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Structural studies of Schiff-base [2 + 2] macrocycles derived from 2,2′-oxydianiline and the ROP capability of their organoaluminium complexes
journal contribution
posted on 2016-12-08, 11:51 authored by Wenxue Yang, Ke-Qing Zhao, Timothy J. Prior, David L. Hughes, Abdessamad Arbaoui, Mark ElsegoodMark Elsegood, Carl RedshawThe molecular structures of a number of solvates of the [2 + 2] Schiff-base macrocycles {[2-(OH)-5-(R)-C6H2-1,3-(CH)2][O(2-C6H4N)2]}2 (R = Me L1H2, tBu L2H2, Cl L3H2), formed by reacting 2,6-dicarboxy-4-R-phenol with 2,2′-oxydianiline (2-aminophenylether), (2-NH2C6H4)2O, have been determined. Reaction of LnH2 with two equivalents of AlR′3 (R′ = Me, Et) afforded dinuclear alkylaluminium complexes [(AlR′2)2L1-3] (R = R′ = Me (1), R = tBu, R′ = Me (2), R = Cl, R′ = Me (3), R = Me, R′ = Et (4), R = tBu, R′ = Et (5), R = Cl, R′ = Et (6)). For comparative studies, reactions of two equivalents of AlR′3 (R′ = Me, Et) with the macrocycle derived from 2,2′-ethylenedianiline and 2,6-dicarboxy-R-phenols (R = Me L4H2, tBu L5H2) were conducted; the complexes [(AlMe)(AlMe2)L5]·2 MeCN (7·2 MeCN) and [(AlEt2)2L4] (8) were isolated. Use of limited AlEt3 with L3H2 or L5H2 afforded mononuclear bis(macrocyclic) complexes [Al(L3)(L3H)]·4toluene (9·4toluene) and [Al(L5)(L5H)]·5MeCN (10·5MeCN), respectively. Use of four equivalents of AlR′3 led to transfer of alkyl groups and isolation of the complexes [(AlR′2)4L1′-3′] (R = L2′, R′ = Me (11); L3′, R′ = Me (12); L1′, R′ = Et (13); L2′, R′ = Et (14); L3′, R′ = Et (15)), where L1′-3′ is the macrocycle resulting from double alkyl transfer to imine, namely {[2-(O)-5-(R)C6H2-1-(CH)-3-C(R′)H][(O)(2-(N)-2′-C6H4N)2]}2. Molecular structures of complexes 7·2 MeCN, 8, 9·4toluene, 10·5MeCN and 11·1 toluene·1 hexane are reported. These complexes act as catalysts for the ring opening polymerisation (ROP) of ϵ-caprolactone and rac-lactide; high conversions were achieved over 30 min at 80 °C for ϵ-caprolactone, and 110 °C over 12 h for rac-lactide.
Funding
Sichuan Normal University and the National Natural Science Foundation of China (grants 51273133 and 51443004). CR thanks the EPSRC for a travel grant (EP/L012804/1).
History
School
- Science
Department
- Chemistry
Published in
Dalton TransactionsVolume
45Issue
30Pages
11990 - 12005Citation
YANG, W. ... et al, 2016. Structural studies of Schiff-base [2 + 2] macrocycles derived from 2,2′-oxydianiline and the ROP capability of their organoaluminium complexes. Dalton Transactions, 45 (30), pp. 11990-12005.Publisher
© The Royal Society of ChemistryVersion
- VoR (Version of Record)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution 3.0 Unported (CC BY 3.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/Publication date
2016-06-20Notes
This is an Open Access Article. It is published by the Royal Society of Chemistry under the Creative Commons Attribution 3.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/.ISSN
1477-9226eISSN
1477-9234Publisher version
Language
- en