Covalent Scrambling in Porous Polyarylthioethers through a Stepwise SNAr for Tunable Bandgap and Porosity

Porous poly(aryl thioether)s offer stability and electronic tunability by robust sulfur-aryl conjugated architecture, but synthetic access is hindered due to limited control over the nucleophilic nature of sulfides and the air sensitivity of aromatic thiols. Here, we report a simple, one-pot, inexpensive, regioselective synthesis of highly porous poly(aryl thioether)s through polycondensation of perfluoroaromatic compounds with sodium sulfide. The unprecedented temperature-dependent para-directing formation of thioether linkages leads to a stepwise transition of the polymer extension into a network, thereby allowing fine control of the porosity and optical band gaps. The obtained porous organic polymers with ultra-microporosity (<1 nm) and sulfur as the surface functional groups show size-dependent separation of organic micropollutants and selective removal of mercury ions from water. Our findings offer easy access to poly(aryl thioether)s with accessible sulfur functionalities and higher complexity, which will help in realizing advanced synthetic designs in applications such as adsorption, (photo)catalysis, and (opto)electronics.     

Spectroscopic investigation of the cathode region of an independent glow discharge in He

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 51, No. 2, pp. 203–207, August, 1989.     

Investigation of the influence of metastable atoms upon the state of the plasma near the cathode

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 53, No. 1, pp. 26–30, July, 1990.     

Sources of Error in Total Reflection X-Ray Fluorescence Analysis and Error Correction Using the Internal Standard Method

An analytical equation is proposed for the fluorescence intensity excited in total reflection X-ray fluorescence analysis. Errors in the results of analysis of solutions of hair samples caused by the mutual influence of elements and by the nonuniformity of the distribution of the material in the emitter are quantitatively estimated. It is shown that these effects are small. They can be efficiently corrected using the internal standard method, provided the difference between wavelengths of the compared lines is small. Otherwise, a decrease in the systematic error is insignificant. Experiments confirmed the theoretical conclusions.