Vinyl-group alignment along the upper rim of a multi-component resorcin[4]arene

Cocrystallization of C-methylcalix[4]resorcinarene 1 with 4-vinylpyridine obtained from MeNO₂ yields a six-component host–guest complex 1·4(4-vinyl-pyridine)·MeNO₂ 2 in which the upper rim of 1 is extended supramolecularly by way of four O–H⋯N(pyridine) hydrogen bonds and the included solvent serves as a guest. The pyridine moieties of 2 assemble along the upper rim of 1 as two stacked dimers in which the vinyl substituents of the aromatic adopt a parallel orientation. The X-ray crystal structure of resorcinol·2(4-vinylpyridine) 3 has also been determined and reveals that the vinyl groups of 3 are aligned in an antiparallel fashion. These observations allow us to suggest that multi-component resorcin[4]arenes which possess vinyl-pyridines as cavity extenders may provide a route to aligning olefinic bonds in the solid state.     

Novel inclusion compounds consolidated by host-host and host-guest hydrogen bonding: Complexes of thiourea with (2-hydroxyethyl)trimethylammonium carbonate and oxalate

New inclusion complexes [(CH₃)₃N⁺CH₂CH₂OH]₂CO₃^2-·6(NH₂)₂CS (1) and [(CH₃)₃N⁺CH₂CH₂OH]₂C₂O₄^2-·2(NH₂)₂CS (2) have been prepared and characterized by X-ray crystallography. In the crystal structure of 1, the choline ions are accommodated within an open channel-type host lattice built of urea molecules and carbonate ions. In complex 2, the choline ions are sandwiched between pleated sheets constructed from the parallel arrangement of thiourea-oxalate ribbons. In both inclusion compounds the guest choline ions form O-H⋯O donor hydrogen bonds with anionic O atoms in the host lattices.     

1D- and 2D-networks based on bis- and tris-(2-R-benzimidazol-1-yl)methanes

The supramolecular entities formed by five polybenzimidazolylmethanes,bis(2-tert-butylbenzimidazol-1-yl)methane 2, bis(2-(adamant-1-yl)benzimidazol-1-yl)methane 3, tris(2-ethylbenzimidazol-1-yl)methane 4, tris(2-isopropyl-benzimidazol-1-yl) methane 5, and tris(2-chlorobenzimidazol-1-yl)methane 6 have been investigated. Compounds 2 and 5 crystallize without any included guest, while compounds 3 (methanol and water), 4 (water), and 6 (cyclohexane) show their host properties.     

Synthesis and IR spectroscopic characterization of fluorinated graphite intercalation compounds with chlorinated derivatives of methane and ethane

We have synthesized (C₂F _x Br_0.01 · yG) _n intercalation compounds with (C₂F _x Br_0.01) _n as a host and G (dichloromethane, chloroform, carbon tetrachloride, and dichloroethane) as a guest (x and y are stoichiometric coefficients). The behavior of the functional groups in the guest and host subsystems has been studied by IR spectroscopy. We have examined the influence of the degree of fluorination of the polymer host (0.5 < x < 1.0) and the nature of the guest on the vibrational frequencies of the C-F and C-Cl bonds.     

2,4,6-tris-4-(bromophenoxy)-1,3,5-triazine: a hexagonal host framework assembled with robust Br⋯Br trimer synthons

Based on the trigonal symmetry of the title triazine 1 and the Br₃ supramolecular synthon, a hexagonal host system has been designed and shown to include hexachlorobenzene, 2,4,6-collidine, 1-methylnaphthalene and mesitylene guests in its porous structure. In the 1.hexachlorobenzene (2:1) inclusion clathrate 2, the guest molecule is ordered and bonded to the host through Cl⋯O interactions. In the channel structures 3, 4 and 5, the solvent molecules are disordered and the host-guest stoichiometry is 1:1. These supramolecular structures highlight the importance of weak hydrogen bonds and heteroatom interactions in the self-assembly of target networks. The generality of the new host system is also demonstrated.     

Ultrahigh and Selective SO2 Uptake in Inorganic Anion‐Pillared Hybrid Porous Materials

The efficient capture of SO₂ is of great significance in gas‐purification processes including flue‐gas desulfurization and natural‐gas purification, but the design of porous materials with high adsorption capacity and selectivity of SO₂ remains very challenging. Herein, the selective recognition and dense packing of SO₂ clusters through multiple synergistic host–guest and guest–guest interactions by controlling the pore chemistry and size in inorganic anion (SiF₆^2?, SIFSIX) pillared metal–organic frameworks is reported. The binding sites of anions and aromatic rings in SIFSIX materials grasp every atom of SO₂ firmly via S^δ+···F^δ? electrostatic interactions and O^δ?···H^δ+ dipole–dipole interactions, while the guest–guest interactions between SO₂ molecules further promote gas trapping within the pore space, which is elucidated by first‐principles density functional theory calculations and powder X‐ray diffraction experiments. These interactions afford new benchmarks for the highly efficient removal of SO₂ from other gases, even if at a very low SO₂ concentration. Exceptionally high SO₂ capacity of 11.01 mmol g^?1 is achieved at atmosphere pressure by SIFSIX‐1‐Cu, and unprecedented low‐pressure SO₂ capacity is obtained in SIFSIX‐2‐Cu‐i (4.16 mmol g^?1 SO₂ at 0.01 bar and 2.31 mmol g^?1 at 0.002 bar). More importantly, record SO₂/CO₂ selectivity (86–89) and excellent SO₂/N₂ selectivity (1285–3145) are also achieved. Experimental breakthrough curves further demonstrate the excellent performance of these hybrid porous materials in removing low‐concentration SO₂.     

Double stranded chains and interwoven structures: the role of conformational isomerism in coordination polymers

The 1:3 and 1:1.5 coordination complexes of 1,3–bis(4–pyridyl)propane, 1, [Ni(1)₂(H₂O)₂][NO₃]₂⋅(1)⋅(H₂O), 2 and [Cd₄(1)₆(NO₃)₈], 3 form a double stranded chain and four-fold interwoven structures, respectively. Complex 2 is an unusual coordination complex where the ligand not only coordinates with the metal salt but also cocrystallizes with the coordination complex. The double stranded linear chains in 2 have 24 membered rings with a Ni···Ni intra-chain distance of 11.53 Å and close-pack to form a two dimensional layered structure. The anions, non-coordinating ligands, and the solvated water molecules sandwich between the layers in a bilayer fashion. Complex 3 forms an open network owing to its T-shaped geometry but the conformational flexibility of the ligand blurs the difference between the expected brick wall pattern and the distorted hexagonal network. The internal dimensions between opposite Cd metal centers in the distorted non-planar network are ca 18.3×23.2×28.5 Å. These open networks readily undergo four-fold parallel interpenetration and result in a carpet like structure.     

Synthesis and properties of (C2F x Br0.01 · y CH3COOC2H5) n (0.5 < x < 1.0) intercalation compounds

We have synthesized layered inclusion (intercalation) compounds with the general formula (C₂F _x Br_0.01 · yG) _n , where (C₂F _x Br_0.01) _n is a host component, G stands for ethyl acetate (guest component), 0.5 < x < 1.0, y ₁ = 0.109–0.162 (stage 1), and y ₂ = 0.052–0.074 (stage 2). Using IR spectroscopy, we studied the behavior of the functional groups in the guest and host subsystems. The influence of the composition (structure) of the polymer host (C₂F _x Br_0.01) _n on the properties of the synthesized compounds was studied using physicochemical characterization techniques (differential thermal analysis and X-ray diffraction).     

Design,Synthesis, and Biological Activity of Novel Aromatic Amide Derivatives Containing Sulfide and Sulfone Substructures

In recent years, the damage caused by soil nematodes has become increasingly serious; however, the varieties and structures of the nematicides available on the market are deficient. Fluopyram, a succinate dehydrogenase inhibitor (SDHI) fungicide developed by Bayer AG in Germany, has been widely used in the prevention and control of soil nematodes due to its high efficiency and novel mechanism of action. In this paper, two series of novel target compounds were designed and synthesized with nematicidal and fungicidal fluopyram as the molecular skeleton in order to introduce sulfide and sulfone substructures. The structures were identified and characterized by ¹H nuclear magnetic resonance (NMR), ¹³C NMR, and high-resolution mass spectrometer (HRMS). The bioassays revealed that most of the compounds showed excellent nematicidal activities at 200 µg·mL⁻¹ in comparison with fluopyram, while the nematode mortality rate dropped sharply at 100 µg·mL⁻¹, except for compounds I-11 and II-6. In terms of fungicidal activity, compound I-9 was discovered to have an excellent inhibitory rate, and a molecular docking simulation was performed that can provide important guidance for the design and exploration of efficient fungicidal lead compounds.     

Halogen···halogen versus OH···O supramolecular interactions in the crystal structures of a series of halogen and methyl substituted cis-9,10-diphenyl-9,10-dihydroanthracene-9,10-diols

The crystal structures of four p-phenyl-substituted cis-9,10-diphenyl-9,10-dihydroanthracene-9,10-diols, carrying chloro- (1), bromo- (2), iodo- (3) and methyl substituents (4), respectively (with 2 being a previously described compound), have been studied in order to compare the effects of these substituents on the crystalline architecture. Ordinary O–H···O hydrogen bonds govern the packing of the methyl-substituted molecules in 4, whereas interhalogen interactions in competition with conventional hydrogen bonds direct the crystalline arrangement of the halogenated homologues 1–3, yielding somewhat lower symmetry and lower packing coefficient for the latter crystals. All short (Cl···Cl<3.49, Br···Br<3.46, I···I<3.86 Å) interhalogen interactions are symmetrical type-I connections with more or less “head-on” directions, where increasing size of the connected halogens seems to increase a tendency towards deviation from the ideal head-on geometry. Substitution of methyl in 4 for chlorine in 1 changed the crystal packing significantly, whereas the chloro-substituted derivative (1) was found to form a crystal isostructural with its bromo-substituted analogue (2). Two of the short interchloro distances in 1 were found to be slightly longer than the corresponding ones in the bromo analogue. This is rather unusual, although extensive inspection of the literature and the Cambridge Structural Database yielded five more examples of pairs of organic chloro and bromo analogues, forming isostructural crystals with direct Cl···Cl contact distances equal to or slightly longer than the corresponding Br···Br distances.     

Reaction of Cd(NO3)2·4H2O with 4,4'–bipyridine (bpy) in MeOH solvent: synthesis and characterization of T-shaped [Cd(bpy)1.5(NO3)2]·3H2O,square grid [Cd(bpy)2(H2O)2](NO3)2·4H2O and linear polymeric [Cd(bpy)(H2O)2(NO3)2]

The influence of concentration of water and metal salt in the reaction between Cd(NO₃)₂·4H₂O and 4,4′–bipyridine in MeOH has been studied and three compounds namely, T-shaped [Cd(bpy)_1.5(NO₃)₂]·3H₂O, 1 square grid [Cd(bpy)₂(H₂O)₂](NO₃)₂ 4H₂O, 2 and one dimensional linear polymer, [Cd(bpy)(H₂O)₂(NO₃)₂], 3 were isolated quantitatively in this process. Compound 1 forms in MeOH at high dilution of the metal salt (5.0 mg/mL or less) and for the metal-to-ligand ratio 1:(1.5–2.0). Compound 2 forms exclusively in the concentration range, 17–33% for water in MeOH by volume and 12–28 mg/mL for the metal salt of the solution. Outside these limits, mixtures of 2 and 3 were isolated. For 1:1 ratio of metal salt to bpy, the linear polymer, 3 was obtained in major quantity and its formation was found to be independent of concentration of water or the metal salt. Compounds 1 and 2 have been characterized by X-ray crystallography. On heating all the compounds decompose through a common intermediate [Cd(bpy)(NO₃)₂] and finally to CdO as monitored by TG.     

Two novel Zn (II)​-based metal–organic frameworks for rapidly selective adsorption and efficient photocatalytic degradation of hazardous aromatic dyes in aqueous phase

Two novel Zn-MOFs constructed from 5-hydroxy-2-nitroisophthalic acid (H₂DIPA) and 5-(4-carboxy-2-nitrophenoxy)-2-nitroisophthalic acid (H₃BPPA), namely: {[Zn₂(DIPA)₂(bimp)₅]·DMF·2H₂O}_n (Zn-MOF 1), {[Zn₂(HBPPA)₂(bibp)₂]·2H₂O}_n (Zn-MOF 2) (bimp = 1,4-di(1H-imidazol-1-yl)butane, bibp = 4,4′-bis(imidazolyl) biphenyl), have been synthesized under solvothermal conditions and characterized by single crystal X-ray diffraction, elemental analysis, IR spectra, powder X-ray diffraction (PXRD) and thermogravimetric analysis (TG). The single-crystal X-ray diffraction analysis indicates that Zn-MOF 1 exhibits an uncommon 3-nodal framework with a (4·6·8)(4·6³·8²)(6⁶) topology, whereas Zn-MOF 1 exhibits an uninodal 4-connected framework with a (4⁴·6²) topology. Moreover, both of the two Zn-MOFs exhibit exceptional dye adsorption capacities towards the organic dyes with high adsorption rates and excellent adsorption amounts. Particularly, Zn-MOF 1 can selectively adsorb the cationic dye malachite green (MG) whereas Zn-MOF 2 adsorb the anionic dye methyl orange (MO) when there exists another kind of dye in the system. The adsorption process can be illustrated by pseudo-second order kinetic and Langmuir isotherm, and the feasible adsorption mechanism could be the electrostatical interactions, hydrogen bonding between the MOFs and the dyes. Meanwhile, the two Zn-MOFs also show good photocatalytic degradation capabilities toward MB/MV dyes under UV irradiation, and the mechanism studies demonstrate that the main active species are ·OH radicals. Therefore, this functional MOF materials can be treated as a convenient and cost-efficient solution for the sewage handling and environmental protection.     

Charakterisierung von ferrocen-FeOCl-intercalat-phasen durch tieftemperatur-Mössbauerspektroskopie

Fe (C₅H₅)₂⁺ (6FeOC1) · e^? intercalation phases were studied by Mössbauer spectroscopy at 4 K. The absorption lines of the guest and host iron components are clearly separated. The isomer shift of the Fe (C₅H₅)⁺₂ guest species relative to α-Fe metal lies between δ = 0.44 ? 0.48 mm/sec. When prepared at room temperature, the intercalated compound represents, at 4 K, a single phase with a paramagnetic and an antiferromagnetic component, as expected for Fe (C₅H₅)₂⁺ (6FeOC1) · e^?. In preparations at higher temperature however, two magnetically ordered systems are revealed at 4 K, both of which differ in their magnetic and quadrupol data from the previously mentioned phase.     

Interpenetrating covalent and noncovalent nets in the crystal structures of [M(4,4′-bipyridine)2(NO3)2]·3C10H8 (M = Co,Ni)

The synthesis and crystal structures of [M(4,4′-bipyridine)₂(NO₃)₂]·3naphthalene (M = Co, 1·3naphthalene; Ni, 2·3naphthalene) are reported. 1·3naphthalene and 2·3naphthalene are isostructural and represent rare examples of interpenetrating planar networks that are chemically and topologically different. It appears that the networks coexist because the (4,4) topology of the cobalt and nickel square grids is complementary to the (6,3) topology of the naphthalene honeycomb network, resulting in an inclined interpenetrated 3D architecture. This observation is discussed in the context of rational design strategies for hybrid solids.     

Molecular complexes of 3-hydroxypyridine with nitro-substituted aromatic and heterocyclic carboxylic acids

Four organic salt complexes of 3-hydroxypyridine (3-HP) with nitro-substituted aromatic and heterocyclic carboxylic acids have been prepared and their X-ray crystal structures reported. These complexes are 3-hydroxypyridinium 5-nitrofuran-2-carboxylate 1, 3-hydroxypyridinium 4-nitrobenzoate 2, 3-hydroxypyridinium 2,4-dinitrobenzoate 3, and 3-hydroxypyridinium 3,5-dinitrobenzoate 4. The hydrogen-bonding networks in each are dominated by interactions from both the protonated heterocyclic nitrogen and the 3-hydroxy group on 3-HP to the carboxylate oxygens. The principal structural unit in complexes 1 and 3 is a tetramer consisting of two of each component molecule, whereas in complexes 2 and 4 the hydrogen-bonded polymers are observed. In all cases additional CH···O interactions to the nitro oxygens are present and add to the hydrogen-bonding array. A review of three previous 3-HP salt structures as well as the four presented in this paper reveals that the hydrogen-bonding distances between nonhydrogen atoms from the heterocyclic nitrogen of 3-HP is slightly longer than that from the 3-hydroxy group [av. 2.658(5) and 2.594(5)].     

Synthesis,crystal structure,and properties of new actinide(VI) arsenates (H<Subscript>3</Subscript>O)[(AnO<Subscript>2</Subscript>)(AsO<Subscript>4</Subscript>)]·3H<Subscript>2</Subscript>O (An = U,Np, Pu)

Previously unknown arsenates of hexavalent U, Np, and Pu, (H₃O)[(UO₂)(AsO₄)]·3H₂O (I), (H₃O)· [(NpO₂)(AsO₄)]·3H₂O (II), and (H₃O)[(PuO₂)(AsO₄)]·3H₂O (III), were synthesized under hydrothermal conditions. The crystal structure of the compounds was determined, and their absorption spectra were measured. The compounds crystallize in tetragonal space group P4/nmm.     

Synthesis of asymmetric biphenyl derivatives for optoelectronic applications

We report the synthesis and optical properties of a series of ten organic compounds with biphenyl as the backbone and asymmetrically modified by triphenylamines, carbazoles and tetraphenylsilanes (BP 1-10). BP 1-10 were synthesized mainly by Ullmann coupling reaction and Suzuki cross-coupling reaction and characterized by EA, NMR, MS, UV–Vis, DSC, TGA, fluorescence spectra and cyclic voltammetry. They exhibit reversible electrochemical behavior with low oxidation potentials and emit intense pure-blue light with high fluorescence quantum yields (up to 80%). BP 1 was fabricated into multi-layered light-emitting diodes as blue-emitting, host and hole transport materials. Based on the performance of BP 1 and the similarity in chemical structure to those compounds reported in literature, these compounds are expected to be good and versatile hole transport, host and blue emitting materials.     

Crystallographic studies on substituted m-terphenyls: identification of weak [CH3···I] interactions

Crystallographic studies of 2,6-bis(2,4,6-trimethylphenyl)-4-methyliodobenzene 1 and 2,6-diphenyl-4-methyliodobenzene 2 were performed and in both cases [CH₃···I] interactions were identified. Theoretical calculation of the dipole moment of 1 and the partial charges of the iodine and methyl hydrogens were performed. These charges, although small, suggest that they are large enough to encourage the formation of weak dipole-dipole interactions in the absence of other stabilizing forces     

Synthesis and characterisation of infinite coordination networks with 1,6-bis(4-pyridyl)hexane and copper nitrate

Crystallisation of 1,6-bis(4-pyridyl)hexane (Py₂C₆H₁₂) with copper nitrate gives two different phases. Phase 1 of composition [Cu(Py₂C₆H₁₂)₃(NO₃)₂]·2[Cu(Py₂C₆H₁₂)₂(H₂O)(NO₃)]·2(NO₃)·EtOH consists of two different infinite chains in a 1:2 ratio that are interlocked. Hydrogen bonds link chains I to II and chains II to II. In contrast phase 2 of composition [Cu₂(Py₂C₆H₁₂)₄(H₂O)₂]·(NO₃)₄·(Py₂C₆H₁₂)·(EtOH)·2(H₂O) is based upon an infinite 3D framework. It consists of four interpenetrating 3D networks that are crystallographically equivalent.