4 Art. 10.— K. Î^Iatsimo : 



as described below. In this investigation I was able to establish 

 the structural fornuilae of all the cobalt complex salts, mentioned 

 above, by the study of their absorption spectra as well as their 

 conductivities and I have explained clearly the bi'ha\i(air in 

 aqueous solution of such colialtanimines as have strong acid 

 radicals in their complex nucleus. 



Theoretical Part. 



The configuration of the trinitrotriammine col>altic salt, 

 [Co (NOa^, (NHg)^], a starting substance of many triammine cobalt 

 complex gaits, has already been determined by Y. Shibata,^'* 

 as follows : 



NH, 



N0„ 



■ NO. 



NH, ' 



NH, 



NO, 



If this salt is treated Avith cone hydrochloric acid 

 [Co CbH,,0(NH,)J(l (9), the so-called dichro-salt, which is of a 

 green colour is obtained. (hi treating the dich.ro-salt with a 

 cold mixture of 2 Vol. of str<jng sulphuric acid and I Vol. of cone, 

 hydrochloric acid, the greenish grey [Co Clg HgO (NH^),] SO,H is 

 produced. On dissolving this last named substance in water and 

 then adding an equal volume of alcohol, [Co CI (H20)2 (.NH,,)s] SO,, 

 an indigo blue coloured powder, is precipitated, ^^'hen the indigo- 

 bluish [CoCl(H20>^(KH,)s] SO, is ground with strong hydrochloric 

 acid, it changes into the grey [Co Cb H2O (NHA] CI ^'"'^ which is the 

 isomer of the green [Co Cb H2O (NH.,)s] CI. If tlie acpieous sohition 

 of [Co C12 H2O (NH,}3] SO^H is warmed on the water l)ath fora htlle 

 while, tiie colour of the solution is changed into dark violet and, 

 when it is evaporated in vacuo, a violet crystalline pi-ecii>itate, 



(1) Jom-n. College, Scienco, Imp. Univ. Tokyo, V. 1. XX'XVH, Art. 2, 1915. 



(2) Wernor : Zeit, anorg. Chem., 15, 143, 1897. 



