Selenium dithiocarbamate complexes

There have been conflicting interpretations of the EPR spectra of these selenium-containing complexes. For example, various X-band EPR spectra of Fe(III) diselenocarbamates recorded in chloroform solutions at 12 K tended to be broad and poorly resolved, except for a series of three resonances centred around g=2 [62]. They also appeared to be very similar to the spectra recorded for Mn(III)-doped Co(III) tris(dithiocarbamate) compounds [76] or Cu(II) di(diselenocarbamate) systems [77]. In another study of EPR spectra recorded for powdered Fe(III) thioselenocarbamates and diselenocarbamates at room temperature [69] broad, poorly resolved lines at g 4... 

Atsuya I, Itoh K, Ariu K. 1991. Preconcentration by coprecipitation of lead and selenium with nickel-pyrrolidine dithiocarbamate complex and their simultaneous determination by internal standard atomic absorption spectrometry with the solid sampling technique. Pure Appl Chem 63(9) 1221-1226. 

There are no oxygen dithiocarbamate complexes and, although dithiocarba-mates do bond to sulfur, forming thiurams, these are considered as a separate class of compound and fall outside the scope of this chapter. While the dithiocarbamate complexes of selenium remain relatively few in number, those of tellurium have been studied more extensively, with particular attention being paid to the different possible coordination numbers and geometries displayed by the metal atom. 

Reaction of selenium(IV) dioxide with sodium dithiocarbamate salts yields the homoleptic selenium(II) bis(dithiocarbamate) complexes [Se(S2CNR2)2] (293-297). No selenium(IV) dithiocarbamate complexes appear to have been authenticated and dithiocarbamate ligands have been successfully employed as a method of separating selenites from selenates (298), as well as from other metal... 

Simultaneous speciation of inorganic selenium and tellurium in water samples by ICP-MS was performed after selective solid phase extraction (SPE), as discussed by Yu et al 9 Under acidic conditions Se (IV) and (TV) complexes with ammonium pyrrolidine dithiocarbamate were formed. The detection limits for Se and species in water samples were found to be 7ngl 1 and 3 ng 1 1, respectively. 

However, while results from various studies involving iron(III) complexes also support the hypothesis that monothiocarbamates are weaker field ligands than dithiocarbamates, the differentiation between dithiocarbamates and their selenium-containing analogues is less clear (33-35). 

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