Sulfur Difluoride Research Articles

Fluorine-19 NMR chemical shift of sulfur difluoride in the gas phase

Fluorine-19 NMR chemical shift of sulfur difluoride in the gas phase

Electronic spectra of sulfur difluoride radicals between 295 and 495 nm observed with resonance-enhanced multiphoton ionization spectroscopy

Spectra of the SF{sub 2} radical were observed between 295 and 495 nm by 2 + 1, 2 + 2, and 3 + 1 resonance-enhanced multiphoton ionization (REMPI) spectroscopy. Vibrational progressions associated with two Rydberg states were assigned. The SF{sub 2} was produced by a variety of methods, including passing SF{sub 6} through a microwave discharge, which provides direct evidence that discharges produce SF{sub 2} radicals.

Alkylidene sulfur difluorides R2CSF2 and alkylidene sulfur difluoride oxides, R2CSF2O

(F3C) 2CSF2 and F5S(F3C)CSF2 are prepared from fluorinated olefines and SF4 under CsF catalysis. Their structure is qualitatively derived from the fact, that there are two different positions for the C-substituents. This indicates a torsionally rigid CS double bond. These compounds undergo easily a 1,2-F-shift reaction, which possibly prevented their earlier detection. The resulting sulfenyl-fluorides, R-S-F, are not stable, either, and undergo further characteristic decomposition reactions.FCO-CHSF2O is made from F-CO-CHSF4 by hydrolysis. It is the only alkylidene sulfur difluoride oxide known, so far. Quite in contrast to the alkylidene sulfur difluorides these CS double bond is freely rotating at room temperature, but the torsional movement can be frozen out at low temperatures, to give two, at the lowest temperature even three isomers.

Alkylidene Sulfur Difluorides: F5S(F3C)CSF2 and (F3C)2CSF2. Synthesis, Structure, and Structure Predictions

The new alkylidene sulfur difluorides R2CSF2 differ structurally and chemically from sulfur ylides . The new compounds have a double bond, as shown by the existence of cis/trans isomers (when the two R groups differ). They rearrange to sulfenyl fluorides, R2FC-SF. Theoretical calculations confirm these results, but predict, in addition, a further planar structural isomer, which, in the case of F2C  SF2, should even be the more stable isomer.

Aminosulfur trifluorides: relative thermal stability [1

The fluorinating reagent, DAST (diethylaminosulfur trifluoride, 1b), has the potential to decompose violently when heated and presents a hazard if not properly handled. This investigation has shown that the decomposition occurs in two steps. First, a non-energetic disproportionation occurs to give sulfur tetrafluoride and bis(diethylamino) sulfur difluoride ( 3b). The less stable difluoride thus formed then undergoes a vigorous exothermic decomposition (detonation). The relative stabilities of DAST and several of its analogs were determined by differential thermal analysis. Morpholinosulfur trifluoride ( 1g, morpho-DAST) was the most stable of the aminosulfur trifluorides examined, and its use in place of the less stable DAST is recommended for fluorinations of alcohols.

ChemInform Abstract: Sulfur/Carbon Double and Triple Bonds

Preparation and structural behaviour of the three classes of sulfur compounds R2C=5F4, R-CSF3 and R2C=SOF2 is described. The alkylidene sulfur tetrafluorides are formed by elimination of C-SF5 compounds or by special isomerization reactions. They exhibit a rigid trigonal bipyramidal structure with the double bonded carbon in the equatorial position, and the carbon substituents in the axial plane. The alkylidyne sulfur trifluorides are analogous to acetylenes, however they are not completely linear, although the extent of this is still disputed. The alkylidene sulfur difluoride oxides are formed hy hydrolysis of the corresponding sulfur tetrafluorides. They show a complicated non rigid behaviour.

Sulfur/carbon double and triple bonds

Abstract

Selected chemical reactions of sulfur difluoride

Sulfur difluoride was discovered in 1969 using microwave and mass spectroscopy [1,2]. It has a strong tendency to disproportionate and dimerises to SF 3SF by condensation. The dimerisation and disproportionation process was investigated very thoroughly [3] and the gas phase structure of SF 3SF has been determined [4]. The best synthesis of SF 2 was found to be the gas phase reaction of COS with F 2 [5]. The chemistry of SF 2 can be studied by cocondensation with various reagents. For example by cocondensation of SF 2 with SF 4 and SSF 2 the new binary sulfur fluorides SF 3SF 3 and SF 3SSF respectively are formed. Further reactions will be presented.

Infrared spectrum of sulfur difluoride in the gas phase around 12.5 μm

Gaseous SF 2 was prepared from COS reacting with cooled F 2. The infrared spectrum of SF 2 was recorded with a Nicolet Fourier Transform Spectrometer. Analysis of the spectrum is achieved between 780 and 860 cm −1. Molecular band parameters (band centers, rotational constants, Coriolis interaction terms, etc.) were derived for both fundamentals ν 1 (838.5299 cm −1) and ν 3 (813.0413 cm −1).

The unusual chemical equilibria F3SSF ⇌ 2 SF2 and CF3SF2SCF3 ⇌ 2CF3SF

In order to understand more about the instability of sulfur difluoride, we have investigated the chemical interrelations between each of the monomers SF2 and CF3SF and the corresponding dimers F3SSF and CF3SF2SCF3. Thus we have found that SF2 and CF3SF exist in chemical equilibria with their dimers. These equilibria are unusual because they involve two different bonds (SF and SS). The equilibrium constants and dissociatíon enthalpies have been determined by i.r. and mass spectroscopic measurements. The equilibrium between F3SSF and SF2 is disturbed by a decomposition reaction of these compounds yielding SF4 and SSF2. In both systems (1) and (2) the achievement of the equilibrium is comparatively slow at −30 to 30 °C. The rates for dissociation and decomposition are strongly surface-dependent and the kinetics of the two processes have been studied separately. Under favorable conditions the half-lives at 298 K for the dissociation of F3SSF and CF3SF2SCF3 are found to be ca. 8.h and ca. 2 h, respectively, and for the decomposition of SF2 to SF4 and SSF2 and CF3SF to CF3SF3 and CF3SSCF3 (p⋍13 mbar) the values are ca. 10 h and 1 year respectively.

ChemInform Abstract: MICROWAVE SPECTRUM OF SULFUR DIFLUORIDE IN THE FIRST EXCITED VIBRATIONAL STATES VIBRATIONAL POTENTIAL FUNCTION AND EQUILIBRIUM STRUCTURE

Chemischer InformationsdienstVolume 10, Issue 49 Physical Inorganic Chemistry ChemInform Abstract: MICROWAVE SPECTRUM OF SULFUR DIFLUORIDE IN THE FIRST EXCITED VIBRATIONAL STATES VIBRATIONAL POTENTIAL FUNCTION AND EQUILIBRIUM STRUCTURE Y. ENDO, Y. ENDOSearch for more papers by this authorS. SAITO, S. SAITOSearch for more papers by this authorE. HIROTA, E. HIROTASearch for more papers by this authorT. CHIKARAISHI, T. CHIKARAISHISearch for more papers by this author Y. ENDO, Y. ENDOSearch for more papers by this authorS. SAITO, S. SAITOSearch for more papers by this authorE. HIROTA, E. HIROTASearch for more papers by this authorT. CHIKARAISHI, T. CHIKARAISHISearch for more papers by this author First published: December 4, 1979 https://doi.org/10.1002/chin.197949008AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume10, Issue49December 4, 1979 RelatedInformation

Microwave spectrum of sulfur difluoride in the first excited vibrational states vibrational potential function and equilibrium structure

Microwave spectra of SF 2 in the first excited states of the three normal modes were observed and analyzed. A comparison of the observed inertia defects in the ν 1 and ν 3 states with those calculated by omitting the contributions of the Coriolis interaction between the two modes led to a ν ̃ 1 - ν ̃ 3 vibrational frequency differences of 25.72 ± 0.33 cm −1, with ν 1 being definitely higher. The inertia defect in the ground state and our measured values for the inertia defect in the ν 2 state and for the ν ̃ 1 - ν ̃ 3 difference were combined with the centrifugal distortion constants of Kirchhoff et al. [J. Mol. Spectrosc. 48, 157–164 (1973)] to improve the harmonic force field. The interaction constant between the two SF stretching coordinates was determined precisely. The third-order and the cubic anharmonic potential constants were calculated from the observed vibration-rotation constants. The equilibrium structure was determined to be r e( SF) = 1.58745 ± 0.00012 A ̊ and θ e (FSF) = 98.048 ± 0.013°.

ChemInform Abstract: GENERALIZED VALENCE BOND STUDIES OF THE ELECTRONIC STRUCTURE OF SULFUR DIFLUORIDE, SULFUR TETRAFLUORIDE, AND SULFUR HEXAFLUORIDE

Chemischer InformationsdienstVolume 8, Issue 20 Physical Inorganic Chemistry ChemInform Abstract: GENERALIZED VALENCE BOND STUDIES OF THE ELECTRONIC STRUCTURE OF SULFUR DIFLUORIDE, SULFUR TETRAFLUORIDE, AND SULFUR HEXAFLUORIDE P. J. HAY, P. J. HAYSearch for more papers by this author P. J. HAY, P. J. HAYSearch for more papers by this author First published: May 17, 1977 https://doi.org/10.1002/chin.197720001AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume8, Issue20May 17, 1977 RelatedInformation

Generalized valence bond studies of the electronic structure of sulfur difluoride, sulfur tetrafluoride, and sulfur hexafluoride

The electronic structure of SF/sub 2/, SF/sub 4/, and SF/sub 6/ is investigated from the standpoint of ab initio generalized valence bond (GVB) calculations. Analysis of the GVB orbitals in these molecules and in the model reaction SF/sub 4/ ..-->.. SF/sub 2/ + 2F leads to the conclusion that the stability of the hypervalent SF/sub 4/ and SF/sub 6/ systems is largely due to the incorporation of charge-transfer configurations, with 3d functions on the sulfur playing a lesser role. Molecular properties of SF/sub 2/ and SF/sub 4/ are reported.

Vibrational spectra of trifluoromethylsulfur trifluoride and bis(trifluoromethyl) sulfur difluoride

Infrared spectra of the gas phase from 2000 to 400 cm −1 and Raman spectra of the liquid phase from 2000 to 100 cm −1 have been obtained for CF 3SF 3 and (CF 3) 2SF 2. For both compounds the assignment of the sulfur—fluorine stretching fundamentals supports equatorial perfluoroalkyl substitution on sulfur.

Fluorine-19 nuclear magnetic resonance spectrum of trifluoromethyl(pentafluoroethyl)sulfur difluoride

Fluorine-19 nuclear magnetic resonance spectrum of trifluoromethyl(pentafluoroethyl)sulfur difluoride

Reactions of sulfur difluoride imides and sulfur dichloride imides

Reactions of sulfur difluoride imides and sulfur dichloride imides

Extensively rearranged derivatives of sulfur tetrafluoride, trifluoromethylsulfur trifluoride, and bis(trifluoromethyl)sulfur difluoride from hexafluoroisopropylideniminolithium reactions

Extensively rearranged derivatives of sulfur tetrafluoride, trifluoromethylsulfur trifluoride, and bis(trifluoromethyl)sulfur difluoride from hexafluoroisopropylideniminolithium reactions

Bis(perfluoroalkyl)sulfur Oxydifluorides

AbstractThe first bis(perfluoroalkyl)sulfur oxydifluorides have been synthesized by the reaction of chlorine monofluoride with bis(perfluoroalkyl) sulfoxides at –78°C. Unlike the NMR spectra of the bis(perfluoroalkyl)sulfur difluorides, the NMR spectra of these new compounds are first order. These sulfur oxydifluorides, (CF3)2S(O)F2, CF3S(O)F2C2F5, and (C2F5)2S(O)F2 are volatile, colorless liquids which are characterized by infrared, NMR, and mass spectra as well as elemental analyses and vapor pressure data.

Bis(perfluoroalkyl)sulfur difluorides and bis(perfluoroalkyl) sulfoxides

Photolysis of CF 3SOC(O)CF 2CF 3 and CF 3SOC(O)CF 2CF 2CF 3 results in the previously unreported sulfides, CF 3SCF 2CF 3 and CF 3SCF 2CF 2CF 3. Fluorination of bis(perfluoroalkyl) sulfides with chlorine monofluoride leads to a new derivatives of sulfur tetrafluoride, CF 3SF 2CF 3, CF 3SF 2CF 2CF 3 and CF 3SF 2CF 2CF 2CF 3. The cesium fluoride catalyzed reaction of SF 4 and C 2F 4 gives CF 3CF 2SF 2CF 2CF 3. Hydrolysis of the products resulting from reaction of the bis(perfluoroalkyl)sulfur difluorides with HCl yields bis(perfluoroalkyl) sulfoxides, CF 3S(O)CF 3, CF 3S(O)CF 2CF 3, CF 3CF 2S(O)CF 2CF 3 and CF 3S(O)CF 2CF 2CF 3. Infrared, NMR and mass spectra, as well as elemental analyses and vapor pressure data, are reported for these new compounds.