Oxyhalides of S, Se, and Te

The known oxyhalides are set out below, the salient points being the absence (at present) of iodides and of any well-characterized compounds of Te, and the existence of a number of more complex compounds of S peculiar to that element. 

Details of the structures of the pyramidal molecules of thionyl halides (SOX2) and SeOF2 and of the tetrahedral molecules of sulphuryl halides (SO2X2), which have been studied as gases, are included in Tables 16.3 and 16.4. The structures of SeOCl2 (and also SeOF2) have been determined in a number of adducts (p. 600). 

The structure of OSF4 is compared with that of SF4 in Fig. 16.2. Apart from the expansion of the equatorial F-S-F bond angle from 103° (mean of e.d. and m.w. values) to 110° the molecules are very similar in shape (S-0, 1-41 A). The S-F bond lengths were compared earlier. 

The structures suggested for SO3F2, (b), and S2O5F2, (c), (and for Te302Fi4 ) have not been confirmed by structural studies. 

---