Section III., 1915 [85] Trans. R.S.C. 



Bromocamphorsulphonic Acid and Oxonium Compounds. 

 By D. McIntosh, F. R.S.C. 



(Read May Meeting, 1915.) 



It has been shown that the halogen hydrides unite with organic 

 bodies containing oxygen, such as ethyl ether, to give compounds of 

 the typeC4Hio O. HX. While the constitutions of the complexes are 

 not fixed with certainty, it seems probable that the oxygen functions 

 as a tetravalent element, and that the compound has the formula 



H 

 C4HioO< . Methyl ethyl ether gives the analogous compound 

 /\ 



CH3 H 



„ TT -^ O "^ • Here the oxygen is asymmetric, and it should be 



L2H5 X 



possible to split the compound into ils right and left optically active 

 isomers. Unfortunately the well known methods for accomplishing 

 such a separation are not applicable, as the compound melts at a low 

 temperature and is decomposed by water. I have attempted to 

 separate the isomers by introducing a single crystal into a supercooled 

 solution of the ether at low temperature. An examination of the 

 separated crystals in solution in the ether at low temperature in a 

 polariscope did not show rotation. 



Oxonium compounds were made by Collie and Tickle from di- 

 methyl pyrone and the halogen acids and have been examined by many 

 chemists. These compounds are more stable than those previously 

 mentioned and are not completely decomposed by water. The for- 

 ce 



mula given to them is I j , and complexes may be made 



X-O-H 



with two or four molecules of acid. I regard these compounds as 

 molecular aggregations i.e., salts with acid of crystallization, although 

 Kendall and others deduce evidence for atomic combination. 



In the hopes of obtaining more stable compounds with an asym- 

 metric oxygen atom, I have attempted to produce oxonium compounds 

 with a solid acid; and to facilitate the separation of the isomers, 

 an optically active acid was used. 



The substance most suitable for this purpose seems to be bromo- 

 camphorsulphonic acid ; for Walden has shown it to be a strong acid 

 in aqueous or alcoholic solutions. 



Sec. Ill, 1915—6 



