Notes on scientific research. 97 



' Chemical Notes. 



Unsaturated compounds like geraniolene, q/c/ogeraniolene, menthene, and oils like 

 oil of turpentine and lemon oil, can serve as catalysts in the oxidation of other bodies. 

 J. Bougault and P. Robin 1 ) obtained from a solution of dichlorodiethyl sulphide (mustard 

 gas) in such an unsaturated compound, in the presence of oxygen, quantitatively dichloro- 

 ethyl sulphoxide. This catalytic oxidation is possible only with substances which will 

 dissolve in the catalyst and the oxidation product of which is insoluble in it. Thus 

 thiodiglycol, which is insoluble in hydrocarbons and in oils, could not be oxidised to 

 thiodiglycolsulphoxide, but was slowly oxidised when dissolved in citral. The reactions 

 indicate that unsaturated compounds play an important part also in the physiology of 

 the living organism. 



The investigation of the mercury derivatives of ethylene had led W. Manchot 2 ) to 

 the conclusion that these bodies are not to be regarded as mercurated ethanoles 



/OH 

 CH 2 OH— CH 2 HgX, but as additive ethylene compounds of the constitution C 2 H 4 Hg<^ . 



In order further to investigate substituted ethylenes (benzene derivatives with an 



unsaturated side chain) in this respect Manchot, F. Bossenecker and F. Mahrlein 2 ) 



mercurated safrOle and eugenol methyl ether each with one molecule of mercuric 



acetate in acid solution. The addition of sodium chloride produced well-defined additive 



/0\ /OH 



compounds of the constitution H 2 C^ ^C 6 H 3 -CH 2 CH=CH 2 -Hg<_ (monoclinic prisms, 



m. p. 136 to 137°) and C 6 H 3 (OCH 3 ) 2 — CH 2 — CH=CH 2 Hg^ (white needles, m. p. 1 12.5°). 



/OH 



In a similar way. the authors prepared the corresponding bromide Ci Hi O 2 Hg^ (white 



x Br 

 /OH 

 needles, m. p. 144 to 145°) and iodide Ci Hi O 2 Hg< (shining needles, m. p. 152.5°) 



of safrole. All these safrole and eugenol methylether derivatives held mercury in 

 strong union. 



Safrole heated with 3 molecules of mercuric acetate in aqueous solution took up 

 another atom of mercury and formed a product of the composition Ci Hi O 2 -HgO-HgCl 2 , 

 which was, however, insoluble and difficult to obtain in the pure condition. 



Contrary to its methylether, eugenol did, in mercuration with 1 molecule of mercuric 

 acetate, not give a well-defined product; with 3 molecules of mercury salt it gave, 

 on the other hand, like safrole a derivative, difficult to purify, richer in mercury. 

 Styrenes, having the methylated side chain in the end position, like isosafrole, 

 H 2 C=0 2 : C 6 H 3 -CH = CH • CH 3 , and isoeugenol (HO)(CH 3 0(C 6 H 3 — CH = CH ■ CH 3 , behaved 

 differently in so far as they reduced the mercury salt when treated in the same way as 

 safrole. Styrene itself (phenylethylene) yielded compounds, rich in mercury, but easily 

 decomposible, the mercury of which was already split off by treatment with caustic soda. 



In a further paper 4 ) Manchot and Bossenecker deal with the mercuration of phenol- 

 ethers. Even with an excess of mercury salt cresolmethylether, anisole and phenetole 

 took up only one atom of mercury. Since the compositions of the products thus 

 obtained distinctly deviate from those calculated for nuclear mercury compounds, the 

 substances are regarded as additive products. As, moreover, the mercury component 



*) Compt. rend. 171 (1920), 353. — 2 ) Liebig's Annalen 420 (1920), 170. — 3 ) Liebig's Annalen 421 (1920), 

 316. — *) Liebig's Annalen 421 (1920), 331. 



