Tunable Photochromism in Air‐Stable, Robust Dithienylethene‐Containing Phospholes through Modifications at the Phosphorus Center

Abstract

Robust photoswitch: The photophysical and photochromic properties of a series of robust dithienylethene-containing phosphole derivatives can be readily tuned by simple modifications at the phosphorus center. Both the open and closed forms of the phosphole compounds are stable in benzene solution and in PMMA film in the dark.

Tunable Photochromism in the Robust Dithienylethene‐Containing Phospholes: Design, Synthesis, Characterization, Electrochemistry, Photophysics, and Photochromic Studies

“…Although phosphole‐containing materials have attracted growing interest and have been studied by a number of groups for decades,5–11 the use of the phosphole moiety as the photochromic dithienylethene backbone has not been reported due to the limited synthetic pathway. It was not until 2013 that the first class of photochromic diarylethene‐containing phospholes was communicated by Yam and co‐workers,12 in which the photochromic behavior has been shown to be readily controlled through simple chemical modifications at the phosphorus center (compounds A – E ) 12…”

“…This new class of photochromic phospholes not only demonstrated the tunable photochromism at the phosphorus center, but the compounds also show good reversibility and thermal stability 12. To further extend the structural diversity and to study the structure–property relationships in this system, herein we describe the design and synthesis of a new series of dithienylethene‐containing phospholes, and their photophysical, electrochemical, and photochromic behavior…”

Photoswitching of Copper(I) Chromophores with Dithienylethene‐Based Ligands

“…[10][11][12][13][14][15][16][17] Yam and co-workers in 2004 first reported 1,10-phenanthroline functionalizedd ithienylethene as al igand for metalc oordination. In these compounds, the thienyl groups are attached to five-or six-memberedr ings such as the cyclopentene moiety to prevent unwanted cis-trans isomerization.M ost modificationso f this basic motif have involvedc hanges to the thienylu nits, but now significant efforts have been extended to replacet he fivemembered ring systems with various heterocycles.…”

Photocatalytic colour switching of redox dyes for ink-free light-printable rewritable paper

“…Conventionally, organic dyes capable of undergoing reversible colour switching based on the photoisomerization of constitute chromophores were proposed for potential use as the imaging layer in rewritable printing media [12][13][14][15][16][17][18][19] . However, only limited progresses have been made in this area because of some major challenges [20][21][22] : (i) colour switching often becomes much slower when dyes are present in solid media instead of solution, as their molecular mobility is markedly restricted 23 , (ii) many switchable dyes retain their colour for only several hours under ambient conditions, which is too short for reading, (iii) the toxicity of switchable dyes is often an issue for daily use and (iv) most switchable dyes involve complex synthesis and are therefore expensive. As a result, it is of high interest to develop rewritable papers based on new colour switching mechanisms 24,25 .…”