Dy(III)-Based Metal-Organic Framework as a Fluorescent Probe for Highly Selective Detection of Picric Acid in Aqueous Medium

A dysprosium metal-organic framework, {[Dy(μ₂-FcDCA)_1.5(MeOH)(H₂O)]·0.5H₂O}_n (1), where FcDCA = 1,1'-ferrocene dicarboxylic acid, was prepared by slow-diffusion technique at room temperature. The crystal structure analysis of 1 by single-crystal X-ray diffraction reveals different binding modes of FcDCA linkers coordinated with Dy(III) metal ions, which forms continuous porous two-dimensional (2D) infinite framework. The resulting 2D layers are linked by π···π interactions to build three-dimensional (3D) supramolecular framework. Observably, this thermally stable 3D architecture was topologically simplified as a three-connected uninodal net with fes topology. Furthermore, the practical applicability of 1 was investigated as a fluorescence sensor for the sensitive detection of picric acid in aqueous medium with an impressive detection limit of 0.71 μM with quenching constant (K_SV) quantified to be 8.55 × 10⁴ M^-1. The distinguished selectivity in the presence of other nitroaromatics suggests the possible incorporation of 1 in real-world futuristic diagnostic kits. Additionally, the electrochemical behavior of 1 exhibits reversible in nature attributed to the ferrocene/ferrocenium cation.

Manganese(II), lead(II) and cadmium(II) coordination complexes containing a tetrazole-based acylamide ligand: synthesis and the influence of the metal ions on the structures

Three new manganese(II), lead(II) and cadmium(II) coordination complexes have been prepared by reaction of N-(1H-tetrazol-5-yl)cinnamamide (HNTCA) with divalent metal salts (MnCl2, PbCl2 and CdCl2) in a mixed-solvent system, affording mononuclear to trinuclear structures namely, bis(methanol-κO)bis[5-(3-phenylprop-2-enamido)-1H-1,2,3,4-tetrazol-1-ido-κ2 N 1,O]manganese(II), [Mn(C10H8N5O)2(CH3OH)2], (1), bis[μ-5-(3-phenylprop-2-enamido)-1H-1,2,3,4-tetrazol-1-ido]-κ3 N 1,O:N 2;κ3 N 2:N 1,O-bis{aqua[5-(3-phenylprop-2-enamido)-1H-1,2,3,4-tetrazol-1-ido-κ2 N 1,O]lead(II)}, [Pb2(C10H8N5O)4(H2O)2], (2), and hexakis[μ2-5-(3-phenylprop-2-enamido)-1H-1,2,3,4-tetrazol-1-ido-κ3 N 1,O:N 2]tricadmium(II), [Cd3(C10H8N5O)6], (3). The structures of these three compounds reveal that the nature of the metal ions and the side groups of the organic building blocks have a significant effect on the structures of the coordination compounds formed. Intermolecular hydrogen bonds link the molecules into two-dimensional [complex (1)] and three-dimensional hydrogen-bonded networks. Complexes (2) and (3) show significant fluorescence, while complex (1) displays no fluorescence.

Zinc and cadmium metal-directed coordination polymers: in situ flexible tetrazole ligand synthesis, structures, and properties

Seven zinc and cadmium coordination frameworks were obtained through in situ tetrazole synthesis. By varying the hydrothermal conditions the unprecedented generation of tetrazole ligands were achieved.

((1H-tetrazol-5-yl) methyl) pyridine-based metal coordination complexes: in situ tetrazole synthesis, crystal structures, luminescence properties

Six novel transition metal coordination complexes based on pyridyltetrazole ligands have been hydrothermally in situ synthesized.

Poly[tetrachlorido{μ4-tetrakis[(imidazol-1-yl)methyl]methane-κ4N3:N3':N3'':N3'''}dizinc(II)] exhibiting a three-dimensional diamond topology

The title novel noncentrosymmetric metal-organic framework, [Zn2Cl4(C17H20N8)]n, was prepared solvothermally using the tetradentate tetrakis[(imidazol-1-yl)methyl]methane (tiym) linker in the presence of zinc nitrate under acidic conditions. The asymmetric unit contains one Zn(II) cation, two Cl(-) anions and a quarter of each of two symmetry-independent tiym ligands. Each Zn(II) cation is four-coordinated by two Cl(-) anions and two imidazole N atoms from two tiym ligands, forming a distorted tetrahedral coordination geometry. The tetrahedral tetradentate tiym linker has a quaternary C atom located on a crystallographic -4 axis. With its four peripheral imidazole N atoms, the linkers are bridged by four [ZnCl2] subunits to generate a three-dimensional diamond topological framework, which is represented by the Schläfli symbol {6(6)}. To the best of our knowledge, the title compound is the first example of a non-interpenetrating diamond net based on the tiym ligand.

trans-Diaqua-bis-[5-(pyridine-3-carboxamido)-tetra-zolido-κ(2)O,N(1)]zinc dihydrate

The title compound, [Zn(C₇H₅N₆O)₂(H₂O)₂]·2H₂O, consists of one Zn^II ion located on the crystallographic inversion centre, two 5-(pyridine-3-carboxamido)­tetra­zolide ligands, two coordinated water mol­ecules and two free water mol­ecules. The Zn^II ion adopts a slightly distorted octa­hedral coordination geometry formed by the N,O-chelating ligands and two O water atoms. The pyridine N atoms are not coordinated. In the crystal, complex mol­ecules are connected by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds, forming a three-dimensional network.