Hydrophobic coatings based on triethoxy(octyl)silane

Russian Chemical Bulletin - Hydrophobic coatings on cellulosic materials were obtained using triethoxy(octyl)silane and its dimer, 1,1,3,3-tetraethoxy-1,3-dioctyldisiloxane, as modifiers. The...     

Inorganic-organic hybrid framework solids

Recent developments in the area of hybrid structures are overviewed with special emphasis on iron phosphate-oxalate materials. The structure of the iron phosphate-oxalates consists of iron phosphate chains or layers that are connected by oxalate moieties completing the architecture. The compounds exhibit interesting magnetic properties originating from the super-exchange interactions that are predominantly anti-ferromagnetic, involving the iron phosphates and the oxalate moieties. One of the materials,IV, also exhibits interesting adsorptive properties reminiscent of aluminosilicate zeolites. The aluminum phosphate-oxalate,VII, indicates that hybrid structures can be formed with zeolite architecture.     

Synthesis of diethoxymethyl[m-(trifluoromethyl)phenyl]silane and triethoxy[m-(trifluoromethyl)phenyl]silane

Summary Diethoxymethy][m-(trifluoromethyl)phenyl]silane and triethoxy[m-(trifluoromethyl)phenyl]silane were synthesized.     

Inorganic-organic hybrid vesicles with counterion- and pH-controlled fluorescent properties

Two inorganic-organic hybrid clusters with one or two covalently linked pyrene fluorescent probes, [(n-C(4)H(9))(4)N](2)[V(6)O(13){(OCH(2))(3)C(NH(CO)CH(2)CH(2)CH(2)C(16)H(9))}{(OCH(2))(3)C-(NH(2))}] ((TBA(+))(2)1) and [(n-C(4)H(9))(4)N](2)[V(6)O(13){(OCH(2))(3)C(NH(CO)CH(2)CH(2)CH(2)C(16)H(9))}(2)] ((TBA(+))(2)2), respectively, are synthesized from Lindqvist type polyoxometalates (POMs). The incorporation of pyrene into POMs results in amphiphilic hybrid molecules and simultaneously offers a great opportunity to study the interaction between hybrid clusters and their counterions. 2D-NOESY NMR and fluorescence techniques have been used to study the role of counterions such as tetrabutyl ammonium (TBA) in the vesicle formation of the hybrid clusters. The TBA(+) ions not only screen the electrostatic repulsions between the POM head groups but also are involved in the hydrophobic region of the vesicular structure where they interrupt the formation of pyrene excimers that greatly perturbs the luminescence signal from the vesicle solution. By replacing the TBA(+) counterions with protons, the new vesicles demonstrate interesting pH-dependent fluorescence properties.     

Inorganic-organic hybrid nonlinear optical films containing bulky alkoxysilane dyes

Two bulky alkoxysilane dyes based on nonlinear optical (NLO)-active triphenylamino derivatives possessing high thermal stabilities, without and with a cyano group substitution on the vinylene moiety (TPAH and TPACN, respectively), were synthesized, characterized, and copolymerized with tetraalkoxysilane (TEOS) with the ratio of 1:5. After a poling and curing process, the resulting side-chain-type sol-gel films with excellent optical qualities were achieved. Second-order NLO coefficients, d33, of 10-20 pm/V have been obtained in the films incorporated with different types of NLO-active dyes. The variation of chromophoric structures on NLO properties was investigated, indicating that the cyano substitution on the vinylene bridge of the chromophore would greatly enhance the temporal stability. This work provides a potential design strategy based on molecular engineering which would lead to more stable dipole orientation.     

Inorganic-organic hybrid compounds based on novel lanthanide-antimony oxohalide nanoclusters

Presented here is the assembly of two inorganic-organic hybrid compounds by the combination of novel praseodymium-antimony oxochloride clusters and dicarboxylic ligands co-directed by 2-MepyH and Fe(1,10-phen)(3) (or Fe(2,2'-bpy)(3)), which feature a two-fold interpenetrating three-dimensionally anionic network and a one-dimensionally helical anionic chain, respectively.     

Inorganic-organic hybrid polyoxometalate: Preparation, characterization and electrochemistry properties

The solid hybrid material (H_3/4pbpy)₄[PMo₁₂O₄₀]·1.25H₂O (1) (pbpy=5-phenyl-2-(4-pyridinyl)pyridine) has been prepared and characterized. A structural feature of compound 1 is that the polyoxometalate anions exhibit a one-dimensional inorganic double chain-like structure via weak interactions of O…O. The organic moiety exhibits regular packing with offset aromatic-aromatic interactions between the pbpys, leading to a compact supramolecular framework structure to accommodate the inorganic chains. Compound 1 was employed to fabricate the three-dimensional bulk-modified carbon paste electrode (1-CPE) to research on its electrochemistry properties. The results indicate that 1 retained Keggin molybdate anion electrocatalytic activities toward the reduction of chlorate, hydrogen peroxide and nitrite.     

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.     

Inorganic-organic hybrid materials with different dimensions constructed from copper-fluconazole metal-organic units and Keggin polyanion clusters

Inorganic-organic hybrid materials based on Keggin polyoxometalate building blocks combined with Cu(II)/Cu(I) and flexible fluconazole ligand [1-(2,4-difluorophenyl)-1,1-bis[(1H-1,2,4-triazol-1-yl)methyl]methanol] (Hfcz) have been obtained by hydrothermal methods, namely, [Cu(II)(2)(Hfcz)(4)(SiW(12)O(40))].3H(2)O (1), [Cu(II)(4)(fcz)(4)(H(2)O)(4)(SiMo(12)O(40))].6H(2)O (2), [Cu(II)(2)(fcz)(2)][Cu(II)(4)(fcz)(4)(SiW(12)O(40))][Cu(II)(2)(fcz)(2)(H(2)O)(2)(SiW(12)O(40))].6H(2)O (3), (Et(3)NH)(2)[Cu(I)(2)(Hfcz)(2)(SiW(12)O(40))].2H(2)O (4), (Et(3)NH)(2)[Cu(I)(2)(Hfcz)(2)(SiW(12)O(40))].H(2)O (5) and [Cu(I)(4)(Hfcz)(4)(SiMo(12)O(40))] (6). Their structures have been determined by single-crystal X-ray diffraction analyses, and the compounds are further characterized by elemental analyses, IR spectra and thermogravimetric (TG) analyses. In 1, Cu(II) cations are bridged by fluconazole ligands to form a 3D lvt coordination polymeric network, which is connected by (SiW(12)O(40))(4-) anions to form a complicated 3D (4,6)-connected framework with the topology of (4(2).6(4))(4(6).6(7).8(2))(2). In 2, two fcz(-) anions chelate two Cu(2+) cations to form a [Cu(fcz)](2)(2+) dimer, which is bridged by (SiW(12)O(40))(4-) polyanions to generate a 2D (4,4) grid. Compound 3 is formed by three types of co-crystallizing subunits including a dimer [Cu(fcz)](2)(2+), a dumbbell molecule [Cu(4)(fcz)(4)(SiW(12)O(40))] and an infinite chain {[Cu(2)(fcz)(2)(H(2)O)(2)(SiW(12)O(40))](2-)}(infinity). In compounds 4 and 5, Hfcz ligands link Cu(+) cations to generate 1D coordination polymeric units, and (SiW(12)O(40))(4-) polyanions connect these metal-organic units to form two types of (6(3)) sheets which are topological isomerism. In compound 6, (SiMo(12)O(40))(4-) polyanions fixed in Cu(I)-Hfcz square rings are further extended into a 2D sheet via linking Cu(I) atoms of different rings. By carefully inspection of the structures of 1-6, it is believed that various transition-metal organic units and Keggin polyanions with different coordination modes are important for the formation of the different structures. In addition, electrochemical behaviors of compounds 1, 2, 5 and 6 have been investigated.     

Inorganic-organic hybrid compounds based on molybdenum oxide chains and tetrazolate-bridged polymeric silver cations

Three inorganic-organic compounds based on [Mo(x)O(y)](n-) chains, [Ag(4)(3-pttz)(2)Mo(3)O(10)] (1) (3-pttz = 5-(3-pyridyl) tetrazolate), [Ag(4)(2-pttz)(2)Mo(4)O(13)] (2) (2-pttz = 5-(2-pyridyl) tetrazolate), and [Ag(4)(pzttz)(2)Mo(4)O(13)] (3) (pzttz = 5-(pyrazinyl) tetrazolate), have been self-assembled, accompanied by in situ formation processes of the 5-substituted tetrazolate ligands under hydrothermal condition. Compound 1 features a 3D framework composed of [Mo(3)O(10)](2-) chains cross-linked by [Ag(4)(3-pttz)(2)](2+) belts. Compounds 2 and 3 reveal the 3D structures based on [Mo(4)O(13)](2-) chains pillared by silver tetrazolate polymeric chains. The three title compounds represent the first three examples that the tetrazolate ligands are introduced into the backbones of the [Mo(x)O(y)](n-) anion chains.     

Inorganic-organic hybrid membranes with anhydrous proton conduction prepared from 3-aminopropyltriethoxysilane and sulfuric acid by the sol-gel method

Inorganic-organic hybrid membranes with anhydrous proton conduction were prepared from 3-aminopropyltriethoxysilane and H2SO4 by the sol-gel method. The membrane has a unique structure: a hexagonal phase formed by the stacking of rodlike polysiloxanes with ion complexes of ammonium groups and HSO4- extruded outside. The membranes showed high conductivity of 2 x 10-3 S cm-1 at 200 degrees C under dry atmosphere. In the membrane, protons probably migrate through the outside of the rodlike polysiloxanes along hydrogen-bond chains formed among HSO4- anions.     

Monodisperse polymer-virus hybrid nanoparticles

Self-assembly of polystyrene sulfonate and modified cowpea chlorotic mottle virus protein yields monodisperse icosahedral nanoparticles of 16 nm size.     

Photodeformable spherical hybrid nanoparticles

We report the first synthesis of spherical nanoparticles of a bridged polysilsesquioxane. The hard, brittle nanoparticles are prepared by a simple sol-gel polymerization without surfactants or templates. Particle size ranges from 50 to 100 nm. The organic component of these hybrid nanoparticles is composed of a photolabile coumarin dimer. Irradiation with UV light dissociates the photodimer resulting in rupture of the cross-links and subsequent deformation and eventual "melting" of the nanoparticles.     

Janus hybrid hairy nanoparticles

Janus hairy nanoparticles (JHNPs) represent a new class of hybrid materials with a nanoparticle core and a layer of bicompartmentalized polymer brushes. This unique structure combines the complex properties of polymer brushes, the amphiphilic nature of surfactant, and the mechanical, optical, and electronic properties of nanoparticles. Over the past decade, tremendous efforts have been devoted to synthesizing JHNPs and understanding their structure and properties. In this review, we will summarize the recent progresses in the field, including fabrication approaches and the self- and directed assembly behavior of such JHNPs. We will specifically focus on the newly developed polymer single crystal directed nanoparticle assembly approach. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 1620–1640     

Analytical potential of hybrid nanoparticles

The growing use of nanoparticles in the analytical process in recent years has set a new trend towards the simplification of analytical methods and improvement of their performance. Miniaturization and nanotechnology have allowed new analytical challenges to be met. Hybrid nanoparticles in particular possess exceptional properties enabling further improvement of analytical methods. Despite the continuous developments in their synthesis and characterization, hybrid nanomaterials have scarcely been used in analytical chemistry, however. This paper discusses the analytical potential of hybrid nanoparticles in terms of their special characteristics and properties, and describes their analytical applications.     

Magnetic nanoparticles with hybrid shape

Co₅₀Ni₅₀ particles with very unusual shapes, resembling dumbbells or diabolos, are obtained by reducing mixtures of cobalt and nickel acetates in sodium hydroxide solution in 1,2-propane diol. These particles consist of a central column richer in cobalt than the overall composition, capped with two terminal platelets that are richer in nickel. These hybrid shapes are the result of a two-step growth mechanism due to a difference in reactivity of the two metal ions. The sodium hydroxide concentration controls the length and diameter of the column, in the ranges 50–250 nm and 5–15 nm, respectively, and the diameter of the platelets in the range 25–50 nm. The X-ray diffraction patterns show a mixture of hcp and fcc phases in various proportions depending on the particle shape. High-resolution electron microscopy shows that the hcp phase is located mainly in the central column and the fcc phase mainly in the terminal platelets. The particles are ferromagnetic at room temperature. When the volume fraction of the central column is high enough and the hcp phase is predominant and not much faulted, high coercivity (up to 1900 Oe) is observed.     

Ordered arrays of gold nanostructures from interfacially assembled Au@PNIPAM hybrid nanoparticles

In this Article, we report on the assembly of hybrid Au@PNIPAM core-shell particles at the air/water interface, their transfer onto solid substrates, and the controlled combustion of the organic material to produce arrays of gold nanoparticles. A detailed investigation on the assembly behavior of such soft hybrid colloids at the air/water interface was performed by correlating the surface pressure-area isotherms with SEM and AFM images from samples transferred at different surface pressures. The hybrid particles display a complex behavior at the interface, and we could distinguish three distinct phases with varying interparticle spacings at different compression. The transfer process presented enables the decoration of topologically structured substrates with gold nanoparticle arrays, and the order of the initial monolayers is retained in the arrays of inorganic gold nanoparticles. The change in monolayer morphology upon compression can therefore be used to tailor the interparticle distance between approximately 650 and 300 nm without exchanging the colloids. More sophisticated gold nanostructures can be patterned into symmetric arrays using a similar protocol, which we demonstrate for nanostars and nanorods.