5698-59-9Relevant articles and documents
Optical absorption spectra of aromatic isothianaphthene oligomers. Theory and experiment
Quattrocchi,Lazzaroni,Bredas,Kiebooms,Vanderzande,Gelan,Meervelt
, p. 3932 - 3938 (1995)
We investigate the optical absorption spectra of aromatic isothianaphthene oligomers, from the monomer up to the tetramer, with a combined theoretical and experimental approach. Geometry optimizations are performed with the semiempirical Austin model 1 method on disilylated isothianaphthene oligomers of increasing chain length. The calculated geometric parameters are compared to those obtained from the single-crystal structure of the 3,3′-bis(tert-butyldimethylsilyl)-1,1′-biisothianaphthene. We then use the intermediate neglect of differential overlap method, coupled to single configuration interaction, to simulate theoretically the optical absorption spectra of the oligomers. The corresponding experimental spectra are recorded in n-hexane solution and their evolution with chain length is discussed on the basis of the theoretical data.
Synthesis of phthalide derivatives and evaluation on their antiplatelet aggregation and antioxidant activities
Fang, Xin,Ma, Qiang,Zhang, Kai-Xia,Yao, Song-Yun,Feng, Yi,Jin, Yong-Sheng,Liang, Shuang
, p. 1176 - 1187 (2020)
As part of our continuing efforts to discover structurally interesting bioactive phthalide derivatives, 23 of them with a structure incorporating thiophen or halogens were designed and synthesized, 17 of which are previously unreported. In vitro antiplatelet aggregation activity screening showed that 14b could significantly inhibit platelet aggregation induced by arachidonic acid, compared with edaravone (p 2O2 were built to evaluate the antioxidant activity of the phthalide derivatives. In SH-SY5Y cells, compared with aspirin, 1a significantly increased the relative cell survival rate (p 0.05). Compared with edaravone, 1a (p 0.01) and 15b (p 0.05) significantly increased the relative cell survival rate. In PC12 cells, 1a (p 0.01), 15b (p 0.01), and 12a (p 0.05) remarkably increased the cell survival rate compared with edaravone. The present study identified lead structures to develop potential anti-ischemic stroke agents.
Multiple-State Emissions from Neat, Single-Component Molecular Solids: Suppression of Kasha's Rule
Chen, Bin,Chen, Yu-Zhe,Tung, Chen-Ho,Weiss, Richard G.,Wu, Li-Zhu,Wu, Ya-Hang,Xiao, Hongyan
supporting information, p. 10173 - 10178 (2020/03/13)
Three rigid and structurally simple heterocyclic stilbene derivatives, (E)-3H,3′H-[1,1′-biisobenzofuranylidene]-3,3′-dione, (E)-3-(3-oxobenzo[c] thiophen-1(3H)-ylidene)isobenzofuran-1(3H)-one, and (E)-3H,3′H-[1,1′-bibenzo[c] thiophenylidene]-3,3′-dione, are found to fluoresce in their neat solid phases, from upper (S2) and lowest (S1) singlet excited states, even at room temperature in air. Photophysical studies, single-crystal structures, and theoretical calculations indicate that large energy gaps between S2 and S1 states (T2 and T1 states) as well as an abundance of intra and intermolecular hydrogen bonds suppress internal conversions of the upper excited states in the solids and make possible the fluorescence from S2 excited states (phosphorescence from T2 excited states). These results, including unprecedented fluorescence quantum yields (2.3–9.6 %) from the S2 states in the neat solids, establish a unique molecular skeleton for achieving multi-colored emissions from upper excited states by “suppressing” Kasha's rule.
Multicolor light-emitting crystal and preparation method and application thereof
-
Paragraph 0049; 0053-0054, (2020/06/20)
The invention discloses a multicolor light-emitting crystal. A compound for forming the crystal is a heteroatom substituted rigid stilbene-like compound and has a large energy gap between the excitedstates of S2 and S1. Intramolecular and intermolecular hydrogen bonds exist in the formed crystal, multicolor luminescence of the excited states of S2 and S1 can be realized at room temperature, and the S2-state fluorescence quantum yield can reach 2.3-9.6%. Meanwhile, the crystal structure can realize multicolor luminescence in an advanced excited state by inhibiting a Kasha rule, so that not only a simple model is provided for inhibiting a solid Kasha rule, but also a new way is opened up for designing other single-component multi-emission light solid organic materials. In addition, the preparation method of the crystal is simple, and the crystal has huge application potential in the fields of flexible displays, solid-state lighting, organic lasers and the like.
Indium-catalyzed direct conversion of lactones into thiolactones using a disilathiane as a sulfur source
Ogiwara, Yohei,Takano, Ken,Horikawa, Shuhei,Sakai, Norio
, (2018/06/15)
An indium-catalyzed reaction of lactones and a disilathiane leading to thiolactones is described. The direct synthesis of thiolactones from lactones with an appropriate sulfur source is one of the most attractive approaches in organic and pharmaceutical chemistry. In this context, we found an indium-catalyzed direct conversion of lactones into thiolactones in the presence of elemental sulfur and a hydrosilane via formation of the disilathiane in situ. On the basis of the previous reaction, the application utilizing the disilathiane as a sulfur source was performed herein for the efficient synthesis of a variety of thiolactone derivatives from lactones by an indium catalyst.
Discovery of a potential anti-ischemic stroke agent: 3-pentylbenzo[c] thiophen-1(3H)-one
Wu, Jing,Ling, Lingjing,Wang, Xuliang,Li, Tingting,Liu, Jingchao,Lai, Yisheng,Ji, Hui,Peng, Sixun,Tian, Jide,Zhang, Yihua
, p. 7173 - 7181 (2012/11/07)
The development of novel antithrombotic agents with strong free radical scavenging activity is of great significance for the treatment of ischemic stroke. In the present study, 3-alkyl/arylalkyl-substituted benzo[c]thiophen- 1(3H)-ones (5a-h) were designed and synthesized. The most active compound 5d significantly inhibited the adenosine diphos-phate (ADP) induced and arachidonic acid (AA) induced in vitro platelet aggregation, superior to clinically used anti-platelet drug aspirin (ASP) and anti-ischemic stroke drugs 3-n-butylphthalide (NBP) and edaravone (Eda). More importantly, in comparison with both NBP and Eda, 5d exhibited stronger antithrombotic and free radical scavenging activities and better or comparable neuroprotective effects against ischemia/reperfusion (I/R) in rats by ameliorating neurobehavioral function, reducing infarct size and brain-water content, attenuating cerebral damage, and normalizing the levels of oxidative enzymes. Overall, our findings may provide an alternative strategy for the design of novel anti-ischemic stroke agents more potent than drugs like NBP and Eda.
Grignard Reactions on Ortho Dicarboxylic Arene Derivatives. Synthesis of 1,3-Dithienylisothianaphthene Compounds
Kiebooms, Rafa?l H. L.,Adriaensens, Peter J. A.,Vanderzande, Dirk J. M.,Gelan, Jan M. J. V.
, p. 1473 - 1480 (2007/10/03)
1,3-Dithienylisothianaphthene (10a) is obtained through ring closure of 1,2-dithienoylbenzene (7a). The synthesis of 7a has been accomplished based on a Grignard reaction by adding 2-thiophene-magnesium bromide to 1,2-di(S-(2-pyridinyl)) benzenedithioate (6b) to obtain 7a in a yield of 95%. The use of 6b avoids the formation of the corresponding 3,3-dithienyl-3H-isobenzofuran-1(3H)-one (dithienylphthalide, 8). The same procedure is applied to obtain 1,3-dithienyl-4,5,6,7-tetradeuterioisothianaphthene (10b) and 1,3-dithienyl-4,5,6,7-tetrafluoroisothianaphthene (10c). The synthesis of the 2,3-dithienoylpyridine (12a), 3,4-dithienoylpyridine (12b), and 2,3-dithienoylpyrazine (12c) however fails. The presence of nitrogen in the central ring system influences the result of the Grignard reaction. Possibly the free electron pair of the nitrogen interferes with the formation of a stable six-membered ring intermediate which is essential for the diketone formation.
Unexpected rearrangements in the synthesis of arylidene- or alkylidene-2-thiophthalides
Paulussen, Harald,Adriaensens, Peter,Vanderzande, Dirk,Gelan, Jan
, p. 11867 - 11878 (2007/10/03)
Mechanistic studies concerning the reaction by which poly(isothianaphthene) (PITN) is synthesized in one step from commercially available monomers by reacting them with phosphorus pentasulphide (P4S10), have led to the idea of synthesizing a chain-stopper molecule which should give rise to suitable quinoid model compounds for PITN. Within this context benzylidenedithiophthalide and pentylidenedithiophthalide were chosen as target molecules. The unexpected rearrangements and the control of these rearrangements in the synthesis of benzylidenedithiophthalide and pentylidenedithiophthalide are reported.
Synthesis of Small-Medium Ring Thioanhydrides
Kates, Michael J.,Schauble, J. Herman
, p. 971 - 978 (2007/10/02)
Reaction of five-membered ring anhydrides with sodium sulfide has previously been employed for synthesis of the corresponding thioanhydrides in low yields.Re-examination of the stoichiometry reveals reaction of cyclic anhydride with sodium sulfide (2:1 respectively), affords the thioanhydride accompanied by the corresponding dicarboxylate in a 1:1 molar ratio.The mechanistic pathway for this reaction has also been elucidated.Optimization of reaction conditions has resulted in the synthesis of a variety of four to seven-membered ring thioanhydride in yields approaching theoretical.
Photochemical and Thermal Transformations of Unsymmetrical Di-O-alkyl-S,S-phthaloyl Dixanthates
Darji, R. R.,Shah, A.
, p. 509 - 511 (2007/10/02)
Phthaloyl chloride (I) reacts with potassium O-alkylxanthates at 0 deg C in ether to give the corresponding unsymmetrical di-O-alkyl-S,S-phthaloyl dixanthates (V).Irradiation of these dixanthates (V) in benzene with a mercury lamp for 7 hr results in the formation of trans-biphthalyl (X).However, thermal decomposition of the dixanthates Va (R = isopropyl) and Vc (R = isoamyl) around 250 deg C for 30 min yields a mixture of X, thiophthalic anhydride (XII), carbonyl sulphide (XIV) and the corresponding O,S-dialkyl xanthates (XIII).
