Three-dimensional Supramolecular Architecture Research Articles

Crystal structure of the heterometallic complex of Co(II) and Nd(III) with phenanthroline

A new heterometallic complex of CoII and NdIII with phenathroline [Co(Рhen)3][Nd(NO3)5(H2O)][Nd(NO3)4(H2O)2]H2O was synthesized for the first time by the self-assembly method. The crystal structure of the complex was determined by X-ray crystallography. The compound is an anion-cation complex and crystallizes in the monoclinic space group P21/n with unit cell parameters a=12.4251(4) Å, b=11.7206(3) Å, c=36.5374(12) Å, ==900, =90.581(3)0. In the crystalline phase, the complex is in the form of a crystal hydrate with a composition of 1:1. The anionic part of the complex consists of two nitrate hydrated NdIII complexes: [Nd(NO3)5(H2O)]2– and [Nd(NO3)4(H2O)2]–, in which the coordination number of neodymium is 11 and 10, respectively. The [Co(Phen)3]3+ ion is a cationic part of the complex in which the CoII atom has a distorted CoN6 octahedral environment, bidentately coordinating three phenanthroline molecules. Due to intermolecular hydrogen bonds (N–HO, O–HO), a three-dimensional supramolecular architecture is formed in the crystal, in which the polymer layers are packed parallel along the crystallographic axis a.

Zn(II)-based 2D coordination polymer bridged by isophthalate and Dipyridylsulphide : Structural characterisation, Schottky diode device and theoretical interpretation

The design of low cost, easy-to-prepare, soft-to-handle and sustainable material-based technology has been growing day-by-day. Coordination polymers (CPs) are such emerging materials those have been instructed as one of the premium resources to serve the electronic industry. In this aspect, we have designed a hetero-bridging Zn(II)-coordination polymer using two different bridging ligands - 4,4′-Dipyridylsulphide (4,4′-DPS) and 5-Nitroisophthalic acid (5-H2NIA), {[Zn(4,4′-DPS)2(5-HNIA)2(H2O)]n} (Zn-CP) and characterize the crystalline compound with Single Crystal X-ray diffraction (SCXRD) technique. The structure demonstrates that Zn-CP consists of two-dimensional (2D) network with distorted trigonal bipyramidal Zn(II) center (ZnN2O3). The self-assembly of 2D network by different non-covalent interactions forms three-dimensional (3D) supramolecular architecture. Hirshfeld surface analysis effectively evaluates the possibilities of non-covalent interactions present in Zn-CP. Density functional theory (DFT) based numerical calculation using crystallographic parameters has estimated the band gap 3.51 eV which implies the semiconducting nature of Zn-CP. This property has been endorsed by the determination of band gap from Tauc's plot (3.71 eV) using UV–Visible absorption data. The electrical conductivity of Zn-CP determined at room temperature is 8.54 x 10–7 S m-1. The DC activation energy of the device is 9.05 × 10–19 eV with the conductivity limit, 4.71 (Ω-m)-1 having Richardson constant, 7.07 × 10–10Am−2K−2and barrier height is 0.87 eV which suggests that the Zn-CP is n-type semiconductor. Thus, the present work may provide a facile pathway for laboratory-to-land application of such energy materials taking into consideration of technological aspect in the highly energy demanding era. Hence, the synthesized Zn-CP may have energy material application in the semiconducting industry.

Synthesis, crystal structures and fluorescence recognition properties of two novel chiral coordination compounds based on alanine derivate

Two novel chiral coordination compounds {[Cd(D-pmala)(2,2′-bipy)(H2O)]⋅1·25H2O}n (1), {[Pb4(D-pmala)4(5,5′-DM-2,2′-bipy)4(H2O)2]⋅7H2O}n (2) (D-pmala = N-(4-carboxyl) benzoyl-d-alanine, 2,2′-bipy = 2,2′-Bipyridine, 5,5′-DM-2,2′-bipy = 5,5′-Dimethyl-2,2′- Bipyridine) have been successfully synthesized under hydrothermal conditions. Their structures were identified using single-crystal X-ray crystallography and characterized by infrared spectroscopy, elemental analysis, thermogravimetric analysis, powder X-ray diffraction and solid-state circular dichroism spectra. Crystallographic analysis indicate that compound 1 features a "Z"-shaped one-dimensional chain structure, which further extends into three-dimensional supramolecular architectures through hydrogen-bonding interactions. Compound 2 displays a two-dimensional layer structure, a two-dimensional double-layer network structures is further formed through the hydrogen-bonding interactions. Moreover, The fluorescence recognition properties of compound 1 indicate that it is highly selective in detecting Cu2+ ions and tyrosine (Tyr) enantiomers in aqueous solutions, which indicates that compound 1 can be expected to be a bifunctional fluorescent recognition sensor to detect metal ions and amino acid enantiomers.

Crystal structure of catena-poly[[methanoldioxidouranium(VI)]-μ-2-[5-(2-oxidophen-yl)-1H-1,2,4-triazol-3-yl]acetato-κ2 O:O'

In the title complex, [U(C10H7N3O3)O2(CH3OH)] n , the UVI cation has a typical penta-gonal-bipyramidal environment with the equatorial plane defined by one N and two O atoms of one doubly deprotonated 2-[5-(2-hy-droxy-phen-yl)-1H-1,2,4-triazol-3-yl]acetic acid ligand, a carboxyl-ate O atom of the symmetry-related ligand and the O atom of the methanol mol-ecule [U-N/Oeq 2.256 (4)-2.504 (5) Å]. The axial positions are occupied by two oxide O atoms. The equatorial atoms are almost coplanar, with the largest deviation from the mean plane being 0.121 Å for one of the O atoms. The benzene and triazole rings of the tetra-dentate chelating-bridging ligand are twisted by approximately 21.6 (2)° with respect to each other. The carboxyl-ate group of the ligand bridges two uranyl cations, forming a neutral zigzag chain reinforced by a strong O-H⋯O hydrogen bond. In the crystal, adjacent chains are linked into two-dimensional sheets parallel to the ac plane by C/N-H⋯N/O hydrogen bonding and π-π inter-actions. Further weak C-H⋯O contacts consolidate the three-dimensional supra-molecular architecture. In the solid state, the compound shows a broad medium intensity LMCT transition centred around 463 nm, which is responsible for its red colour.

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.