Synthesis of r-4-ethoxycarbonylamino-t-3-hydroxy-c-2-(δ -methoxycarbonylbutyl)-thiophan

Condensation of 4-ethoxycarbonylamino-3-oxothiophan with methyl γ-formylbutyrate gives 4-ethoxycarbonylamino-3-oxo-2-(δ-methoxycarbonlybutyl)thiophan, its oxime, and r-4-eth-oxycarbonylamino-t-3-hydroxy-c-2-(δ-methoxycarbonylbutyl)thiophan.     

The electron temperature distribution of laser erosion plume after ablation of a tantalum target with excimer laser in vacuum

The erosion plume resulting from an ablation of a tantalum target in vacuum with an excimer laser radiation (308 nm) was studied using the Langmuir probe technique. The spatial and temporal dependencies of the electron probe currents were obtained in real time. The electron temperature of different plume regions was determined from a series of I–U characteristics taken at different distances between the probe and the target. We determined that the plume electron temperature is non-uniform and has a maximum value in front of the plume.     

Erratum to: A NEW POLYMORPH OF THE [ReCl3(MeCN)(PPh3)2] COMPLEX AND ITS OXIDATION PRODUCTS

Journal of Structural Chemistry - An Erratum to this paper has been published: https://doi.org/10.1134/S0022476622030131     

Longitudinal dispersion associated with the motion of an adsorbed mixture in a column filled with porous granules

The effect of the radial nonuniformity of the linear flow velocity on the radial nonuniformity of the adsorbate concentration distribution over the cross section of a column and on the longitudinal dispersion is estimated for the diffusion model, and the legitimacy (for relatively small adsorber radii) of using a one-dimensional diffusion model for describing the interphase mass transfer in cylindrical adsorbers is thereby determined.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 4, pp. 93–101, July–August, 1987.     

Experimental study of cylinder drag in a rarefied gas

Results are presented of experimental studies of the drag of a cylinder in transverse rarefied gas flow.The flow regimes varied from free-molecular to nearly continuum. The physical pendulum method was used to obtain experimental curves showing the effect of the temperature factor T_w/T₀, Reynolds number R₀ and cylinder fineness ratio L/D on the aerodynamic drag coefficient.     

An asymmetric iodolactonization reaction catalyzed by a zinc bis-proline–phenol complex

The intramolecular zinc bis-proline-phenol complex 2a was found to promote enantioselective iodolactonization reactions of both electron-rich and electron-poor 5-aryl-5-hexenoic acids affording δ-iodolactones in good chemical yields with up to 82% enantiomeric excess. The reactions were found to be insensitive to air and moisture, providing an experimentally simple protocol for synthetically useful compounds.     

Synthesis and Crystal Structures of Manganese(II) and ­Cobalt(II) Complexes with 2, 6‐Dimethoxybenzoic Acid and Additional N‐Donor Ligands

Three coordination compounds [Mn₃(dmb)₆(H₂O)₄(4, 4′‐bpy)₃(EtOH)]_n ( 1 ) and [M(dmb)₂(pyz)₂ (H₂O)₂] [M^II = Co ( 2 ), Mn ( 3 )] (Hdmb = 2, 6‐dimethoxybenzoic acid, 4, 4′‐bpy = 4, 4′‐bipyridine, pyz = pyrazine) were synthesized and characterized by single‐crystal X‐ray diffraction analysis. Compound 1 consists of infinite 1D polymeric chains, in which the metal entities are bridged by 4, 4′‐bpy ligands. There are four crystallographically independent Mn^II atoms in the linear chain with different coordination modes, which is only scarcely reported for linear polymers. The isostructural crystals of 2 and 3 are composed of neutral mononuclear complexes. In crystal the complexes are combined into chains by intermolecular O–H ··· N hydrogen bonds and π–π interactions between antiparallel pyrazine molecules.