Single-crystalline photochromism of diarylethene dimers bridged by a spiro structure
作者:Seiya Kobatake、Shunpei Kuma、Masahiro Irie
DOI:10.1002/poc.1196
日期:2007.11
dimers bridged by a spiro structure were synthesized. One of their dimers formed three kinds of polymorphicforms by recrystallization from different solvents: hexane (1a-α), acetone (1a-β), and acetonitrile (1a-γ). In crystals of 1a-α and 1a-β the molecules are packed in solvent-free crystalstructures, whereas crystal 1a-γ includes acetonitrile molecules in the crystal. The difference of significant
Tetrathiafulvalene (TTF) derivatives with diarylethene moieties have been synthesized. A derivative having 2,4,5-trimethylthiophene rings as the aryl groups showed photochromism, while a derivative with 2,5-dimethylthiophene rings did not show any color change by UV irradiation. The different reactivity was ascribed to the difference in the conformation of thiophene rings in the two derivatives.
Photoswitchable N-Heterocyclic Carbenes: Using Light to Modulate Electron-Donating Properties
作者:Bethany M. Neilson、Vincent M. Lynch、Christopher W. Bielawski
DOI:10.1002/anie.201105032
日期:2011.10.24
Ligands in the limelight: Light was used to change the electron‐donating properties of an N‐heterocyclic carbene (NHC) moiety within chalcogen and metal adducts. Photoinduced electrocyclic ring closure of a photochromic 4,5‐dithienylimidazolone increased its νCO frequency. Likewise, UV irradiation of an analogous photochromic [(NHC)Ir(CO)2Cl] complex decreased the carbene's electron‐donating ability
Syntheses and Photochromic Studies of Dithienylethene-Containing Imidazolium Derivatives and Their Reactivity towards Nucleophiles
作者:Gongping Duan、Nianyong Zhu、Vivian Wing-Wah Yam
DOI:10.1002/chem.201001319
日期:2010.11.22
studied, and the closed forms are found to be solvatochromic due to the donor–acceptor interaction with the solvent molecules. The closed form of the imidazolium salt shows a much higher affinity towards nucleophiles over the open form of the salt. A reaction pathway has been proposed to account for this reactivity difference based on the structure–property relationship, and the possible structure
Behavior of Benzoins and Hydroxy ketones in Acid Media: I. Reaction of 1-Aryl-2-(2,5-dimethylthiophen-3-yl)-2-hydroxyethanones with Thiols in Trifluoroacetic Acid
作者:M. M. Krayushkin、B. V. Lichitskii、A. P. Mikhalev、A. A. Dudinov、S. N. Ivanov
DOI:10.1007/s11178-005-0125-y
日期:2005.1
Reactions of 1-aryl-2-(2,5-dimethylthiophen-3-yl)-2-hydroxyethanones with thiols in trifluoroacetic acid lead to formation of substituted 1-aryl-2-(2,5-dimethylthiophen-3-yl)-2-sulfanylethanones.