Synthesis and Molecular and Crystalline Structure of Polyfluoro-1,3-Diazafluorenes

Reactions of 2-amino-3-(1-imino-2,2,2-trifluoroethyl)hexafluoro-1H-indene with carboxylic acid anhydrides and chlorides afforded 2-alkyl(aryl)-4-trifluoromethyl-5,6,7,8,9,9-hexafluoro-1,3-diazafluorenes. The molecular and crystalline structure of the products was studied by NMR spectroscopy and X-ray diffraction. 5,6,7,8,9,9-Hexafluoro-2-phenyl-4-trifluoromethyl-1,3-diazafluorene in crystal gives rise to infinite ladder chains via -stacking interaction between the benzene ring of one molecule and tetrafluorobenzene fragment of the other.     

Role of the alkyl fragment of initiating alkoxyamine in nitroxide mediated polymerization of styrene

The role of the alkyl fragment of alkoxyamine initiating the homopolymerization of styrene is experimentally and theoretically studied in the case of 2,2,6,6-tetramethylpiperidine-1-oxyl derivatives. The rate constants of homolysis and recombination are measured for the alkoxyamines under study. The characteristics of polymerization initiated by these compounds are experimentally examined. The kinetics of polymerization is theoretically calculated with allowance for the measured kinetic parameters and the experimentally detected side reaction of hydrogen-atom transfer to the nitroxide radical during the thermolysis of alkoxyamine 2-cyano-2-isopropyl-TEMPO.     

Fluoroindenes. 10. Cyclization of difluorocarbene to perfluoro-3-methylindene and perfluoro-1-methyleneindane. Thermolysis and bromination of the resultant cyclopropane derivatives

Conclusions Upon reaction of perfluoro-3-methylindene and perfluoro-1-methyleneindane with hexafluoropropylene oxide at 225°C the corresponding cyclopropane derivatives are formed: perfluoro-la-methyl-1,1a,6,6a-tetrahydrocycloprop[a]indene and perfluorospiro[indane-1,1-cyclopropane], which are transformed during thermolysis in the presence of bromine into 1-bromo-2-difluorobromomethylperfluoro-1-methylindane and 1-bromo-1-(2-bromotetrafluoroethyl)perfluoroindane respectively, and in the absence of bromine into the starting olefins.Deceased.For previous report, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1839–1845, August, 1988.     

Generation of Perfluoro- and 1-Chloroperfluoro-Indanyl and -Benzocyclobutenyl Cations with Perfluoroalkyl Groups in the Aliphatic Ring

Russian Journal of Organic Chemistry - Perfluoro(alkylbenzocycloalken-1-yl) cations were generated in a SbF5?SO2ClF medium from perfluorinated indane and benzocyclobutene derivatives...     

Generation of perfluoro- and 1-chloropolyfluorobenzocycloalken-1-yl cations and their relative stability

Treatment of perfluorinated benzocyclobutene, indan, and tetralin with SbF₅-SO₂Cl₂, as well as of their 1,1-dichloro analogs with SbF₅, gave 1-chloropolyfluorobenzocycloalken-1-yl cations whose structure was studied by ¹⁹F and ¹³C NMR and confirmed by their transformations into perfluorinated ketones upon hydrolysis. Dissolution of perfluorinated benzocyclobutene, indan, and tetralin in excess SbF5 generated perfluorobenzocycloalken-1-yl cations in equilibrium with their precursors. The relative stability of perfluoro- and 1-chloropolyfluorobenzocycloalken-1-yl cations decreases as the size of the alicyclic fragment increases.     

Non-empirical and DFT calculations of <Superscript>19</Superscript>F and <Superscript>13</Superscript>C chemical shifts in the NMR spectra of substituted pentafluorobenzenes

Chemical shifts in ¹⁹F and ¹³C NMR spectra of substituted pentafluorobenzenes are calculated by Hartree-Fock and density functional theory methods. The calculated values are compared with the experimental data known from the literature. It is shown that chemical shifts in non-polar solvents can be predicted sufficiently accurately by the GIAO-DFT(PBE/L22) method. This method is used to predict the ¹⁹F and ¹³C chemical shifts of a heptafluorobenzyl cation in the SbF₅ medium. The best agreement between the calculated and experimental values is achieved when the counterion effect is taken into account.     

Formation of Fluoroderivatives of 1,2,3,4-Tetrahydro-1,3-diazafluorene from 2-Dialkylamino- 3-(1-imino-2,2,2-trifluoroethyl)hexafluoroindenes

2-Dimethylamino-3-(1-imino-2,2,2-trifluoroethyl)hexafluoroindene in the presence of DMSO or NEt₃ undergoes isomerization into 1-methyl-4-trifluoromethyl-5,6,7,8,9,9-hexafluoro-1,2,3,4-tetrahydro-1,3-diazafluorene, and from 1-(1-amino-2,2,2-trifluoroethylidene)octafluoroindane by the treatment with water solution of NHEt₂ 2-methyl-4-trifluoromethyl-1-ethyl-5,6,7,8,9,9-hexafluoro-1,2,3,4-tetrahydro-1,3-diazafluorene was obtained.     

Conversion of perfluoro-1-indanone to perfluorochroman in the H2O2-HF-SbF5 system

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2463–2464, October, 1990.     

Fluoroindenes. 12. Interaction of perfluorinated 3-methyl- and 3-ethylindenes, 1-methylene-, 1-ethylidene-, and 1-vinylindans with ammonia and aliphatic amines

In the reactions with ammonia and alkylamines, perfluoro-3-ethylindene is more reactive than perfluoro-1-ethylideneindan, whereby the last two compounds undergo mutual conversion in the presence of F^–. In the interaction of perfluoro-1-ethylideneindan with aqueous amines, products of the substitution of the vinyl F atom in the initial compound are obtained; in the case of dry amines in the presence of CsF, the products of the substitution of the F atom at the double bond of perfluoro-3-ethylindene are chiefly obtained. The monoamino derivatives, which contain an available atom of H, are converted to the disubstituted derivatives by the action of an excess of the amines. Both the amine and the hydroxy anion may thereby emerge as the nucleophile in the reaction of 2-aminoperfluoro-3-ethylindene, as well as perfluoro-1-ethylideneindan, with aqueous dialkylamines. The perfluoro-1-vinylindan and aqueous NH₃ yield 1-(aminocyanomethylene)octafluoroindan and 2-amino-3-(iminocyanomethyl)hexafluoroindene; and perfluoro-1-methyleneindan yields 2-amino-3-cyanohexafluoroindene. The last is formed together with 2-aminoperfluoro-3-methylindene in the reaction of perfluoro-3-methylindene with aqueous NH₃.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1856–1865, August, 1990.