Varying Ligand Backbones for Modulating the Interpenetration of Coordination Polymers Based on Homoleptic Cobalt(II) Nodes

Abstract

To explore the influence of ligand backbones on the structures of coordination architectures, three structurally related rodlike ligands bearing different backbones, 1,4-bis(benzoimidazol-1-yl)-phenyl (L 1 ), 1,4-bis(imidazol-1-yl)-benzene (L 2 ), and 4,4′-bis(imidazol-1-yl)-biphenyl (L 3 ), have been employed to react with Co(ClO4)2·6H2O, and three three-dimensional interpenetrating coordination polymers, {[Co(L 1 ) 2 ](ClO 4 ) 2 }∞ (1), {[Co(L 2 ) 3 ](ClO 4 ) 2 (CHCl 3 ) 2 }∞ (2), and {[Co(L 3 ) 3 ](ClO 4 ) 2 }∞ (3), have been obtained under similar conditions. Compound 1 forms a 3-fold interpenetrating network with diamondoid topology based on a tetrahedrally coordinated CoII node, whereas complex 2 takes a double interpenetrating network with α-polonium-type topology and compound 3 exhibits a 3-fold interpenetrating network with β-Sn topology. Compared with the tetrahedrally coordinated CoII node in compound 1, the CoII nodes in compounds 2 and 3 are both octahedrally coordinated. To the best of our knowledge, the 3-fold interpenetrating network of compound 3 is the first example of β-Sn 485463 topology in coordination polymers. Our results reveal that ligand backbones (including terminal groups and spacer conformations) may be the major influence on the structure topology of coordination architectures, and significantly, the coordination mode and spacer length play important role in controlling the degree of interpenetration of coordination polymers.

Syntheses, crystal structures and properties of three novel coordination polymers with tripodal imidazole-containing ligands and benzenetetracarboxylate

“…However, coordination polymers with rigid imidazole-containing ligands and multi-carboxylate as mixed ligands are less documented [8][9][10][11]. In our previous study, the rigid tripodal ligand 1,3,5-tris(1-imidazolyl)benzene (tib) was used to react with different benzenedicarboxylic acids for systematically investigating the impact of dicarboxylate auxiliary ligands and the counteranions on the structure of the complexes, and a series of coordination polymers have been obtained with novel structures and interesting topologies [12].…”

Adamantane-based Bidendate Metal Complexes in Crystalline and Solution State

“…In addition, the significant role of ligand backbone modification by altering the terminal groups at the coordination sites was revealed in studies concerning the influence of molecular shapes and steric hindrances for the generation of metal-organic frameworks. 45,46 Although the functionalization of adamantane spacers has provided various metal-organic frameworks, the precise prediction of the direction and shape of the polymerization with multidentate organic ligands has remained a difficult problem due to the reversible coordination bond property and the diversity of the metal-ligand combinations. In addition, not enough attention has been given to complexes fabricated on the basis of the combination of several multidentate ligands and metals called as coordination oligomers.…”

Hydrothermal Synthesis, Crystal Structures, and Luminescent Properties of Two Cadmium(II) Coordination Polymers Based on Dicarboxylate and Imidazole‐Containing Coligands

“…[11][12][13] Many reports illustrate the use of aromatic dicarboxylic acids acting as organic ligands in the preparation of metal-organic coordination polymers in which the carboxylate groups display diverse chelating and bridging modes for constructing coordination polymers. [14][15][16] On the other hand, the increasing interest has been concentrated on the N-donor bridging ligands due to their diversities in coordination modes and versatile conformations according to the restrictions imposed by the coordination environment of the metal ion. Among various N-donor ligands, bis(imidazole)-containing ligands have been widely used in the construction of coordination polymers and yield many fascinating architectures.…”