Dithiocarbamate Complexes of Platinum Group Metals: Structural Aspects and Applications

Abstract

The incorporation of dithiocarbamate ligands in the preparation of metal complexes is largely prompted by the versatility of this molecule. Fascinating coordination chemistry can be obtained from the study of such metal complexes ranging from their preparation, the solid-state properties, solution behavior as well as their applications as bioactive materials and luminescent compounds, to name a few. In this overview, the dithiocarbamate complexes of platinum-group elements form the focus of the discussion. The structural aspects of these complexes will be discussed based upon the intriguing findings obtained from their solid- (crystallographic) and solution-state (NMR) studies. At the end of this review, the applications of platinum-group metal complexes will be discussed.

The Coordination Chemistry of Imidomethanedithiolate Di-anions: A Structural Comparison with Their Dithiocarbamate Analogs

“…The majority of dithiocarbimate complexes for which 1 H NMR data are available are either palladium(II) or platinum(II) complexes. In the 1 H NMR of these complexes, the protons of the α-carbon atom (HCN=CS 2 ), where present, are found in the 3.10-5.60 ppm region, with a mean of 4.56 ppm, which compares to the 1.80-4.55 ppm region recently reported for related platinum group metal dithiocarbamate complexes [7]. As with the dithiocarbamates, the shifts were generally observed to be greater in the palladium(II) com-plexes than in the platinum(II) complexes.…”

“…The free ligand K 2 [S 2 C=N(CN)], for example, has a reported shift of 228 ppm. More typically, the shifts are observed in the region of 140-185 ppm (mean = 171 ppm), which is somewhat lower than that observed in dithiocarbamate complexes [7].…”

“…Structure (III) contributes 40% to the overall electronic structure of dithiocarbamate anions, while resonance forms (I) and (II) each contributes 30%. This electronic distribution readily explains the ability of dithiocarbamate ligands to complexify heavy element centers and to stabilize higher-than-usually observed oxidation states [2][3][4][5][6][7]. While not the focus of the present survey, canonical form (III) also accounts for the ability of the MS 2 C chelate ring with significant metalloaromatic characteristics [15] to function as an acceptor for structure-directing C-H•••π(chelate ring) interactions with significant energy of stabilization in, for example, over a third (37%) of the crystals of homoleptic nickel dithiocarbamate complexes [16][17][18].…”

“…This assertion is no better vindicated than by a search of the Cambridge Structural Database [1], which reveals over 4300 entries containing dithiocarbamate anions, esters, or ligands. This importance is also borne out by the regular appearance of authoritative bibliographic reviews of the coordination chemistry of dithiocarbamates [2][3][4][5][6][7], reviews of specific aspects of their coordination and supramolecular chemistry [8][9][10][11][12][13], and recently of their mono-and di-seleno analogs [14].…”

Selective Anticancer and Antimicrobial Metallodrugs Based on Gold(III) Dithiocarbamate Complexes

“…For this purpose, achieving drugs based on dithiocarbamate complexes with different action mechanisms would have a remarkable benefit against the lack of selectivity [ 25 , 26 , 27 ]. Based on these previous results, even with metals other than gold [ 28 , 29 , 30 , 31 ], in this work we focused on the synthesis of different cyclometalated gold(III) dithiocarbamate complexes with formula [Au(C^N)(DTC)]PF 6 using biphenyl ligands such as 2-( p -tolyl)pyridinate (tpy) and 2-phenylpyridinate (ppy) as cyclometalating ligands for a potential chemotherapy application.…”