Near-infrared photochromic diarylethenes based on the changes in the π-conjugated system and the electronic properties of the heteroaryl moieties

Abstract

It is very challenging to construct photochromic materials with absorption and reactivity in the near-infrared (NIR) spectral region. Herein, four unsymmetrical diarylethene derivatives 1o-4o, which contain both indole and thiophene moieties, have been successfully synthesized, and their photochromic behaviors have been shifted to the NIR region. These newly developed NIR photochromic materials are highly sensitive and responsive to photostimuli both in solution and in poly(methyl methacrylate) films. It has been shown that 1o-4o exhibit remarkable UV/Vis and fluorescence spectral changes, allowing them to behave as reversible optical molecular switches in the NIR region. Four unsymmetrical diarylethene derivatives, 1o-4o, which contain both indole and thiophene moieties, have been successfully synthesized, and their photochromic behaviors have been shifted to the NIR region. The photophysical and photochromic properties of 1o-4o were comprehensively investigated by NMR, UV/Vis, fluorescence spectral and X-ray crystallographic analysis. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.