194-65-0Relevant articles and documents
Dinaphtho[2,1-b:1′,2′- d] thiophenes as high refractive index materials exploiting the potential characteristics of "dynamic thiahelicenes"
Ishikawa, Ken,Kuwata, Shigeki,Mineyama, Kenji,Nambu, Yoko,Nishikubo, Tadatomi,Takata, Toshikazu,Tsurui, Keisuke,Yanagi, Shohan,Yoshitake, Yoko
supporting information, p. 726 - 733 (2022/01/22)
Dinaphtho[2,1-b:1′,2′-d]thiophene (DNT) is one of the "dynamic thiahelicenes"that is obtained as a racemate due to its low energy barrier for enantiomerization. A careful evaluation of both the metastable DNT film and the stable films of DNT/polymethyl methacrylate (PMMA) blends revealed that DNT has an extra-high refractive index of 1.808 at 633 nm, which is rarely achieved in organic small molecules. The fundamental factors responsible for the unusual observation of DNT were explored by comparing the properties of DNT with those of a flat-shaped dibenzothiophene (DBT) both in experiments and DFT calculations, and by analysing them using the Lorentz-Lorenz equation. It became clear that the unique properties of DNT were based on its flexible dynamic thiahelicene structure, leading to metastable film-forming ability, high compatibility with PMMA, and exhibition of an extra-high refractive index caused by dense packing in the amorphous film. Chemical modification of DNT provided new halogen-free vinyl monomers, which could be easily polymerized to form vinyl polymers with high refractive indices of 1.72-1.74, as well as film-forming ability, high thermal stability, and high transparency in the visible region. Thus, we could demonstrate that the DNT structure is a new promising candidate for organic polymeric high refractive index materials.
Thiolate-Initiated Synthesis of Dibenzothiophenes from 2,2′-Bis(methylthio)-1,1′-Biaryl Derivatives through Cleavage of Two Carbon-Sulfur Bonds
Chatani, Naoto,Kawashima, Yuki,Kodama, Takuya,Masuya, Yoshihiro,Tobisu, Mamoru
supporting information, p. 1995 - 1999 (2019/10/22)
A catalytic reaction involving the cleavage of two carbon-sulfur bonds in 2,2′-bis(methylthio)-1,1′-biaryl derivatives is reported. This reaction does not require a transition-metal catalyst and is promoted by a thiolate anion. Notably, based on DFT calculations, the product-forming cyclization step is shown to proceed through a concerted nucleophilic aromatic substitution (CS N Ar) mechanism.
METHOD FOR PRODUCING HETEROCYCLIC COMPOUNDS
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Paragraph 0051, (2017/10/05)
PROBLEM TO BE SOLVED: To provide heterocyclic compounds in high yield and by simple compositions. SOLUTION: The method for producing heterocyclic compounds comprises: a step of heating a raw material solution containing a solvent having a raw material substrate dissolved; and a step of cooling the raw material solution after the heating step where, in the heating step, the state of the solvent is a subcritical fluid or a supercritical fluid. The term supercritical fluid refers to a state of a metrial under the a temperature and pressure of the critical point or more. The term subcritical fluid refers to a liquid under high temperature and high pressure below the critical point. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2017,JPOandINPIT