Disulfur difluoride

Nonmeta.ls, Sulfur reacts with fluorine to yield the remarkably stable sulfur hexafluoride, SF. Operating conditions must be controlled because a mixture of the lower fluorides such as disulfur difluoride [13709-35-8] 2 2 disulfur decafluoride [5714-22-7] 2 10 sulfur tetrafluoride [7783-60-0] SF4, may also be formed. When this reaction is carried out between 310 and 340°C, SF is primarily obtained and essentially no SF and only trace amounts of lower fluorides. Below 300°C, and preferably at ca 275°C, SF is the primary product. At 450—500°C, a mixture comprising ca 50% SF and the lower sulfur fluorides is formed (see Fluorine compounds, inorganic-sulfur). 

Structural isomers are molecules that have the same formula but in which the atoms are connected in a different order. Two isomers of disulfur difluoride, S2F2, are known. In each the two S atoms are bonded to each other. In one isomer each of the S atoms is bonded to an F atom. In the other isomer, both F atoms are attached to one of the S atoms, (a) In each isomer the S—S bond length is approximately 190 pm. Are the S—S bonds in these isomers single bonds or do they have some double bond character (b) Draw two resonance structures for each isomer, (c) Determine for each isomer which structure is favored by formal charge considerations. Are your conclusions consistent with the S—S bond lengths in the compounds ... 

It is well established that disulfur difluoride (S2F2) exists in two isomeric forms, the nonplanar disulfane FSSF and the branched thiosulfoxide form p2S=S, with the latter found to be the more stable isomer. Both isomers have been characterized by microwave spectroscopy, mass spectrometry, infrared and Raman spectroscopy as well as photoelectron spectra [6] (and refer-... 

Disulfur difluoride, 22 829 Disulfuric acid, 23 765 Ditallowalkylamines, melting point,... 

FLUORINECOMPOUNDS,INORGANIC - SULFUR - SULFUR FLUORIDES] (Vol 11) Disulfur difluoride [13709-35-8]... 

These are rather different from the other halides and are appropriately dealt with separately. There are seven sulfur fluorides, six of which are depicted, along with their properties, in Table 12-4. The isomeric disulfur difluorides are actually thermodynamically unstable. The compound FSSF prepared by fluorination of sulfur with AgF, readily isomerizes to SSF2, which can also be obtained in other ways. However, SSF2 itself in the presence of acid catalysts (e.g., HF or BF3) rapidly dispropor-tionates ... 

Thiothionyl fluoride, 8=8F2 (an isomer of 82F2), is also known, although it is not especially stable it is often obtained mixed with disulfur difluoride, but may be obtained directly by reaction of NF3 with sulfur or by the fluorination of 82CI2 with KF in 8O2. 

In the case of hydrogen disulfide, the S—S bond length as determined by Stevenson and Beach (211) from electron diffraction indicates that branching does not occur. Electron diffraction studies by Palmer (184) and Guthrie (188) on disulfur dichloride show an unbranched, nonplanar structure. Smyth (206) has discussed the dipole moments of hydrogen disulfide, disulfur dichloride, and diselenium dichloride on the same basis and Hooge and Ketelaar (145), the vibrational spectra of hydrogen disulfide and disulfur difluoride, dichloride, and dibromide. 

A mixture of gaseous disulfur difluoride, dinitrogen tetra-fluoride, and sulfur tetrafluoride is placed in an effusion apparatus, (a) Rank the gases in order of increasing effusion rate, (b) Find the ratio of effusion rates of disulfur difluoride and dinitrogen tetrafluoride. (c) If gas X is added, and it effuses at 0.935 times the rate of sulfur tetrafluoride, find the molar mass of X. 

There are two isomers of disulfur difluoride, S=Sp2 and FSSF. Explain how you could distinguish the isomers and determine the structure of each by electron diffraction. What other methods could be used to determine their structures ... 

The lower fluorides, S2F2 and SF4, disproportionate readily into sulfur and SF6. The difluoro compound, S2F2, demonstrates unusual structural isomerism in that it can exist in two forms disulfur difluoride, F—S—S—F (12.8) and thiothionyl fluoride, S=SP2 (12.9). 

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