Selected Controlled Synthesis of Three-Dimensional 4d−4f Heterometallic Coordination Frameworks by Lanthanide Carboxylate Subunits and Silver Centers

Abstract

By control of mixed ligands with particular coordination sites, three novel three-dimensional (3D) 4d−4f heterometallic coordination polymers, [Ln4(H2O)2Ag(1,3-bdc)4(inic)5]·nH2O (Ln = Nd (1), n = 0.25; Eu (2), n = 0; 1,3-H2bdc = 1,3-benzenedicarboxylic acid and Hinic = isonicotinic acid) and [Nd(H2O)Ag(1,2-bdc)(inic)2] (3) (1,2-H2bdc = 1,2-benzenedicarboxylic acid), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, thermogravimetric (TG) analysis, and single-crystal X-ray diffraction. Compounds 1−3 crystallize in the monoclinic system, space group C2/c. Compounds 1 and 2 are isostructural and exhibit novel 3D coordination frameworks constructed from two-dimensional (2D) wavelike lanthanide carboxylate layers and Ag(inic)4 complexes. To the best of our knowledge, they represent the first examples of 3D 4d−4f heterometallic coordination frameworks, in which the transition metal complexes bond to a 3D lanthanide carboxylate supramolecular framework with nanometer-sized channels built up from 2D wavelike layers. Compound 3 possesses an unusual 3D framework based on linkage of neodymium−carboxylate chains and silver(I) centers by inic ligands. The difference between both kinds of frameworks can be ascribed to the geometry effect of benzenedicarboxylate. Furthermore, the luminescent properties of 2 were studied.