Sonochemical synthesis of a novel nanorod diaqua(pyridine-2,6-dicarboxylato)copper(II) 3-D supramolecular network: new precursor to prepare pure phase nanosized copper(II) oxide

A nanosized copper(II) supramolecular compound, [Cu(dipic)(H₂O)₂] _n (1) [dipic?=?2,6-pyridinedicarboxylate], has been synthesized by sonochemical method and characterized by elemental analysis, scanning electron microscopy, X-ray powder diffraction, IR spectroscopy, TGA/DTA, and BET surface area studies. The structure of single crystalline 1 developed from nanosized 1 has been determined by X-ray crystallography and further characterized by scanning electron microscopy, TGA/DTA, and BET surface area studies. The XRD studies reveal that nanorod copper(II) supramolecular compound adopts a 3-D supramolecular network owing to extensive hydrogen-bonding and π–π stacking. Solvent effects on size and morphology of nanosized 1 have been studied. Calcination of nanosized 1 at 500°C under air yields CuO nanoparticles.     

A Facile Sonochemical Method for Synthesis of Mercury Selenide Nanostructures

Mercury selenide (HgSe) nanostructures has been achieved from N–N′-bis(salicylaldehyde)-1,2-phenylenediimino mercury [Hg(salophen)] as a new precursor. Cubic phase HgSe nanoparticles with the size of mostly 20–40 nm were produced by sonication of the Hg(salophen) precursor. The products were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, photoluminescence, energy dispersive X-ray spectroscopy and Fourier transformed infrared spectroscopy. The results of this paper show that the shape and size of mercury selenide nanostructures can be controlled systematically by adjusting reaction parameters, such as the ultrasonic power, temperature, capping agent and reaction time.     

Molecular and supramolecular properties of a Hg(II) complex with (E)-N,N′-bis(2-pyridyl)iminoisoindoline: synthesis,spectroscopy, X-ray structure and Hirshfeld surface analyses,and DFT calculations

A scarcity of metal complexes containing (E)-N,N′-bis(heteroaryl)iminoisoindolines has prompted us to investigate the coordinating ability and supramolecular behavior of (E)-N,N′-bis(2-pyridyl)iminoisoindoline (2-pyimiso), a versatile iminobis(pyridyl) ligand. The 1:1 reaction of HgCl₂ with 2-pyimiso in MeOH afforded a dinuclear complex, [{HgCl(2-pyimiso)}₂(μ-Cl)₂] (1). The complex has been characterized by elemental microanalysis, vibrational spectroscopy (FTIR and FT-Raman) and ¹H NMR spectroscopy. DFT calculations at the B3LYP-D3/LACV3P** level have been used in support of our vibrational analysis. Single-crystal X-ray diffraction data have shown that the coordination geometry of 1 is intermediate between the trigonal pyramidal and seesaw shapes insofar as each Hg(II) is four-coordinate and 2-pyimiso is a monodentate ligand. X-ray structure and Hirshfeld surface analyses have revealed that the supramolecular arrangement of 1 comprises perpendicular 1-D chains along the [011] direction assembled by nonclassical C–H?Cl–Hg and C–H?π hydrogen bonds. Moreover, adjacent sheets parallel to the bc-plane are interconnected by C–H?N_py, π–π_py stacking, and Hg?π_py interactions.     

Hydrothermal synthesis and crystal structure of (H2bpp)3[Mo5P2O23]·H2O: a twofold interpenetrating 3D supramolecular architecture constructed of Standberg-type polyoxometalate

A novel three-dimensional (3D) supramolecular assembly of Standberg-type polyoxometalate and flexible organic molecule (H₂bpp)₃[Mo₅P₂O₂₃]·H₂O (1) [bpp = 1,3-bis(4-pyridyl)propane] has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR spectra, elemental analysis and thermogravimetric analysis (TGA). X-ray analyses show that compound 1 represent a twofold interpenetrating 3D supramolecular architecture constructed of Standberg-type polyoxometalate and bpp molecular through the hydrogen bonds as well as electrostatic interactions.     

The first X-ray crystal structure of a mercury(II) complex with an SP(N)3-based ligand: Synthesis and crystal structure of SP(NC5H10)3 and [Hg{SP(NC5H10)3}Cl2]2

The synthesis, spectral characteristics (IR and NMR), elemental analysis and X-ray crystal structure of phosphorothioic triamide SP(NC₅H₁₀)₃ (1) and its dinuclear mercury(II) complex [Hg₂(μ-Cl)₂(Cl)₂{SP(NC₅H₁₀)₃}₂] (2) were investigated. A survey using the Cambridge Structural Database (CSD, version 5.38, May 2017) shows structures of coordination compounds of Au, Ag, Cd, Cu, Li, Mo, Ni, Pd, Te, Ti, Zn, and Zr with sulfur-donor SP(N)₃-based ligands; the complex 2 is the first example of a mercury complex with the SP(N)₃-based ligand studied by X-ray crystallography. Valence bond calculation was performed for the Hg–S bond in 2 and compared with the Hg–O bond in the only structure with a Cl₂Hg–OP(N)₃ structural motive in the CSD. The calculation confirms a more covalent nature of the Hg–S bond with respect to the Hg–O bond made by the EP(N)₃-based ligands (E?=?S, O). The supramolecular structures based on C–H···S?=?P contacts in 1 and C–H···S═P and C–H···Cl–Hg assemblies in 2 are discussed.     

Novel 3-D Supramolecular Architectures Constructed from Zn^2＋ ions, Oxybis（4-benzoate） and Di（2-pyridyl）amine Ligands

Using the V-shaped oba dianions as bridging ligands and dpa molecules as terminal ligands, a new 1D helical coordination-polymeric chain, [Zn（oba）（dpa）]n [oba=oxybis（4-benzoate）, dpa=di（2-pyridyl）amine], was synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, UV-Vis and IR spectra, and TGA analysis. X-ray structural analysis revealed that, oba and dpa ligands played an important role in the self-assembly of the helical chains by providing potential supramolecular recognition sites for π-π aromatic stacking and hydrogen-bond interactions, resulting in the self-assembly of the （4,4） networks to give a 3-D supramolecular framework. The photoluminescence properties of the title compound were also investigated, showing intense blue photoluminescence properties at room temperature.     

Assembly of a new circle connecting circle chain through exerting the template role of a Keggin polyoxometalate

By using the flexible bis(triazole) ligand 1,2-bis(1,2,4-triazol-1-yl)ethane (bte), a polyoxometalate-templated compound, [Zn₂(bte)₄(SiW₁₂O₄₀)]·2H₂O (1), was synthesized under hydrothermal conditions. The compound was characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, photoluminescence spectroscopy, and cyclic voltammetry. Compound 1 is constructed from two motifs: the [SiW₁₂O₄₀]^4? polyanion and a bi-nuclear metal-organic circle [Zn₂(bte)₂]⁴⁺. The polyanion exerts a template role, inducing the formation of the bi-nuclear circle. The circles build a 1-D circle connecting circle chain through sharing the same Zn ions. Adjacent circles in the chain are vertical with each other. The template polyanion is surrounded by four circles from four different 1-D chains, forming a 3-D supramolecular structure.     

Synthesis and structural characterization of three supramolecular coordination polymers constructed from different metal ions and 2,2′-bipyridyl-3,3′-dicarboxylic acid

Three new supramolecular coordination polymers based on 2,2′-bipyridyl-3,3′-dicarboxylic acid (H₂BPDC) and Mn(II), Fe(II), and Zn(II) were synthesized under hydrothermal conditions and characterized with single-crystallographic X-ray analysis and IR spectrum. Complex 1 exhibits a 1-D, chain-like structure, which is further connected to 2-D supramolecular layer structure through hydrogen bonds. Complex 2 exhibits a 3-D supramolecular structure constructed from 1-D chains through hydrogen bonds and π–π interactions. Like 1, 3 also shows 2-D supramolecular layer structure based on 1-D chains. Furthermore, the fluorescence of 3 was studied.     

Stimuli-responsive,thixotropic bicomponent hydrogel of melamine–Zn(II)-orotate complex

Zinc(II)-orotate complex (ZnOA) has been synthesised, and it is used to produce supramolecular complex with melamine (M) at 1:1 molar ratio. During sonication for 5–6 min, the supramolecular complex is transformed into a bi-component hydrogel (S-gel). The spectroscopic tools such as FTIR and UV–vis spectra suggest that the H-bonding interaction between M and ZnOA produces a supramolecular complex which further forms J-aggregates during gelation. The circular dichroism spectra indicate the change in ellipticity with temperature that arises from the molecular dissymmetry during stacking of the ZnOAM complexes. The microscopic images indicate that the hydrogel network is formed with short helical nano-fibres. The energy-minimised structure of ZnOAM complex exhibits a well-defined d value of 11.3 Å obtained from X-ray scattering of the xerogel. The frequency-dependent rheological experiment (storage modulus (G′) is greater than loss modulus (G″)) characterises it as a gel. The gel shows thixotropic and stimuli-responsive behaviour.     

New nano-particle La(III) supramolecular compound as a precursor for preparation of lanthanum oxybromide-, hydroxide-, and oxide-nanostructures

Nano-particles of a new La(III) supramolecular compound [La(4,4′-bipy)(H₂O)₂(NO₃)_3.75Br_0.25] · (4,4′-Hbipy) (1), have been synthesized from reaction of 4,4′-bipy with La(NO₃)₃ and NaBr by the sonochemical method. For the first time LaOBr, La(OH)₃ and La₂O₃ nano-structures were prepared from [La(4,4′-bipy)(H₂O)₂(NO₃)_3.75Br_0.25] · (4,4′-Hbipy) (1) by calcination at 400, 500, and 700°C, respectively. The structure of 1 was determined by X-ray crystallography and the nano-structures were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). Thermal stabilities of nano and crystal samples of 1 were studied and compared with each other.     

A water chain with trimeric/hexameric clusters trapped in a POM/Ln compound

A new 3-D supramolecular compound based on a Keggin polyoxometalate and lanthanide (Ln) coordination cations [Ce(H₂O)₃L₃]₂[HSiMo₁₂O₄₀]₂[L] ? 7H₂O (1) (L = isonicotinic acid) has been synthesized and characterized by routine methods. Compound 1 has a water chain with trimeric and hexameric water clusters trapped in the network. The isonicotinic acid plays a key role in forming the 1-D water chains. Compound 1 shows intense photoluminescence at room temperature.     

Hydrothermal synthesis,crystal structure and characterization of a new 1-D supramolecular ladder based on a binuclear CdII complex [Cd2L4(3,5-DNBA)2](H2O) with L as a bridging ligand (L=3-(2-pyridyl)pyrazole; 3,5-DNBA=3,5-dinitrobenzoate)

A new 1-D cadmium(II) mixed ligand dimer supramolecular ladder [Cd₂ L ₄(3,5-DNBA)₂]H₂O (1), (L?=?3-(2-pyridyl)pyrazole and 3,5-DNBA?=?3,5-dinitrobenzoate) was synthesized by hydrothermal methods. X-ray structural analysis of complex 1 revealed that two cadmium(II) cores are bridged by two deprotonated pyrazole groups of L, leading to dinuclear cadmium(II) [Cd₂ L ₄(3,5-DNBA)₂]. The dimers are joined by hydrogen-bonding interactions between two different cadmium(II) dimers to form a one-dimensional ladder-like framework and stabilized by weak π–π interactions. Moreover, the fluorescence spectrum of compound 1 exhibits blue fluorescent emission in the solid state at room temperature.     

Copper(II) coordination frameworks with 1H-benzimidazole-5,6-dicarboxylic acid: syntheses,crystal structures and magnetic properties

Cu(II) polymers of Hbidc (1H-benzimidazole-5,6-dicarboxylate), namely [Cu₂(Hbidc)₂(H₂O)₄·3H₂O] _n (1) and [Cu(Hbidc)] _n (2), were synthesized under hydrothermal conditions by variation of the reaction temperature and characterized by physico-chemical, spectroscopic and single-crystal X-ray diffraction studies. At temperatures from 100 to 170 °C, we only obtained the 2-D structure compounds 1 and 2, in which the bridging mode of the Hbidc ligand increases from μ ₃ to μ ₅ and the number of water ligands decreases to 0. Both compounds have 3-D supramolecular architectures extended by hydrogen bonding and π–π interactions between the adjacent layers. Magnetic studies revealed that compound 1 shows weak antiferromagnetic properties and compound 2 exhibits ferromagnetic coupling between the two Cu(II) ions in the dimeric units.     

Synthesis and supramolecular features of hybrid POM/onium solid-state assemblies

Abstract

Polyoxomolybdate-based organic?inorganic hybrid architectures were synthesised and characterised by X-ray crystallography. The supramolecular assemblies present rows of metallic clusters H-bonded by ammonium cations, with a 1:2 molybdate/ammonium ratio. The organic moieties of the ammonium cations establish hydrophobic contact among them such as van der Waals, C–H?π and π?π interactions that stabilise the supramolecular architectures. In particular, for compound 5 the n-alkyl tails pack closely together giving a lipid-like bilayer. In compound 6, the aromatic phenyl rings of the organic cation allow the stabilisation of the supramolecular architecture by C–H?π and π?π interactions. Regarding the X-ray structure of the compound 11, the tetraanionic octa-molybdate [Mo₈O₂₆]^4? cluster is surrounded by four ethyl-triphenyl-phosphonium cations. Running along the b-axis open channels are occupied by DMF solvent molecules. Interestingly, a soaking experiment in n-pentane with the corresponding crystals of compound 11 afforded to a crystal structure very different from the native one.     

Hydrothermal synthesis and crystal structure of Na(NH4)[C13N2H16]2[Mo7O24]?·?8H2O: A novel 3-D extended supramolecular network with 1-D channels

A novel three-dimensional (3-D) supramolecular assembly of organic bicapped heptamolybdate Na(NH₄)[C₁₃N₂H₁₆]₂[Mo₇O₂₄]·8H₂O has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR spectra, elemental analysis, and thermogravimetric analysis (TGA). X-ray analyses show that compound 1 represent a novel 3-D extended supramolecular “host” networks with 1-D channels encapsulating flexible cation “guests”. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

An inorganic-organic compound with 1D honeycomb-like channels constructed from non-covalent linkage: synthesis and properties

An inorganic-organic hybrid compound {[Cu(phen)₃]₂PW₁₁VO₄₀ ·?2H₂O (1) has been hydrothermally prepared and structurally characterized by elemental analyses, IR, CV, TG, magnetic susceptibility measurements and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space group C2/c with a =?27.232(2) Å, b =?25.351(2) Å, c =?16.2748 (4) Å, β?= 105.20°, V =?10842.3 ų, Z =?4, R₁ =?0.0490 and wR₂ =?0.1362. The structure of 1 exhibits a three-dimensional supramolecular network, formed by hydrogen-bonding and π–π stacking interactions. The three-dimensional network consists of one-dimensional honeycomb channels, which accommodate free water molecules. The size of the channel is 10.4 ×?10.4 Å. Electrochemistry of 1 shows it undergoes three one-electron reversible redox processes. Variable-temperature magnetic measurements show typical antiferromagnetic interactions in the 2–300 K temperature range.     

Hydrothermal synthesis of a nano-rod mercury(ii) metal-ligand coordination compound

A novel nano-rod mercury(II) coordination compound [Hg (BINH)I₂] (1), (BINH is the abbreviation of benzylideneisonicotinohydrazide) is synthesized by a hydrothermal method that produces the coordination compound at a nanosize level. The new nanostructure is characterized by scanning electron microscopy, powder X-ray diffraction, elemental analysis, and IR spectroscopy. Compound 1 was structurally characterized by single crystal X-ray diffraction and the single-crystal structure of this complex shows that each mercury(II) center is four-coordinated with two N-donor atoms from tow BINH ligands and tow iodo anions. Self-assembly of this complexes is pereformed by CH?I and π-π stacking interactions. The supramolecular features in these complexes are controlled by weak directional intermolecular interactions.     

(±) Benzomalvins E isolated from Penicillium sp. SYPF 8411 in the rhizosphere soil of Codonopsis clematidea

Abstract

(+) Benzomalvins E (1) and (-) Benzomalvins E (2), a pair of epimeric derivatives, together with three known benzomalvins (3–5), were isolated from solid cultures of a interrhizospheric fungus Penicillium sp. SYPF 8411. The planar structure of (+) Benzomalvins E (1) has been previously reported. While, the absolute configuration of compound 1 was established by X-ray crystallographic analysis for the first time. The planar structure of the new compound 2 were elucidated by detailed interpretation of their HR ESI-TOF MS and NMR spectroscopic data. The absolute configuration of compound 2 was established by Rh₂(OCOCF₃)₄-induced CD spectral data and the electronic circular dichroic (ECD) method. Furthermore, the epimerization induced by pH, temperature and H₂O was revealed. Benzomalvins (1–3, 5), a type of indoximod, enhanced the cytotoxic capability of 5-fluorouracil against A549.     

Heterobimetallic Mn(II)-Hg(II) polynuclear complexes containing Hg(SCN)4 unit - Synthesis, spectroscopic investigations, X-ray studies and magnetic properties

Two novel heterobimetallic coordination polymers with Hg(SCN)₄²⁻ as a linker have been synthesized and characterised by means of IR, EPR, magnetic measurements and single crystal X-ray. The compounds [Mn(bpzm)Hg(SCN)₄]_n (1) and [Mn(bdmpzm)₂Hg(SCN)₄]_n (2) form supramolecular framework structures. The compound 1 creates a three-dimensional coordination polymer and compound 2 has one-dimensional chain structure extending along the crystallographic direction [1 0 0]. Variable-temperature magnetic susceptibility measurements show very weak antiferromagnetic interactions between the paramagnetic Mn(II) centres of structures 1 and 2.     

The supramolecular assembly of tetraaqua-(pyridine-2,5-dicarboxylato)-copper(II) complex: crystal structure,TD-DFT approach,electronic spectra,and photoluminescence study

The copper(II) complex, {[Cu(2,5-pdc)(H₂O)₄]·H₂O} (1) [2,5-pdc?=?pyridine-2,5-dicarboxylate], has been synthesized and characterized by elemental analysis, IR spectroscopy, and X-ray crystallography. The metal shows a distorted octahedral coordination sphere and in solid state the complex forms a 3-D supramolecular network via hydrogen bonding and off-center anti-parallel π–π stacking interactions between py rings. At room temperature, 1 exhibits fluorescence in methanolic solution [λ_ex?=?226?nm, λ_em?=?309, 330, and 341?nm]. The geometry optimization at the B3LYP/LanL2DZ level led to a five-coordinate copper having a distorted square pyramidal geometry. The electronic spectrum of this compound is compared with the results obtained by employing density functional theory (DFT) and time dependent density functional theory calculations.