Comprehensive Exploration of Optics and Magnetism in a Hydrothermally Synthesized Nickel(II) Complex

The hydrothermal reaction of 2-MeIm (2-MeIm: 2-methylimidazole) with nickel sulfate hexahydrate in methanol afforded a mononuclear complex formulated as [Ni(SO4)(2-MeIm)2(H2O)3]·CH3OH (1). The title compound was described by X-ray single-crystal diffraction, thermal assessment, IR, and UV-vis spectroscopy. The crystal structure of 1 is composed of segregated [Ni(SO4)(2-MeIm)2(H2O)3] neutral entities and a solvent methanol molecule. Two (2-MeIm) ligands, a sulfate group, and a water molecule reside in the equatorial positions of the vertices in this 6-fold coordination. Two aqua ligands lay in the apical positions, resulting in a subtly distorted octahedral framework, as was supported by spectroscopic analysis. The complex's self-assembly is firmly governed by robust O-H···O/N-H···O interactions. Further details on these bonds have been furnished via Hirshfeld surface scrutiny and 2D fingerprint plots. As proven by TGA/DSC analysis, raising the temperature of 1 above 60 °C instigates progressive decomposition stages, which culminates in the production of metal oxide as the ultimate product at 700 °C. The optical analysis suggests the dielectric nature of the material with large direct and indirect gap energies of 5.25 and 4.96 eV, respectively. The results of magnetic studies suggest that 1 undergoes a transition to a magnetically ordered state below 6 K.

Tuning Dimensions of Complexes through Selective In Situ Reaction, Mechanistic Insights into Ni(II)-Catalyzed Br-OH Exchange, Magnetic Properties, and Density Functional Theory Studies

Two coordination polymers (CPs), namely, [Mn₃(L)₂(4,4'-bipy)₂(H₂O)₂]_n (1) and [Ni(L₁)(1,4-bib)(H₂O)]_n (2) (H₃L = 5-(3-bromo-4-carboxyphenoxy)isophthalic acid, H₂L₁ = 5-(3-hydroxyphenoxy)isophthalic acid, 4,4'-bpy = 4,4'-bipyridine, and 1,4-bib = 1,4-bis(1H-imidazol-1-yl)benzene), were synthesized under hydrothermal conditions. Most notably, with the help of the bromine atom-inducing effect, ligand transformation was observed in the structure of complex 2, which was scrutinized thoroughly by single crystal X-ray crystallography and X-ray photoelectron spectroscopy (XPS). Strikingly, Ni(II) ions were utilized as both coordinated atoms and as a catalyst for in situ Br-OH exchange of H₃L in the process, as a result of which the product would have preferred to form a one-dimensional chain. The same reaction cannot happen in 1, leading to form a two-dimensional structure. Moreover, Ni(II)-catalyzed and magnetic exchange mechanisms were well interpreted using density functional theory (DFT) calculations. Finally, complexes 1-2 show three-dimensional (3D) supramolecular structures because of intermolecular weak interactions (C-Br···π, C-H···π, C-H···O, and π···π stacking) and exhibit utterly different antiferrimagnetic coupling interactions.

Stable Nickel-Based Metal–Organic Framework Containing Thiophene/Diimidazole Units for Effective Near-Infrared Photothermal Conversion

Herein, a new Ni-based metal–organic framework (MOF, 1) bearing highly structural stability is synthesized by the reaction of utilizing a rigid and functionalized linker, 2,6-bis(pyridin-4-yl)-1,7-dihydrobenzo[1,2-d:4,5-d′]diimidazole (BBI4PY), in combination with Ni(NO3)2·6H2O and dibenzo[b,d]thiophene-3,7-dicarboxylic acid 5,5-dioxide (L1) under solvothermal conditions. The crystal structure of complex 1 is determined by single-crystal X-ray diffraction and is demonstrated to be a two-dimensional layered structure. In addition, PXRD, IR, TGA and UV/Vis-NIR spectra are also tested carefully to explore the solid structure of this complex. Remarkably, although no significant accumulation effect could be observed between the two-dimensional layers, a stacking interaction between DMF solvent molecules and ligand L1 could be found, which might promote non-radiative transitions and trigger obvious near-infrared photothermal conversion. Under 660 nm laser (0.6 W cm−2) illumination, the temperature of complex 1 increased rapidly from room temperature to 45.2 °C, with good thermal stability and cycle durability. Its photothermal conversion efficiency could reach 10.75%. This work provides an efficient way for assessing the promise of materials in the field of photothermal therapy.

Size-Induced Highly Selective Synthesis of Organometallic Rectangular Macrocycles and Heterometallic Cage Based on Half-Sandwich Rhodium Building Block

The controlled synthesis of organometallic supramolecular macrocycles cages remains interesting and challenging work in the field of supramolecular chemistry. Here, two tetranuclear rectangular macrocycles and an octuclear cage were designed and synthesized utilizing a rigid and functionalized pillar linker, 2,6-bis(pyridin-4-yl)-1,7-dihydrobenzo [1,2-d:4,5-d']diimidazole (BBI4PY) based on three half-sandwich rhodium building blocks bearing different sizes. X-ray crystallography in combination with 1H NMR spectroscopy elucidated that the two building blocks with shorter spacers only result in rectangular macrocycles. However, the building block of bulkier size to avoid the π-π stacking interactions between two ligands BBI4PY led to the formation of an octuclear cage complex. The latter cage contains two types of metal ions, namely Rh3+ and Cu2+, showing significant characteristics of heterogeneous metal-assembling compounds. In addition, the cage accommodates two free isopropyl ether solvent molecules, thus displaying host-guest behavior.

Synthesis and structure of a zinc(II) coordination polymer assembled with 5-(3-carboxybenzyloxy)isophthalic acid and 1,2-bis(4-pyridyl)ethane

A zinc(II) coordination polymer [Zn(cyip)(bpe)] n (1), (cyipH2 = 5-(3-carboxybenzyloxy)-isophthalic acid, bpe = 1,2-bis(4-pyridyl)ethane), has been synthesized under hydrothermal conditions. Its structure was determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis and IR spectra. Complex 1 crystallizes in the monoclinic space group I2/a. In 1, the [cyip]2– ligand bridges the Zn(II) cations to form infinite chains, which are connected through O–H···O hydrogen bonds into layers in the form of 2-fold interpenetrated nets.

The crystal structure of poly[(μ2-terephthalato-κ4 O,O′: O″,O‴)-(μ4-terephthalato-κ4 O:O′:O″:O‴)-{μ4-(1,2,4,5-tetrakis(1,2,4-triazol-1-ylmethyl)-benzene-κ4 O:O′:O″,O‴)}dicadmium(II)] – water – acetronitrile (1/2/2), C38H36N14O10Cd2

C38H36N14O10Cd2, triclinic, P 1 ‾ $P\overline{1}$ (no. 2), a = 10.220(2) Å, b = 10.685(2) Å, c = 10.777(2) Å, α = 84.18(3)°, β = 72.02(3)°, γ = 75.28(3)°, V = 1082.3(4) Å3, Z = 1, R gt (F) = 0.0268, wR ref (F 2) = 0.0732, T = 293(2) K.

Stable Zinc-Based Metal-Organic Framework Photocatalyst for Effective Visible-Light-Driven Hydrogen Production

Herein, a new Zn-MOF material, [Zn(L1)(L2)], 1, was built successfully through a one-pot solvothermal method. The 3D MOF structure was determined by Single X-ray diffraction analysis, IR, and elemental analysis. A series of PXRD tests of 1 after being immersed in different solvents and pH solutions demonstrated the good stability of 1. Interestingly, this material displayed high catalytic activity for the visible-light-driven hydrogen generation under the illumination of white LED in pure water or a mixture of DMF and H₂O without additional photosensitizers and cocatalysts. Besides, the studies also showed that the catalytic activity changed constantly as well as the solvent ratio adjustment of DMF and H₂O from 4:6 to 2:8. Additionally, the catalytic activity reached the best value (743 μmol g^-1 h^-1) when the solvent ratio was 4:6. The heterogeneous nature and recyclability of the MOF catalyst, as well as several factors that affect the catalytic activity, were investigated and described in detail. Moreover, the photocatalytic mechanism for the hydrogen generation of 1 was also proposed based on the fluorescence spectra and UV-vis absorption.

The crystal structure of poly[diaqua-(μ2-1,2,4,5-tetrakis(1,2,4-triazol-1-ylmethyl)-benzene-κ2N:N′)-bis(μ3-terephthalato-κ3O:O′:O′′)dicadmium(II)], C17H15N6O5Cd

C17H15N6O5Cd, monoclinic, P21/c (no. 14), a = 10.095(2) Å, b = 13.380(3) Å, c = 14.968(5) Å, β = 115.16(2)°, V = 1829.9(9) Å3, Z = 4, R gt (F) = 0.0267, wR ref (F 2) = 0.0602, T = 293(2) K.

Zn/Cu Complexes Constructed through Selective in Situ Br−Cl Exchange: Synthesis, Structures, Properties, and DFT Insights into the Cu-Catalyzed Mechanism

Two coordination polymers (CPs) [Cu2(L1)(µ3-OH)(H2O)]n (1) and {[Zn4(L)2(4,4′-bipy)3]•4H2O}n (2) were synthesized under solvothermal conditions. It is unexpectedly found the transformation of aryl−Br to aryl−Cl (Br-Cl exchange) in the formation of...

The syntheses, structures, and magnetic properties of two mononuclear manganese(II) complexes involving in situ hydrothermal decarboxylation

Two new mononuclear compounds [Mn(3-Br-pydc)(H2O)3] (1) and {[Mn(5-Br-pyc)(bipy)(H2O)(Cl)]·2H2O (2) (3-Br-H2pydc = 3-Br-pyridine-2,6-dicarboxylic acid, 5-Br-Hpyc = 5-Br-pyridine-2-carboxylic acid, bipy = 2,2′-bipyridine) have been synthesized by traditional solution reaction and hydrothermal reaction, respectively. In both compounds, the MnII center is six-coordinated in a distorted octahedral geometry, formed by one tridentate chelate 3-Br-pydc dianion and three water molecules in 1, while the coordination sphere consists of one bidentate chelate 5-Br-pyc anion, one bipy, one water molecule, and one chloride anion in 2 (MnNO5 for 1 and MnN3O2Cl for 2). O–H⋯O hydrogen bonds, Br⋯O halogen bonds, and/or π-π stacking assist in the construction of the three-dimensional (3D) network structures of 1 and 2. Notably, the 5-Br-Hpyc ligand was generated in situ by decarboxylation of the 3-Br-H2pydc precursor under hydrothermal conditions. Variable-temperature magnetic susceptibility data in the 2–300 K temperature range indicate weak antiferromagnetic coupling in both 1 and 2.

The crystal structure of catena-poly(μ2-4,4′-bipyridine-κ2N:N′)-tetrakis(μ2-2-((3,5,6-trichloropyridin-2-yl)oxy)acetato-κ2O:O′)dinickel(II)], C19H10Cl6N3NiO6

C19H10Cl6N3NiO6, tetragonal, I4̄ (no. 82), a = 13.1205(4) Å, c = 14.2717(6) Å, V = 2456.84(18) Å3, Z = 4, Rgt(F) = 0.0384, wRref(F2) = 0.0756, T = 293.2(3) K.

Sonochemical synthesis and characterization of four nanostructural nickel coordination polymers and photocatalytic degradation of methylene blue

Four nanostructural nickel(II) coordination polymers {[Ni(ttpa)(1,4-ndc)(H₂O)₂]·2H₂O}_n (1), {[Ni(ttpa)(1,3-bda)]·2H₂O·DMF}_n (2·2H₂O·DMF), {[Ni(ttpa)(1,4-bdc)]·H₂O}_n (3) and {[Ni(ttpa)(aip)(H₂O)]·3H₂O}_n (4·3H₂O) were synthesized using hydrothermal and sonochemical methods (ttpa = tris(4-(1,2,4-triazol-1-yl)phenyl)amine, 1,4-ndc = 1,4-naphthalenedicarboxylate, 1,3-bda = 1,3-benzenediacetate, 1,4-bdc = 1,4-benzenedicarboxylate, aip = 5-aminoisophthalate), and characterized by elemental analysis, IR spectra, scanning electron microscopy, single-crystal and powder X-ray diffraction analysis, optical band gaps, VB XPS spectra and luminescence. The effects of sonication power, time and frequency on the size and morphology of nano-sized 1-4 have been studied. 1 exhibits an unusual 2D + 2D → 3D inclined polycatenated motif based on the (3,3)-coordinated 6³-hcb topology. 2 shows a (3,4)-coordinated 2D network of the bey topology. 3 presents a rare example of the 4-fold interpenetrating array of (3,5)-coordinated 3D network belonging to the 35T1 topology type. 4 displays an unusual 2D → 3D polythreaded network based on 2D sql networks. 1-4 exhibit luminescent emissions at 409, 399, 413 and 402 nm, respectively. 1-4 are semiconducting in nature, with E_g of 2.12 eV (1), 2.34 eV (2), 2.32 eV (3), and 2.47 eV (4). 1-4 are good catalysts for the degradation of MB under visible light irradiation. The effects of the size and morphology of nano-sized 1-4 on the photocatalytic efficiencies were studied. The higher sonication frequency obtains uniform and smaller nano-sized coordination polymers which have higher catalytic efficiencies.

Crystal structure of poly[aqua(μ2-5-methoxyisophthalato-κ2 O,O′:O′′)-(1,2-bis(imidazol-1′-yl)ethane-κ2 N:N′)cobalt(II), C34H36Co2N8O12

C34H36Co2N8O12, triclinic, P1̄ (no. 2), a = 8.5834(8) Å, b = 10.2975(10) Å, c = 22.727(2) Å, α = 78.325(1)°, β = 82.934(1)°, γ = 69.214(1)°, V = 1836.3(3) Å3, Z = 2, R gt(F) = 0.0319, wR ref(F 2) = 0.0761, T = 296 K.

Crystal structure of catena-poly[triaqua-(μ2-5-methoxy-isophthalato-κ2O:O′)copper(II)], C9H12CuO8

[Cu(C9H6O5)(H2O)3], monoclinic, C2/c (no. 15), a = 21.678(13) Å, b = 9.071(6) Å, c = 13.786(9) Å, β = 122.738(7)°, V = 2280(2) Å3, Z = 8, Rgt(F) = 0.0613, wRref(F2) = 0.1682, T = 296(2) K.

Coordination polymers of 5-substituted isophthalic acid

The synthesis and characterisation of five coordination polymers - Ni2(mip)2(H2O)8·2H2O (1), Zn6(mip)5(OH)2(H2O)4·7.4H2O (2), Zn6(mip)5(OH)2(H2O)2·4H2O (3), Mn(HMeOip)2 (4), and Mn3(tbip)2(Htbip)2(EtOH)2 (5) - are reported. Preliminary nitric oxide release data on compounds 2 and 3 are also given.

Syntheses, structural diversity and photocatalytic properties of various Co(ii) coordination polymers based on a “V”-shaped 1,3-di(4′-carboxyl-phenyl)benzene acid and different imidazole bridging ligands

Various polymeric structures of complexes 1–4.