Photoresponsive crown ethers. Part 18. Photochemically 'switched-on' crown ethers containing an intra-annular azo substituent and their application to membrane transport

Seiji Shinkai, Kiminori Miyazaki, Osamu Manabe

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

Photoresponsive crown ethers (3) having an intra-annular azo substituent have been synthesized. These crown ethers have been designed so that the crown-metal interaction can only occur upon photoisomerisation of the intra-annular azo substituent from trans to cis. In thermal cis-to-trans isomerisation, the first-order rate constants (k) were suppressed to 14 - 66% by the addition of Na+ or K+, indicating that an additional free energy of activation (1.0 - 5.0 KJ mol-1) is required to disrupt the favourable crown-metal interactions. From the plots of k vs. [M +] the association constants (Kc) for the cis-forms were estimated to be 104.07 - 104.81 l mol-1, which are comparable with the Kc for regular crown ethers. The spectral study established that the high metal affinity of the cis-forms is due to the co-ordination of one of the azo nitrogens to the metal ion. In two-phase extraction of alkali-metal cations the Ex% values for cis-(3) were always higher than those for trans-(3). In particular, the dramatic photoirradiation effect was observed for Na+: cis-(3) extracts Na+ (8.1-14.1%), whereas trans-(3) extracts no Na+. This system was applied to ion transport across a liquid membrane. As expected, Na+ transport occurred only when the membrane phase was irradiated by u.v. light. The marked difference can be used to control the ion permeability by an on-off light switch.

Original languageEnglish
Pages (from-to)449-456
Number of pages8
JournalJournal of the Chemical Society, Perkin Transactions 1
Publication statusPublished - 1987
Externally publishedYes

Fingerprint

Crown Ethers
Metals
Membranes
Ions
Alkali Metals
Photoisomerization
Liquid membranes
Isomerization
Free energy
Metal ions
Cations
Rate constants
Nitrogen
Chemical activation
Switches
Association reactions

All Science Journal Classification (ASJC) codes

  • Chemistry(all)

Cite this

@article{4abea51547274e0ab5e4f141d821c6b8,
title = "Photoresponsive crown ethers. Part 18. Photochemically 'switched-on' crown ethers containing an intra-annular azo substituent and their application to membrane transport",
abstract = "Photoresponsive crown ethers (3) having an intra-annular azo substituent have been synthesized. These crown ethers have been designed so that the crown-metal interaction can only occur upon photoisomerisation of the intra-annular azo substituent from trans to cis. In thermal cis-to-trans isomerisation, the first-order rate constants (k) were suppressed to 14 - 66{\%} by the addition of Na+ or K+, indicating that an additional free energy of activation (1.0 - 5.0 KJ mol-1) is required to disrupt the favourable crown-metal interactions. From the plots of k vs. [M +] the association constants (Kc) for the cis-forms were estimated to be 104.07 - 104.81 l mol-1, which are comparable with the Kc for regular crown ethers. The spectral study established that the high metal affinity of the cis-forms is due to the co-ordination of one of the azo nitrogens to the metal ion. In two-phase extraction of alkali-metal cations the Ex{\%} values for cis-(3) were always higher than those for trans-(3). In particular, the dramatic photoirradiation effect was observed for Na+: cis-(3) extracts Na+ (8.1-14.1{\%}), whereas trans-(3) extracts no Na+. This system was applied to ion transport across a liquid membrane. As expected, Na+ transport occurred only when the membrane phase was irradiated by u.v. light. The marked difference can be used to control the ion permeability by an on-off light switch.",
author = "Seiji Shinkai and Kiminori Miyazaki and Osamu Manabe",
year = "1987",
language = "English",
pages = "449--456",
journal = "Journal of the Chemical Society, Perkin Transactions 2",
issn = "1472-7781",
publisher = "Chemical Society",

}

TY - JOUR

T1 - Photoresponsive crown ethers. Part 18. Photochemically 'switched-on' crown ethers containing an intra-annular azo substituent and their application to membrane transport

AU - Shinkai, Seiji

AU - Miyazaki, Kiminori

AU - Manabe, Osamu

PY - 1987

Y1 - 1987

N2 - Photoresponsive crown ethers (3) having an intra-annular azo substituent have been synthesized. These crown ethers have been designed so that the crown-metal interaction can only occur upon photoisomerisation of the intra-annular azo substituent from trans to cis. In thermal cis-to-trans isomerisation, the first-order rate constants (k) were suppressed to 14 - 66% by the addition of Na+ or K+, indicating that an additional free energy of activation (1.0 - 5.0 KJ mol-1) is required to disrupt the favourable crown-metal interactions. From the plots of k vs. [M +] the association constants (Kc) for the cis-forms were estimated to be 104.07 - 104.81 l mol-1, which are comparable with the Kc for regular crown ethers. The spectral study established that the high metal affinity of the cis-forms is due to the co-ordination of one of the azo nitrogens to the metal ion. In two-phase extraction of alkali-metal cations the Ex% values for cis-(3) were always higher than those for trans-(3). In particular, the dramatic photoirradiation effect was observed for Na+: cis-(3) extracts Na+ (8.1-14.1%), whereas trans-(3) extracts no Na+. This system was applied to ion transport across a liquid membrane. As expected, Na+ transport occurred only when the membrane phase was irradiated by u.v. light. The marked difference can be used to control the ion permeability by an on-off light switch.

AB - Photoresponsive crown ethers (3) having an intra-annular azo substituent have been synthesized. These crown ethers have been designed so that the crown-metal interaction can only occur upon photoisomerisation of the intra-annular azo substituent from trans to cis. In thermal cis-to-trans isomerisation, the first-order rate constants (k) were suppressed to 14 - 66% by the addition of Na+ or K+, indicating that an additional free energy of activation (1.0 - 5.0 KJ mol-1) is required to disrupt the favourable crown-metal interactions. From the plots of k vs. [M +] the association constants (Kc) for the cis-forms were estimated to be 104.07 - 104.81 l mol-1, which are comparable with the Kc for regular crown ethers. The spectral study established that the high metal affinity of the cis-forms is due to the co-ordination of one of the azo nitrogens to the metal ion. In two-phase extraction of alkali-metal cations the Ex% values for cis-(3) were always higher than those for trans-(3). In particular, the dramatic photoirradiation effect was observed for Na+: cis-(3) extracts Na+ (8.1-14.1%), whereas trans-(3) extracts no Na+. This system was applied to ion transport across a liquid membrane. As expected, Na+ transport occurred only when the membrane phase was irradiated by u.v. light. The marked difference can be used to control the ion permeability by an on-off light switch.

UR - http://www.scopus.com/inward/record.url?scp=37049082045&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=37049082045&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:37049082045

SP - 449

EP - 456

JO - Journal of the Chemical Society, Perkin Transactions 2

JF - Journal of the Chemical Society, Perkin Transactions 2

SN - 1472-7781

ER -