Toluene dithiol complex

Dr. Herber One of the organic compounds we synthesized some years ago was a toluene dithiol complex that apparently forms a polymer, is quite stable, and produces a suitable Mossbauer spectrum at room temperature. 

The reaction of toluene-3,4-dithiol(3,4-dimercaptotoluene) and antimony trichloride ia acetone yields a yeUow soHd Sb2(tdt)2, where tdt is the toluene-3,4-dithiolate anionic ligand (51). With the disodium salt of maleonitnledithiol ((Z)-dimercapto-2-butenedinitrile), antimony trichloride gives the complex ion [Sb(mnt)2] , where mat is the maleonitnledithiolate anionic ligand. This complex has been isolated as a yeUow, crystalline, tetraethyl ammonium salt. The stmctures of these antimony dithiolate complexes have apparendy not been unambiguously determiaed. 

Modified spectrophotometric procedures are described for the quantitative determination of cobalt and molybdenum as the 2-nitrosonaphth-l-olate and toluene-3,4-dithiolate complexes in carbon tetrachloride. The extraction, chelation and phase separation steps permitted rapid sample handling, controlled interferences more effectively and provided accurate assays. The molar absorptivities for cobalt and molybdenum were 5.1 x 104 and 2.5 xl04mol/lcm, respectively, and the detection limits for both elements were 4 ng/g. 

Organotin 1,2-dithiolate complexes were featured in many studies the ligands used include aliphatic derivatives, e.g. ethane-1,2-dithiolate -SCH2CH2S-(EDT), -SCH2CHMeS-, alkenyl derivatives, e.g. -SCH=CHS-, maleonitriledithiolate (MNT), aryl derivatives, 1,2--SC6H4S (BDT) and toluene-3,4-dithiolate (TDT), as well as heterocyclic derivatives, l,3-dithiane-2-one-4,5-dithiolate (DMIO) and l,3-dithiane-2-thione-4,5-dithiolate (DMIT)191. 

Reactions of the toluene-dithiolate-bridged complex, Fe2(GO)6(/x-SG6H4MeS), with a range of phosphines and phosphites have been studied.With phosphites, both mono- and disubstituted products are formed at 70 °G, while with Ph2PH disubstitution occurs at room temperature however, for dppm only a monosubstituted product is seen even after prolonged heating at 80 °G. 

Toluene-3,4-dithiol, usually called dithioP, yields a slightly soluble, dark-green complex, (CH3.C6H3.S2)3Mo(VI), with molybdenum(VI) in a mineral acid medium, which can be extracted by organic solvents. The resulting green solution is used for the colorimetric determination of molybdenum. 

The Au-S bond length at 2.30 A is very similar to that in the gold(III) analogue (2.299-2.312 A) and other gold(III) complexes like Au(toluene-3,4-dithiolate) (2.31 A) suggesting substantial covalent character in the bond. 

Microgram amounts of pertechnetate can be determined by measuring the extinction of its colored complex with toluene-3,4-dithiol in 2.5 N hydrochloric acid after extraction into carbon tetrachloride . One hour must be allowed for the development of the color. The molar extinction coefficient at 450 nm is 15,000. Beer s law is followed over the range of 1.5 to 16.5 fig Tc per ml. The overall error does not exceed a standard deviation of 5%. Because many cations interfere, an initial separation of technetiiun is necessary. 

The complex formation of technetium, rhenium, and molybdenum with toluene-3,4-dithiol and its analytical application have been studied by Koyama et al. . 

As well as the above 2,3-dimercaptoalkanes a few other vicinal dithiols have also been sythesized. The interaction of methylmercury(II) with chelating agents such as BAL involves linear two-coordinate complexes and in only a few cases has chelation involved a bidentate ligand. In a search for evidence of thiol-containing bidentate chelation, Alcock et al.311 synthesized three sterically constrained dithiols - cyclohexane-1,2-dithiol, toluene-3,4-dithiol and bicyclo[2.2. l]heptane-2,3-dithiol - and demonstrated by spectroscopy and crystallography their formation of chelates with methylmercury(II) of the form (40). 

The dianion of toluene-3,4-dithiol (TDT2-) forms unique complexes [Mu(TDT)2 ] with transition metals that are readily oxidized via a ligand-centered process to Mm(TDT). 14 Figure 10.4 illustrates the cyclic voltammetry for the latter complexes of Cu, Ni, Co, and Fe. Not only does each Afm(TDT)2 complex undergo a reversible one-electron reduction, but the Ni(III), Co(III), and Fe(III) complexes also exhibit a somewhat reversible oxidation to the M(IV) valence state. For example... 

Arene-1,2-dithiols are completely stable and are valuable precursors to dithiolene complexes. Benzenedithiol is the most common member of this class of ligands, but related derivatives include toluene-3,4-dithiol (10), 3,4,5,6-tetrachlorobenzenedithiol (11), 3,4,5,6-tetramethylbenzenedithiol (12), 2,3-naphthalenedithiol (13), and quinoxalinedithiol (14) (Fig. 2). 

The room temperature solution electronic absorption spectrum of (L-N3) MoO(bdt) is presented in Fig. 6. This spectrum is representative of virtually all (L-A i)MoO(dithiolene) complexes (19, 23) with the possible exception of (L-/Vi)MoO(qdt) (20, 22), where qdt = quinoxaline-2,3-dithiolate, see below. However, the transitions observed for (L-A MoChtdt) (19), where tdt = toluene-1,2-dithiolate, are generally shifted to slightly lower energies relative... 

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