Transition metals dithiocarbamate complexes, Table

Transition metal dithiocarbamate complexes were probably first prepared in 1907 by Delepine (2) and over the following century, dithiocarbamate complexes of all the transition elements have been prepared and in a wide range of different oxidation states (Table 1). Perhaps most impressive is their ability to stabilize molybdenum in seven oxidation states ranging from - -6 to 0 (Fig. 24). 

Perhaps the most characteristic feature of transition metal dithiocarbamate complexes are their IR spectra (16, 17, 511). Three regions can be identified (1) the backbone v(C—N) vibration at between 1450 and 1550 cm (2) the v(C—S) vibrations between 950 and 1050 cm (3) v(M—S) vibrations between 300 and 400 cm Variations in v(C—N) and v(C—S) as a function of the substituents are generally quite consistent within a particular class of complex. Some typical values for nickel bis(dithiocarbamate) complexes are given in Table IX. 

Depending on their carbon skeleton, DTCs can be categorized into three subclasses, that is,dimethyldithio-carbamates (DMDs), ethylenebis(dithiocarbamates) (EBDs), and propylenebis(dithiocarbamates) (PBDs) (Table 26.1).They are mainly produced as complexes of transition metals, preferably manganese and zinc. In the case of EBD and PBD, it is unclear if the complexes are monomer or polymer in type. Therefore, the stmcture formulae presented in Table 26.1 only provide composition. The two metal-free fungicides in use are thiram and dazomet. Dazomet is mainly used as soil sterilant (precursor of methyl isothiocyanate), whereas DTCs are typically applied to aerial parts of plants. 

Currently, the Cambridge Structural Database contains data for 1500 chelating dithiocarbamate ligands. Table III provides structural data for simple diethyldithiocarbamate complexes of aU the transition metals (where available). 

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