Blomstrand-Jprgensen model

Addition of silver nitrate to this pentamine led to precipitation of only two equivalents of silver chloride. This observation was rationalized within the framework of the traditional Blomstrand-Jprgensen model by assuming that elimination of one ammonia molecule from the hexamine left one CF ion directly linked to the metal cation and therefore unreactive (Fig. 6). Electric conductivity measurements of aqueous solutions of the pentamine would later show that the solutions contained... 

Fig. 6 Left The structures of complex salts according to the Blomstrand-Jprgensen model. Right The structures suggested by Werner...

Years of contentious discussion followed Werner s publication of his new model in 1893. Werner went on to prepare two nitrite complexes, the tetraamine [Co(N02)2(NH3)4](N02) and the trisamine [Co(N02)3(NH3)3], and measure their electrical conductivities in aqueous solution. Both the Blomstrand-Jprgensen and the Werner model suggest that two of the three nitrite ions in [Co(N02)2(NH3)4] (NO2) should be bonded directly to the metal atom. This means that an aqueous solution should contain just two ions, a [Co(N02)2(NH3)4] cation and a nitrite anion, and this was indeed found to be the case. 

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