw, C. (in press). Co-polymerization of propylene oxide and CO2 using early transition metal (groups IV and V) metallocalix[n]arenes (n = 4, 6, 8). Journal of Applied Polymer Science, Article 50513.

Journal Article Type Article
Acceptance Date Jan 10, 2021
Online Publication Date Jan 26, 2021
Deposit Date Jan 26, 2021
Publicly Available Date Jan 27, 2022
Journal Journal of Applied Polymer Science
Print ISSN 0021-8995
Electronic ISSN 1097-4628
Publisher Wiley
Peer Reviewed Peer Reviewed
Article Number 50513
Keywords Catalysts; Non‐polymeric materials and composites; X‐ray
Public URL
Publisher URL


Article (930 Kb)

Copyright Statement
©2021 The authors. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder

You might also like

Downloadable Citations