Organic-inorganic Hybrid Structures Research Articles

One step processing of aminofunctionalized gate oxides

A plasma discharge process has been developed that allows the growth of biosensor gate oxides with adapted surface properties for the direct application of biomolecular immobilization cascades. The process involves an accurate selection of processing conditions, mainly, low temperature evaporation of (3-aminopropyl)triethoxysilane (APTS) and dynamic power and flow conditions. Room temperature evaporation of APTS was achieved by designing a vessel with an internal capillary network. The initial high power (100W) plasma conditions were replaced by milder molecular fragmentation (50W, 25W) in a pure Ar discharge. Under these conditions the thin SiO2 layers presented graded properties with a denser layer at the Si (100) interface and a hybrid organic–inorganic structure at the surface. The chemistry of the films was analysed by Fourier transformed infrared spectroscopy (FTIR) and Rutherford backscattering spectroscopy combined with elastic recoil detection analysis (RBS, ERDA), which confirmed the presence of the SiO2 and organic phases. Contact angle measurements indicate the higher contribution of the basic polar component to the surface free energy. Furthermore, the higher affinity of the surface towards biomolecular immobilization was confirmed by fluorescence microscopy. Finally, penetration of nitrobenzaldehyde was obtained by application of a molecular permeation method evaluated by UV–vis spectroscopy onto fused silica substrates.

Inorganic–Organic Hybrid Structures: Open‐Framework Iron Phosphite–Oxalates of Varying Dimensionality

Inorganic-organic hybrid structures belonging to the family of iron phosphite-oxalates have been prepared by employing hydrothermal methods. Their structures, determined by single-crystal X-ray diffraction, show a hierarchy within the family. While compounds I and II are low dimensional, III-VI have three-dimensional structures. Compound I has edge-shared ladders of iron phosphite with oxalate units hanging from the iron centers. Compound II has a layer structure with a honeycomb-like arrangement. The three-dimensional hybrid structures have the oxalate units connected in both in-plane and out-of-plane modes. A newly identified secondary building unit (SBU-7) and the oxalate units satisfying the valence and coordination requirements in the structure of V are novel and noteworthy structural features. Magnetic studies show that the dominant interactions between the iron centers are antiferromagnetic. Similar to other known hybrid structures, the phosphite-oxalate structures appear to show wide compositional and structural diversity.

(C2N2H10)2Mg(HP2O7)2·2H2O synthesis and crystal structure

(C2N2H10)2Mg(HP2O7)2·2H2O, is a new inorganic organic hybrid structure. It has been synthetized using wet chemistry. Its crystal structure consists of cis- and trans-edge sharing [MgO4(H2O)2] octahedra resulting in chains, which are linked via [HP2O7] units to form [Mg(HP2O7)2(H2O)2]4− layers. The Mg2+ cations and the ethylendiammonium cations are located on centers of inversion. The ethylendiammonium cations are alternately located in the interlayer space. The cohesion of the crystal is well ensured by coulombic interactions between anions and cations and by several hydrogen bonds. The diphosphate anion shows an eclipsed conformation.

In Situ Investigation of Complex BaSO4Fiber Generation in the Presence of Sodium Polyacrylate. 2. Crystallization Mechanisms

The formation mechanisms of complex BaSO(4) fiber bundles and cones in the presence of polyacrylate sodium salt via a bioinspired approach at ambient temperature in an aqueous environment are reported. These complex organic-inorganic hybrid structures assemble after heterogeneous nucleation of amorphous precursor particle aggregates on polar surfaces, and the crystallization area can be patterned. In contrast to earlier reports, three different mechanisms based on the oriented attachment of nanoparticles were revealed for the formation of typical fibrous superstructures depending on the supersaturation or on the number of precursor particles. (A) High supersaturation (S > 2): large amorphous aggregates stick to a polar surface, form fiber bundles after mesoscopic transformation and oriented attachment, and then form a narrow tip through polymer interaction. (B) Low supersaturation (S = 1.02-2): only a few fibers nucleate heterogeneously from a single nucleation spot, and amorphous particles stick to existing fibers, which results in the formation of a fiber bundle. (C) Vanishing supersaturation (S = 1-1.02): nucleation of a fiber bundle from a single nucleation spot with self-limiting repetitive growth as a result of the limited amount of building material. These growth processes are supported by time-resolved optical microscopy in solution, TEM, SEM, and DLS.

新規シルセスキオキサンの合成と触媒機能

Preparation of novel oligosilsesquioxanes-based materials and metal-containing ones as homogeneous and heterogeneous catalysts of excellent activity are reviewed. The authors examined the activity of a V-containing silsesquioxane as a homogeneous catalyst for the photo-oxidation of simple alkanes. For the epoxidation of alkenes catalyzed by Ti-silsesquioxanes, the presence of alkenylsilyl substituents around the Ti center shows significant promotional effects. By utilizing silsesquioxanes bearing appropriate functional groups, novel caged molecules with organic-inorganic hybrid structures were prepared as well as soluble cooligomers, starburst-type polymers, and a dendrimer containing metallasilsesquioxanes. Furthermore, the authors found that these metal-containing silsesquioxanes can be good precursors of oxide catalysts with high BET surface areas and uniformly-controlled pores. Remarkably, the catalysts containing V and Al species were found to show excellent activity for photo-assisted aerobic oxidation of methane into methanal and the cracking of cumene, respectively.

Novel Organic‐Inorganic Hybrid Coordination Polymer [(DBU‐H)(PbI3)]n: Synthesis, Crystallographic Structure and Quantum Chemical Investigation.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Preparation of Novel Materials for Catalysts Utilizing Metal-Containing Silsesquioxanes

Recent progress of the preparation of novel materials for catalysts utilizing metal-containing silsesquioxanes are reviewed in the following categories: (i) activities of vanadium or titanium-containing silsesquioxanes as homogeneous catalysts for oxidative reactions, (ii) preparation of immobilized or polymeric catalysts, and (iii) preparation of porous oxide catalysts utilizing metal-containing silsesquioxanes. The present authors found that the liquid phase photo-oxidation of cyclohexane in the presence of a vanadium-containing silsesquioxane as a homogeneous catalyst selectively afforded cyclohexanol and cyclohexanone in high yields. Facile synthetic methods for group 4 metal-containing silsesquioxanes with functionalized silyl (or germyl) groups are presented. Remarkably, titanocene(IV)-containing silsesquioxanes have been synthesized for the first time. The presence of alkenylsilyl substituents shows a promotional effect on the epoxidation of cycloalkenes, which was found to be more significant for titanium-bridged silsesquioxanes. By utilizing these silsesquioxanes, polymeric, starburst-like, and dendritic silsesquioxanes were prepared as well as novel caged or macrocyclic molecules with organic–inorganic hybrid structures. The controlled calcination of these metal-containing silsesquioxanes at around 823 K produces porous oxides with high BET surface areas of 300–520 m2g−1 and uniformly-controlled micropores of 0.5–0.6 nm diameter. The oxides are found to include a well-dispersed metallic oxide species. From group 13 elements-containing silsesquioxanes Bronsted acidic oxides are produced. Among them, aluminum-containing oxides show excellent activities for the cracking of cumene even at low temperature, 523 K, in spite of their amorphous nature.

Inorganic–organic hybrid structure: Synthesis, structure and magnetic properties of a cobalt phosphite–oxalate, [C 4N 2H 12][Co 4(HPO 3) 2(C 2O 4) 3

A hydrothermal reaction of a mixture of cobalt (II) oxalate, phosphorous acid, piperazine and water at 150 °C for 96 h followed by heating at 180 °C for 24 h gave rise to a new inorganic–organic hybrid solid, [C 4N 2H 12][Co 4(HPO 3) 2(C 2O 4) 3], I. The structure consists of edge-shared CoO 6 octahedra forming a [Co 2O 10] dimers that are connected by HPO 3 and C 2O 4 units forming a three-dimensional structure with one-dimensional channels. The amine molecules are positioned within these channels. The oxalate units have a dual role of connecting within the plane of the layer as well as out of the plane. Magnetic susceptibility measurement shows the compound orders antiferromagnetically at low temperature ( T N = 22 K ). Crystal data: I, monoclinic, space group= P2 1/ c (No. 14). a = 7.614 ( 15 ) , b = 7.514 ( 14 ) , c = 17.750 ( 3 ) Å , β = 97.351 ( 3 ) ° , V = 1007.30 ( 3 ) Å 3 , Z = 2 , ρ calc = 2.466 g / cm 3 , μ ( Mo K α ) = 3.496 mm - 1 , R 1 = 0.0310 and w R 2 = 0.0807 data [ I > 2 σ ( I ) ] .

Alternating-current electroluminescence from an organic heterojunction sandwiched between two amorphous SiO2 layers

We report alternating-current electroluminescence (ACEL) from an organic heterojunction sandwiched between two amorphous SiO2(α-SiO2) layers, i.e., ITO\α-SiO2\poly[2-methoxy-5-(2′-ethylhexyloxy)-p-phenylene vinylene](MEH-PPV)\Alq3\α-SiO2\Al. Besides the exciton radiation from Alq3 (peak at 520 nm) and MEH-PPV (peak at 587 nm), an additional broad blue emission around 410 nm is observed in its ACEL spectrum. By studying the ACEL and brightness wave form of the device, we found both hot-electron-impact excitation and injection carriers recombination are combined in its emission mechanism for this hybrid organic-inorganic structure, and the origin of the broad blue emission around 410 nm is discussed.

Crosslinked organic–inorganic hybrid chitosan membranes for pervaporation dehydration of isopropanol–water mixtures with a long-term stability

Crosslinked organic–inorganic hybrid chitosan membranes were obtained from blending chitosan and γ-(glycidyloxypropyl)trimethoxysilane (GPTMS) in acetic acid aqueous solution. The hydrophilicity of the modified membranes was not significantly decreased, so as to result in good permselectivity and high permeation flux in pervaporative dehydration on a 70 wt.% isopropanol–water (IPA–H 2O) solution. A flux of 1730 g/(m 2 h) and a separation factor of 694 were found with the chitosan membrane containing 5 wt.% GPTMS. Both of the crosslinked and organic–inorganic hybrid structures contribute to stabilize the membranes to maintain the performance of the membranes in a 140 days long-term operation.

Hydrothermal synthesis, structural characterization and magnetic studies of the new pillared microporous ammonium Fe(III) carboxyethylphosphonate: [NH 4][Fe 2(OH){O 3P(CH 2) 2CO 2} 2

The preparation by hydrothermal reaction and the crystal structure of the iron(III) carboxyethylphosphonate of formula [NH 4][Fe 2(OH){O 3P(CH 2) 2CO 2} 2] is reported. The green-yellow compound crystallizes in the monoclinic system, space group Pc ( n . 7 ) , with the following unit-cell parameters: a=7.193(3) Å, b=9.776(3) Å, c=10.17(4) Å and β=94.3(2)°. It shows a typical layered hybrid organic–inorganic structure featuring an alternation of organic and inorganic layers along the a-axis of the unit cell. The bifunctional ligand [O 3P(CH 2) 2CO 2] 3− is deprotonated and acts as a linker between adjacent inorganic layers, to form pillars along the a-axis. The inorganic layers are made up of dinuclear Fe(III) units, formed by coordination of the metal ions with the oxygen atoms originating from the [O 3P−] 2− end of the carboxyethylphosphonate molecules, the oxygen atoms of the [−CO 2] − end group of a ligand belonging to the adjacent layer and the oxygen atom of the bridged OH group. Each Fe(III) ion is six-coordinated in a very distorted octahedral environment. Within the dimer the Fe–Fe separation is found to be 3.5 Å, and the angle inside the [Fe(1)–O(11)–Fe(2)] dimers is ∼124°. The resulting 3D framework contains micropores delimited by four adjacent dimers in the ( bc) planes of the unit cell. These holes develop along the a-direction as tunnel-like pores and [NH 4] + cations are located there. The presence of the μ-hydroxo-bridged [Fe(1)–O(11)–Fe(2)] dimers in the lattice is also responsible for the magnetic behavior of the compound at low temperatures. The compound contains Fe 3+ ions in the high-spin state and the two Fe(III) ions are antiferromagnetic coupled. The J/k value of −16.3 K is similar to those found for other μ-hydroxo-bridged Fe(III) dimeric systems having the same geometry.

New Functional Polymers and Materials Based on 2,2′:6′,2″‐Terpyridine Metal Complexes

AbstractNew inorganic–organic hybrid structures based on metal complexes have become of increasing interest over the last few decades in the search for new materials. Many different polypyridyl metal complexes have been investigated. Recently, a strong increase in interest regarding 2,2′:6′,2″‐terpyridine has been observed. In particular, octahedral bis‐2,2′:6′,2″‐terpyridine metal complexes offer the advantages of increased symmetry and, in the case of ruthenium(III)/ruthenium(II) complexation, an entrance to a directed complexation technique. Apart from the combination with polymeric systems, ordered inorganic–organic structures on surfaces are becoming better understood concurrently with the development of sophisticated nanotechnology characterization techniques. There are many ongoing efforts that include terpyridine complex structures, especially concerning photophysical processes such as solar light to energy conversion. This review deals with the incorporation of terpyridine complexes into polymeric structures such as poly(ethylene glycol), poly(styrene), dendrimers, biomacromolecules, micelles, and resins, as well as the combination of terpyridine complexes with surfaces for electrocatalytic, photophysical, and self‐assembly purposes.

Novel acidic porous clay heterostructure with highly ordered organic–inorganic hybrid structure: one-pot synthesis of mesoporous organosilica in the galleries of clay

A new class of organic–inorganic hybrid porous clay heterostructures (HPCHs) have been prepared through the surfactant-directed assembly of organosilica in the galleries of montmorillonite. The reaction involved hydrolysis and condensation of phenyltriethoxysilane and tetraethoxysilane in the presence of intragallery surfactant templates (dodecylame and cetyltrimethylammonium ion). The surfactant templates were removed from the pores by solvent-extraction. The products were characterized by X-ray diffraction (XRD), N 2 adsorption, solid-state 29Si and 13C NMR, and FTIR. XRD patterns indicated a regular interstratification of the clay layers for HPCHs. Depending on loading of phenyl groups, HPCHs had BET surface areas of 390–771 m 2 g −1, pore volumes of 0.3–0.59 cm 3 g −1, and the framework pore sizes in the supermicropore to small mesopore range (1.2–2.6 nm). HPCHs were hydrophobic and acidic.

Structure of inorganic–organic hybrid polymer assembled by mercury(II) iodide and sulfur-rich compound

The metal complex, [Hg 2I 4(PEDT)] ∞ ( 1), PEDT=4,5-(phenyl-ethylenedithio)-1,3-dithiole-2-thione, has been synthesized and characterized by single crystal X-ray diffraction. It is found to be an unusual organic–inorganic hybrid structure. The inorganic layer is composed of chains of Hg with bridging I, in one case doubly bridged and in the other singly, interconnected by further bridging I to complete the two dimensional connectivity. The organic layers contain pairs of centrosymmetrically related, and therefore head to tail, face to face molecules. Each molecule of such a pair participates in the formation of short S⋯S contacts with a molecule of a centrosymmetrically related neighboring molecule pair thus creating chains of molecules. The connectivity within the organic layer is completed by C–H⋯π contacts between the chains. Connectivity between the organic and inorganic layers is achieved by participation of the thione S in the coordination of one type of Hg.

The effect of carboxymethyl chitosan on the precipitation of calcium carbonate

It is believed that chitosan plays an important role on the formation of specific inorganic–organic hybrid structure of shells. In this paper, insoluble chitoan was modified to a water-soluble macromolecule—carboxymethyl chitosan (CMCS), and further used as an additive in the crystallization process of calcium carbonate (CaCO 3). The combination investigation of XRD, Micro FT-IR and SEM on the precipitated crystals shows that the addition of CMCS obviously changed the crystal morphology, but did not induce the transformation of the crystal form, i.e., CaCO 3 keeps calcite form in all the cases no matter whether CMCS exists or not in the precipitation systems. The morphological variation of CaCO 3 strongly depends on the CMCS concentration in the aqueous solutions.

Proton Conducting Borosiloxane Solid Electrolytes and Their Composites with Nafion

A variety of proton conducting borosiloxane solid electrolytes containing -SO3H groups as proton sources were prepared. The presence of boron as a Lewis acid in the inorganic-organic hybrid structure was thought to lead to enhanced -SO3H dissociation, while the incorporation of alkyl groups overcame the tendency of the materials towards deliquescence at high temperatures and high relative humidity. Robust films, prepared from composites of borosiloxane electrolyte and Nafion® 117, were thermally stable and exhibited superior proton conducting characteristics to Nafion® 117.

Synthesis of layered organic–inorganic nanohybrid material: an organic dye, naphthol blue black in magnesium–aluminum layered double hydroxide inorganic lamella

Open lamella systems such as layered double hydroxides (LDHs) can be used to generate new nanostructured materials of layered organic–inorganic nanohybrid type. The synthesis of a new nanocomposite material consisting of inorganic layers, Mg–Al-LDH (MAL) as a host and naphthol blue black (NBB), an organic dye as a guest was successfully done. Various concentrations of NBB, ranging from 0.001 to 0.0015 M were used to prepare the nanocomposite under different Mg/Al molar ratios and pH. The concentration of NBB of 0.0015 M at pH 10 was found to be able to give a well-ordered nanolayered organic–inorganic hybrid structure with basal spacing of 19.6 Å.

Optoelectronic devices based on hybrid organic–inorganic structures

Conjugated polymers have become attractive for a range of device applications as light emitting diodes (display), photo-voltaic cells, transistors, and lasers. While there is true value in making all plastic devices most of the currently made ones involve the use of inorganic layers and or substrates. In this paper we outline some of the attractive properties of such devices and show that the hybridization on a nano-scale (as in blends) could be a powerful tool.

ChemInform Abstract: Inorganic Hybrid Open-Framework Structures: Synthesis and Structure of a Cobalt Phosphate-Oxalate, [C4N2H12]0.5 [Co2(HPO4)(C2O4)1.5

: A new open-framework inorganic-organic hybrid structure involving cobalt, [N2C4H12](0.5)[Co-2(HPO4)(C2O4)(1.5)], has been synthesized for the first time by hydrothermal methods. The three-dimensional structure is formed by the edge-shared CoO6 and CoO5 polyhedra forming a [Co2O9] dimer, that are connected with the PO4 polyhedra and the oxalate units forming one-dimensional channels. The amine molecules are located within these channels. The oxalate units have a dual functionality of connecting within the plane of the layer as well as out of the plane. The material is thermally stable up to 350 degrees C and orders anti-ferromagnetically at low temperatures. Crystal data: a = 7.494(1), b = 7.726(1), c = 17.852(3) Angstrom, beta = 97.7(1)degrees; V = 1024.2(2) Angstrom(3): space group = P2(1)/c (no. 14); Z = 4; M = 389.9; D-calc = 2.529 g cm(-3), lambda(Mo-K-alpha) = 3.451 mm(-1); lambda = 0.71073 Angstrom: R-1 = 0.04; wtR(2) = 0.10 and S = 1.13

Inorganic hybrid open-framework structures: synthesis and structure of a cobalt phosphate-oxalate, [C4N2H12]0.5[Co2(HPO4)(C2O4)1.5

A new open-framework inorganic–organic hybrid structure involving cobalt, [N2C4H12]0.5[Co2(HPO4)(C2O4)1.5], has been synthesized for the first time by hydrothermal methods. The three-dimensional structure is formed by the edge-shared CoO6 and CoO5 polyhedra forming a [Co2O9] dimer, that are connected with the PO4 polyhedra and the oxalate units forming one-dimensional channels. The amine molecules are located within these channels. The oxalate units have a dual functionality of connecting within the plane of the layer as well as out of the plane. The material is thermally stable up to 350°C and orders anti-ferromagnetically at low temperatures. Crystal data: a=7.494(1), b=7.726(1), c=17.852(3) Å, β=97.7(1)°; V=1024.2(2) Å3; space group=P21/c (no. 14); Z=4; M=389.9; Dcalc.=2.529 g cm−3; λ(Mo–Kα)=3.451 mm−1; λ=0.71073 Å; R1=0.04; wR2=0.10 and S=1.13.