Interaction of two spin subsystems with different wavevectors

The possibility of the transition of a spin system from an incommensurable to a commensurable phase via a phase with different wavevectors of individual subsystems is shown in the mean-field approximation.     

Vinyl C-F cleavage by Os(H)3Cl(P(i)Pr3)2

Os(H)(3)ClL(2) (L = P(i)Pr(3)) reacts at 20 degrees C with vinyl fluoride in the time of mixing to produce OsHFCl([triple bond]CCH(3))L(2) and H(2). In a competitive reaction, the liberated H(2) converts vinyl fluoride to C(2)H(4) and HF in a reaction catalyzed by Os(H)(3)ClL(2). A variable-temperature NMR study reveals these reactions proceed through the common intermediate OsHCl(H(2))(H(2)C=CHF)L(2), via OsClF(=CHMe)L(2) and OsHCl(H(2))(C(2)H(4))L(2), all of which are detected. DFT(B3PW91) calculations of the potential energy and free energy at 298 K of possible intermediates show the importance of entropy to account for their thermodynamic accessibility. Calculations of unimolecular C-F cleavage of coordinated C(2)H(3)F confirms the high activation energy of this process. Catalysis by HF is thus suggested to account for the fast observed reactions, and scavenging of HF with NEt(3) changes the product to exclusively Os(H)(2)Cl(CCH(3))L(2). The analogous reaction of Os(H)(3)ClL(2) with H(2)C=CF(2) produces exclusively OsHFCl(=CCH(3))L(2) and HF, and the latter is again suggested to catalyze C-F scission via the observed intermediates Os(H)(2)Cl(CF(2)CH(3))L(2) and OsHCl(=CFMe)L(2).     

Nucleophilic substitution in ethyl fluorosulfonoxydifluoroacetate

Conclusions Ethyl fluorosulfonoxydifluoroacetate undergoes nucleophilic replacement with the formation of derivatives of difluoroacetic acid. The reaction with fluoride anion mainly features cleavage of the S-O bond leading to the acid fluoride of the monoethyl ester of oxalic acid.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1435–1437, June, 1985.     

Catalytic addition of alcohol to ethyl polyfluorovinyl ethers

Russian Chemical Bulletin -     

Perfluoro-2,3-dimethylbutadiene

Conclusions 2,3-Bistrifluoromethyl-1,1,1,3,3,3-hexafluorobutane was obtained by the electrolysis of monohydro-perfluoroisobutyric acid, the dehydrofluorination of which gives perfluoro-2,3-dimethylbutadiene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp.459–460, February, 1973.