Isomeric Photochromic Diarylethene Research Articles

Photochromism of isomeric diarylethenes with a methylpyridine substituent

Two new isomeric photochromic diarylethenes with a methylpyridine unit have been synthesized and their structures have been determined by single-crystal X-ray diffraction analysis. Both diarylethenes exhibited photochromism in both solution and PMMA films. In the single crystalline phase, the two isomeric compounds displayed different photochromism based on their various molecular conformations. In addition, their fluorescent properties are also diverse due to the distinct substitution position of the methyl group on the terminal pyridine.

Research on Photochromic Compounds with Efficient Synthesis and Photochromic Properties of 1-(2-methyl-5-phenyl-3-thienyl)-2-[2-methyl-5-(4-pentylphenyl)-3-thienyl] perfluorocyclopentene

A novel isomeric photochromic diarylethene, 1-(2-methyl-5-phenyl-3-thienyl)-2-[2-methyl-5-(4-pentylphenyl)-3-thienyl] perfluorocyclopentene, was designed and synthesized. Its fluorescent and photochromic properties were also studied in detail. The compound exhibited excellent photochromism, changing from colorless to bule after irradiation with UV light both in solution and in PMMA film. In addition, the fluorescence intensity of the photochromic diarylethene 1a declined remarkably, when irradiation with UV light.

Synthesis and Properties of a Novel Unsymmetrical Diarylethene{1-[2-methyl-5-(10-phenanthrenyl)-3-thienyl]-2-{2-methyl-5-[4-(2-(1,3-dioxolane))phenyl]-3-thienyl}} Perfluorocyclopentene

A novel unsymmetrical isomeric photochromic diarylethene based on phenanthrene unit, {1-[2-methyl-5-(10-phenanthrenyl)-3-thienyl]-2-{2-methyl-5-[4-(2-(1,3-dioxolane)) phenyl]-3-thienyl}} perfluorocyclopentene (1o), was designed and synthesized. Its properties were investigated in detail, including photochromic, kinetics and fluorescent. The results showed that the compound exhibited excellent photochromism, changing from colorless to violet after irradiation with UV light in solution. What is more, the kinetic experiments illustrated that the cyclization/cycloreversion process of this compound was determined to be the zeroth/first reaction. Furthermore, the fluorescence intensity of the photochromic diarylethene1odeclined dramatically.

Study on Photochromic Materials of 1-(2-benzyl)-2-[2-methyl-5-(10-phen-anthrenyl)-3-thienyl]Perfluorocyclopentene

A new unsymmetrical isomeric photochromic diarylethene, 1-[2-methyl-3-benzene]-2-[2-methyl-5-(10-phenanthrenyl)-3-thienyperfluorocyclopentene, was designed and synthesized. Its photochromic and fluorescent properties were also investigated in detail. The compound exhibited excellent photochromism, changing from colorless to orchid after irradiation with UV light both in solution and in PMMA film. Furthermore, the fluorescence intensity of the photochromic diarylethene 1a declined remarkably, when irradiation with UV light. Using this diarylethene 1a as optical storage and fluorescence switches was performed successfully.

Study on Photochromic Materials with Photochromic and Optical Storage Composite Properties of a Novel Diarylethene

A new unsymmetrical isomeric photochromic diarylethene, 1-[2-methyl-3-naphthalen-2-[2-methyl-5-(10-phenanthrenyl)-3-thienyperfluorocyclopentene, was designed and synthesized. Its photochromic and fluorescent properties were also investigated in detail. The compound exhibited excellent photochromism, changing from colorless to red after irradiation with UV light both in solution and in PMMA film. Furthermore, the fluorescence intensity of the photochromic diarylethene1adeclined remarkably, when irradiation with UV light.

Photochromism and Optical Recording of a Novel Photochromic Diarylethene Material Bearing a Phenanthrenyl Unit

A novel unsymmetrical isomeric photochromic diarylethene based on benzofuran, 1-[2-methyl-3-benzofura-2-[2-methyl-5-(10-phenanthrenyl)-3-thienyperfluorocyclopentene, was designed and synthesized. Its fluorescent and photochromic properties were also investigated in detail. The compound exhibited excellent photochromism, changing from colorless to hot pink after irradiation with UV light both in solution and in PMMA film. Furthermore, the fluorescence intensity of the photochromic diarylethene 1a declined remarkably, when irradiation with UV light. Using this diarylethene 1a as optical storage and fluorescence switches was performed successfully.

Study on Photochromic Materials with Photochromic and Optical Storage Composite Properties of a Novel Diarylethene

A new unsymmetrical isomeric photochromic diarylethene, 1-[2-methyl-3-benzothiophen-2-[2-methyl-5-(10-phenanthrenyl)-3-thienyperfluorocyclopentene, was designed and synthesized. Its photochromic and fluorescent properties were also investigated in detail. The compound exhibited excellent photochromism, changing from colorless to medium violetred after irradiation with UV light both in solution and in PMMA film. Furthermore, the fluorescence intensity of the photochromic diarylethene1adeclined remarkably, when irradiation with UV light. Using this diarylethene 1a as optical storage and fluorescence switches was performed successfully.

The effect of the fluorine atom position upon isomeric photochromic diarylethenes bearing a pyrrole unit

Abstract A new class of isomeric diarylethenes bearing a pyrrole moiety have been synthesized, and their properties including photochromism, fluorescence, and electrochemical properties have been discussed systematically. Each of the diarylethenes exhibited evident photochromism and functioned as a remarkable fluorescent switch in both solution and PMMA films. Their photoconversion ratios were larger than 90%, and the fluorescent modulation efficiencies were greater than 88% in the photostationary state. The absorption maxima, quantum yields of cyclization and cycloreversion, and band-gaps of the closed-ring isomers increased whereas the emission intensity and band-gaps of the open-ring isomers greatly decreased when the fluorine atom was attached at any of the three positions on the terminal benzene ring. Cyclic voltammograms suggested that the oxidation onsets and band-gaps of the open-ring isomers were much bigger than those of the closed-ring isomers. The fluorine atom and its substituted position could availably modulate their optical and electrochemical behaviors.

Efficient One‐step Synthesis and Properties of Photochromic Diarylethenes Having an Indene Bridging Unit

AbstractTwo novel isomeric photochromic diarylethenes with an indene bridging unit have been prepared by a simple and efficient one‐step synthesis method. Their properties, including photochromic behavior, fluorescent properties and fatigue resistance, have been investigated. These two isomeric compounds showed photochromic back‐and‐forth reactions with ultraviolet and visible light both in solution and in PMMA film. Their ring‐open forms exhibited appreciable fluorescence, which was quenched by the ring‐closed forms. All results indicated that diarylethenes derivatives with indene‐aryl bridges exhibited rather high fatigue resistance and good thermally irreversible photochromic properties.

The effect of substituent position upon unsymmetrical isomeric diarylethenes bearing a methoxy group

Three unsymmetrical isomeric photochromic diarylethenes bearing a methoxy group at either the para-, meta- or ortho-positions on one terminal benzene ring were synthesized and their optical and electrochemical properties investigated. Each of the compounds exhibited high photo-reactive sensitivity and functioned as a fluorescent photo-switch both in solution and in PMMA film. The molar absorption coefficients of both of the open-ring and closed-ring isomers decreased when the methoxy group was attached at any of the three positions on the terminal benzene ring whereas the cycloreversion quantum yield gradually increased in going from the para- to meta- to the ortho-position of substitution. Oxidation waves were clearly observed at 0.55, 0.74 and 0.58 V from cyclic voltammograms for some compounds but not for others at these voltages.

Substituent position effect on the properties of isomeric photochromic diarylethenes bearing chlorine atoms

Three new isomeric photochromic diarylethenes, namely 1,2-bis[2-methyl-5-(4-chlorophenyl)-3-thienyl]perfluorocyclopentene ( 1o), 1,2-bis[2-methyl-5-(3-chlorophenyl)-3-thienyl]perfluorocyclopentene ( 2o), and 1,2-bis[2-methyl-5-(2-chlorophenyl)-3-thienyl]perfluorocyclopentene ( 3o) which bear two chlorine atoms at the para-, meta-, and ortho-position of both terminal phenyl groups, have been synthesized. The substituent position effect of chlorine atoms on their optoelectronic properties, including photochromic behavior and fluorescence, both in solution and in PMMA amorphous film, and electrochemical properties were investigated in detail. The results elucidated that the chlorine atoms and their substituent positions had a significant effect on the optoelectronic properties of these compounds. These diarylethene derivatives bearing two chlorine atoms have shown good photochromic behavior and fluorescent switching both in solution and in PMMA film. For diarylethenes 1– 3, the cycloreversion quantum yields were gradually increased when the chlorine atom was attached to the para-, meta- and ortho-positions of the two terminal benzene rings; but, their absorption maxima, cyclization quantum yields and the molar absorption coefficients both of their open-ring and closed-ring isomers were remarkably decreased one by one. Furthermore, the clear oxidation waves of diarylethenes 1c, 2c and 3c were observed at 1.01, 0.92 and 0.98 V by performing the cyclic voltammograms experiments.

Efficient Synthesis and Properties of Isomeric Photochromic Diarylethenes Having a Pyrrole Unit

Two new isomeric photochromic diarylethenes with a pyrrole unit have been developed. Their properties, including photochromic behavior, crystal structures, and fluorescent properties, have been investigated. The two isomeric compounds show distinctly different photochromism, both in solution and in the single-crystalline phase: one turns red upon photocyclization whereas the other turns blue, which may be attributed to the different substituent effects.