Two-dimensional Polymeric Network Research Articles

Poly[(μ2-2,2-dimethylpropane-1,3-diyl diisocyanide)-μ2-nitrato-silver(I)]: a powder study

In order to investigate the effect of counter-anions on the polymeric structure of (2,2-dimethylpropane-1,3-diyl diisocyanide)silver(I) complexes, the novel title polymeric compound, [Ag(NO(3))(C(7)H(10)N(2))](n), has been synthesized. The crystal structure was determined by simulated annealing from X-ray powder diffraction data collected at room temperature. The current structure is similar to the recently reported structure of the analogue with chloride replacing nitrate. This study illustrates that both the chloride and nitrate complexes crystallize in the orthorhombic system in the Pbca space group with one monomer in the asymmetric unit, and also gives a strong indication that the counter-anion does not have a considerable effect on the polymeric structure of the complex. The Ag centre lies in a distorted tetrahedral environment and is bonded to two 2,2-dimethylpropane-1,3-diyl diisocyanide ligands to form chains. The nitrate anions crosslink the Ag centres of the chains to form a two-dimensional polymeric network structure.

Fine Tuning of the Cu(II)-Bis(imidazole) Networks by Changing Sulfonate Anions

In this paper, seven new compounds [Cu(biim-4)2(L1)2] (1), [Cu(biim-4)2(L2)2] (2), [Cu(biim-4)2(H2O)](L3)2·H2O (3), [Cu(L4)2](H2biim-4)·8H2O (4), [Cu(biim-4)1.5(H2O)3](L5)·2H2O (5), [Cu(biim-6)3](L1)2 (6), and [Cu(biim-6)3](L2)2·H2O (7), where HL1 = 3-amino-4-methylbenzenesulfonic acid, HL2 = 2-amino-3,5-dimethylbenzenesulfonic acid, HL3 = 4-amino-2,5-dichlorobenzenesulfonic acid, H2L4 = 8-hydroxyquinoline-5-sulfonic acid, H2L5 = 1,5-naphthenedisulfonic acid, biim-4 = 1,1′-(1,4-butanediyl)bis(imidazole), and biim-6 = 1,1′-(1,6-hexanediyl)bis(imidazole), were successfully synthesized. The sulfonate anions of compounds 1, 2, and 4 coordinate to copper ions, while the sulfonates of 3 and 5–7 only act as counterions. In compounds 1–3, 6, and 7, copper ions are bridged by biim-4 or biim-6 ligands to form two-dimensional (2D) polymeric networks; in compound 5, copper ions are bridged by biim-4 ligands to form a one-dimensional (1D) ladder structure. In 4, [Cu(L4)2]2– anions, [H2biim-4]2+ cations and lattice–water molecules are linked through hydrogen bonds and π−π interactions to give a three-dimensional (3D) supramolecular framework.

1-Oxoisoindoline-2-carboxamide

The title mol­ecule, C9H8N2O2, is essentially planar. The crystal structure is stabilized by hydrogen bonding. An intra­molecular N—H⋯O hydrogen bond results in a six-membered ring. Each mol­ecule inter­acts with two others through N—H⋯O and C—H⋯O hydrogen bonding, resulting in the formation of nine-membered rings. These hydrogen bonds generate a two-dimensional polymeric network. There are also π–π inter­actions between the aromatic and heterocyclic rings [centroid–centroid distance 3.638 (2) Å].

Gold Nanoparticle Aggregate Morphology with Controllable Interparticle Spacing Prepared by a Polyelectrolyte Network Template

Gold nanoparticle self-assembly behaviour on a mica surface was investigated. A large-scale modified partially hydrated polyacrylamide network on a mica surface was successfully fabricated with a simple method. Gold nanoparticles were self-assembled onto a two-dimensional polymer network template by electrostatic interaction, and an interesting nanostructured gold morphology with controllable interparticle spacing was formed on the mica surface. By adjusting the gold aqueous concentrations, the particle distance could be optimized to approach strongest coupling between adjacent particles and match the plasmon resonance wavelength to the laser excitation wavelength. Thus, the spacing between nanoparticles could be controlled for tunable surface-enhanced Raman scattering substrates for optimal signal amplification.

Two-dimensional polymer networks near percolation

We report an extensive finite-size study of polymer networks near the percolation threshold, using numerical techniques. The polymers are modeled by random walks occupying the bonds of a two-dimensional square lattice. We measure the percolation threshold and critical exponents of the networks for various polymer lengths. We find that the critical occupation probability is a decreasing function of the polymer length, and the percolation of polymers with a fixed polymer length belongs to the same universality class as ordinary bond percolation. By adding particles to the lattice cells we can study the diffusion process in polymer networks. Measuring the current near percolation, we observe that its critical exponent is also independent of polymer length.

Synthesis, crystal structure and fluorescent property of two-dimensional Cu(I) coordination polymers with cyanide, thiocyanate and triazole bridges

Hydrothermal reaction of CuCN, K 3[Fe(CN) 6] with 4-(6-amino-2-pyridyl)-1,2,4-triazole (apt) afforded a coordination polymer [Cu 7(CN) 7(apt) 2] n ( 1), while solvothermal reaction of CuSCN with apt in acetonitrile afforded a coordination polymer [Cu 2(SCN) 2(apt)] n ( 2). Complex 1 shows two-dimensional polymeric network with large hexagonal channels constructing by CuCN chains and tridentate apt ligands. Complex 2 shows two-dimensional polymeric framework assembled by ladder-like [Cu(SCN)] n chains and bidentate apt ligands, in which thiocyanate acts as a tridentate bridging ligand. Both polymers are thermal stable and strong fluorescent in the solid state.

Simulation studies of permeation through two-dimensional ideal polymer networks

We study the process of diffusion through an ideal polymer network, using numericalmethods. Polymers are modelled by random walks on the bonds of a two-dimensionalsquare lattice. Molecules occupy the lattice cells and may jump to the nearest-neighbourcells, with probability determined by the occupation of the bond separating the two cells.Under subjection to a concentration gradient across the system, a constant average currentflows in the steady state. Its behaviour appears to be a non-trivial function ofpolymer length, mass density and temperature, for which we offer qualitativeexplanations.

Poly[μ-salicylato-lead(II)

In the title compound, [Pb(C7H4O3)]n, the PbII atom is coordinated by five O atoms from four salicylic acid ligands with Pb—O distances of 2.318 (16)–2.605 (15) Å. Each ligand acts in a penta­dentate mode that leads to the formation of a two-dimensional polymeric network.

Impact of ethyl tris-2-methoxyethoxy silane on the passivation of graphite electrode in Li-ion cells with PC-based electrolyte

The aim of this work was to study the influence of ethyl tris-2-methoxyethoxy silane (compound belonging to the class of silanes referred to as silicon tripodands) on the formation of passive layer (often called solid electrolyte interphase) on the electrode made of highly graphitic material during first reduction in propylene carbonate-based (PC) electrolytes. The podand molecules were introduced to the system as additives (co-solvents) to PC and as surface pre-treatment agents for graphite electrodes. It was found that in the presence of podand graphite anode functions properly in PC-containing electrolytes and no detrimental solvent co-intercalation is observed. These phenomena have been ascribed to partial hydrolysis of podand molecules on the graphite surfaces, leading to the formation of a two-dimensional polymeric network via Si–O–Si bonds. Electrochemical characterization involved galvanostatic charging/discharging and cycling voltammetry experiments. On the basis of the presented findings new industrially viable, low-cost, low-temperature Li-ion cell designs can be developed.

Crystal structure, spectroscopic and magnetic properties of 2D network high-spin cobalt(II) complex with diethyl 2-pyridylmethylphosphonate

The crystal and molecular structure of a cobalt(II) compound of the formula [Co(2-pmpe) 2(H 2O) 2](ClO 4) 2, where 2-pmpe is diethyl 2-pyridylmethylphosphonate was determined by single crystal X-ray diffraction. The geometry of CoN 2O 4 chromophore shows an elongated tetrahedron, resulting from the didentate N,O-bonded two chelate ligands and two water molecules with pyridyl nitrogen atoms in an axial positions and oxygen atoms in the basal plane. Every mononuclear unit is linked to others ones via two extended Co–O–H⋯O–Cl–O⋯H–O–Co bridges, forming one-dimensional hydrogen bond system. Additional CH⋯π hydrogen bonds link the chains to form a two-dimensional (2D) polymeric network. Spectroscopic, EPR and magnetic measurements (1.8–300 K) results are presented in the light of the crystal structure. Magnetic measurements reflect the molecular character of the compound with very weak exchange interaction, transmitted through H-bonds where the moments are enhanced due to an important orbital contribution via spin–orbit coupling.

The hydrogen-bonding network in (E)-1,2-bis(1-ethylbenzimidazol-2-yl)ethene dihydrate

The title compound, C20H20N4·2H2O, contains centrosymmetric (E)-1,2-bis­(1-ethyl­benzimidazol-2-yl)ethene mol­ecules with parallel benzimidazole fragments separated by 0.131 (4) Å. The structure consists of layers parallel to (100). In each layer, alternating chains of water mol­ecules, linked by O—H⋯O hydrogen bonds, and columns of alkene mol­ecules are linked to each other by O—H⋯Nimine hydrogen bonds to form a two-dimensional polymeric network. An inter­planar separation of 3.413 (3) Å between alkene mol­ecules in a given column is consistent with substantial π–π inter­actions.

X-ray crystal structures of discrete and polymeric chiral silver complexes of monoterpenoid alkenes

X-ray crystal structures are reported for five silver(I) complexes of four monoterpenoid alkenes. Discrete mononuclear complexes of the chiral alkenes (1S)-(−)-α-pinene and (1S)-(−)-β-pinene with silver perchlorate and silver hexafluorophosphate are described. The achiral diene γ-terpinene forms a discrete mononuclear adduct with silver hexafluorophosphate and a two-dimensional polymeric network structure with silver triflate. The chiral diene (R)-(+)-limonene forms a one-dimensional chiral coordination polymer with silver hexafluorophosphate. In all structures the silver atom is η 2-bonded to the carbon–carbon bond(s) of the monoterpene with slightly longer bond distances to the more substituted carbon of the alkene moiety.

Self-Assembly of Mercaptane−Metallacarborane Complexes by an Unconventional Cooperative Effect: A C−H···S−H···H−B Hydrogen/Dihydrogen Bond Interaction

The existence of a dihydrogen bond (S-H...H-B) and its combination with a C-H...S hydrogen bond in an unusual cooperative effect are demonstrated from a combination of experimental and theoretical methods. This cooperative effect seems to be responsible for self-assembly of mercaptane-metallacarborane complexes such as closo-[3-Ru(eta6-C6H6)-8-HS-1,2-C2B9H10] (1) and closo-[3-Co(eta5-C5H5)-8-HS-1,2-C2B9H10] (3), which present identical supramolecular two-dimensional polymeric networks. The findings, besides documenting structurally the first S-H...(H-B)2 dihydrogen bond and the unconventional cooperative ability of a boron-attached SH group, prove that substituted carboranes have the potential to serve as building blocks for assembling complex structures.

Synthesis and electrochemical investigation of oligo-(arylenevinylenes) intended for the preparation of two-dimensional polymer networks

Four phenylenevinylene oligomers ( 1– 4) have been synthesized and characterized by cyclic voltammetry, absorption spectroscopy and photoluminescence (PL). Two of the oligomers contain a tri-substituted central benzene ring, while one contains a tetra-substituted central ring. These oligomers were prepared in an effort to increase hole and electron mobility in organic materials via extension of conjugation to two dimensions. Optical and electrochemical evidence is given for significant interactions of the alkoxy-substituted styryl units of 3 that are attached to the central benzene ring in meta positions. The tetra-substituted oligomer ( 4) also exhibits strong interactions between the pair of para substituted arms. The photoluminescence (PL) quantum yield for the tetra-substituted oligomer is high, indicating that it is an excellent candidate for the active layer in organic light-emitting diodes.

Molecular Weight Dependence of Viscoelastic Properties in Two-Dimensional Physical Polymer Networks: Amphiphilic Lipopolymer Monolayers at the Air−Water Interface

Lipopolymers are known to form a two-dimensional physical network (physical gel) at the air−water interface that is stabilized by two different types of associative interactions: microcondensation of alkyl chains of lipopolymers to form small clusters and physical junction zones linking neighboring polymer chains stabilized by hydrogen bonding of water molecules. In this study we present surface rheology and film balance experiments on amphiphilic PEG lipopolymers of different molecular weights of their polymer moiety (MW: 750, 1000, 2000, 3000, 5000) at the air−water interface. Our experimental data show that the gelation transition shifts within the MW range of 1000−5000 to smaller areas per molecule as the polymer chain length gets shorter until it reaches a specific minimum area where no further change is observed (MW = 1000). Surface rheology data of the storage modulus indicate a qualitative difference between higher MW species (MW: 2000, 3000, 5000) and lower MW species (MW: 750, 1000). While t...

Synthesis, X-ray crystal structures and magnetic properties of Cu(II)(NITpPy) 2[N(CN) 2] 2·solv (NITpPy=nitronyl nitroxide radical, solv=H 2O or CH 3CN). From discrete molecules to 2-D polymeric coordination compounds

The synthesis, X-ray crystal structures and magnetic properties of five new copper(II) complexes containing nitroxide radicals Cu(NITpPy) 2(NO 3) 2 ( 1), Cu(NITpPy) 2(CH 3COO) 2 ( 2), Cu(NITpPy) 2[N(CN) 2] 2·(H 2O) 2 ( 3), Cu(NITpPy) 2[N(CN) 2] 2·3CH 3CN ( 4) and Cu(NITpPy) 2[N(CN) 2] 2·2CH 3CN ( 5) are reported. Compounds 1– 3 consists of discrete molecules in the solid state, but in compounds 4 and 5 the Cu(NITpPy) 2 2+ units are connected through N(CN) 2 − bridging ligands in μ 2 coordination developing, respectively, into one-dimensional and two-dimensional polymeric networks. For all compounds, the magnetic properties have been investigated and antiferromagnetic interactions dominate at low temperature.

Tethered pyrazolyl phosphinate: pyrazolyl-N- and phosphoryl-O-metal coordination in Ph(2)P(O)[OCH(2)CH(2)(3,5-Me(2)Pz)

Phosphorus pyrazolides, P(O)(3,5-Me(2)Pz)(3) or RP(E)(3,5-Me(2)Pz)(2) [E = S or O, R = Me or Ph], are hydrolytically sensitive particularly upon interaction with transition metal ions. In this paper, we report a new tethered pyrazolyl phosphinate, Ph(2)P(O)[OCH(2)CH(2)(3,5-Me(2)Pz)] DPEP (1), where the pyrazolyl group is separated from the phosphorus by means of an ethyleneoxy spacer. 1 has two potential coordination sites in the form of a phosphoryl oxygen atom and a pyrazolyl nitrogen atom. 1 forms hydrolytically stable complexes, (DPEP-CoCl(2))(n)(2), (DPEP)(2)-CuCl(2) (3), (DPEP-ZnCl(2))(n )(4), and (DPEP)(2)-PdCl(2) (5). The cobalt(II) and the zinc(II) complexes 2 and 4 show a zigzag polymeric structure in the solid state with a tetrahedral coordination geometry around the metal ion; the ligand DPEP coordinates through its phosphoryl oxygen and the pyrazolyl nitrogen to two neighboring metal ions and functions as a bridging ligand to form the polymeric structure. In contrast to 2 and 4, the copper(II) and the palladium(II) complexes 3 and 5 show a square-planar geometry around the metal ion. Exclusive coordination through the pyrazolyl nitrogens of the ligand 1 is observed. An extensive supramolecular sheetlike two-dimensional polymeric network is observed in the solid-state structures of 3 and 5 as a result of two weak interactions: (a) an intermolecular C-H- - -O interaction involving the phosphoryl oxygen and an aromatic C-H and (b) a pi-pi face-to-face stacking interaction between the phenyl groups of two adjacent molecules.

Synthesis and crystal structure determination of [PPh 4][WO 2S 2(CuPPh 3)] and of [Et 4N] 2[WS 4(CuNCSe) 4] with a sheet polymeric anion. Synthesis and characterisation of [PPh 4] 2[WO 2S 2(CuNCS)

Three new copper(I) complexes, [PPh 4][WO 2S 2(CuPPh 3)] ( 1), [PPh 4] 2[WO 2S 2(CuNCS)] ( 2), and [Et 4N] 2[WS 4(CuNCSe) 4] ( 3), have been prepared and characterised. The [WO 2S 2(CuPPh 3)] − anion in 1 represents the first example of copper coordination to the [WO 2S 2] 2− moiety that has been characterised by X-ray crystallography, in contrast to numerous studies involving [WOS 3] 2− and [WS 4] 2−. The dithio- and tetrathiotungstate groups in 1 and 3 act as bidentate ligands through two sulphur atoms chelating copper atoms. This is consistent with the infrared spectra, which exhibit low-frequency WS b stretching bands. There is no coordination of oxygen atoms to copper. The copper atom in 1 has trigonal coordination with triphenylphosphine as the third ligand. In 3 the selenocyanate ligands function as bridges, with nitrogen coordinated to one copper atom and selenium to another; pairs of copper atoms are linked by two of these bridges across an inversion centre, to give a two-dimensional polymeric network anion.

Photopatterning of a fluorescent polymer Langmuir–Blodgett film by crosslinking reaction

A fluorescent two-dimensional network patterning was fabricated with polymer LB films. An amphiphilic polymer consisting of N-dodecylacrylamide, N-11-acryloylundecyl-4-vinylpyridinium salt and 1-pyrenylacrylamide forms a stable monolayer, which is transferred onto solid substrates yielding LB films. The absorption and emission spectra of the LB films indicate that pyrene chromophore exists in the LB film. On irradiation, photo-crosslinking reaction of the acryloyl group, which is aligned on each interlayer hydrophobic tail surface of LB films occurs efficiently. Consequently, the irradiated polymer LB film becomes insoluble in organic solvents due to the formation of the two-dimensional polymer network in the LB film. The patterned fluorescent polymer LB film was confirmed by the fluorescence microscopy.

Poly[[diaquacadmium(II)]-μ3-(1-carboxybenzene-3,5-dicarboxylato)

The crystal structure of the title complex, poly­[[di­aquacadmium(II)]-μ3-(1-carboxy­benzene-3,5-di­carboxyl­ato-O1:O3,O3′:O5,O5′)], [Cd(C9H4O6)(H2O)2]n, features two-dimensional polymeric network layers which are hydrogen-bonded to one another. The Cd atom is coordinated by seven O atoms, two of which belong to water mol­ecules arranged trans to each other, above and below the layers. Each polymeric layer is tiled with (Cd)3(C9O6)3 rings formed by alternating Cd atoms and (C9O6) ligands. The layers are parallel to the \overline 101 crystal plane and the neighbouring layers are separated by 3.2508 (2) Å.