Synthesis, Structures, and Magnetism of Copper(II) and Manganese(II) Coordination Polymers with Azide and Pyridylbenzoates

Isostructural coordination polymers of the tethering naphthalene anchored bis(2-methylpyridinecarboxamide) ligand: single crystal, XPS, EDS and theoretical studies

Interesting correlation between various analytical techniques has been made in this work concerning new isostructural CPs.

A novel self-assembled Na{Cu12Zn4} multifunctional material: first report of a discrete coordination compound for detection of Ca2+ions and selective adsorption of cationic dyes in water

A novel discrete Na{Cu₁₂Zn₄} unit is discovered with the ability to sense calcium ions (with ultra-low detection limit) as well as to adsorb cationic dyes in the aqueous phase with high performance.

Water-stable LnIII-based coordination polymers displaying slow magnetic relaxation and luminescence sensing properties

Six Ln-CPs were synthesized: Dy-CP shows slow magnetic relaxation, and Eu-CP and Tb-CP exhibit recyclable and multi-responsive sensing for Fe³⁺, MnO₄⁻, Cr^VI-anions (CrO₄²⁻, Cr₂O₇²⁻) and TNP in an aqueous system.

Three-in-one is really better: exploring the sensing and adsorption properties in a newly designed metal-organic system incorporating a copper(ii) ion

A 2-D copper(ii)-based coordination polymer, [Cu(SCN)(hmp)]_n CP (1), was crystallized via the slow evaporation method after the reaction of CuSO₄·5H₂O, 2-pyridinemethanol (hmpH), sodium thiocyanate and sodium hydroxide in water for functional applications. CP (1) was characterized via elemental analysis, FTIR, PXRD, magnetic, EPR, crystallographic and TGA studies. The crystal structure and EPR data confirmed a square pyramidal geometry around the Cu(ii) ions. The topological analysis revealed that CP 1 has a {6^{^}3} point symbol with a [6.6.6] extended point symbol and 3-c net, uninodal net having hcb and Shubnikov hexagonal plane net/(6,3) type of uncommon topology. The magnetic studies suggested the strong antiferromagnetic nature of CP (1). The fluorescence sensing property of CP (1) was investigated with different nitro aromatic compounds and hazardous metal ions. CP (1) demonstrated high selectivity and sensitivity towards nitrobenzene, even in the presence of other competitive nitro aromatics. In addition, CP (1) showed excellent selectivity and sensitivity toward Fe³⁺ over other metal ions. The possible detection mechanisms were proposed employing UV-visible and fluorescence spectroscopy and DFT calculations. CP (1) also showed excellent recyclability towards both analytes, and its initial intensity was almost regained after several washings. Moreover, CP (1) acted as an excellent adsorbent material for natural dyes with different charges and sizes, i.e., methylene blue (MB), methyl orange (MO) and Rhodamine-B. Furthermore, CP (1) was utilized repeatedly for the effective adsorption of MB from wastewater without significant loss in its adsorption capacity. Hence, the present CP (1) was designed to relate coordination chemistry with various functional applications of interest.

Three novel topologically different metal–organic frameworks built from 3-nitro-4-(pyridin-4-yl)benzoic acid

The design and synthesis of metal–organic frameworks (MOFs) have attracted much interest due to the intriguing diversity of their architectures and topologies. However, building MOFs with different topological structures from the same ligand is still a challenge. Using 3-nitro-4-(pyridin-4-yl)benzoic acid (HL) as a new ligand, three novel MOFs, namely poly[[(N,N-dimethylformamide-κO)bis[μ2-3-nitro-4-(pyridin-4-yl)benzoato-κ3 O,O′:N]cadmium(II)] N,N-dimethylformamide monosolvate methanol monosolvate], {[Cd(C12H7N2O4)2(C3H7NO)]·C3H7NO·CH3OH} n , (1), poly[[(μ2-acetato-κ2 O:O′)[μ3-3-nitro-4-(pyridin-4-yl)benzoato-κ3 O:O′:N]bis[μ3-3-nitro-4-(pyridin-4-yl)benzoato-κ4 O,O′:O′:N]dicadmium(II)] N,N-dimethylacetamide disolvate monohydrate], {[Cd2(C12H7N2O4)3(CH3CO2)]·2C4H9NO·H2O} n , (2), and catena-poly[[[diaquanickel(II)]-bis[μ2-3-nitro-4-(pyridin-4-yl)benzoato-κ2 O:N]] N,N-dimethylacetamide disolvate], {[Ni(C12H7N2O4)2(H2O)2]·2C4H9NO} n , (3), have been prepared. Single-crystal structure analysis shows that the CdII atom in MOF (1) has a distorted pentagonal bipyramidal [CdN2O5] coordination geometry. The [CdN2O5] units as 4-connected nodes are interconnected by L − ligands to form a fourfold interpenetrating three-dimensional (3D) framework with a dia topology. In MOF (2), there are two crystallographically different CdII ions showing a distorted pentagonal bipyramidal [CdNO6] and a distorted octahedral [CdN2O4] coordination geometry, respectively. Two CdII ions are connected by three carboxylate groups to form a binuclear [Cd2(COO)3] cluster. Each binuclear cluster as a 6-connected node is further linked by acetate groups and L − ligands to produce a non-interpenetrating 3D framework with a pcu topology. MOF (3) contains two crystallographically distinct NiII ions on special positions. Each NiII ion adopts an elongated octahedral [NiN2O4] geometry. Each NiII ion as a 4-connected node is linked by L − ligands to generate a two-dimensional network with an sql topology, which is further stabilized by two types of intermolecular OW—HW...O hydrogen bonds to form a 3D supramolecular framework. MOFs (1)–(3) were also characterized by powder X-ray diffraction, IR spectroscopy and thermogravimetic analysis. Furthermore, the solid-state photoluminescence of HL and MOFs (1) and (2) have been investigated. The photoluminescence of MOFs (1) and (2) are enhanced and red-shifted with respect to free HL. The gas adsorption investigation of MOF (2) indicates a good separation selectivity (71) of CO2/N2 at 273 K (i.e. the amount of CO2 adsorption is 71 times higher than N2 at the same pressure).

Topology, magnetism and dye adsorption properties of metal organic frameworks (MOFs) synthesized from bench chemicals

Two new MOFs (CuMOF-1 and CoMOF-2) are synthesized, characterized by spectral and magnetic studies and employed for selective dye adsorption properties.

Slow magnetic relaxation in a μ1,1'-azido cobalt(ii) methylquinoline chain complex

A [Co(N3)2(mqu)] complex with a 1D chain architecture (mqu - 4-methylquinoline) displays the paramagnetic behaviour with a slight exchange interaction of antiferromagnetic nature among Co(ii) centres. It shows slow magnetic relaxation with three distinct modes. The relaxation time strongly depends upon the applied external field. The slowest relaxation time refers to the low-frequency mode τLF = 1.6(2) s at BDC = 0.8 T and T = 1.9 K.

Anion-dependent self-assembly of copper coordination polymers based on pyrazole-3,5-dicarboxylate and 1,2-di(4-pyridyl)ethylene

By utilizing a pyrazole-3,5-dicarboxylic acid (H₃pzdc) and flexible 1,2-di(4-pyridyl)ethylene (dpe) with various copper(ii) salts under the same solvothermal synthetic conditions, six novel coordination polymers, namely, {[Cu₂(pzdc)(dpe)₂]X}_n (X = NO₃^- (1), ClO₄^- (2), BF₄^- (3), SCN^- (4)), {[Cu(ii)₄Cu(i)₄(pzdc)₄(dpe)₆](H₂O)₄}_2n (5), and {[Cu₅(HPO₄)₂ (pzdc)₂(dpe)₃](H₂O)₅}_n (6) were obtained. The structural diversity of compounds 1-6 depends on the starting Cu(ii) salts. Compounds 1-4 are isostructural and exhibit a 3D porous cationic pillar-layered coordination framework with lattice monoanions incorporated into the channels of the framework. When using copper(ii) sulfate as a reagent, a neutral mixed-valence Cu(i,ii) 2D + 2D → 2D parallel interpenetrated layer of 5 was obtained. In the case of a phosphate trianion, compound 6 shows a 3D coordination framework which contains μ₄-HPO₄^2- linking between Cu(ii) centers. The anion-exchange properties of 1-4 were studied. Interestingly, compounds 1-4 exhibit the irreversible chemisorption of the thiocyanate anion instead of anion exchange without the destruction of their structural framework as confirmed by PXRD, IR, UV-Vis, and AA spectroscopy. Moreover, the anion-induced structural transformation of 1-4 was observed when exchanging with an azide anion. The luminescent properties of 1-6 and exchanged products were also investigated.

Unprecedented photosensitivity of heterotrimetallic copper(ii)/sodium/mercury(ii) coordination polymer based thin film semiconductor device

A photosensitive, heterotrimetallic copper(ii)/sodium/mercury(ii) coordination polymer has been used to fabricate a Schottky diode device.

Ferromagnetic ordering and slow magnetic relaxation observed in a triple-bridged azido-Cu(ii) chain compound with mixed carboxylate/ethanol linkers

A triple-bridged Cu(ii) chain compound with μ-1,1-(EO)azido, syn,syn-carboxylate, and μ2-ethanol linkers exhibits slow-relaxation and long-range magnetic ordering.

Coligand modifications fine-tuned the structure and magnetic properties of two triple-bridged azido-Cu(ii) chain compounds exhibiting ferromagnetic ordering and slow relaxation

Two triple-bridged azido-Cu(ii) compounds with different benzoates as coligands exhibit distinct magnetic properties.

A substituent effect of phenylacetic acid coligand perturbed structures and magnetic properties observed in two triple-bridged azido-Cu(ii) chain compounds with ferromagnetic ordering and slow magnetic relaxation

Two triple-bridged azido-Cu(ii) chains exhibit distinct magnetic behaviors.

Stabilization of Cu7 clusters in azide networks: syntheses, structures and magnetic behaviour

Two new azide bridged copper(II) coordination polymer compounds, [Cu7(N3)14(C3H10N2)(C4H13N3)]n (I) and [Cu7(N3)14(C3H10N2)(C5H15N3)2]n (II) [where C3H10N2 = 1,2-diaminopropane (1,2-DAP); C4H13N3 = diethylenetriamine (DETA); C5H15N3 = N-2-aminoethyl-1,3-propanediamine (AEDAP)] were prepared by employing a room temperature diffusion technique involving three layers. Single crystal studies reveal that both compounds I and II, have similar connectivity forming Cu7 clusters through end-on (EO) bonding of the azide. The Cu7 clusters are connected through end-to-end (EE) connectivity of the azides forming three-dimensional structures. Magnetic studies confirmed the ferromagnetic interactions within the Cu7 units and revealed the occurrence of concomitant ferro- and antiferro-magnetic interactions between these clusters. As a result I behaves as a weak-ferromagnet with TC = 10 K.

A novel coordination polymer based on Co(ii) hexanuclear clusters with azide and carboxylate bridges: structure, magnetism and its application as a Li-ion battery anode

A Co(ii) coordination polymer with azide and a viologen-based tetracarboxylate ligand shows a relatively high reversible capacity with good cycling and rate performance as lithium-ion battery anode.

Controllable synthesis of nucleotide complex based on pH control: a small-molecule fluorescent probe as an auxiliary ligand to indicate the pre-organization of the nucleotide complex in solution

Different CMP-bpe-M(ii) (CMP = cytidine monophosphate, bpe = bis(4-pyridyl)ethylene, M(ii) = Mn(2+) and Co(2+)) complexes are synthesized controllably based on pH control and well studied by X-ray single-crystal diffraction analysis. Interestingly, the suitable pH conditions are explored by considering the pre-organization modes of CMP, bpe, and M(2+) in aqueous solution by fluorescence spectroscopy based on acid/basic titration. The organic base bpe serves as a small-molecule fluorescent probe to indicate the changes of pre-organization modes along with the changes of the solution acidity. Furthermore, a perfect self-complementary sugar-base hydrogen bond is first reported based on the crystal structure analysis in this work, and different chiralities and SHG activities of CMP-bpe-Mn(ii) complexes obtained at different pH values are studied.

Spin-canting magnetization in 3D metal organic frameworks based on strip-shaped Δ-chains

Three 3D frameworks built from strip-shaped Δ-chains were prepared and magnetically characterized. The Cu(ii) compound shows spin canting, magnetic ordering and metamagnetism, while the Co(ii) and Ni(ii) compounds show canted antiferromagnetism.

Recent advances in metal–organic frameworks based on pyridylbenzoate ligands: properties and applications

In this mini-review we discuss the properties and applications of metal–organic frameworks based on pyridylbenzoate.

Influence of ionic liquids on the syntheses and structures of Mn(ii) coordination polymers based on multidentate N-heterocyclic aromatic ligands and bridging carboxylate ligands

[RMI]Br probably serves as a template directing agent for the formation of a cluster helicate in 2, while it serves as a mineralizing agent in 3–6. Additionally, [RMI]Br could obviously improve the crystal yield of 7.

Structural diversity of five new bitriazole-based complexes: luminescence, sorption, and magnetic properties

Employing a new bitriazole ligand, five complexes were assembled that display diverse structures, selective CO₂/CH₄ adsorption, luminescent sensing, and antiferromagnetic properties.

Three new europium(III) methanetriacetate metal-organic frameworks: the influence of synthesis on the product topology

Three new metal-organic framework structures containing EuIIIand the little explored methanetriacetate (C7H7O63−, mta3−) ligand have been synthesized. Gel synthesis yields a two-dimensional framework with the formula [Eu(mta)(H2O)3]n·2nH2O, (I), while two polymorphs of the three-dimensional framework material [Eu(mta)(H2O)]n·nH2O, (II) and (III), are obtained through hydrothermal synthesis at either 423 or 443 K. Compounds (I) and (II) are isomorphous with previously reported GdIIIcompounds, but compound (III) constitutes a new phase. Compound (I) can be described in terms of dinuclear [Eu2(H2O)4]6+units bonded through mta3−ligands to form a two-dimensional framework with topology corresponding to a (6,3)-connected binodal (43)(466683)-kgdnet, where the dinuclear [Eu2(H2O)4]6+units are considered as a single node. Compounds (II) and (III) have distinct three-dimensional topologies, namely a (41263)(4966)-nianet for (II) and a (41065)(41164)-K2O2; 36641net for (III). The crystal density of (III) is greater than that of (II), consistent with the increase of temperature, and thereby autogeneous pressure, in the hydrothermal synthesis.