Activator‐Controlled High Temperature In‐Situ Ligand Synthesis for the Formation of Rare Earth Thiolate Amide Coordination Polymers

Abstract 1D rare earth thiolate amide coordination polymers can be obtained by an activator‐controlled in situ ligand synthesis in reactions of molten 2‐mercaptobenzimidazole with lanthanide metals. Catalytic amounts of mercury activate the metals and induce a C–S bond cleavage that in situ forms 2,2′‐bibenzimidazole. The latter then reacts as a linker ligand to give 1∞[Ln2(Mbim)4(Bbim)], Mbim– = C7H5SN2–, Bbim2–, C14N4H82–. In addition cinnabar is formed. Stoichiometric amounts of mercury cause the complete transformation of 2‐mercaptobenzimidazole to 2,2′‐bibenzimidazole. Instead of thiolate coordination polymers the reaction then yields sulfur‐free monomeric bibenzimidazolate complexes (BimH2)+[Ln(BbimH)4]–, (BimH2)+ = C7H6N2+, BbimH– = C14N4H9–. Thus the amount of Hg also controls the dimensionality of the products by defining the reaction path.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)