A text-book of inorganic chemistry / by A.F. Holleman...rendered into English by Hermon C. Cooper with the co-operation of the author.

  • Holleman, A. F. (Arnold Frederick), 1859-1953.
Date:
1902
Catalogue details

Licence: In copyright

Credit: A text-book of inorganic chemistry / by A.F. Holleman...rendered into English by Hermon C. Cooper with the co-operation of the author. Source: Wellcome Collection.

    464/500 (page 446)
    44G of ammonia by negative groups or elements. The neutral complex C°^ 3 is then converted into a negative ion. Thus we have the senes- Co(NII3)a X3 Co (NII3)5 Luteo salt r0o(Nn.). |_O0( NO,), Hexamine cobalt nitrite NO, Xantho salt X,; Co(NH.), LO(NO,j4 (NII3)4 (N02)» Croceo salt / K X; Tetramiue potassium coballic nitrite As the last one of the series we must regard the potassium cobaltic nitrite described in § 310 : [Co(NO*)a]'K3. The number of compounds containing such a complex MXa as trivalent ion is very large. It is here sufficient to note that potassium ferricyanide K3[FeCys] and the analogous cyanides of cobalt, iridium, rhodium, etc., belong in this category. In the other classes where the metal is quadrivalent (Pt) or bivalent (Ni) the relations correspond throughout. Whenever a molecule of NH3 goes out, one of the negative atoms or groups enters the complex cation, which thus gradually becomes less positive and finally acts as an anion. There are also numerous compounds of this class whose composition for- merly appeared to be absolutely irregular. From [Pt(NH3)«]X4 we obtain the indifferent platinamines pt (Nll3), x4 while a substitution of the last two NII3 groups by halogen leads to the bivalent anion (PtXa), which must be assumed in potassium platinic chloride and elsewhere (§ 310). In connection with these we also have analogous compounds of tin, as (NH4)2(SnCla), pink salt, and further hydrofluosilicic acid H2(SiFc) and its salts, etc., etc. By an analogous substitution of ammonia in [M(NII3)«]X2 we arrive again in the third subdivision (see above) at a number of known com- pounds. Complete substitution of NH3 by negative groups or atoms must lead here to a quadrivalent anion and experiments show this to be true; an illustration is found in potassium ferrocvanide and its analogues. Numerous metal-ammonia compounds and “ double salts ” thus come to arrange themselves in a simple classification, based on the hypothesis that the metals in question have the property of forming complex ions with six molecules (NH,, HaO, etc.) or atoms. This hypothesis leads to various other conclusions, the discussion of which, however, will not be undertaken here. G .butf - . .