Topic
Xanthene
About: Xanthene is a research topic. Over the lifetime, 2132 publications have been published within this topic receiving 34803 citations. The topic is also known as: Xanthene & dibenzo[a,e]pyran.
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3 citations
01 Jan 2010
TL;DR: In this article, the authors proposed a method to detect triphenyl and pyridine in poly(2-trifluoromethyl-4-aminophenoxy) compounds.
Abstract: 一新 poly 氟化(醚酰胺) 生氧杂蒽组从 9,9 二度被准备[4-(2-trifluoromethyl-4-aminophenoxy ) 苯基] 有 9,9 二度的氧杂蒽(BTFAPX )[4-(4-carboxyphenoxy ) 苯基] 氧杂蒽(BCAPX ) 面对 triphenyl 磷酸盐和 pyridine (Py ) 。聚合物有重量一般水准 69,000 的分子的重量( Mw )和数字一般水准 39,000 的分子的重量( Mn )，显示出 267 的玻璃转变温度( Tg )钾离子的集中和 0.2520 mmol/L 的一个线性察觉范围( R2 = 0.9977 )与 9 的察觉限制被获得
3 citations
TL;DR: In this article , a one-pot method using polymeric aluminum chloride (PAC), silica gel, and reaction raw materials under mechanical grinding conditions was reported for the preparation of xanthene and pyrimidinone compounds.
Abstract: The use of mechanical ball milling to facilitate the synthesis of organic compounds has attracted intense interest from organic chemists. Herein, we report a new process for the preparation of xanthene and pyrimidinone compounds by a one-pot method using polymeric aluminum chloride (PAC), silica gel, and reaction raw materials under mechanical grinding conditions. During the grinding process, polymeric aluminum chloride and silica gel were reconstituted in situ to obtain a new composite catalyst (PAC–silica gel). This catalyst has good stability (six cycles) and wide applicability (22 substrates). The Al–O–Si active center formed by in situ grinding recombination was revealed to be the key to the effective catalytic performance of the PAC–silica gel composites by the comprehensive analysis of the catalytic materials before and after use. In addition, the mechanism of action of the catalyst was verified using density functional theory, and the synthetic pathway of the xanthene compound was reasonably speculated with the experimental data. Mechanical ball milling serves two purposes in this process: not only to induce the self-assembly of silica and PAC into new composites but also to act as a driving force for the catalytic reaction to take place. From a practical point of view, this “one-pot” catalytic method eliminates the need for a complex preparation process for catalytic materials. This is a successful example of the application of mechanochemistry in materials and organic synthesis, offering unlimited possibilities for the application of inorganic polymer materials in green synthesis and catalysis promoted by mechanochemistry.
3 citations
TL;DR: One CuII complex, [Cu 2 (L) 3 (2bpy) 2 ](ClO 4 )(H 2 O) 0.25 (1), with mixed xanthene-9-carboxylate and chelating 2,2′-bipyridine ligands was synthesized and structurally characterized by single crystal X-ray diffraction analysis as discussed by the authors.
Abstract: One CuII complex, [Cu 2 (L) 3 (2bpy) 2 ](ClO 4 )(H 2 O) 0.25 (1), with mixed xanthene-9-carboxylate (L) and chelating 2,2′-bipyridine (2bpy) ligands was synthesized and structurally characterized by single crystal X-ray diffraction analysis. Complex 1 has a dinuclear structure which is further interlinked via inter-molecular C–H⋅⋅⋅O hydrogen-bonding and C–H⋅⋅⋅π interactions to generate a 3-D supramolecular framewrok. The magnetic properties of 1 were investigated, which exhibited weak antiferromagnetic coupling, with the corresponding coupling constant value of J = –1.1 cm −1 .
3 citations
TL;DR: In this article, the ion-pair formation of carbanions of xanthene (XH) and thioxanthene with alkali metal cations has been investigated by optical absorption and emission spectroscopy.
Abstract: The ion-pair formation of the carbanions of xanthene (XH–) and thioxanthene (TxH–) with alkali metal cations has been investigated by optical absorption and emission spectroscopy. The absorption spectra depend on solvent, counter ion and temperature in the same way as has been found for other carbanions. The XH– fluorescence spectrum exhibits an unexpected dependence on temperature; from TxH– no fluorescence has been observed.The absorption spectra have been analysed by deconvolution into Gaussian curves and are interpreted with the aid of the results of π-electron SCF-MO calculations. The enthalpies and entropies of the conversion of the contact ion pairs into the solvent-separated ion pairs of both carbanions have been calculated from the spectral data at different temperatures. The excited state acidity of XH2 has been determined from the absorption and fluorescence spectra. The experimental results are discussed in connection with those of some related systems.
3 citations