Issue 33, 2015

Chromophoric materials derived from a natural azulene: syntheses, halochromism and one-photon and two-photon microlithography

Abstract

In addition to their use as colorants in food and cosmetics, various natural dyes possess photophysical properties that could enable their use as modular building blocks for preparing eco-friendly and non-toxic chromophores. Among the natural pigments, guaiazulene holds great potential due to its unique optical and electronic properties. Thus, in order to explore and understand the properties of guaiazulene-containing chromophores, a series of 4-styrylguaiazulenes 3a–l were prepared by condensation of the C-4 methyl group of naturally-occurring guaiazulene 1 with various aromatic carboxaldehydes 2a–l. Treatment of these analogs 3a–l with a strong acid protonates the electron-rich C-3 position and reveals a reversible halochromic behavior where the optical energy gap responds predictably to the electron-donor strength and the degree of π-conjugation. Additionally, acid-doping is accompanied by efficient fluorescence switch-on, where 3e(H+) and 3g(H+) exhibited considerably higher fluorescence quantum yields than the neutral precursor. These properties facilitated the design of a new non-erasable 3D fluorescence readout (permanent or write-once read-many, WORM) system, which is comprised of a switch-on fluorescent guaiazulene-containing chromophore 3e and a commercially available iodonium photo-acid generator (PAG) in thin polymethyl methacrylate (PMMA) films.

Graphical abstract: Chromophoric materials derived from a natural azulene: syntheses, halochromism and one-photon and two-photon microlithography

Supplementary files

Article information

Article type
Paper
Submitted
22 May 2015
Accepted
28 Jun 2015
First published
01 Jul 2015

J. Mater. Chem. C, 2015,3, 8495-8503

Chromophoric materials derived from a natural azulene: syntheses, halochromism and one-photon and two-photon microlithography

E. H. Ghazvini Zadeh, S. Tang, A. W. Woodward, T. Liu, M. V. Bondar and K. D. Belfield, J. Mater. Chem. C, 2015, 3, 8495 DOI: 10.1039/C5TC01459J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements