Cobalt complex compounds cations, ammine

In the complex [Co(NH3)6]Cl3, the cation is [Co(NH3)6]3+, and it is named first. The coordinated ammonia molecules are named as ammine, with the number of them being indicated by the prefix hexa. Therefore, the name for the compound is hexaamminecobalt(III) chloride. There are no spaces in the name of the cation. [Co(NH3)5C1]C12 has five NH3 molecules and one CN coordinated to Co3+. Following the rules just listed leads to the name pentaamminechlorocobalt(III) chloride. Potassium hexacyanoferrate(III) is K3[Fe(CN)6j. Reinecke s salt, NH4[Cr(NCS)4(NH3)2], would be named as ammonium diamminetetrathiocyanatochro mate (III). In Magnus s green salt, [Pt(NH3)4][PtCl4], both cation and anion are complexes. The name of the complex is tetraammineplatinum(II) tetrachloroplatinate(II). The compound [Co(en)3](N03)3 is named as tris(ethylenediamine)cobalt(III) nitrate. 

The ligands include one Cl- ion and five NH3 molecules. The chloride ion is designated as chloro, and each ammonia molecule is designated ammine. The prefix penta- indicates that there are five NH3 ligands present. The name of the complex cation is therefore pentaamminechloro-cobalt(III). Note that the ligands are named alphabetically, disregarding the prefix. Since the counter ions are chloride ions, the compound is named as a chloride salt ... 

We start by naming the complex cation. The ligands are named alphabetically with ammine first and then chloro. There are four ammonias and two chlorides, so the prefixes tetra- and di- are used. The cobalt oxidation state is determined by tracing the charges back as follows The net charge on the complex cation must be 1 + to balance the one 1 — chloride anion. Since there are two 1 — chlorides in the coordination sphere, the cobalt must be 3+ in order for the net charge on the cation to come out as 1+. With all this in mind, the full name of the compound is... 

It is also possible to have more complicated inorganic ions to balance the charge of a sulfatometallate. The neodymium compounds with hydrazinium and hydroxylammonium counterions have been synthesized and characterized by thermoanalytical methods (Bukovec, 1985 Bukovec and Bukovec, 1985). Sakamoto (1984) has reported the preparation and properties of a series of La compounds with cobalt ammine complex cations, e.g., [Co(NH3)g][La(S04)3] H2O. 

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