Preparation, Crystal Structures, and Properties of a Series of Crystalline Tetra(4-sulfonatophenyl)porphyrinato Histidine 4f-3d Porphyrinic Compounds

A series of novel 4f-3d crystalline porphyrinic compounds, {[Co(TPPS)](2) [Ln(Histidine)(H2O)][Ln(H3O)(3)]}(n)center dot nH(2)O (Ln = Sm (1), Eu (2), Dy (3); TPPS = 5,10,15,20-tetra(4-sulfonatophenyl)porphyrinato) with TPPS and histidine as mixed ligands, have been prepared and characterized by single-crystal X-ray diffraction technique. Complexes 1-3 are isomorphous and characteristic of a three-dimensional (3D) framework with the lanthanide ions in two kinds of coordination geometries, i.e., eightfold square antiprism and ninefold monocapped square antiprism. The porphyrin macrocycles adopt a saddle-distorted nonplanar conformation with an embedded cobalt ion binding to four pyrrole nitrogen atoms. As revealed by the photoluminescence measurement, they exhibit blue emission. Variable-temperature magnetic susceptibility reveals that complexes 1-3 are antiferromagnetic. Their FTIR, CV, DPV, and UV/vis results are also studied in detail.