Binding forms of gold(III) from solutions by cadmium diethyl dithiocarbamate: Thermal behavior and role of secondary interactions in the supramolecular self-assembly of polymeric complexes ([Au{S2CN(C2H5)2}2][AuCl4]) n and [Au{S2CN(C2H5)2}Cl2] n

Gold(III) ionic complexes [Au{S2CN(C2H5)2}2]Cl and ([Au{S2CN(C2H5)2}2][AuCl4]) n : Synthesis, supramolecular self-assembly, polymorphism, and thermal behavior

“…Let us consider the main causes of the distinctions between these structures. In the described structure [7], the mutual spatial orientation of complex cations and anions is such that the angle between the [AuS 4 ] and [AuCl 4 ] chromophore planes is nearly right (88.61(1)°); for comparison, this angle in our case is 15.09(1)°. For this reason, the Au⋅⋅⋅S secondary bonds proves to be unrealistic, and the polymer chain is built only due to Au⋅⋅⋅Cl and S⋅⋅⋅Cl secondary bonds of 3.7784(3) and 3.4993(4) Å [7], respectively.…”

“…In the described structure [7], the mutual spatial orientation of complex cations and anions is such that the angle between the [AuS 4 ] and [AuCl 4 ] chromophore planes is nearly right (88.61(1)°); for comparison, this angle in our case is 15.09(1)°. For this reason, the Au⋅⋅⋅S secondary bonds proves to be unrealistic, and the polymer chain is built only due to Au⋅⋅⋅Cl and S⋅⋅⋅Cl secondary bonds of 3.7784(3) and 3.4993(4) Å [7], respectively. In turn, the weakening of the cation-anion bond strength is manifested as a considerable increase in the Au(1)⋅⋅⋅Au(2) distance to 5.4832(4) Å [7] (for compar ison, the corresponding interatomic distance in the chain is only 4.5245(5) Å in our case).…”

“…3 The gold atom of each [Au{S 2 CN(C 2 H 5 ) 2 } 2 ] + 3 The concept of secondary bonds was first proposed in the work [23] for the description of interactions between atoms at dis tances comparable with the sums of their van der Waals radii. It should be noted that the complex ([Au{S 2 CN(C 2 H 5 ) 2 } 2 ][AuCl 4 ]) n has already been pre paratively isolated earlier in studies of the reaction between binuclear cadmium diethyldithiocarbamate and AuCl 3 [7]. However, its polymeric structure as taken from the crystals obtained from methanol con siderably differs from the above discussed structure.…”

“…For this reason, the Au⋅⋅⋅S secondary bonds proves to be unrealistic, and the polymer chain is built only due to Au⋅⋅⋅Cl and S⋅⋅⋅Cl secondary bonds of 3.7784(3) and 3.4993(4) Å [7], respectively. In turn, the weakening of the cation-anion bond strength is manifested as a considerable increase in the Au(1)⋅⋅⋅Au(2) distance to 5.4832(4) Å [7] (for compar ison, the corresponding interatomic distance in the chain is only 4.5245(5) Å in our case). Moreover, the [AuCl 4 ]complex anion in the earlier described struc ture [7] is centrosymmetric.…”

“…One new trend in the study of dithiocarbamate complexes is determined by their ability to efficiently binding gold from acidic solutions, so they can be considered as potential chemosorbents for the extraction of gold from dilute technological solutions. Moreover, the use of this technique enables the synthesis of new various polynuclear and heteropolynuclear gold(III) and gold(I) compounds of different structures and compo sitions [6][7][8][9][10][11]. Dithiocarbamate halide complexes of this kind are distinguished by high cytotoxicity and therefore are of considerable interest as a new class of promising antitumor agents [12,13].…”