Mono- and diesters of N-benzoylaminoacetic acid as antiwear additives to synthetic oils

Mono- and diesters of N-benzoylaminoacetic acid, which exhibit high wear-preventive properties in a synthetic ester oil, were synthesized.     

Synthesis of bicyclo[2.2.1]hept-5-enyl methyl esters of haloacetic acids

Synthesis of norbornenyl methyl esters of a number of haloacetic acids via [4+2] cycloaddition of cyclopentadiene to allyl esters of these acids was examined. The yield and isomer composition of the synthesized compounds were examined in relation to the reaction conditions, and the best conditions for their preparation were found.     

Synthesis of 1,4,5,6-tetrachloro-7,7-dimethoxybicyclo[2.2.1]hepta-2,5-dienylmethyl esters of p-substituted benzoic acids

The possibility of preparing 1,4,5,6-tetrachloro-7,7-dimethoxybicyclo[2.2.1]hepta-2,5-dienyl-methyl esters of p-substituted benzoic acids by [4+2]cycloaddition of tetrachlorodimethoxycyclo-pentadine to propargyl esters of the corresponding acids was examined. The optimal synthesis conditions were found. The structure of the compounds synthesized was confirmed by independent synthesis and by IR and ¹H NMR spectroscopy.     

Synthesis of <Emphasis Type="Italic">para</Emphasis>-substituted 1,4,5,6,7,7-hexachlorobicyclo-[2.2.1]hepta-2,5-dien-2-ylmethyl benzoates

[4 + 2]-Cycloaddition of hexachlorocyclopentadiene to para-substituted prop-2-yn-1-yl benzoates gave the corresponding 1,4,5,6,7,7-hexachlorobicyclo[2.2.1]hepta-2,5-dien-2-ylmethyl benzoates. The structure of the adducts was confirmed by independent synthesis, esterification of para-substituted benzoic acids with 1,4,5,6,7,7-hexachlorobicyclo[2.2.1]hepta-2,5-dien-2-ylmethanol.     

Distribution of aluminum and indium impurities in crystals of Ge-Si solid solutions grown from the melt

The problem regarding the distribution of aluminum and indium impurities in bulk crystals of solid solutions with a variable composition Ge_1−x Si _x (0 ≤ x ≤ 0.3) is solved in order to establish regularities of the changes in the segregation coefficients of impurities with variations in the composition of the host lattice in the germanium-silicon system. Aluminum-and indium-doped crystals of Ge_1−x Si _x (0 ≤ x ≤ 0.3) solid solutions with a silicon content decreasing along the crystallization axis are grown by a modified Bridgman method with the use of a silicon seed. The concentration distribution of impurities over the length of the crystals is determined from Hall measurements. It is demonstrated that the experimental data on the concentration distribution of impurities in the crystals are in good agreement with the results obtained from the theory according to which the equilibrium segregation coefficients of impurities vary linearly with a change in the composition of Ge-Si solid solution crystals.

     

Synthesis of 1,4,5,6,7,7-hexachlorobicyclo[2.2.1]hepta-2,5-dienylmethyl haloacetates

Hexachlorobicyclo[2.2.1]hepta-2,5-dienylmethyl haloacetates were prepared by [4+2]-cycloaddition of hexachlorocyclopentadiene to the corresponding propargyl haloacetates.     

Synthesis and properties of aminomethyloxy derivatives of (1-Propylsulfanyl)pentane

New 2-aminomethyloxy derivatives of 1-(propylsulfanyl)pentane were prepared by condensation of 1-(propylsulfanyl)pentan-2-ol with formaldehyde and secondary amines. The starting 1-(propylsulfanyl)pentan-2–ol was synthesized by the reaction of 1–propanethiol with 1–bromopentan–2–ol. The structures of the products were proved by elemental analysis, IR and ¹H NMR spectroscopy, and mass spectrometry. The compounds were tested as antimicrobial additives to lubricating oils and as antiseptics against bacteria and fungi.     

Synthesis and properties of methyleneoxyamine derivatives of 1-(propylthio)octane

Synthesis of new methyleneoxyamine derivatives of 1-(propylthio)octane by condensation of 1-(propylthio)octane with secondary amines and formaldehyde was carried out. Structure of the synthesized compounds was proved by elemental analysis, IR, ¹H NMR, and mass spectra. Compounds were tested as antimicrobial additives to lubricating oils. They were found to suppress effectively the activity of microorganisms.     

Electroactive complex in thermally treated Ge-Si 〈Cu,Al〉 crystals

It is shown by Hall measurements that quenching complexly doped Ge_{1 − x} Si _x 〈Cu, Al〉 (0 ≤ x ≤ 0.20) crystals from 1050–1080 K leads to the formation of additional electroactive acceptor centers in them. The activation energy of these centers increases linearly with an increase in the silicon content in the crystal and is described by the relation E _k ^x = (52 + 320x) meV. Annealing these crystals at 550–570 K removes the additional acceptor levels. It is established that the most likely model for the additional electroactive centers is a pair composed of substituent copper and aluminum atoms (Cu _s Al _s ) or interstitial copper and substituent aluminum atoms (Cu _i Al _s ). It is shown that the generation of additional deep acceptor levels must be taken into account when using the method of precise doping of Ge_{1 − x} Si _x 〈Al〉 crystals with copper.