Three-Dimensional Polymeric Thallium(I) Morpholinedithiocarbamate [Tl2{S2CN(CH2)4O}2]
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and Its Capability of Binding Gold(III) from Solutions: Chemisorption Synthesis of a Heteronuclear Gold(III)–Thallium(III) Complex of the Ionic Type, ([Au{S2CN(CH2)4O}2][TlCl4])
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, the Role of Secondary Interactions Tl…O, Tl…S, and Au…S in the Supramolecular Self-Organization, 13C MAS NMR, and Thermal Behavior