Integral equations for four identical particles with separable two-particle interactions

The problem of four identical spinless particles with separable two-particle interactions is considered. The integral equations of motion for four particles in the bound states and in the continuum states with two non-ihteracting subsystems in the initial channel are formulated. The angular-momentum reduction of the obtained equations is given.     

Synthesis of hydrothioxanthenes. II

Ethylenedicyclohexanone and phosphorus pentasulfide give 9-methyloctahydrothioxanthene (II) (yield ～37%), a small amount of 9-methylperhydrothioxanthene (IV) (～2%), and 9-methylthioxanthene (VI) (～1%). Reaction with hydrogen sulfide gives a high yield of thioxanthene II (64–65%). The behavior of II in dehydrogenation over Pd/C, and of II and IV to oxidation are investigated. IR spectrum data are given for II and its sulfone.     

Reactions of sym-octahydrothioxanthylium salts with bases and structure of 4-(sym-octahydrothioxanthen-9-yl)-1,2,3,5,6,7,8-heptahydro-2H-thioxanthene

The reaction of sym-octahydrothioxanthylium salts with pyridine or aqueous sodium bicarbonate leads to the formation of 4-(sym-octahydrothioxanthen-9-yl)-1,2,3,5,6,7,8-heptahydro-2H-thioxanthene, whose structure was established by x-ray diffraction analysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 479–482, April, 1989.     

Modeling of Lidar Sounding of Meteorological Parameters of the Atmosphere in the Spectral Region of 2 μm

Results of the numerical modeling of lidar sounding of meteorological parameters of the atmosphere by the differential absorption method in the spectral region of 2 m are reported. A choice of the steam absorption lines suitable for sounding temperature and moisture content profiles in the lower troposphere is made. Systematic errors in reconstruction of temperature profiles are analyzed. It is shown that the errors in reconstruction of temperature and moisture content profiles have acceptable values within the entire range of heights 0–2 km.     

Complexation of thiacalix[4]arene methylphosphonic and sulphonic acids with amino acids

In this paper, host–guest complexation process of thiacalix[4]arene tetrakis–methylphosphonic and tetrakis–sulphonic acids with amino acids by HPLC and molecular modelling methods has been studied. It was shown that thiacalix[4]arene tetrakis–methylphosphonic acid due to transformability of macrocyclic skeleton and flexibility of methylphosphonic substituents can adopt its conformation for strong multicentre binding of the amino acids with association constant values 530–10,140 M^? 1 in water.     

Dibutylphosphinoylmethyloxythiacalix[4]arenes. Synthesis,structure, americium,europium and technetium extraction

A series of thiacalix[4]arenes bearing one, two or four chelating dibutylphopshinoylmethoxy groups have been synthesised and studied in the context of this paper. The synthesis consisted of precise Williamson alkylation of thiacalixarene tetrols with tosylate of dibutylhydroxymethyl phosphine oxide in the presence of alkali metal carbonates or sodium hydride. Stereochemical yield of the reaction (cone or 1,3-alternate conformer) depends on the nature of alkali metal. Small-sized ‘hard’ sodium cation organises the macrocyclic platform in the cone conformation, but larger and ‘soft’ potassium and cesium cations stabilise the macrocycle in the 1,3-alternate conformation. All synthesised compounds (except monophosphine monoxide) possess either moderate or high extraction ability towards pertechnetate ion. The cone-shaped thiacalix[4]arene tetraphosphine tetraoxide due to cooperative (macrocyclic) effect of eight oxygen atoms of the phosphinoylmetoxy-binding groups effectively extract spherical americium, europium cations due to cooperative (macrocyclic) effect of eight oxygen atoms of the phosphinoylmetoxy-binding groups. The extraction ability is very similar to that of calix[5]arene pentaphosphine pentaoxide existing in the cone conformation.