1
|
Matthews SE, Cecioni S, O'Brien JE, MacDonald CJ, Hughes DL, Jones GA, Ashworth SH, Vidal S. Fixing the Conformation of Calix[4]arenes: When Are Three Carbons Not Enough? Chemistry 2018; 24:4436-4444. [PMID: 29338100 DOI: 10.1002/chem.201705955] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Indexed: 01/17/2023]
Abstract
Calix[4]arenes are unique macrocycles that through judicious functionalisation at the lower rim can be either fixed in one of four conformations or remain conformationally flexible. Introduction of propynyl or propenyl groups unexpectedly provides a new possibility; a unidirectional conformational switch, with the 1,3-alternate and 1,2-alternate conformers switching to the partial cone conformation, whilst the cone conformation is unchanged, under standard experimental conditions. Using 1 H NMR kinetic studies, rates of switching have been shown to be dependent on the starting conformation, upper-rim substituent, where reduction in bulk enables faster switching, solvent and temperature with 1,2-alternate conformations switching fastest. Ab initio calculations (DFT) confirmed the relative stabilities of the conformations and point towards the partial cone conformer being the most stable of the four. The potential impact on synthesis through the "click" reaction has been investigated and found not to be significant.
Collapse
Affiliation(s)
- Susan E Matthews
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Samy Cecioni
- Institut de Chimie et Biochimie Moléculaires et Supramoléculaires, CO2-Glyco, UMR 5246, CNRS, Université Claude Bernard Lyon 1, 43 Boulevard du 11 Novembre 1918, 69622, Villeurbanne, France
| | - John E O'Brien
- School of Chemistry, University of Dublin, Trinity College, Dublin 2, Ireland
| | - Colin J MacDonald
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - David L Hughes
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Garth A Jones
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Stephen H Ashworth
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Sébastien Vidal
- Institut de Chimie et Biochimie Moléculaires et Supramoléculaires, CO2-Glyco, UMR 5246, CNRS, Université Claude Bernard Lyon 1, 43 Boulevard du 11 Novembre 1918, 69622, Villeurbanne, France
| |
Collapse
|
2
|
D'Alessio D, Skelton BW, Sobolev AN, Krause‐Heuer AM, Fraser BH, Massi M, Ogden MI. Lanthanoid Complexation by a Tris‐Tetrazole‐Functionalised Calix[4]arene. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201600938] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Daniel D'Alessio
- Department of Chemistry Nanochemistry Research Institute Curtin University GPO Box U 19876845PerthWestern AustraliaAustralia
| | - Brian W. Skelton
- Centre for Microscopy, Characterisation and Analysis The University of Western Australia 6009PerthWestern AustraliaAustralia
| | - Alexandre N. Sobolev
- Centre for Microscopy, Characterisation and Analysis The University of Western Australia 6009PerthWestern AustraliaAustralia
- School of Chemistry and Biochemistry, M310 The University of Western Australia 6009PerthWestern AustraliaAustralia
| | - Anwen M. Krause‐Heuer
- Australian Nuclear Science and Technology Organisation Locked Bag 20012232Kirrawee DCNew South WalesAustralia
| | - Benjamin H. Fraser
- Australian Nuclear Science and Technology Organisation Locked Bag 20012232Kirrawee DCNew South WalesAustralia
| | - Massimiliano Massi
- Department of Chemistry Nanochemistry Research Institute Curtin University GPO Box U 19876845PerthWestern AustraliaAustralia
| | - Mark I. Ogden
- Department of Chemistry Nanochemistry Research Institute Curtin University GPO Box U 19876845PerthWestern AustraliaAustralia
- School of Chemistry and Biochemistry, M310 The University of Western Australia 6009PerthWestern AustraliaAustralia
| |
Collapse
|