Nucleophilic substitution in 5,6,7,8-tetrafluoro- and 6,7-difluoro-1,2,3,4-tetrahydro-9-alkenyl-1,4-methanonaphthalenes and related compounds. A search for homoallylic conjugation

The second-order rate constants for the nucleophilic replacement of fluorine by isopropoxide in 5,6,7,8-tetrafluoro- and 6,7,-difluoro-1,2,3,4-tetrahydro-9-alkenyl-1,4-methanonaphthalenes and related 9-alkyl systems have been measured. A factor of 6 - 7 separates the most reactive compounds [the 9- (4′-trifluoromethylbenzylidene) derivatives] from the least reactive compounds [the syn-9-isopropyl derivatives] in both the tetrafluoro- and difluoro-series. It is concluded for these small reactivity differences.     

Investigation of charge-transfer complex of poly(N-vinylcarbazole) with fluoranyl

Russian Chemical Bulletin -     

Synthetic studies in the field of the porphyrins. synthesis of a mesoporphyrin and of a diacetyldeuteroporhyrin

A method is proposed for the synthesis of porphyrins based on the cyclization of a tetrapyrrole system with methyl and formyl groups at the ends of the molecule. The synthesis of mesoporphyrin IX and diacetyldeuteroporphyrin IX has been effected.     

Mathematical model of substance active transport via cytoplasmic membrane of microbial cell along concentration gradient

Applied Biochemistry and Biotechnology - Considering the process of methane generation by methanogenic bacteria as an example, the model describes the distribution of methane concentration inside...     

Adsorption and thermodynamic properties of active sites of a pyrogenic aluminium oxide surface

Differential isosteric adsorption heats and entropies of adsorption of both n-pentane and diethyl ether on hydrated and dehydrated surfaces of pyrogenic alumina (S=140 m²/g) in the coverage range of 0.15–1.0 have been calculated from the adsorption isotherms.     

Laser photolysis study of the triplet states of nitroaromatic amides

The spectrokinetic indices of the triplet states of nitroaromatic amides were established. The quenching of triplet states by tertiary aromatic amines in apolar solvents leads to the formation of triplet exciplexes. A charge transfer state makes the major contribution to the structure of these exciplexes. Hydrogen atom transfer proceeds efficiently in the case of secondary aromatic amines, leading to the formation of the corresponding neutral radicals.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1912–1915, August, 1989.     

Hydrosilylation of N-allylpyrrolidine and N-allylpiperidine

It was found that the hydrosilylation of N-allylpyrrolidine and N-allylpiperidlne by trialkylsilanes, triethoxysilane, and 3H-heptamethyltrisiloxane in the presence of H₂PtCl₆ · 6H₂O proceeds to form -adducts.Communication XXXII from the series Nitrogen-Containing Organosilicon Compounds. See [1] for communication XXXI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 485–487, April, 1972.     

Synthesis of heterocyclic compounds on the basis of carboxylic acid arylamides

The exchange and cyclization of phenyliminooxalyl chloride with ammonium thiocyanate, sodium azide, aniline, amidoximes, and diphenylthiourea, and with 2-aminopyridine, 2-aminobenzothiazole, and 2-amino- and 2-mercaptobenzimidazole were studied. The cyclization products are derivatives of thiazolidine, imidazo[1,2-a]pyridine, imidazo[2,1-b]benzothiazole, imidazo[1,2-a]benzimidazole, and thiazolo[3,2-a]benzimidazole. A trimer of 1-phenyltetrazole-5-carboxylic acid was obtained when an attempt was made to convert its azide to the corresponding isocyanate.See [1] for communication II.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 471–474, April, 1971.     

Etude de l''addition des organomagnesiens satures et benzyliques aux enynes conjugues, simples et fonctionnels

Saturated and benzylic organomagnesium compounds are shown to readily undergo addition reactions with the conjugated enynes H$\text{C}\text{4}$$\text{C}\text{3}$C$\text{H}\text{2}$$\text{C}\text{1}$HCH₂R′, with R′ = alkyl, OH, OC₄H₉, NHC₂₅, N(C₂H₅)₂, by refluxing for several hours in benzene or toluene.This reaction leads to both υ-acetylenic compounds (1,2-addition) and β-allenic compounds (1,4-addition).