Configuration of Aquotri- ami iliaunnini' Cobalt Complexes. 25 



[Co (H2O) (NHs)^] CI3 = [Co (HO) (NH,\] Cl, + HCl 



According to Urbain' s^'^ opinion, such reactions are not so 

 simple and it is more probable that they are in equilibrium under 

 definite surrounding conditions. No doubt the equilibrium can 

 be affected by the atoms, atom groups and molecules coordinated 

 around the central metallic atom, as well as by the atoms and 

 atom groups outside the complex nucleus. One of sucli com- 

 plicated examples will be shown below : 



[Co(NH3)5X]X2 + H.,0 ^ [CoH20(NH3)JX3 X [Co(OH)(NH3)5]X, + HX 



[Co(NH3)5(OH)]X, + H.,0 :t [Co(NH3),H,0]^^ 



The above assumption is exactly in keeping with my experi- 

 ments. In the case of the diammine and triammine cobalt 

 complex salts the substitutions are apt to take place wlien tlie 

 dilution is large. It seems that the absorption spectra of 

 [Co(NH3)3(H20),Cl]SO, and [Co (NHpJ., (KPX CI] SO, confirm the 

 reverse of the conclusion that the chlorine atom is not separated 

 from the complex nucleus, but it can be soon restored, re-establish- 

 ing the equilibrium. 



Thus, I have given a clear explanation, by means of al;)sorp- 

 tion spectra and conductivity measurements, of the substitution 

 phenomena in aqueous solutions of the cobaltammines, in which 

 the strong acid radicals coordinate. 



In conclusion, I will describe the complex salt wJiich is 

 obtained by tlie action of silver nitrate upon [Co CI CsO^^NHgV]. 



(H,0), 

 Werner^'^ gave to it the molecular formula of Co CgO, NO,, 



^ (NH3), J 



but I also prepared this salt in the same waj^ and after analysis 

 found it must be amended to [Co NO3 C-A (NH3)3]-H20. The follow- 

 ing data will confirm this : 



0,1023gr. and 0, 1090 gr. of the salt gave 0,0620 gr. and 0,0642 

 gr. C'o SO4. After heating for one hour and a half at the tempera- 

 ture of 100°-115°C, it loses the weight of one molecule of water. 



(1) Introduction à la Chimie des Complexes (P, 178) 



(2) Zeit, anorg. Chem., 15, 162, 1897. 



