E. V. Balagurova

Selective fluorination of o0 and m-carboranes. Synthesis of 9-monofluoro-, 9,12-difluoro-1,8,9,12-trifluoro-, and 8,9,10,12-tetrafluoro-o-carboranes and 9-monofluoro-, and 9,10-difluoro-m-carboranes. Molecular structure of 8,9,10,12-tetrafluoro-o-carborane

Abstract Reaction of o - and m -carboranes 1 with antimony pentafluoride results in replacement of hydrogen by fluorine at the boron atoms, to give in succession 9-fluoro-; 9,12-difluoro-; 8,9,12-trifluoro-; 8,9,10,12-tetrafluoro- o -carboranes and 9-fluoro-; 9,10-difluoro- m -carboranes. An X-ray structural study of the 8,9,10,12-tetrafluoro- o -carborane has been carried out. The compounds synthesized have been characterized by elemental analysis and 1 H, 11 B{ 1 H}, 19 F NMR spectroscopy.

Destruction ofB-polyfluorosubstitutedo-carboranes into anions ofB-fluorosubstitutednido-7,8-dicarbaundecaborates by the action of ethanolic alkali and amines

The destruction ofB-polyfluorosubstitutedo-carboranes by the action of ethanolic alkali and amines was studied. The destraction of trifluoro-o-carborane was found to occur regioselectively. The nature of the amine was shown to affect the stereochemistry of the destruction of trifluoro-o-carborane. The intermediate of the reaction of tetrafiuoro-o-carborane with diethylamine was detected.

Fluorosubstituted rhodacarboranes 3,4-(R3P)2-3-H-3,1,2-RhC2B9H11−n F n (n=1, 2, 4): Synthesis, molecular structure, and catalytic properties in hydrosilylation of styrene and phenylacetylene

Hydridorhodacarboranes 3,3-(Ph2RP)2-3-H-3,1,2-RhC2B9H11−nFn (R=Ph, Me;n=1, 2, 4) containing F atoms at the B atoms of the π-carborane ligand were synthesized from (Ph3P)3RhCl or (Ph2MeP)3RhCl andnido-7,8-C2B9H12−nFn− (n=1, 2, 4) salts. Hydridorhodacarboranes 3,3-(Ph2MeP)2-3-H-3,1,2-RhC2B9H11−nFn readily exchange the H atom at the Rh atom for the Cl atom under the action of CH2Cl2 to give 3,3-(Ph2MeP)2-3-Cl-3,1,2-RhC2B9H11−nFn. The structures of the 3,3-(Ph3P)2-3-H-3,1,2-RhC2B9H7F4 and 3,3-(Ph2MeP)2-3-Cl-3,1,2-RhC2B9H9F2 complexes were determined by X-ray diffraction analysis. Catalytic properties of the rhodacarbonanes obtained in hydrosilylation of styrene and phenylacetylene by PhMe2SiH were studied.

Synthesis of 9-C6H5-3-(π-C5H5)-3,1,2-CoC2B9H10 by cross-coupling reaction of 9-I-3-(π-C5H5)-3,1,2-CoC2B9H10 with C6H5ZnCl catalyzed by palladium complexes

The cross-coupling reaction of 9-I-3-(π-C5H5)-3,1,2-CoC2B9H10 with organozinc compounds catalyzed by palladium complexes was used to synthesize the first representative ofB-phenyl-substituted carboranes, 9-C6H5-3-(π-C5H5)-3,1,2-CoC2B9H10.

ESR STUDY OF CARBORANE CONTAINING ORGANOFLUORINE RADICALS

It has been shown by ESR that the addition of photochemically generated boroncentered carboranyl radicals to branched fluoroalkenes affords stable spin-adducts. It has been found that the addition of boron-centered radicals with 1-substituted 2-fluoroalkenyl-o-carborane gives stable α-carboranyl radicals. Negligible variations in the values of the constants of hyperfine coupling of the unpaired electron with the nucleus of the β-11B atom in radicals of various structures imply the stability of the carborane conformation with respect to the 2pz-orbital of the unpaired electron. This may be caused by hyperconjugation between the boron atom and the unpaired electron as well as steric interaction.

Preparation of ultrafine metal particles in processes of pulse mechanical action

Ultrafine metal particles (UFMP) (iron and cobalt) have been obtained in solid-state redox reactions of cyclopentadienyl-π-(3)-1,2-dicarbollyliron or cyclopentadienyl-π-(3)-1,2-dicarbollylcobalt with elemental sulfur ((C5H5)Fe3+(C2B9H11)-S, (C5H5)Co5+C2B9H11-S). These reactions are realized by the action of elastic wave (EW) pulses on powder compositions of these substances. Study of the UFMP obtained by the ferromagnetic resonance (FMR) method has shown that the sizes ofn · Co0 UFP lie in the range from 1 to 13 nm. UFP of cobalt and iron are also formed under the action of EW on samples containing (C5H5)Fe3+(C2B9H11)-S or (C5H5)Co3+(C2B9H11)-S within the film of tetrafluoroethylene and perfluoro-4-methyl-3,6-dioxaoct-7-ene-1-sulfonyl fluoride copolymer (CP). It is shown by the FMR method that FMR lines broaden on going from powder systems to systems containing CP films. It is supposed thatn · Co0 and n · Fe0 particles interact with polymeric matrices in the course of formation and stabilization of UFMP in the matrices.

Alkylation of aromatic hydrocarbons by 1-fluoromethyl-o,m-carboranes by the action of AlCl3

Conclusions1-Fluoromethyl-o, m-carboranes undergo the Friedel-Crafts reaction with aromatic hydrocarbons in the presence of AlCl3.

Synthesis and some transformations of trifluorocyclobutenyl-o-carboranes

Conclusion1.The reaction of 1-organyl-2-lithium-o-carboranes with 1-phenyl-3,3,4-trifluoro-4-chloro-1-butene gave 1-organyl-2-(1-phenyl-2,3,3-trifluoro-1-cyclobutene)-o-carboranes. The hydrolysis of these o-carboranes leads to 1-organyl-2-(1-phenyl-2-fluoro-1-cyclobuten-3-one)-o-carboranes.2.An unusual cleavage of the cyclobutene ring was found upon the action of AlH2Cl on 1-methyl-2-(1-phenyl-2-fluoro-1-cyclobuten-3-one)-o-carborane with the formation of 1-methyl-2-(2-phenyl-3-fluoro-2-buten-4-al)-o-carborane.