The Coordination Chemistry of Benzimidazole-5,6-dicarboxylic Acid with Mn(II), Ni(II), and Ln(III) Complexes (Ln = Tb, Ho, Er, Lu)

Abstract

The first coordination chemistry of a multidentate ligand benzimidazole-5,6-dicarboxylic acid (H2L) was investigated, and six novel two-dimensional (2D) coordination polymers based on this ligand, namely, [MnL] n (1), {[Ni2L2(H2O)4]·3H2O} n (2), {[Tb(L)(HL)(H2O)]·H2O} n (3) and {[Ln2L2(HL)2(H2O)2]} n (Ln = Ho (4), Er (5), Lu (6)), were synthesized under hydrothermal conditions. Compund 1 shows a novel coordination network with 4462 topology and contains unusual five-coordinated one-dimensional {Mn−O} n chains along the b-axis. Compound 2 is a 2D layer structure of 4.82 topology in the ab plane and displays a three-dimensional (3D) supramolecular network via multiple intermolecular hydrogen bonds. Compound 3 also shows a 4462 topology, but its coordination network is completely different from compound 1. Compounds 4−6 were isostructural, and each Ln (Ln = Ho (4), Er (5), Lu (6)) center in the framework acts as a five-connected node to give rise to a unique network with a (3.4.6)(32.4.5.62.74) topology in the ab plane. Six complexes exhibit six types of bridging modes of the ligand. The numbers of L ligands around the metal centers increase from 3 (Ni) to 4 (Mn) and finally to 5 (Ln) as a result of an increase in metal ionic radii. The temperature-dependent magnetic susceptibility data have been explained with the Fisher model, with parameters g = 2.05, J = −3.06 cm−1 for 1, and g = 2.09, J = −0.35 cm−1 for 2, indicating antiferromagnetic coupling. The luminescent properties of 3 were studied.

Synthesis, Structure and Biological Properties of a Novel Copper (II) Supramolecular Compound Based on 1,2,4-Triazoles Derivatives

“…[20][21][22] At this stage, many researches have been devoted to the metal-organic supramolecular architectures derived from aromatic heterocyclic ligands such as the pyridine-based, the imidazole-based as well as the triazolebased ligands which have been widely used as multifunctional linkers to construct compounds with novel structural features and potential properties. [23][24][25][26][27][28][29][30] It has been well documented that the rigid 1,2,4-triazoles possess five-membered aromatic rings containing three nitrogen heteroatoms 31 which can afford coordinate sites to bridge transition metal ions together.…”

Synthesis, structures, and luminescence of lanthanide coordination polymers constructed from benzimidazole-5,6-dicarboxylate and oxalate ligands

“…Among the reported network lanthanide N-Heterocyclic carboxylates, Benzimidazole-5,6-dicarboxylic acid(H 3 bidc), as the derivatives of 4, 5-imidazoledicarboxylic acid (H 2 imdc), which remains largely unexplored, H 3 bidc exhibits several interesting characteristics: (i) The multifunctional coordination sites provide a high likelihood for construction of high-dimension a land high-connected frameworks. (ii) It can be partially or completely deprotonated to generate H 2 bidc -, Hbidc 2-, and bidc 3-by controlling the pH carefully, which allows Benzimidazole-5,6-dicarboxylate anions to display various coordination modes [10,11]. Furthermore, compared to MOFs that contain only one carboxylate ligands, reports on MOF built from two different carboxylate bridging ligands are relatively rare [12,13].…”

Lead(II) Hybrid Materials from 3‐ or 4‐Phosphonobenzoic Acid

“…Several heterodifunctional molecules have been already used for the design of hybrid structures and several of them can be classified among the rigid molecules (e.g. pyridine-carboxylic acid, [12] bipyridine-polycarboxylic acid, [13] pyridinephosphonic acid, [14] carboxypyridine oxide, [15] imidazolecarboxylic acid, [16] quinolinecarboxylic acid, [17] benzimidazolecarboxylic acid, [18] phosphonic acid-sulfonic acid, [19] phosphonic acid-carboxylic acid [20] ). On our side, we have investigated the use of 3-phosphonobenzoic acid as a rigid organic building block.…”