Ethylenediamine dihydrochloride complexes

Nitrite alternatively may be determined via the diazotization with sulfanilic acid followed by the coupling with N-(l-naphthyl)ethylenediamine dihydrochloride, detection limits being 10 moll . Possible enhancement of the sensitivity could be achieved by adsorptive cathodic stripping of this complex. 

Among the more widely studied 2,3-C-disubstituted ligands related to ethylenediamine are sbn and stien (Table 3). These ligands can exist in meso and racemo forms and the properties e.g. solubility) of transition metal complexes (especially Co" ) with the two forms of this type of ligand are often sufficiently different as to allow amine isomer separation to be achieved without separation of the amine mixture. Meso and racemic 5bn are prepared together by the reduction of dimethyl-glyoxime and can be separated by fractional crystallization of the dihydrochloride salts. There are, however, stereospecific synthetic routes available for the meso and racemo forms of stien (Table 6). 

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