Sulfur chlorides and oxochlorides

Physical appearance and Colourless fuming White solid at low Colourless solid White solid at low temp.  

The structure of S2CI2,15.32, resembles that of S2F2, while SCI2 is a bent molecule (S—Cl = 201 pm, ZCl-S-Cl = 103°). Decomposition of both chlorides by water yields a complex mixture containing S, SO2, H2S5O5 and HCl. Equation 

17 showed the use of S2CI2 in the formation of an S ring. Condensation of S2CI2 with polysulfanes (equation 15.66) gives rise to chlorosulfanes that can be used, for example, in the formation of various sulfur rings (see structures 15.6 and 15.7). 

Thionyl chloride, SOCI2 (prepared, for example, by reaction 15.64 or 15.67), and sulfonyl chloride, SO2CI2 (prepared by reaction 15.68) are colourless, fuming liquids SOCI2, bp 351K, SO2CI2, bp 342 K. Their ease of hydrolysis by water accounts for their fuming nature, e.g. equation 15.69. 

The structural parameters shown for SOCI2, 15.33, and SO2CI2, 15.34, are for the gas-phase molecules. 

The range of sulfur chlorides and oxochlorides (which are aU hydrolysed by water) is more restricted than that of the corresponding fluorides. There are no stable chloro analogues of SF4, SFg and S2F10. One example of a high oxida-ti(Mi state chloride is SCIF5, prepared as shown in Fig. 16.13. 

Both SOCI2 and SO2CI2 are available commercially. Thionyl dichloride is used to prepare acyl chlorides (eq. 16.74) and anhydrous metal chlorides (i.e. removing water of crystallization by reaction 16.73), while SO2CI2 is a chlorinating agent. 

Show that SCI2 belongs to the C2v point group. 

Sulfuryl difluoride is also called sulfonyl difluoride or sulfonyl fluoride. 

Sulfuryl dichloride is also called sulfonyl dichloride or sulfonyl chloride. 

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