THE ACTION OF SULPHUR TRIOXIDE ON SHJCON 



TETRACHLORIDE.! 



By Charles Robert Sanger and Emile Raymond Riegel.^ 

 Presented by O. L. Jackson, November 13. 1912. Recaivod, October 24, 1912. 



The reaction between sulphur trioxkle and carbon tetrachloride 

 yields phosgene and pyrosulphuryl chloride.^ 



2SO3 + CCI4 = COCI2 + S2O6CI2 



Since the two elements carbon and silicon resemble each other so 

 closely, it was reasonable to suppose that a similar reaction might take 

 place if silicon tetrachloride were substituted for the carbon tetra- 

 chloride. In order to test this, or to find out what reaction, if any, 

 took place, this research was undertaken. 



The only reference to the subject we can find in the literature is the 

 following note of Gustavson, quoted in extenso: 



"Silicon tetrachloride gives with sulphur trioxide pyrosulphuryl 

 chloride." ^ 



This information Dammer * enlarges into the following reaction : 



4SO3 + SiCli = 2S2OBCI2 + SiOo 



Our investigation showed that on mixing pure melted sulphur tri- 

 oxide and silicon tetrachloride, there is at first mere solution, but on 

 standing, a reaction takes place, exceedingly slowly in the cold, but 

 more rapidly at about 50°, resulting in the formation of a liquid which 

 when freed by distillation from the unchanged materials boils between 

 135° and 150° at atmospheric pressure, whereas sulphur trioxide and 

 silicon tetrachloride boil below 60°. This distillate fumes weakly in 



1 This research was suggested by the late Professor C. R. Sanger and most 

 of the work was done under his direction, until he was prevented by illness 

 from continuing its supervision, when Professor T. W. Richards took charge 

 of it. The material was prepared for publication with the aid of Professor 

 C. L. Jackson after the lamented death of Professor Sanger, who is therefore 

 in no way responsible for its arrangement or presentation. I am very grateful 

 to Professors Richards and Jackson for their respective aid. E. R. R. 



The work described in this paper formed part of a thesis presented to the 

 Faculty of Arts and Sciences of Harvard University for the Degree of Doctor 

 of Philosophy by Emile Raymond Riegel. 



2 If water is present, a certain amount of chlosulphonic acid is formed, very 

 nearlv proportional to the quantity of water. See Sanger and Riegel, These 

 Proceedings 47, 673 (1912); Zeit. anorg. Chem., p. 79 (1912). 



3 Ber.. 1872, 5, 332. 



4 Dammer, Inorg. Chem. 1, 667. 



