Dithio anions

Only salts of the dithio anions with large cations can be prepared177,178). Addition of Co+2,Pb+2, and Ce+3 to solutions of ammonium dithiomolybdate yielded solids that showed the absence of Mo-S bonding at 480—450 cm-1 178). Dithio salts so far prepared177) are given in Table 6. The salt Cs2W02Se2 has been also isolated as a stable solid by the addition of cesium chloride to a water solution of(NH4)2W02S2177). 

Fusion of KNCS and polymeric NbS2Cl2 followed by dissolution of the melt in water and addition of cations led to isolation of salts of the centrosymmetric dithio anion [(SCN)4NbIV]2(//2-r/2 r 2-S2)2 4 (223).518 519 This species features eight-coordinate Nb13" and a formal Nb—Nb single bond. One-electron oxidation provided a species whose EPR properties were consistent with an unpaired electron interacting with two equivalent Nb atoms in a Nbv,iv2 core. 

Petrov, M.L. Turbanova, E.C. KuzminaNYa, Stepanova N.P. Petrov, A. A. Interaction of dithio-anions with hexafluorobutyne. Zhurn. Org. Khimi. 1984, 20, 2627-2628. 

Other 11(IV) compounds with dithio anion ligands (Ti-6 and 11-7) were employed for the polymerizations of MMA and styrene via the reverse ATRP using a pseudohalogen transfer... 

The salts of alkyl xanthates, A/,A/ -di-substituted dithio-carbamates and dialkyidithiophosphates [26] are effective peroxide decomposers. Since no active hydrogen is present in these compounds, an electron-transfer mechanism was suggested. The peroxide radical is capable of abstracting an electron from the electron-rich sulfur atom and is converted into a peroxy anion as illustrated below for zinc dialkyl dithiocarbamate [27] ... 

In contrast, a-ketosulphoxides react with isocyanates to give the products of a monoaddition only550 (equation 290). Reaction of dimsyl anion with trithiocarbonates 481 followed by alkylation results in the formation of (methylsulphinyl)ketene dithio-acetals 482551 (equation 291). 

In complexes of the dithiolene type ligands the oxidation number of the metal cannot unambiguously be determined, due to the uncertainty of the charge on the ligand. R2C2S2 can be considered either as a dinegative dithiolato anion or as a neutral dithio-keto ligand. 

It can also be seen from Fig. 5.33 that with the increase of (1-carbonic sodium-2-acetaic sodium) propanic sodium dithio carbonic sodium (TX4), the negative zeta potential of marmatite, pyrrhotite and arsenopyrite increase. The negative zeta potential reach the maximum and remained stable at the concentration of TX2 60 mg/L. The zeta potential in the presence of TX2 increases in the order of arsenopyrite > pyrrhotite > marmatite, which is corresponding to the adsorption order of TX2 on the three minerals. Figure 3.33 also suggests that the adsorption of anionic depressant TX2 on negatively charged marmatite, arsenopyrite and pyrrhotite may be due to the chemical interaction. 

Many newer methods for generating cyclohexane derivatives from carbohydrates still depend on the intramolecular attack of nucleophilic carbon species at electrophilic centers, and the range of options is now extensive. Thus, the nucleophiles may be carb-anions stabilized by carbonyl, phosphonate, nitro, or dithio groups, and they may bond to carbonyl carbon atoms, or to those that carry appropriate leaving groups or are contained in epoxide rings, or as jj-centers of a,p-unsaturated carbonyl systems. Otherwise, the nucleophilic activity at the 7-centers of allylsilanes or a-positions of vinyl silanes may be used to react with electrophilic carbon atoms. 

A detailed study of the electronic spectra of the d8 complexes [M(dto)2]2 (M = Ni, Pd, Pt) and [Au(dto)2] has been reported. The spectra are virtually identical in a variety of solvents, indicating that axial perturbations due to the solvent are minimal. Dithiooxalate has a high position among square-planar NiS4 chromophores in the spectrochemical series for dithio ligands the series is maleonitriledithiolate < (CF3)2C2S2 < diethyl dithiophosphate < ethyl xanthate < diethyl dithio-carbamate < 2,3-dimercaptopropanol anion < dithiomalonate dithiooxalate.145... 

Ellman s reagent, 5,5 -dithio-bis-(2-nitrobenzoic acid), or DTNB, is a compound useful for the quantitative determination of sulfhydryls in solution (Ellman, 1958,1959). The disulfide of Ellman s reagent readily undergoes disulfide exchange with a free sulfhydryl to form a mixed disulfide and release of one molecule of the chromogenic substance 5-sulfido-2-nitrobenzoate, also called 5-thio-2-nitrobenzoic acid (TNB). The intense yellow color produced by the TNB anion can be measured by its absor-... 

---