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Nitrofluoren-9-one and nitrofluoren-9-dicyanomethylene electron acceptors 7, 8, and 11 functionalized with a terminal thioctic acid unit have been synthesized from 2,4,5,7-tetranitrofluorenone. The self-assembled monolayers (SAMs) of these compounds on gold, formed via gold−sulfur interaction, have been fully characterized by electrochemical, FTIR, ellipsometry, and contact angle measurements. Cyclic voltammetry of SAMs reveals two reversible single-electron reduction waves for fluorenone derivatives 7a,b and 11, and three single-electron reductions for the dicyanomethylene−fluorene 8b, providing the first observation of a radical trianion species in SAMs. The tendency of the thioctic anchor to form multilayers via disulfide links is noted.

A simple and efficient method for the attachment of functionalized arene chromium carbonyls to a polymeric support has been developed. A highly efficient solid-phase synthesis of tertiary alcohols and esters was performed in a traceless manner using this strategy. The linker-fabrication protocol permits simultaneous immobilization of various substrates on the solid support.

Abstract: Epitaxial layers of Pb1−xSnxTe (x≈0.2), undoped and doped with cadmium, are grown in a quasi-closed volume using the hot-wall method on BaF2 fragments. The doping impurity is introduced directly into the material of the vapor source before synthesis in an equi-atom ratio with additional tellurium. The boundary of the limit of homogeneity from the side of the metallic components and in the region of the stoichiometric composition of the epitaxial layers doped with cadmium and the undoped epitaxial layers is established. The electrical conductivity and the Hall effect are investigated in the 77–450 K temperature range, and the temperature dependences of the intrinsic concentrations and of the ratio of the electron and hole mobilities are established. The temperature dependence of the Hall mobility is also investigated. The stability of the electrical parameters of the epitaxial layers are studied. It is shown that doping with cadmium enables highly stable n-type epitaxial layers to be obtained.

Conclusions 1.Errors of laminated plastimeters used in measuring maximum sheering stress (MSS) of lubricant greases are analyzed. This analysis is applicable to investigating the precision of plastometers with other shapes of their longitudinally displaceable surfaces.2.The suggested formula (6) serves to eliminate the systematic error due to the protrusion of a part of the displaced surface out of the lubricant grease in repeated MSS measurements of the same specimen without reloading the plastometer's test unit and formula (7) for finding corrections for MSS values produced by the effect of a part of the lubricant being carried away by the displaced surface.3.A measurement technique is suggested which serves to reduce random errors in measuring the MSS, in particular those due to temperature, boundary-layer sliding, bad preparation of the lubricant specimen, and untimely functioning of the devices which unload the displaceable surface.

Without Abstract:

The thermal emission of thin mantles and rods of a mixture of thorium and cerium oxides in flames is discussed, in the light of radical-recombination processes and the partial transparency of these oxides. The application of Lambert's law for the emission from a mass of incandescent semitransparent substance is shown to be satisfactorily explained by an examination of the features of the luminescence of Auer-Welsbach mantles in flames.

A resin-based chromium catalyst for performing [6π + 2π] cycloaddition reactions has been prepared from chloromethylated polystyrene. The catalyst provides cycloadducts in yields comparable to the photochemical and thermal versions of these transformations, and the process is effective with a wide range of 6π and 2π reaction partners.

Barium fluoride (111) cleaved surfaces have been used with the hot-wall method to grow epitaxial Pb1−xSnxTe films from source materials either undoped or doped with 0.1, 0.5, or 1 at. % cadmium and having x=0.2. The absorption in the wavelength range 2–13 μm has been measured together with the spectral dependence of the photoluminescence. The cadmium affects the optical width of the forbidden band and the high-frequency dielectric constant, as well as the photoluminescence intensity. The optical absorption spectra of the doped epitaxial films contain additional absorption bands due to the impurity level in the forbidden band. The position of the impurity level has been determined and the shift in it relative to the bottom of the conduction band as the temperature is reduced.

Three optically active oxazolines with a cymantrenyl substituent at position 2 of the heterocycle have been prepared. Metallation of these compounds withn-BuLi proceeds only at the two diastereotopic a- and a'-positions of the Cp-ring to an equal extent. The dependence of the sign of Cotton effect in the region of 300–350 nm upon the absolute configuration of chiral centers remote from the Cp-ring has been demonstrated.