3d–4d–4f Heterotrimetallic 3D Chiral Frameworks Based on Octahedral {Ni6Ag8S12Cl} or Trigonal Dipyramidal {Co2Ag3S6} Clusters: Synthesis, Crystal Structures, and Characterization

The self-assembly reactions of AgNO3, Ln­(NO3)3 (Ln = La, Eu, and Tb), d-penicillamine (d-pen, H2L), and NiCl2 (or CoCl2) lead to the formation of six new compounds: (H3O)3[LnNi6Ag8L12Cl­(Ac)­(H2O)4]­(H2O)28 (Ln = La (1); Eu (2); and Tb (3)) and (H3O)2[LnCo2Ag3L6]­(H2O)3 (Ln = La (4); Eu (5); and Tb (6)). Single crystal X-ray analyses show that 1, 2, and 3 are isomorphous and have a 3D anionic framework in which the nodes are octahedral {Ni6Ag8S12Cl} clusters, and Ln3+ ions and the connectors are the CCHCOO chains of the d-pen ligands. Moreover, 4, 5, and 6 are also isomorphous, possessing a 3D anionic framework with trigonal dipyramidal {Co2Ag3S6} clusters, Ln3+ as nodes, and the CCHCOO chains of the d-pen ligands as connectors. Topology analysis indicates that the two series of 3d–4d–4f heterotrimetallic frameworks have (3,3)-connected utg and (6,6)-connected pcu networks, respectively. The frameworks are rigid and stable. The porosity is retained after the guest molecules are removed and can take back guest molecules again. Solid-state UV–vis spectroscopy experiments show that compounds 1–6 are all medium gap semiconductors with band gaps of 1.82, 1.80, 1.83, 1.68, 1.71, and 1.72 eV, respectively.