Polymeric complexes ([Au{S2CN(CH2)4O}2]2[ZnCl4] · 2H2O) n and ([Au{S2CN(CH2)4O}2]Cl · 2H2O) n as individual gold(III)-binding forms in the [Zn2{S2CN(CH2)4O}4] n -[AuCl4]−/2M HCl chemisorption system: Supramolecular self-organization and thermal behavior