Photoisomerization reaction of unsymmetrical azobenzene disulfide self-assembled monolayers: Modification of azobenzene dyes to improve thermal endurance for photoreaction

Kaoru Tamada, Haruhisa Akiyama, Tian Xin Wei, Seung Ae Kim

Research output: Contribution to journalArticle

53 Citations (Scopus)

Abstract

Recently we have developed an unsymmetrical azobenzene disulfide with a short alkyl side chain, 4-hexyl-4′-(12-(dodecyldithio)-dodecyloxy)azobenzene (C6AzSSC12), aiming of a high efficiency in photoisomerization in SAMs on planar gold surfaces (Tamada, K.; et al. Langmuir 2002, 18, 5239). In this paper, we introduce an additional modification on the molecule to improve the thermal endurance for the photoreaction by attachment of a methyl group to the azobenzene ring, thus avoiding dye aggregation sterically. A "methyl-derivatized" azobenzenethiol (C6Az(Me)SH) SAM revealed a significant improvement in their photoreactivity compared with an unmodified azobenzenethiol (C6AzSH) SAM due to the steric effect of the methyl group. A "methyl-derivatized" unsymmetrical azobenzene disulfide (C6Az(Me)SSC12) SAM exhibited quite a similar photoresponse to that of C6AzSSC12 SAM before heat treatment owing to the free volume given by the unsymmetrical structure; however, only the C6Az(Me)SSC12 SAM could retain high photoreactivity in phase-segregated domains formed by annealing, unlike the C6AzSSC12 SAM. The C6Az(Me)SH and C6Az(Me)SSC12 SAMs exhibited a reaction kinetics different from that of C6AzSSC12 SAM due to a different quantum yield and the molecular tilt angle of the azobenzene unit. The C6Az(Me)SH SAM exhibited a typical character of "congested surface", where the reaction rate from cis to trans was faster, while that from trans to cis was slower compared with those of C6Az(Me)SSC12 SAM.

Original languageEnglish
Pages (from-to)2306-2312
Number of pages7
JournalLangmuir
Volume19
Issue number6
DOIs
Publication statusPublished - Mar 18 2003
Externally publishedYes

Fingerprint

Photoisomerization
Azobenzene
endurance
disulfides
Self assembled monolayers
Disulfides
Durability
reaction kinetics
Coloring Agents
Dyes
dyes
Photoreactivity
attachment
heat treatment
gold
annealing
rings
Free volume
molecules
Quantum yield

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

Cite this

Photoisomerization reaction of unsymmetrical azobenzene disulfide self-assembled monolayers : Modification of azobenzene dyes to improve thermal endurance for photoreaction. / Tamada, Kaoru; Akiyama, Haruhisa; Wei, Tian Xin; Kim, Seung Ae.

In: Langmuir, Vol. 19, No. 6, 18.03.2003, p. 2306-2312.

Research output: Contribution to journalArticle

@article{906b3edeebc74e6f8cf641339cbe8800,
title = "Photoisomerization reaction of unsymmetrical azobenzene disulfide self-assembled monolayers: Modification of azobenzene dyes to improve thermal endurance for photoreaction",
abstract = "Recently we have developed an unsymmetrical azobenzene disulfide with a short alkyl side chain, 4-hexyl-4′-(12-(dodecyldithio)-dodecyloxy)azobenzene (C6AzSSC12), aiming of a high efficiency in photoisomerization in SAMs on planar gold surfaces (Tamada, K.; et al. Langmuir 2002, 18, 5239). In this paper, we introduce an additional modification on the molecule to improve the thermal endurance for the photoreaction by attachment of a methyl group to the azobenzene ring, thus avoiding dye aggregation sterically. A {"}methyl-derivatized{"} azobenzenethiol (C6Az(Me)SH) SAM revealed a significant improvement in their photoreactivity compared with an unmodified azobenzenethiol (C6AzSH) SAM due to the steric effect of the methyl group. A {"}methyl-derivatized{"} unsymmetrical azobenzene disulfide (C6Az(Me)SSC12) SAM exhibited quite a similar photoresponse to that of C6AzSSC12 SAM before heat treatment owing to the free volume given by the unsymmetrical structure; however, only the C6Az(Me)SSC12 SAM could retain high photoreactivity in phase-segregated domains formed by annealing, unlike the C6AzSSC12 SAM. The C6Az(Me)SH and C6Az(Me)SSC12 SAMs exhibited a reaction kinetics different from that of C6AzSSC12 SAM due to a different quantum yield and the molecular tilt angle of the azobenzene unit. The C6Az(Me)SH SAM exhibited a typical character of {"}congested surface{"}, where the reaction rate from cis to trans was faster, while that from trans to cis was slower compared with those of C6Az(Me)SSC12 SAM.",
author = "Kaoru Tamada and Haruhisa Akiyama and Wei, {Tian Xin} and Kim, {Seung Ae}",
year = "2003",
month = "3",
day = "18",
doi = "10.1021/la0258493",
language = "English",
volume = "19",
pages = "2306--2312",
journal = "Langmuir",
issn = "0743-7463",
publisher = "American Chemical Society",
number = "6",

}

TY - JOUR

T1 - Photoisomerization reaction of unsymmetrical azobenzene disulfide self-assembled monolayers

T2 - Modification of azobenzene dyes to improve thermal endurance for photoreaction

AU - Tamada, Kaoru

AU - Akiyama, Haruhisa

AU - Wei, Tian Xin

AU - Kim, Seung Ae

PY - 2003/3/18

Y1 - 2003/3/18

N2 - Recently we have developed an unsymmetrical azobenzene disulfide with a short alkyl side chain, 4-hexyl-4′-(12-(dodecyldithio)-dodecyloxy)azobenzene (C6AzSSC12), aiming of a high efficiency in photoisomerization in SAMs on planar gold surfaces (Tamada, K.; et al. Langmuir 2002, 18, 5239). In this paper, we introduce an additional modification on the molecule to improve the thermal endurance for the photoreaction by attachment of a methyl group to the azobenzene ring, thus avoiding dye aggregation sterically. A "methyl-derivatized" azobenzenethiol (C6Az(Me)SH) SAM revealed a significant improvement in their photoreactivity compared with an unmodified azobenzenethiol (C6AzSH) SAM due to the steric effect of the methyl group. A "methyl-derivatized" unsymmetrical azobenzene disulfide (C6Az(Me)SSC12) SAM exhibited quite a similar photoresponse to that of C6AzSSC12 SAM before heat treatment owing to the free volume given by the unsymmetrical structure; however, only the C6Az(Me)SSC12 SAM could retain high photoreactivity in phase-segregated domains formed by annealing, unlike the C6AzSSC12 SAM. The C6Az(Me)SH and C6Az(Me)SSC12 SAMs exhibited a reaction kinetics different from that of C6AzSSC12 SAM due to a different quantum yield and the molecular tilt angle of the azobenzene unit. The C6Az(Me)SH SAM exhibited a typical character of "congested surface", where the reaction rate from cis to trans was faster, while that from trans to cis was slower compared with those of C6Az(Me)SSC12 SAM.

AB - Recently we have developed an unsymmetrical azobenzene disulfide with a short alkyl side chain, 4-hexyl-4′-(12-(dodecyldithio)-dodecyloxy)azobenzene (C6AzSSC12), aiming of a high efficiency in photoisomerization in SAMs on planar gold surfaces (Tamada, K.; et al. Langmuir 2002, 18, 5239). In this paper, we introduce an additional modification on the molecule to improve the thermal endurance for the photoreaction by attachment of a methyl group to the azobenzene ring, thus avoiding dye aggregation sterically. A "methyl-derivatized" azobenzenethiol (C6Az(Me)SH) SAM revealed a significant improvement in their photoreactivity compared with an unmodified azobenzenethiol (C6AzSH) SAM due to the steric effect of the methyl group. A "methyl-derivatized" unsymmetrical azobenzene disulfide (C6Az(Me)SSC12) SAM exhibited quite a similar photoresponse to that of C6AzSSC12 SAM before heat treatment owing to the free volume given by the unsymmetrical structure; however, only the C6Az(Me)SSC12 SAM could retain high photoreactivity in phase-segregated domains formed by annealing, unlike the C6AzSSC12 SAM. The C6Az(Me)SH and C6Az(Me)SSC12 SAMs exhibited a reaction kinetics different from that of C6AzSSC12 SAM due to a different quantum yield and the molecular tilt angle of the azobenzene unit. The C6Az(Me)SH SAM exhibited a typical character of "congested surface", where the reaction rate from cis to trans was faster, while that from trans to cis was slower compared with those of C6Az(Me)SSC12 SAM.

UR - http://www.scopus.com/inward/record.url?scp=0037453617&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037453617&partnerID=8YFLogxK

U2 - 10.1021/la0258493

DO - 10.1021/la0258493

M3 - Article

AN - SCOPUS:0037453617

VL - 19

SP - 2306

EP - 2312

JO - Langmuir

JF - Langmuir

SN - 0743-7463

IS - 6

ER -