Mg(II) Coordination Polymers Based on Flexible Isomeric Tetracarboxylate Ligands: Syntheses, Structures, Structural Transformation and Luminescent Properties

By using a new flexible tetracarboxylic acid, bis(3,5-dicarboxyphenyl) adipoamide, H₄L¹, and its isomer, bis(2,5-dicarboxyphenyl)adipoamide, H₄L², three Mg(II) coordination polymers, {[Mg₂(L¹)(H₂O)₂]·2EtOH·3H₂O}_n, 1, [Mg₂(L¹)(H₂O)₈]_n, 2, and {[Mg₂(L²)(H₂O)₆]·H₂O}_n, 3, have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complexes 1 and 2 are the solvent ratio-dependent hydrothermally stable products. The tetracarboxylate ligand of complex 1 connects eight Mg(II) ions through nine oxygen atoms, resulting in a three-dimensional (3D) 5-connected uninodal net with a rare non-interpenetrating (4⁴.6⁶)-pcu-5-Pmna topology, whereas those of 2 and 3 link four Mg(II) ions through four oxygen atoms and six Mg(II) ions through six oxygen atoms, forming a 1D linear chain and a 3,6-connected 2-nodal 3D net having {4.6²}₂{4².6¹⁰.8³}-rtl topology, respectively. Complex 1 shows a series of structural transformations on heating to 200 °C and almost reversible structural transformation when the activated products were immersed in a mixture of ethanol and water or on hydrothermal. Likewise, complex 2 exhibits a reversible structural transformation on heating/hydrothermal, while 3 exhibits irreversible structural transformations. All three complexes exhibit blue light emissions, with that of complex 3 being much more intense.

Modulation of the relaxation dynamics of linear-shaped tetranuclear rare-earth clusters through utilizing different solvents

Nine tetranuclear centrosymmetric linear complexes have been synthesized and the two differently solvated Dy^III complexes exhibit different magnetic relaxation behaviors.

A series of pyridyl-amide-based ZnII/CdII coordination polymers and their polypyrrole-functionalized composite materials for tuning their photocatalytic properties

Six pyridyl-amide-based Zn^II/Cd^II coordination polymers have been solvothermally synthesized and decorated by polypyrrole for tuning their photocatalytic properties under visible irradiation.

The assembly of thiophene-based bis-pyridyl-bis-amide CoII coordination polymers and their polypyrrole-functionalized hybrid materials for boosting their photocatalytic performances

A series of thiophene-based bis-pyridyl-bis-amide coordination polymers have been synthesized and decorated with polypyrrole for boosting their photocatalytic properties under visible light irradiation.

Alkyl linker effects on the coordination topology of ditopic di(2-pyridylmethyl)amine carboxylate ligands with ZnIIand CuII: polymersvs.macrocycles

Di(2-pyridylmethyl)amine carboxylates with short alkyl linkers afford coordination polymers whereas the longer homologues favour macrocyclic topologies.

Assembly and Properties of Four New Metal–Organic Complexes Based on 1,4-Naphthalenedicarboxylate: Effect of Four Bis-pyridyl-bis-amide Ligands with Diverse Spacers in the Structures

Four new complexes based on 1,4-naphthalenedicarboxylic acid (1,4-H2NDC) and four bis-pyridyl-bis-amide ligands with various spacers (3-bpye = N,N′-bis(3-pyridinecarboxamide)-1,2-ethane; 3-bpfp = bis(3-pyridylformyl)piperazine; 3-bpcd = N,N′-bis(pyridin-3-yl)cyclohexane-1,4-dicarboxamide; and 3-bpcb = N,N′-bis(3-pyridinecarboxamide)-1,4-benzene), namely [Cu2(1,4-NDC)2(3-bpye)(H2O)] (1), [Cu(1,4-NDC)(3-bpfp)0.5] (2), [Cu3(1,4-NDC)3(3-bpcd)3]·2H2O (3), and [Cu(1,4-NDC)(3-bpcb)] (4), have been hydrothermally synthesized. Complex 1 is a 3D coordination network and represents an 8-connected {420.68} topology. Complex 2 shows a 2-fold interpenetrating 3D architecture with a 6-connected {412.63} topology. Complexes 3 and 4 possess similar 2D sql layers with the {44.62} topology, but the coordination modes of 1,4-NDC ligands and the conformations of the two bis-pyridyl-bis-amide ligands are different. The adjacent layers for 3 and 4 are further linked by hydrogen bonding interactions to form 3D supramolecular networks. The successful assemblies of complexes 1–4 imply that by using the different bis-pyridyl-bis-amide ligands with diverse spacers can produce diverse metal–organic networks. Furthermore, the fluorescence and photocatalytic properties of complexes 1–4 have been investigated.