Sensitivity to NH3 Vapor: Synthesis and Characterization of Five New Coordination Polymers Based on 2,2-Dimethylglutaric Acid and Bis(triazole)-Derived Ligands

Five new coordination polymers (CPs) were obtained as a result of hydrothermal reactions of 2,2-dimethylglutaric acid (H2dmg) and 1,4-bis(1H-1,2,4-triazol-1-ylmethyl)benzene (pbtx)/1,2-bis(1H-1,2,4-triazol-1-ylmethyl)benzene (obtx) ligands with some metal ions [Co(μ-dmg)(μ-obtx)]n (1), [Zn(μ-dmg)(μ-obtx)]n (2), [Cd(μ-dmg)(μ-obtx)]n (3), [Co2(μ-dmg)2(μ-pbtx)2]n (4), and [Cd(μ-dmg)(H2O)(μ-pbtx)]n (5). All of the compounds were characterized by elemental analysis, FT-IR spectroscopy, single-crystal X-ray diffraction, powder X-ray diffraction, and thermal analysis techniques. The single-crystal X-ray studies show that all compounds exhibit 2D layer structures. To examine the ammonia sensing properties of five new coordination complexes (1-5), the absorption and emission spectra of CPs embedded in ethyl cellulose thin films were measured by exposure to different concentrations of ammonia (NH3) vapor. The [Co2(μ-dmg)2(μ-pbtx)2]n (4)-based sensor agent was found to show promising sensor properties in detecting NH3 vapor.

MoS2 Decoration Followed by P Inclusion over Ni-Co Bimetallic Metal-Organic Framework-Derived Heterostructures for Water Splitting

Demonstrating a highly efficient non-noble bifunctional catalyst for complete water electrolysis remains challenging because of kinetic limitations and crucial importance for future energy harvesting. Herein, a low-cost, integrated composite of a Ni-Co metal-organic framework decorated with thin MoS₂ nanosheets was synthesized by a simple hydrothermal method followed by carbonization and phosphorization for electrochemical oxygen and hydrogen evolution reactions. Such a composite heterostructure exhibits outstanding performance in the electrocatalysis process with a lower overpotential of 184 mV for the oxygen evolution reaction (OER) and 84 mV for the hydrogen evolution reaction (HER) in 1.0 M KOH and 0.5 M H₂SO₄ electrolytes to reach a current density of 10 mA cm^-2, with a slight Tafel slope of 63 mV dec^-1 for the OER and 96 mV dec^-1 for the HER. The obtained results are far better than those of the commercial benchmark catalyst. Furthermore, online gas chromatography quantifies the amount of hydrogen generation in a symmetric cell as equal to 0.002121 moles with an energy efficiency of about 2.237 mg/kWh. Thus, the composite electrode's remarkable performance is further demonstrated as a potentially viable alternative non-noble electrocatalyst for energy conversion reactions.

Structural diversity and photocatalytic activity of six Co(ii)/Ni(ii) complexes with three flexible phenylenediacetate isomers

Six coordination polymers show structural diversity have been reported. Their photocatalytic for the degradation of dye have been well studied.

Four 3D coordination polymers based on layers with single syn-anti carboxylate bridges: synthesis, structures, and magnetic properties

Four novel coordination polymers (CPs) based on a new 4-(3,5-dicarboxylphenyl) picolinic acid ligands (H₃L), [M₃(L)₂(H₂O)₆]·4H₂O (M₃ = Mn₃, 1; Co₃, 2; Ni₃, 3, Co_1.01Ni_1.99, 4), have been hydrothermally synthesized, and structurally and magnetically characterized. In these isomorphous CPs, octahedrally coordinated metal ions are linked by the single syn–anti carboxylate bridge (μ-COO) to give linear trinuclear motifs. The motifs are connected through the other single syn–anti carboxylate bridge (μ-COO) to give a 2D (4,4) layer, and the layers are interlinked by the L ligands into 3D frameworks. Magnetic measurement indicates that antiferromagnetic interactions between metal ions are mediated through the single syn–anti carboxylate bridges in 1 and 2, while the same carboxylate bridges in 3 transmit ferromagnetic couplings. The bimetallic CP 4 shows interesting complicated magnetic behaviors due to the competition effect of Co(ii) and Ni(ii) ions.

Four 3D carboxylate-bridged metal(II) compounds were prepared. Mn(II) and Co(II) compounds show AFM interactions, while FM coupling is found in Ni(II) compound. The bimetallic shows interesting competition effect of FM and AFM interactions.

Six novel coordination polymers based on the 5-(1H-tetrazol-5-yl)isophthalic acid ligand: structures, luminescence, and magnetic properties

Six coordination polymers containing clusters or chains have been synthesized by a combination of one tetrazolate-isophthalate ligand and N-donor ligands. Their structures, magnetic properties and luminescence properties were discussed in detail.

Structural assembly from 1D to 3D motivated by the linear co-ligands, and the magnetic and photocatalytic properties of five NiII coordination polymers with 5-(4′-carboxylphenyl)nicotinic acid

Five structural diversity nickel(ii) complexes based on 5-(4′-carboxylphenyl) nicotinic acid and linear co-ligands are described. The antiferromagnetic interactions exist in them expect for 2. All of them could accelerate the degradation rate of MO under visible light irradiation.

Homochiral coordination polymers constructed from V-shaped oxybisbenzoyl-based amino acid derivatives: structures, magnetic and photoluminescence properties

Five novel amino acid-modified HCPs have been prepared using the V-shaped semi-rigid 4,4′-oxybis(benzoic acid) instead of usual rigid polycarboxylate units.