Gold complexes with dithiocarbamates

Dimeric gold(I) complexes with dithiocarbamate ligands possess a strong propensity to aggregate and form chains with short intermolecular Au Au contacts, they have been known for a long time but new structural characterizations have come into light. Thus compounds of the type... 

Synthesis and structural characterization of luminescent trinuclear gold(I) complexes with dithiocarbamates, M. Bardaji, A. Laguna, P. G. Jones, A. K. Fischer, Inorg. Chem. 2000, 39, 3560. 

Arias, J., Baradaji, M. and Espinet, P. (2008) Mononuclear, dinuclear, and hexanuclear gold(l) complexes with (aza-15-crown-5) Dithiocarbamate. Inorganic Chemistry, 47, 1597-1606. 

Homoleptic gold(III) derivatives with dithiolate, ligands of the type [Au(S-S)2] are well known and are usually prepared from [AuC14] with the dithiol some examples are with 1,2-benzene dithiolate, maleonitriledithiolate, dmit, and so on, [164, 336]. Similar complexes have been reported for bidentate sulfur ligands such as dithiocarbamates, dithiophosphates, and so on, [41]. Other derivatives as the trinuclear species [Au(C6F5)(S2C6H4)]3 [337] or the complex with one nido and one closo-carborane dithiolate are known [338]. Figure 1.72 collects some of these complexes. 

Crystal structures of [Au2(E E)2]2+ (E = chalcogen donor atom) have been described with dithiocarbamate [265-271], xantate [272], MNT [273-275], dithiopho-sphonate [276], dithiophosphinate [277], dithiophosphate [278, 279] or trithiocarbo-nate [280] ligands. The gold-gold interaction in complexes shown in Figure 2.48 has been analyzed by ab initio Hartree-Fock calculations [281]. 

Gold(I) forms dinuclear complexes with A,A-dialkyl dithiocarbamates, -diisopropyl dithiophosphate, aud... 

There are also two smaller reduction waves at more positive potentials. Similar cyclic voltammograms displaying three cathodic reduction peaks and two anodic oxidation peaks were obtained for the other complexes in this series. The main reduction peak for each gold complex is similar to the peak obtained from the polarographic study (see Table 4, values labeled c). The nonintegral n values and the complex CVs were attributed to dissociation of the dithiocarbamate ligand upon reduction of Aum(dtc)3 to [Au ldtchl2, followed by reaction of free dtc with the mercury electrode (see Scheme 1). 

Amberlite XAD polymeric adsorbents have been used for the preconcentration of trace elements in batch procedures followed by AAS or photometric measurements. The adsorbent series also shows promise in on-line preconcentration systems. Plantz et al.[24] used XAD-4 (polystyrene divinyl benzene based) to collect the bis(carboxymethyl)-dithiocarbamate complexes of Co, Cu, Cr, Ni, Mo, Pt, and V by reversed phase adsorption, and eluted the complexes with 0.1 M NH4OH, with the subsequent determination made by ICP-MS. Xu et al.[25] used the polyacrylate adsorbent XAD-8 to collect the chloro-complex of gold, which was subsequently eluted by ethanol and determined by flame AAS. 

Figure 244. Examples of dimeric gold(I) complexes with a single dithiocarbamate bridge.

Bardaji, M Laguna, A., Laguna, M. and Merchan, F. (1994) Methyl dithiocarbamate gold(l) and gold(lll) complexes. Synthesis and reactivity with amines. Inorganica Chimica Acta, 215 (1-2), 215-218. 

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