REACTIONS OF TRIPHENYLPHOSPHINE AND TRIBUTYLPHOSPHINE WITH TETRAETHYLTHIURAM DISULFIDE AND DIETHYLDITHIOCARBAMATE COMPLEXES OF TELLURIUM(II) AND TELLURIUM(IV)

Triphenylphosphine reduces tetrakis(diethyldithiocarbamato)tellurium(I V), TeL(4) [L = diethyldithiocarbamate, (C2H5)(2)NCS2-] to the telluri um(II) complex TeL(2), on which PPh(3) has no effect. The reaction of the tellurium(IV) complex, TeL(2)X(2) (X = I, Br, Cl) with PPh(3) in t he molar ratio of 1:1 results in the formation of TeLX, CS2 and an ami nophosphonium halide, (C2H5)(2)NP(+)Ph(3)X(-). Another mole of PPh(3) reduces TeLX further to elemental tellurium. The reactions of TeL(3)X (X = I, ClO4, PF6) systems with excess PPh(3) lead interestingly to th e formation of TeL(2) and elemental tellurium, with the concomitant fo rmation of CS2, (C2H5)(2)NP(+)Ph(3)X(-) and (C2H5)(2)NC(S)P(+)Ph(3)X(- ). The reactions were performed in dichloromethane solutions and P-31 NMR spectroscopy was widely used for the identification of various pho sphorus containing species.