360-91-8Relevant academic research and scientific papers
The isolation, characterisation, gas phase electron diffraction and crystal structure of the thermally stable radical [CF3CSNSCCF3]
Brownridge, Scott,Du, Hongbin,Fairhurst, Shirlcy A.,Haddon, Robert C.,Oberhammer, Heinz,Parsons, Simon,Passmore, Jack,Schriver, Melbourne J.,Sutcliffe, Leslie H.,Westwood, Nicholas P. C.
, p. 3365 - 3382 (2007/10/03)
The first structural characterisation of a heterocyclic free radical in all phases has been achieved. 4,5-Bis(trifluoromethyi)-l,3,2-dithiazol-2-yl, [CF3CSNSCCF3]' 4d, a In radical, was prepared quantitatively on reduction of [4d][AsF6] with various reducing agents. It is a blue gas over a green paramagnetic liquid [19F NMR o-59.7], which freezes to a diamagnetic black-green solid. There is a remarkably large volume increase on melting implying that the liquid consists of discrete monomeric radicals, and consistently there is no tendency to dimerise in CC13F solution and the vibrational spectra attributable to the monomer are essentially identical in all phases. The thermodynamic properties obtained for the vapourisation, sublimation and melting processes are very similar to those of related diamagnetic materials. 4d is remarkably thermochemically robust giving decomposition products identical to those from photochemical decomposition, a quantitative mixture of CF3CSSCCF3 (and its oligomers) and CFjCNSNCCF3. The reaction chemistry is described. The crystal structure shows radical 4d to be a planar heterocyclic ring which associates in the solid as a diamagnetic tetramer. The structure of the gaseous monomer determined by electron diffraction is very similar to that in the solid phase. Comprehensive physical measurements were made including the UV-visible spectra of the bright blue solutions, variable temperature magnetic susceptibility and quantitative variable temperature ESR spectra both of which confirm a phase change from a diamagnetic solid to a paramagnetic liquid on melting, the vibrational spectra, and the photoelectron spectrum of the gaseous free radical. A study of the behavior of RCSNSCR' (R = H, CH3 or CF3) given by the reduction of RCSNSCR on increase of concentrations of radical is reported, including the isolation of HCSNSCCF/ at low temperature. The experimental and calculated [UMPW1PW91/6-31+G ] structures of 4d are in good agreement. These and related calculations also support the interpretation of the vibrational and photoelectron spectra, and the thermodynamic properties of 4d, as well as provide possible explanations for the relative stabilities of RCSNSCR', and imply that the weak intramolecular interactions in 4d in the solid state are largely ionic Sff interactions. The Royal Society of Chemistry 2000.
Preparation and Crystal Structure of the Paramagnetic Solid AsF6: Implications for the Indentity of
Cameron, T. Stanley,Haddon, Robert C.,Mattar, Saba M.,Parsons, Simon,Passmore, Jack,Ramirez, Arthur P.
, p. 1563 - 1572 (2007/10/02)
4,5-Bis(trifluoromethyl)-1,2,3-trithiolylium hexafluoroarsenate, which contains the 7? radical cation, the first example of a cationic carbon-sulfur heterocycle, has been prepared and characterised.It was prepared as a purple solid in 90 percent yield by the reaction of F3CCCCF3 with a 1:1 mixture of S4(AsF6)2 and S8(AsF6)2 in SO2 at 50 deg C for 2 weeks.Small amounts of a homopolyatomic sulfur cation (probably S82+) were removed by work-up with fresh F3CCCCF3 and AsF5 in SO2 at 50 deg C for 8d.The AsF6 was characterised in the solid state by chemical analyses, IR, mass spectrometry and X-ray crystallography.The crystal structure consists of layers containing both monomeric, planar radical cations and AsF6- anions .A powder photograph of the bulk product correlated with the single-crystal data, and a variable-temperature magnetic susceptibility study indicated that AsF6 is a paramagnetic solid, exhibiting oridinary Curie-Weiss behaviour, μ = 1.68, Θ = -0.6 K (μ = 2.1 in SO2 solution at room temperature).The ESR spectrum of in SO2 is identical to that previously reported for , which suggested that spectra long assigned to 1,2-dithiete cations are in fact due to 1,2,3-trithiolium cations.This is supported by the ESR spectrum of , which consisted of a singlet at g = 2.017, with two sets of 33S satellites in a 2:1 intensity ratio, with very similar 33S coupling constants (8.0 and 8.9 G).The salt AsF6 is reduced by KI to give a mixture of neutral cyclic polysulfides including (43percent) and the previously unknown (23percent).Attempts to oxidise with AsF5 were unsuccessful.
Halogen-Carbon-Sulfur Compounds: Synthesis and Modes of Reactions of 4,5-Bis(trifluoromethyl)-1,3-dithiole Derivatives
Maletzko, Christian,Sundermeyer, Wolfgang,Pritzkow, Hans,Irngartinger, Hermann,Huber-Patz, Ursula
, p. 2025 - 2031 (2007/10/02)
The chemistry of the bis(trifluoromethyl)-1,3-dithiole system is thoroughly investigated starting from the 2-thione 6.By its oxidation the sulfine 2 and the ketone 7 are obtained.Further oxidation of 2 leads to the spiro compound 3.By chlorination of 6 th
NIOBIUM ORGANOMETALLIC CHEMISTRY. X. SYNTHESIS OF NEW (η2-DISULFIDO) COMPLEXES; COMPARISON OF THEIR REACTIVITY WITH THAT (η2-DIOXO) DERIVATIVES
Migot, Jean-Louis,Sala-Pala,Jean,Guerchais, Jacques-E.
, p. 427 - 436 (2007/10/02)
The new compounds 5-C5H5)2(X-X)R> ( with M = Nb : X = S, R = Me, Bu, η1-C5H5; X = Se, R = Me; with M = Ta : X = S, R = Me) are described.The reactions of 5-C5H5)2(S-S)Me> (A) with some nucleophiles and electrophiles have been studied.A reacts with triphenylphosphine to give the corresponding monosulfido complex.Loss of the S2 ligand and formation of a μ-oxoderivative 5-C5H5)2Me>2O> X2 * 2OH2 (X = I or BF4) occurs upon treatment of A with CH3I or Ph3CBF4. 5-C5H5)2Me I>I, MeSSMe, have also been identified as product from the reactionwith CH3I.Reaction of A with hexafluorobutyne gives an unexpected new compound, the nature of which is discussed.
