Investigation of structure of protonated forms of complexons on the basis of13C resonance

¹³C NMR spectra have been investigated for the following compounds in aqueous solutions, over a pH range from 1 to 13: acetic acid (ac), glycine (gl), iminodiacetate (ida), nitrolotriacetate (nta), ethylenediaminetetraacetate (edta), and diethylenetriaminepentaacetate (dtpa). The addition of one proton leads to simultaneous protonation of two (gl), three (ida) or four (nta, edta, dtpa)donor groups with closure of one, two, or three rings between the nitrogen atom and carboxyl groups, and also rapid exchange of protons between bound and unbound groups. It has been established that in the monoprotonated form of the ligand, a convoluted structure is realized, this being the most reactive structure, since the formation of bounds with hydrogen prepares the ligand to accept the metal. With further protonation there is a gradual unwinding of the structure, owing to mutual repulsion of protons.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 3, pp. 316–322, May–June, 1989.     

Dilatometric method of investigating the phase transitions of elastomers in the deformed state

A method is proposed for investigating crystallization and melting processes in vulcanizates in relation to the change of volume of specimens in the compressed or extended state. The method combines the advantages of dilatometry (accuracy of quantitative estimates) and mechanical methods (possibility of acceleration of crystallization associated with orientation of the macromolecules). The vulcanizates are tested under realistic conditions. Vulcanizates of NT Nairit and cis-1,4-polybutadiene have been tested by means of the method described; the crystallization kinetics are shown to depend on the degree of extension and compression of the specimens.Lebedev All-Union Scientific-Research Institute of Synthetic Rubber, Leningrad. Translated from Mekhanika Polimerov, No. 5, pp. 780–784, September–October, 1970.     

Reduction of 1,2,3,4-tetrahydro-γ-carbolines with alkali metal borohydrides in trifluoroacetic acid

A preparative method for the synthesis of 9- (2,2,2-trifluoroethyl)-1,2,3,4,4a, 9a-hexahydro--carbolines by the action of alkali metal borohydrides in trifluoroacetic acid on 1,2,3,4-tetrahydro--carbolines was developed. The indicated trifluoroethyl derivatives can also be obtained by reaction of the same reagents with 1,2,3,4,4a,9a-hexahydro--carbolines, which are intermediates in the overall reduction-trifluoroethylation process.See [1] for a preliminary communication.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1383–1386, October, 1980.     

Eigenschaften von polymolekularen Wasserfilmen auf der Oberfläche von Quarzkapillaren

Ohne Zusammenfassung     

Effect of crystalline phase on the elasticity of rubbers

The dynamic mechanical properties of crystallizing divinyl and isoprene rubbers have been investigated over a wide temperature range. It is shown that the formation of a crystalline phase in the rubber leads to a regular increase in rebound resilience in the transition temperature range. The demonstrated relation between these quantities shows that the minimum elasticity can be used as a measure of the crystalline phase present in the polymer.Mekhanika Polimerov, Vol. 1, No. 3, pp. 15–20, 1965     

Synthesis of α-myrcenol acetate and propionate from isobutenylcarbinol

A synthesis of -myrcenol acetate and propionate was carried out by a controled combination of suitable isobutenylcarbinol derivatives according to the Wurtz reaction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 591–594, March, 1990.