Lanthanide complexes dithiocarbamates

As we shall show later the results confirm this approach). Therefore, for a specific nmr nucleus in an iron(III) dithiocarbamate the parameters a, 6 and y in equation (4) would not change significantly for the N-CH2 protons in tris(N,N-diethyldithiocarbamato) iron(III) from solvent to solvent and we shall treat these parameters as constant for a specific proton in an iron(III) dithiocarbamate. This is analogous to the recent method used to analyse the nmr shifts in a series of lanthanide complexes(15). Hence the temperature dependent nmr results for the N-CH2 protons in tris(N,N-diethyldithiocarbamato) iron(IIl) in all solvents may be analysed as a single set of data using equation (4) where the energy separation of the Aj and T2 states, E, and the distortion parameter 6 are allowed to vary from solvent to solvent. The best fit yields... 

To our knowledge dithio complexes with either scandium or yttrium still have not been prepared. Since 1968 two reports have appeared that deal with the lanthanide dithiocarbamate complexes. 

The thiocyanate complexes Ln(phen)3(NCS)3 (Ln = Pr, Nd) and Pr(bipy)3(NCS)3 are all nine-coordinate monomers. A considerable number of bipy (and phen) adducts of lanthanide dithiocarbamates [Ln(S2CNR2)3(L)]... 

Compounds such as fluorinated /3-ketones have been used mainly for the extraction of lanthanides and actinides, as more effective ligands than fluorinated dithiocarbamates for complexation with f-block elements. In addition to complex formation, some analytes (e.g. tervalent lanthanides) require the presence of a small amount of water containing 5% methanol — which act as matrix and solvent modifier, respectively — for quantitative extraction [89]. Also, a synergistic effect on the SFE of actinides [90,91] and of lanthanides from cellulose [92] and acid solutions [93] was observed when using a mixture of tributylphosphate (TBT) and a fluorinated /3-diketone. The effect was ascribed to competition of TBT with the matrix for the unoccupied coordination sites of lanthanides and actinides. Thus, the formation of adducts with the complexes of these analytes with fluorinated /3-ketones in supercritical COj facilitates their removal from the solid matrix. 

Sulfur donor ligands. Complexes of actinides or lanthanides ions with sulfur donor ligands such as dithiocarbamate (S2CNR2)... 

It is not clear when dithiocarbamates were first prepared, but certainly they have been known for at least 150 years, since as early as 1850 Debus reported the synthesis of dithiocarbamic acids (1). The first synthesis of a transition metal dithiocarbamate complex is also unclear, however, in a seminal paper in 1907, Delepine (2) reported on the synthesis of a range of aliphatic dithiocarbamates and also the salts of di-iTo-butyldithiocarbamate with transition metals including chromium, molybdenum, iron, manganese, cobalt, nickel, copper, zinc, platinum, cadmium, mercury, silver, and gold. He also noted that while dithiocarbamate salts of the alkali and alkali earth elements were water soluble, those of the transition metals and also the p-block metals and lanthanides were precipitated from water, to give salts soluble in ether and chloroform, and even in some cases, in benzene and carbon disulfide. 

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