Popis: |
A new sulfur containing oxocarbon derivative, the dipotassium salt of 1,2-dimercapto-3,4,5-cyclopentenetrione (potassium dithiocroconate) has been synthesized by reaction of dimethyl croconate with alcoholic potassium hydrogen sulfide. Solutions containing the dianion of this salt react to form intensely colored complexes of varying hues with several transition metal ions. Spectral and esr measurements on Ni(II) and Cu(II) indicate complexes with 2:1 ligand/metal ratio having dithiolene properties are formed in solution. Visible-uv and infrared studies suggest dithiocroconate dianion has less resonance stabilization than croconate dianion. |