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This paper presents the results of numerical calculations of two-phase flow taking into account the coagulation of a polydisperse condensate in the combustion chamber of a solid rocket motor. The effect of fluctuations in the particle velocity on the evolution of their mean size is analyzed.

Double cyclization of N-acetyl-2-(cyclopent-2-enyl)aniline initiated by ozonolysis resulted in 9-acetyl-2-hydroxy-2,3,4,4a,9,9a-hexahydropyrano[2,3-b]indole.

An unusual direction of the reaction of 2-(cyclopent-2-enyl)aniline hydrochloride with dimethyldioxirane was found: the formation of two isomeric products,viz., 3- and 6-chloro-2-(cyclopent-2-enyl)anilines, was observed.

Tunneling conductance spectra were observed by point contact junction of SIN on single crystals of BSCCO (2212). Outside of the definite gap structure edge, significant fine structures were observed almost reproducibly ranging to 0.2 eV. The conductance derivative peaks both in positive and negative bias range were found in well one by one correspondence with the phonon spectrum peaks reported by Renker et al . [1]. Most of the peak modes were attributed to the optical phonons due to the oxygen oscillations in and around the [CuO 2 ] n net-plane. Numerical computation in terms of the Eliashberg gap equation was carried out, and the electron-phonon coupling intensity function α 2 F ( ω ) was elucidated and it turns out that the breathing mode relating to the polaronic valence fluctuations are predominant as compared with the B 1 g mode regarding the spin correlations.

The influence of the halogen on the strength of the adjacent C-Li bond has been evaluated on the basis of thermodynamic and quantum-chemical calculations, and it has been shown that monomolecular decomposition is preferable for LiCHCl2, LiCCl3, LiCF3, and o-FC6H4Li under the conditions of the experiment, while such decomposition is impossible for LiCH2Cl.

The literature data on the methods for the synthesis of unstable intermediate species (arynes and carbenes) from organoelement compounds, mainly from o- and ?-halogeno-derivatives, are surveyed and examined critically. It is shown that the ease of decomposition of the initial compound is determined by the possibility of the formation in the transition state of the coordinate bond between the groups or atoms eliminated and the theoretical proof of this mechanism is given. The bibliography includes 322 references.

1. Theoretical grounds have been given for a consistent single-stage mechanism for the decomposition of geminal and vicinal organometallic halogen compounds (OMHC) with the formation of carbenes and arynes, the driving force of which is intramolecular coordination of the halogen and metal atoms. 2. Within the framework of this mechanism, an analysis has been made on the manner in which OMHC stability depends on the heat effect of the decomposition reaction, the difference in energies of the coordinating orbitals, and the distance between the atoms that split out.

1. The formation of biphenylene in the decomposition of o-halophenyllithiums takes place with the intermediate participation of the corresponding 2-halo-2′-lithiobiphenyls, the cyclization of which into biphenylene is considerably accelerated by adsorption or by complex-formation with aromatic compounds. 2. On the basis of decomposition reactions of o-halophenyllithiums, a method has been developed for the synthesis of biphenylene with a yield of 50–60%.

It was shown that the basic rules of the reactions of organometallic compounds with organic halides, in particular, the formation of free radicals in these reactions, can be explained within the framework of the theory of molecular Orbitals and their interactions.

1. The significant weakening of the C-Hal bond in halomethyl and o-halophenyl anions in comparison to the corresponding radicals has been demonstrated on the basis of the results of quantum-chemical calculations (the MINDO/2 and MINDO/3 methods). 2. The probability of a carbanion mechanism for the formation of carbenes and arynes as a result of the reaction of the chlorine-containing derivatives with bases in strongly solvating media has been substantiated.

A study was made of the hydrolytic polycondensation and exchange reaction of methyltrichlorosilane with sodium metasilicate and it was shown that when the reaction proceeds in alkaline medium (pH> 7) the pH of the reaction medium, and not the functionality of the system, exerts the predominant effect on gel formation, but when the reaction is run in acid medium (pH 2) a direct relation is observed between the yield of insoluble products and the functionality of the system.

1. In the reaction of Mg vapors with 1,1-dibromo-2,2-dimethylcyclopropane at 77°K in a medium of solvating solvents, debromination of the starting gem-magnesium dibromide by a radical mechanism with subsequent cleavage of hydrogen atoms from the solvent by the radicals formed is the basic direction of the reaction. 2. The capacity of metal vapors to debrominate gem-dibromocyclopropanes decreased in the order of Mg, Al, Zn. 3. In the reaction of Cr, Ti, Fe, and Cu vapors with CH2Cl2 and CH2Br2 at 77°K, cleavage of one halogen atom and recombination of the ·CH2X radicals generated occurred with formation of 1,2-dihalogenated ethanes.

1. A mechanism was proposed for aromatic nucleophilic substitution, which consists in attack of the nucleophile on the substituted bond, with electron transfer to the aromatic substrate and the formation of a pair of free radicals. 2. The probability of the free radicals recombining to the σ-complex decreases with increase in the activity of the nucleophile and the acceptor capacity of the aromatic substrate. 3. The theory was expressed that the formation of free radicals is possible in the coordinated reactions that are forbidden because of the symmetry via one-electron transfer as the result of the convergence of the levels of the boundary orbitals of the reactants.

Starting with the assumption that the progress of the process is synchronous, the application of the simple MO theory makes it possible to explain the experimentally observed stereo- and regioselectivity of electrophilic addition reactions, including the Markovnikov rule.

1. According to the data of the PMR spectra, low-temperature cryoscopy, and differential thermal analysis,o-fluorophenyllithium in the presence of no less than equivalent amounts of an ether in hydrocarbon solutions at temperatures from −100 to −40° exists in the form of a tetrasolvated tetramer (o-FC6H4Li)4 (R2O)4. 2. The similarity of the PMR spectra of etherates ofo-fluorophenyllithium and phenyllithium indicates that phenyllithium and probably other ArLi as well also form tetramer complexes of the (ArLi)4L4 type in the presence of ethers or trialkylamines. 3. The steric structures of etherates of aromatic lithium compounds and the mechanism of the decomposition ofo-fluorophenyllithium with the formation of dehydrobenzene were discussed.

A new general synthesis is proposed for bicyclo[1.1.0]butanes, by 1,3-cyclization of 1-bromo-chloromethylcyclopropanes, and a two-step synthesis of the latter from available allyl chlorides has been developed.

1. A study of the hydrolytic polycondensation of methyltrichlorosilane (MTCS) in the presence of a hydrogen chloride acceptor, using various solvents as the medium, disclosed that in a solvent medium in which water is readily soluble the process proceeds with the formation of soluble polycyclic compounds and is independent of the methyltrichlorosilane concentration. 2. The formation of soluble hydrolytic polycondensation products of MTCS is due to the faster rate of the intramolecular condensation reaction, which leads to a termination of the growing chain.

1. The radical-anions of chloromethanes and 1-chloro- and 1,1-dichlorocyclopropanes were calculated by the MINDO/3 method with variation of all the independent degrees of freedom. 2. The accumulation of chlorine atoms at one carbon atom leads to weakening of the C-Cl bond in the chloroalkane and to increase in the adiabatic electron affinity. The last effect predominates and leads to an increase in the strength of the C-Cl bond in the radical-anion with the accumulation of chlorine atoms.

When the decomposition of o-fluorophenyllithium tetrahydrofuranate was carried out in the presence of furan, it was shown that ∼50% of the dehydrobenzene formed has kinetic freedom.

On the example of the electroreduction of tetrabromoneopentane it was shown that the electrochemical cyclization of 1,3-dibromides to cyclopropanes proceeds with the intermediate involvement of the 3-bromopropyl anions.

1. The addition of carboxylic acid bromides to 2-oxaspiro-[3,2]-hexane proceeds without rearrangement, leading to the corresponding esters of 1-bromomethylcyclopropylcarbinol. 2. The addition of HCl to 2-oxaspiro-[3,2]-hexane at 0° leads to 1-chloromethylcyclopropylcarbinol, and the analogous reaction with HBr to a mixture containing 1-bromomethylcyclopropylcarbinol. 3. Prepared for the first time are the acetate, fluoroacetate, and trifluoroacetate of 1-bromomethylcyclopropylcarbinol.

1. The action of zinc dust on tribromoneopentyl benzenesulfonate gives a good yield of methylenecyclobutane. 2. A preparative method for the synthesis of methylenecyclobutane has been proposed.

A simple method has been developed for the reduction of gem-dibromocyclopropanes to give monobromocyclopropanes by the action of a readily available nonmetallic reagent, sodium hydrosulfite, at 90–100‡C in a mixture of 2-propanol, water, and DMF. This method gives 75–86% yields of the desired products and the complete absence of the products of complete reduction.

A convenient preparative method was developed for the synthesis of 3,3-disubstituted cyclopropenes in yields up to 90% for 3,3-dimethylcyclopropene, spiro[2.3]hex-1-ene, and 3-methyl-3-phenylcyclopropene from the corresponding monohalocyclopropanes by the action of solid KOH in DMSO in the presence of phase transfer catalysts.

Cycloalkylation of cyclopentadiene with 1, 2-dibromo-n-alkanes with phase-transfer catalysis affords the spiro[2,4]-4,6-heptadienes in 70–85% yields. When the original 1, 2-dibromoalkanes contained one or two bromine atoms attached to tertiary carbon, none of the spiro[2,4]heptadienes were obtained.

The cycloalkylation of cyclopentadiene by 1,4-dihalo-2-alkenes under phase-transfer catalysis conditions gives 1-vinyl- and 1-(1-propenyl)spiro[2.4]hepta-4,6-dienes in 55–60% yield.