Three-dimensional Supramolecular Architecture Research Articles

Synthesis, structure and photoluminescence properties of heterometallic-based coordination polymers of trimesic acid.

Reacting trimesic acid (H3TMA, C9H6O6) with CaCl2 and MCl2 at 110 °C under hydrothermal conditions gave the isostructural heterobimetallic coordination polymers (CPs) catena-poly[[tetraaquazinc(II)]-μ-5-carboxybenzene-1,3-dicarboxylato-[tetraaquacalcium(II)]-μ-5-carboxybenzene-1,3-dicarboxylato], [CaZn(HTMA)2(H2O)8]n, 1, and catena-poly[[tetraaquacobalt(II)]-μ-5-carboxybenzene-1,3-dicarboxylato-[tetraaquacalcium(II)]-μ-5-carboxybenzene-1,3-dicarboxylato], [CaCo(HTMA)2(H2O)8]n, 2. Compounds 1 and 2 crystallize in the monoclinic space group C2/c. The solid-state structures consist of eight-coordinate CaII ions and six-coordinate MII ions. These ions are connected by a doubly deprotonated HTMA2- ligand to create a one-dimensional (1D) zigzag chain. Poly[[decaaquabis(μ3-benzene-1,3,5-tricarboxylato)calcium(II)dizinc(II)] dihydrate], {[CaZn2(TMA)2(H2O)10]·2H2O}n, 3, was found incidentally as a minor by-product during the synthesis of 1 at a temperature of 140 °C. It forms crystals in the orthorhombic space group Ccce. The structure of 3 consists of a two-dimensional (2D) layer composed of [Zn(TMA)] chains that are interconnected by CaII ions. The presence of aromatic carboxylic acid ligands and water molecules, which can form numerous hydrogen bonds and π-π interactions, increases the stability of the three-dimensional (3D) supramolecular architecture of these CPs. Compounds 1 and 2 exhibit thermal stability up to 420 °C, as indicated by the thermogravimetric analysis (TGA) curves. The powder X-ray diffraction (PXRD) data reveal the formation of unidentified phases in methanol and dimethyl sulfoxide, while 1 exhibits chemical stability in a wide range of solvents. The luminescence properties of 1 dispersed in various low molecular weight organic solvents was also examined. The results demonstrate excellent selectivity, sensitivity and recyclability for detecting acetone molecules in aqueous media. Additionally, a possible sensing mechanism is also outlined.

Six polyoxotungstate-based transition metal compounds for electrochemical capacitor application and a comparative analysis of factors affecting capacitances.

Six different polyoxotungstate-based transition metal complexes were synthesized, namely [Cu5(2,2'-bpy)5(μ2-Cl)2(PO4)2(H2O)2][HPW12O40]·2H2O (1), [Cu1.5(2,2'-bpy)1.5(inic)2(H2O)1.5]3[H1.5PW12O40]2·16.25H2O (2), [Cu(2,2'-bpy)2]2[SiW12O40]·10H2O (3), [Zn(phen)3]2[PWVWVI11O40]·5H2O (4), [Zn(phen)2(H2O)]2[SiW12O40]·2H2O (5), and [Zn(2,2'-bpy)2]2[SiW12O40] (6) (2,2'-bpy = 2,2'-bipyridine, inic = isonicotinic acid, phen = 1,10-phenanthroline). Compound 1 is based on [HPW12O40]2- anions, which are accommodated within the open channels of a supramolecular network formed by novel Cu-P-Cl coordination clusters. Compound 2 is constructed from [H1.5PW12O40]1.5- and novel [Cu1.5(2,2'-bpy)1.5(inic)2(H2O)1.5]+ coordination fragments, and polyoxoanions are encapsulated within the pores created by the copper coordination fragments, resulting in a unique three-dimensional supramolecular architecture. Compound 3 is a two-dimensional structure formed through the covalent linkage between [SiW12O40]4- and [Cu(2,2'-bpy)2]2+. Compound 4 is a supramolecular architecture formed by [PWVWVI11O40]4- and [Zn(phen)3]2+ coordination fragments, while compound 5 is a supramolecular structure based on POM bi-supported Zn coordination complexes. Compound 6 is a two-dimensional framework structure constituted by [SiW12O40]4- and [Zn(2,2'-bpy)2]2+via covalent interactions. In addition, electrochemical measurement results show that the copper-based tungstate compounds 1-3 and zinc-based tungstate compounds 4-6 exhibit different performances and durabilities as electrochemical capacitors (compound 1 shows the highest specific capacitance of 94.0 F g-1 at 1.5 A g-1, whereas compound 6 maintains the best cycling stability with the capacity retention of 80.7% after 1000 cycles at 4 A g-1.). This study contributes to the development of POM-based transition metal complexes with high capacitance by providing insights into the design and synthesis process.

Stanevansite, Mg(C2H3O3)2·2H2O, A New Hydrous Glycolate Mineral, from the Santa Catalina Mountains, Tucson, Arizona, USA

Abstract A new organic mineral species, stanevansite, ideally Mg(C2H3O3)2·2H2O, was discovered from the western end of Pusch Ridge in the Santa Catalina Mountains (32° 21′ 42″ N, 110° 57′ 30″ W, at the elevation of 975 m), north of Tucson, Arizona, USA. It occurs as sprays of bladed crystals (up to 0.40 × 0.07 × 0.03 mm). Associated minerals include lazaraskeite, chrysocolla, malachite, wulfenite, mimetite, phosphohedyphane, cerussite, hematite, calcite, microcline, phlogopite, and quartz. Stanevansite crystals are colorless in transmitted light, transparent with white streak and vitreous luster. They are brittle and have a Mohs hardness of ∼1½; cleavage is perfect on {100}. Twinning is common on (100). The measured and calculated densities are 1.69(5) and 1.682 g/cm3, respectively. Optically, stanevansite is biaxial (+), with α = 1.539(5), β = 1.545(5), γ = 1.558(5), 2Vmeas. = 62(2)°, 2Vcal. = 69°. It is insoluble in water, but slowly dissolves in hydrochloric acid. An electron-microprobe analysis yielded an empirical formula, based on 8 O apfu and Σ(Mg + Zn) = 1 apfu, of (Mg0.95Zn0.05)Σ1.00(C2H3O3)2·2H2O, which can be simplified as (Mg,Zn)(C2H3O3)2·2H2O. Stanevansite is monoclinic with space group P21/c and unit-cell parameters a = 11.4927(2), b = 5.85470(10), c = 12.4711(2) Å, β = 91.1610(10)°, V = 838.96(2) Å3, and Z = 4. It is isostructural with several synthetic glycolate compounds having the general chemical formula M2+(C2H3O3)2·2H2O, where M2+ = Co2+, Mn, Zn, and Mg. The crystal structure of stanevansite is characterized by the mononuclear complex [Mg(C2H3O3)2(H2O)2], with such complexes being connected to one another by hydrogen bonds to form a three-dimensional supramolecular architecture. In a [Mg(C2H3O3)2(H2O)2] complex, Mg is octahedrally coordinated by two chelating glycolate ligands and two H2O molecules. Stanevansite represents the first hydrous glycolate mineral and is believed to have formed through the interaction of fluids containing glycolic acid (C2H4O3) derived from decaying plant materials or bacterial activities with Mg produced by the alteration of primary and secondary minerals. Its discovery, together with other glycolate minerals documented recently, namely lazaraskeite Cu(C2H3O3)2, jimkrieghite Ca(C2H3O3)2, and lianbinite (NH4)(C2H3O3)(C2H4O3), not only implies that more glycolate minerals may be found in nature, but also suggests that glycolate minerals may serve as a potential reservoir for biologically fixed carbon.

Synthesis and crystal structures of two solvates of 1-{[2,6-bis-(hy-droxy-meth-yl)-4-methyl-phen-oxy]meth-yl}-3,5-bis-{[(4,6-di-methyl-pyridin-2-yl)amino]meth-yl}-2,4,6-tri-ethyl-benzene.

In the crystal structures of the formamide monosolvate (1a) and the n-propanol/H2O solvate/hydrate (1b) of the title compound, C38H50N4O3 (1), the tripodal host mol-ecule adopts a conformation in which the substituents attached to the central benzene ring are arranged in an alternating order above and below the ring plane. As a result of the different nature of the involved guest species, the crystal components in 1a create a three-dimensional supra-molecular architecture, while the crystal structure of 1b consists of two-dimensional supra-molecular aggregates extending parallel to the crystallographic ab plane.

Synthesis and crystal structure of the copper (II) carboxylate with 2,2-bipyridine, [Cu(4-mba)2(bipy)(H2O)

The new Cu(II) carboxylate complex, aqua(2,2'-bipyridine-κ2N,N')bis(4-methylbenzoato-κO)copper(II) [Cu(4-mba)2(bipy)(H2O)] (4-mba: 4-methylbenzoate, bipy: 2,2'-bipyridine) was synthesized, and the molecular structure of the complex was characterized by the single crystal X-ray diffraction technique. The X-ray diffraction analysis indicated that the asymmetric unit comprises an independent molecule. Crystal data for [Cu(4-meb)2(2,2-bipy)(H2O)]: Triclinic, space group P-1 (no. 2), a = 7.0452(13) Å, b = 11.260(2) Å, c = 16.635(3) Å, α = 103.543(7)°, β = 91.002(7)°, γ = 104.106(6)°, V = 1240.4(4) Å3, Z = 2, T = 296 K, μ(MoKα) = 0.918 mm-1, Dcalc = 1.360 g/cm3, 51364 reflections measured (5.054° ≤ 2Θ ≤ 57.38°), 6258 unique (Rint = 0.0398, Rsigma = 0.0284) which were used in all calculations. The final R1 was 0.0392 (I > 2σ(I)) and wR2 was 0.1021 (all data). The Cu(II) ion was found to be coordinated with two nitrogen atoms of the 2,2'-bipyridine ligand, two oxygen atoms of the 4-methyl benzoate molecule, and one oxygen atom of the aqua ligand. In the three-dimensional supramolecular architecture, molecules are connected through pairs of O-H···O and C-H···O intermolecular interactions, consisting of chains. The molecule also demonstrates Cg···Cg intermolecular interactions between six-membered rings of 2,2'-bipyridine.

Four Novel Cobalt(II) Coordination Polymers Based on Anthracene-Derived Dicarboxylic Acid as Multi-functional Fluorescent Sensors toward Different Inorganic Ions

A series of Co(II)–H2L coordination polymers were prepared with different auxiliary ligands, namely {[Co(L)(bibp)]}n 1, {[Co(L) (bpy)(H2O)]2·2H2O}n 2, {[Co(L)(bipd)]}n 3, and {[Co(L)(bbibp)]·H2O}n 4 (H2L = 5-{(anthracene-9-ylmethyl)amino}isophthalic acid, bibp = 4,4′-bis(imidazolyl)biphenyl, bpy = 2,2′-bipyridine, bipd = 3,5-bis(1-imidazoly)pyridine, and bbibp = 4,4′-bis(benzoimidazo-1-yl)biphenyl), by a similar solvothermal method. X-ray diffraction analyses revealed that 1, 3, and 4 exhibit a two-dimensional (2D) structure, which further builds the three-dimensional (3D) supramolecular architecture via the weakly interacting hydrogen bonds of C–H···O, while 2 displayed a one-dimensional (1D) double-chain architecture extended from two 1D zigzag chains by intermolecular hydrogen bonding interactions. The sensing experiments revealed that 1 and 2 can serve as either individual- and/or multi-responsive sensors to selectively detect Cr3+, Al3+, and Pb2+ ions through the fluorescence turn-on effect, while 3–4 exhibited fluorescence turn-off sensing behavior for Fe3+ ions. Moreover, 1–4 can effectively detect and recognize Cr2O72– and CrO42– due to their high selectivity and sensitivity for fluorescence quenching in aqueous solutions, and the sensing mechanism for various ions has been discussed.

Organic–Inorganic Manganese (II) Halide Hybrid Combining the Two Isomers Cis/Trans of [MnCl4(H2O)2]: Crystal Structure, Physical Properties, Pharmacokinetics and Biological Evaluation

A manganese (II) complex templated by hexahydro-1,4-diazepinediium as a counter ion was grown by slow evaporation from an aqueous solution at room temperature. The X-ray diffraction analysis revealed that the compound (C5H14N2)[MnCl4(H2O)2] crystallizes in the centrosymmetric space group P2/c of the monoclinic system. The crystal structure of the Mn(II) complex is characterized by an alternation of 0-dimensional organic and inorganic stacks linked together by N/O-H…Cl and N-H…O hydrogen bonds, which lead to a three-dimensional supramolecular architecture. In this structure, the inorganic layer is built up by independent anionic moieties combining the two isomers cis/trans of [MnCl4(H2O)2]2−. The thermal decomposition was studied by TGA-DTA techniques. The optical band gap and Urbach energy were obtained by Tauc’s equation. The direct and indirect band gap values are found to be 4.58 and 4.44 eV, respectively. Weak antiferromagnetic interactions are present in the molecule under study, according to magnetic measurements. An agar well diffusion technique was used to assess the synthetic compound’s biological activity, and the results showed that it has potent antibacterial (Gram-positive and Gram-negative) properties. Interestingly, the synthesized compound also displayed antilipase activity. These biological activities have been confirmed by the bioavailability and pharmacokinetic analyses.

Synthesis, Crystal Structure, Hirshfeld Surface and Molecular Docking Analysis of bis(N,N-diethylenediamine)cadmium(II)] dichloride

A new Cd(II) complex, bis(N,N-diethylenediamine)cadmium(II)] dichloride, C12H32CdCl2N4, was synthesized by the reaction between cadmium(II) chloride hexahydrate, sodium hydroxide, and N,N-diethylenediamine in aqueous methanol. The crystal structure was characterized by single-crystal X-ray diffraction analysis technique. The crystal structure is monoclinic, space group P21/c with parameters a=6.8959(3) Å, b=16.0795(10) Å, c=16.4406(8) Å, α=90°, β=100.23(4)°, γ=90°, V=1794(16) Å3, Z=4. The X-ray structure analysis reveals that the Cd(II) cation coordinated by four N atoms of the N,N-diethylenediamine units and two Cl atoms, giving it a octahedral geometry. In the crystal, the molecules are linked by N−H···Cl hydrogen bond, forming a three-dimensional supramolecular architecture. A Hirshfeld surface analysis was performed to record various intermolecular interactions, indicating the stabilization of the Cd(II) complex structure by the intermolecular weak N−H···Cl hydrogen bonds. The major interactions are H···H (80.2%) and Cl···H (19.8%) interactions for the title complex.

Exploration of Variable Temperature Magnetism and Electrical Properties of a Pyridyl-isonicotinoyl Hydrazone Bridged Three-Dimensional Mn-Metal–Organic Framework with a Thiophene Dicarboxylato Link

In emerging trends in our technology-dependent society, the applicability of multifunctional coordination polymers (CPs) and metal–organic frameworks is highly stimulating. In search of such chemical compounds, a Mn(II), d5, based metal–organic framework (MOF), {[Mn2(tdc)2(pcih)2(EtOH)]n} (1), has been designed with the coordination of multidentate ligands tdc2– (2,5-thiophene dicarboxylato) and pcih (pyridine-4-carboxaldehyde isonicotinoylhydrazone). The structure determination by single crystal X-ray diffraction has revealed the formation of three-dimensional (3D) supramolecular architecture via the combined nearly perpendicular bridging of pcih and tdc2– ligands. A variable temperature magnetic measurement of 1 shows weak antiferromagnetism (χMT, 9.41 cm3 K mol–1 at 300 K) with two as good as “isolated” Mn(II) centers (S = 5/2 with g ≈ 2.07). Magnetic exchange is considered through 9/10 carboxylato bridged atoms inclusively spanning two Mn(II) centers at a distance of 4.114 Å. Interestingly, the 3D assembly of 1 exhibits electrical conductivity in the semiconducting region (band gap, 3.72 eV; barrier height, 0.65 eV; series resistance, 0.03 Ω). A Schottky barrier diode feature is recorded at a threshold potential of 0.19 V and follows a non-ohmic relation (I α V2), and the conductivity is 3.42 × 10–5 S m–1. A galvanostatic charge–discharge (GCD) experiment measures the moderate specific capacitance of 1 F/g at a 2 mV/s scan rate.

Supramolecular architecture and SHG activity of organic crystals formed between the amidinothiourea and nicotinic acid

The single crystals of [1-(diaminomethylene)thiouron-1-ium] pyridine-3-carboxylate were grown using a solution growth technique. Depending on the concentration of the 1: 1 amidinothiourea: nicotinic acid solution, two different forms of 1: 1 crystal (orthorhombic non-centrosymmetric, P212121,(1), and monoclinic centrosymmetric, C2/c, (2)) were obtained. These phases differ in ordering, the orthorhombic phase is ordered, and in the monoclinic phase the 1-(diamino-methylene)-thiouron-1-ium cation is disordered and has two non-equivalent orientations with occupations of around 0.80 and 0.20. This ordering/disordering is due to the rate of crystallization: slow crystallization from a dilute solution leads to an ordered orthorhombic phase and quick crystallization from a saturated solution leads to a disordered monoclinic phase. Multiple recrystallizations of 1 and 2 from heavy water gives deuterated analogs 1d and 2d The conformation of the 1-(diaminomethylene)thiouron-1-ium cation in both phases is very similar and slightly non-planar. In the orthorhombic phase the plane of the carboxylate group is more twisted in relation to the plane of the pyridine ring than in the monoclinic phase. The oppositely charged components of the crystals, i.e., 1-(diaminomethylene)thiouron-1-ium cations and pyridine-3-carboxylate anions interact each other forming three-dimensional supramolecular architecture. Both compounds were also characterized by IR and Raman spectroscopy. Assignment of the vibrational bands were supported by the DFT calculations and the isotropic frequency shift. The SHG efficiency of the powdered orthorhombic phase relative to potassium dihydrogen phosphate (KDP) was found to be 1.70.

Selective luminescent sensing of teflubenzuron and oxyfluorfen by a resorcin[4]arene-based metal-organic framework

In this work, a new resorcin[4]arene-based metal–organic framework, [Zn4L(H2O)10]·10H2O, has been synthesized by incorporating Zn(II) cations and a dodecacarboxylic-functionalized resorcin[4]arene (H12L) ligand. The structure of [Zn4L(H2O)10]·10H2O was characterized using a single-crystal X-ray diffraction technique. The two-dimensional layered structures were linked to adjacent layers by hydrogen bonds to form a three-dimensional supramolecular architecture. [Zn4L(H2O)10]·10H2O exhibits excellent stability in water and various organic solvents, therefore, it was used as a luminescent probe to detect pesticides, such as teflubenzuron and oxyfluorfen. Teflubenzuron can significantly enhance the luminescence intensity of [Zn4L(H2O)10]·10H2O due to the hydrogen bond interaction, whereas oxyfluorfen can decrease the luminescence intensity of [Zn4L(H2O)10]·10H2O, which is attributed to the charge transfer and energy transfer. The luminescence mechanism was supported by the density functional theory calculations. The limit of detection for teflubenzuron and oxyfluorfen was 0.18 μM and 4.08 μM, respectively.

3D supramolecular assembly of Cu(II) CP containing 1D zig-zag chain and 2D paddle-wheel net: Structural elucidation and investigation of band gap

A new Cu(II) based coordination polymer (CP) [Cu3(ipa)3(4-clpy)(H2O)2][Cu(ipa)(4-clpy)2(CH3OH)]·3CH3OH (1); (H2ipa = isophthalic acid or benzene-1,3-dicarboxylic acid and 4-clpy = 4-chloropyridine) has been synthesized by slow diffusion method in a single pot technique. Single crystal X-ray analysis reveals that compound 1 consists of both one-dimensional (1D) zig-zag chain and two-dimensional (2D) paddle-wheel net, resulting the formation of a three-dimensional (3D) supramolecular architecture via extensive hydrogen bonding, π⋯π stacking and halogen⋯π interactions. The strength of non-covalent interactions in compound 1 has been investigated by Hirshfeld surface analysis. The semiconducting nature of compound 1 was also explored by HOMO-LUMO band-gap calculation using density functional theory (DFT) computation.

Construction of a 1D Cu(I)-based coordination polymer as a luminescent sensor for antibiotics and a photocatalyst for dye degradation

Antibiotics are a typical contaminants existing in water that now are polluting the aquatic environment thereby affecting the aquatic life and human health. To address this issue, we have synthesized luminescent Cu(I)-based coordination polymer with composition{[CuI(bb)]·Cl}n(1) (bb = 4,4’-bis(imidazoly)biphenyl) and characterized. In crystalline state, 1 forms a non-covalently bonded one-dimensional (1D) chain, which is stacked into a three-dimensional (3D) supramolecular architecture. The polymer, when used as luminescent sensor against antibiotics, attained a limit of detection (LOD) down to 1.21 ppm and a Ksv of 1.67 × 103 M −1for antibiotic nitrofurantoin (NFT) which shows its sensitivity towards NFT. The CP manifested a high efficiency for catalytic photodegradation of NFT 91.41% decomposition within 100 min under 100 W mercury lamp. The plausible sensing and photocatalytic mechanism have been addressed with the help of theoretical calculations.

A novel Ga(III) coordination complex as an efficient sensitizer for enhancing photocatalytic activity of TiO2/rGO nanocomposite

Narrow solar-light response range and rapid charges recombination are the main technical barriers in TiO2 photocatalysis technology. To overcome these restrictions, in this work we synthesized a novel binuclear gadolinium (III) coordination complex, [Gd2(DPDB)6(DMF)6(H2O)2] (DPDB = [(4-dimethylamino)phenyldiazenyl] benzenesulfonate), which was used as an inorganic sensitizer for boosting the visible light-harvesting and quantum efficiency of TiO2 supported-reduced graphene oxide (rGO) nanocomposite. Crystal structure of [Gd2(DPDB)6(DMF)6(H2O)2] (Gd-CMP) was determined from single-crystal X-ray diffraction data, which indicates three-dimensional (3D) supramolecular architecture through hydrogen bonding and CH··· πph interactions. The prepared nanohybrid (Gd-CMP/TG) reveals significantly enhanced visible-light-induced photocatalytic activity for degradation of acetaminophen (ACT). The complete removal of 10 mg/L ACT is achieved over Gd-CMP/TG, and the corresponding rate constant of ACT degradation of nanohybrid is 40-fold higher than that of bare TiO2. In prepared ternary nanohybrid, metal-coordination sensitizer (Gd-CMP) acts as an electron donor, and at the same time, rGO serves as an electron acceptor, and the synergistic effect between them efficiently enhances charges separation and inhibits e/h pair recombination in the hybridized species. The radical scavenger tests indicate that the photo-induced O2−• radicals dominate ACT degradation. On the basis of the experimental results and calculated energy of electronic levels, a possible mechanism for the improved photocatalytic activity is discussed.

Three-Dimensional Supramolecular Architectures with MnII Ions Assembled from Hydrogen Bonding Interactions: Crystal Structures and Antiferromagnetic Properties.

Two novel cocrystal MnII compounds were successfully synthesized. The composition of two kinds crystals correspond to [Mn(hfac)2La2·Mn(hfac)2La(H2O)·Mn(hfac)2(H2O)2] (1) and [Mn(hfac)2Lb2·Mn(hfac)2(H2O)2·0.5(C6H14)] (2) [La = 1,3-bis(1′-oxyl-3′-oxido-4′,4′,5′,5′-tetramethyl-4,5-dihydro-1H-imidazol-2-y1)benzene; Lb = 1-(1′-oxyl-4′,4′,5′,5′-tetramethylimidazolin-2-yl)-3-(1′-oxyl-3′-oxo-4′,4′,5′,5′-tetramethylimidazolin-2-yl)benzene; hfac = hexafluoroacetylacetonato). Surprisingly, the compounds were not polymeric or clusters but, more interestingly, different ratio biradical–metal coordination compound cocrystals. The extensive intramolecular H-bonds are the cause of formation of the cocrystal structures by assembly in the two manganese(II) derivatives; and another factor is the halogen bonds between CF3 of hfac groups. Furthermore, three-dimensional supramolecular architectures were formed. The magnetic susceptibility of both compounds showed strong antiferromagnetic interactions involving the coordinated radical unit and the metal and lesser contribution from ferromagnetic interactions between the radical units. For compound 1, a good fit was obtained for gMn = 2.08, grad = 2.00 (fixed), J1 = −294.3 cm–1, J2 = 6.2 cm–1 and J3 = 10.8 cm–1. A reasonable fit for compound 2 was obtained for gMn = 2.04, grad = 2.00 (fixed), J1′ = −273.4 cm–1 and J2′ = 8.6 cm–1.

Crystal structure and Hirshfeld surface analysis of tris-(acetohydrazide-κ2 N,O)(nitrato-κO)(nitrato-κ2 O,O')terbium(III) nitrate.

In the title lanthanide(III) compound, [Tb(NO3)2(C2H6N2O)3]NO3, the asym-metric unit contains one Tb3+ ion, three acetohydrazide (C2H6N2O) ligands, two coordinated nitrate anions, and an isolated nitrate anion. The Tb3+ ion is in a ninefold coordinated distorted tricapped trigonal-prismatic geometry formed by three oxygen atoms and three nitro-gen atoms from three different acetohydrazide ligands and three oxygen atoms from two nitrate anions. In the crystal, the complex mol-ecules and the non-coordinated nitrate anions are assembled into a three-dimensional supra-molecular architecture through extensive N-H⋯O hydrogen-bonding inter-actions between the amine NH groups of the acetohydrazide ligands and the nitrate oxygen atoms. Hirshfeld surface analysis was performed to aid in the visualization of inter-mol-ecular contacts.

Thermodynamics and Catalytic Properties of Two Novel Energetic Complexes Based on 3-Amino-1,2,4-triazole-5-carboxylic Acid.

For energetic materials (EMs), the key point of the present research is to improve the energetic property and reduce sensitivity. In this work, two new energetic complexes, Mn(atzc)2(H2O)2·2H2O (1) and Zn(atzc)2(H2O) (2) (Hatzc = 3-amino-1,2,4-triazole-5-carboxylic acid), were synthesized by solvent evaporation and diffusion methods, respectively. The structural analyses illustrate that 1 and 2 exhibit zero-dimensional structural units, which are linked by hydrogen-bonding interactions to give three-dimensional supramolecular architectures. For complexes 1 and 2, the detonation velocities (D) are 10.4 and 10.2 km·s–1 and detonation pressures (P) are 48.7 and 48.6 GPa, respectively. They are higher than most of the reported EMs, which present prominent detonation characteristics. In addition, two complexes can accelerate the thermal decomposition of ammonium perchlorate and exhibit excellent catalytic activity. Therefore, the two complexes can serve as a new class of promising EMs, which have potential application in the design of new high-efficiency solid catalysts.

Synthesis, characterization, crystal structure and antibacterial activity studies of cobalt(II) and zinc(II) complexes containing halogen quinoline Schiff base ligand

This work presented the synthesis, characterization and biological activity of Co(II) and Zn(II) complexes derived from 4‑chloro-2-((quinolin-6-ylimino)methyl)phenol (HL), their structures were characterized using IR, NMR and single-crystal X-ray diffraction. The HL was crystallized in the orthorhombic crystal systems, space groups of Pccn, and two HL molecules contained its smallest asymmetric unit. The self-assembly of HL with metal (II) (M=Co, Zn) led to the formation of CoL2 (1) and ZnL2 (2) by solvothermal method in methanol-water system. The basis of spectroscopic techniques, single-crystal X-ray diffraction and powder X-ray diffraction analysis further revealed that 1 and 2 were isomorphous with similar coordination mode and similar structural features. The introduction of a chlorine atom and C=N group to the ligand facilitated the collaboration of electrostatic interaction, hydrogen bonding, π⋯π stacking interaction and the rare C—H⋯Cl interaction, which resulted in the formation of three-dimensional supramolecular architectures. The synthesized complexes exhibited significant antimicrobial activity when evaluated against six phytopathogenic fungi, 2 exhibited a wider range antimicrobial activity compared to HL and 1.

Supramolecular structure and spectroscopic characterization of new 1,3,5-triaza-2-boracyclohex-3-en derivative formed under mild conditions between 2-imino-4-thiobiuret and boric acid

Reaction of 2-imino-4-thiobiuret with boric acid (in molar ration of 1:1) in aqueous solution at the mild conditions leads to formation of a heterocyclic compound of 2,2-dihdroxy-4-amino-6-thio-1,3,5-trihydrotriaza-2-boracyclohex-3-en (1). This compound crystallizes directly from the reaction solution after a few days, giving light yellowish transparent monoclinic crystals (P21/n). X-ray single crystal analysis shows that the heteroring and the thio- and amine groups are co-planar, whereas the plane of hydroxyl groups linked to boron are almost perpendicular to plane of the ring. The 2,2-dihdroxy-4-amino-6-thio-1,3,5-trihydrotriaza-2-boracyclohex-3-en molecules are arrangement via O–H...S hydrogen bonds in the stacks along b-axis, and the stacks are interacting each other via N–H...O hydrogen bonds forming a three-dimensional supramolecular architecture. The qualitative and quantitative intermolecular interactions in the crystal were analyzed using the Hirshfeld surface and 2D-fingerprint plots. The compound was also characterised by the FT-IR and Raman spectroscopy. The IR and FT-Raman spectra were made for protiated (1) and its deuterated analogue (1d). The IR and FT-Raman spectra for molecule in the gas-phase were calculated using DFT. DFT calculations and the isotropic frequency shift are helpful in assignments of the vibration bands. The calculated HOMO and LUMO energy gap explain the charge transfer interactions taking place within the molecule.

Synthesis and crystal structure of catena-poly[[hexa-aqua{μ3-2-[bis-(carboxyl-atometh-yl)amino]-terephthalato}dicobalt(II)] penta-hydrate] containing water tapes and penta-mers.

The title coordination polymer, {[Co2(C12H7NO8)(H2O)6]·5H2O} n , was crystallized at room temperature from an aqueous solution of 2-aminodi-acetic terephthalic acid (H4adtp) and cobalt(II) nitrate. The asymmetric unit consists of one adtp4- ligand, one and two half CoII ions, six water ligands coordinated to CoII ions and five uncoordinated water mol-ecules. Two of the cobalt cations lie on centres of inversion and are coordinated in octa-hedral O2(OH2)4 environments, whereas the other adopts a slightly distorted octa-hedral NO3(OH2)2 environment. The crystal structure contains parallel stacked, one-dimensional zigzag chains, {[Co2(C12H7NO8)(H2O)6]} n , which assemble into a three-dimensional supra-molecular architecture via networks of hydrogen bonds involving the coordinated and free water mol-ecules. One-dimensional 'water tapes' are formed, containing alternating six-membered and twelve-membered rings of water mol-ecules, together with water penta-mers, in which a central uncoordinated water mol-ecule is hydrogen bonded to two coordinated and two free water mol-ecules in a tetra-hedral arrangement.