Synthesen von α,β-ungesättigten 2-(2-Oxo-benzazolin-3-yl)-3-hydroxy-dithio-carbonsäure-alkylestern und entsprechend substituierten Keten-S,S-acetalen sowie deren Kristall- und Molekülstruktur

Summary The new alkyl 2-(2-oxo-benzazoline-3-yl)-3-hydroxy dithiocrotonates and dithiocinnamates4 and the corresponding ketene dithioacetals2 and5 are obtained by dithiocarboxylation of the 3-acceptormethyl substituted benzazoline-2-ones1 or3. Alkylation at room temperature gives compounds4 whereas at higher alkylation temperature2 or5 are formed. The results of X-ray analyses performed for methyl 3-hydroxy-p-chloro-dithiocinnamate4d and of N-[1-(4-chloro-benzoyl)-2,2-bis(methylthio)-vinyl]-benzothiazoline-2-one5e are discussed.

     

Quantum chemical calculations of the molecular structure of diphenylguanidine and experimental studies of its tautomerism in solution

MNDO-PM3 and AM1 quantum chemical calculations of the molecular structure of N,N′-diphenyl-guanidine (DPG) prove that the molecule preferably exists as an asymmetric tautomer with a basic center C = N−. IR and UV spectral data, dipole moments, and average molecular weights of DPG solutions in nonpolar and low-polar solvents confirm the results of calculations, indicating formation of hydrogen-bonded cyclic self-associates of DPG in solution. Translated fromZhumal Strukturnoi Khimii, Vol. 39, No. 4, pp. 618–625, July–August, 1998.     

The uranium-Xylidyl Blue I complex and its application in linear sweep polarography

The linear sweep polarographic wave of the uranium-Xylidyl Blue I complex in ethylenediamine-1,10-phenanthroline-hydrochloric acid medium has been studied. The complex, corresponding to UO(2)(XBI)(2-)(2) with log beta' = 9.09 (by polarography), 8.81 (by spectrophotometry), is strongly adsorbed on the surface of the mercury electrode. The polarographic wave is attributed to the reduction of Xylidyl Blue I in the complex. The method is very sensitive with a detection limit of 3 x 10(-8)M. The wave height is proportional to the concentration of uranium over the range 8 x 10(-8)-7 x 10(-6)M. Solvent extraction is used to separate possible interferences. The recommended procedure has been applied to the determination of trace amounts of uranium in ores.     

Substitutive sulfotrioxidation of unsaturated and araliphatic organofluorine compounds

Conclusions Reaction of SO₂ or SO₃/[B₂O₃] with terminal fluoroolefins or fluoroalkylbenzenes gives the corresponding fluoroalken-2-yl fluorosulfates and fluorobenzyl fluorosulfates.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2791–2795, December, 1982.     

Functional derivatives of thiophene. I. Synthesis and 1H-NMR spectra in the 2-aminothiophene series

The preparation of 2-amino-5-nitrothiophene, 2-formamido-5-nitrothiophene, 2-acetamido-5-nitrothiophene and 2-t-butyloxycarbonylamino-5-nitrothiophene are described. Abnormal values of the coupling constants J_3.4 had been observed in the ¹H-nmr spectra of compounds obtained.     

Fluoro-substituted DPP-bisthiophene conjugated polymer with azides in the side chains as ambipolar semiconductor and photoresist

Photoresists are essential for the fabrication of flexible electronics through all-photolithographic processes. Single component semiconducting photoresist exhibits both semiconducting and photo-patterning properties, and as a result, the device fabrication process can be simplified. However, the design of semiconducting polymeric photoresist with ambipolar semiconducting property remains challenging. In this paper, we report a single component semiconducting photoresist (PFDPPF4T-N₃) by incorporating azide groups and noncovalent conformation locks into the side alkyl chains and conjugated backbones of a diketopyrrolopyrrole-based conjugated polymer, respectively. The results reveal that PFDPP4FT-N₃ exhibits ambipolar semiconducting property with hole and electron mobilities up to 1.12 and 1.17 cm² V^?1 s^?1, respectively. Moreover, field effect transistors with the individual photo-patterned thin films of PFDPPF4T-N₃ also show ambipolar semiconducting behavior with hole and electron mobilities up to 0.66 and 0.80 cm² V^?1 s^?1, respectively. These results offer a simple yet effective design strategy for high-performance single component semiconducting photoresists, which hold great potential for flexible electronics processed by all photolithography.

     

Microanalysis of Si,S and Zn in GaSb by use of direct observation of (p,p′γ) reactions

The use of direct observation of nuclear reactions (p,p′γ) is discussed. The main characteristics of this method are presented and applied to the case of the miroanalysis of Si, S and Zn in GaSb.