Homogeneously dispersed organic–inorganic hybrid nanocomposites can be obtained by increasing the interfacial interactions between both components via the formation of hydrogen bonds or covalent bonds, by mixing various polymers or via the adequate choice of the inorganic precursors The mechanical response of these advanced functional materials is an issue of paramount importance when industrial applications are targeted Large progress in the understanding of the mechanical properties of O–I hybrids has been gained by testing these materials under different conditions (static and dynamic, low and large deformations up to fracture) and using specific techniques developed for the mechanical characterization of conventional materials such as polymers, glasses or ceramics However, the mechanical properties of hybrid O–I materials are dependent on their micro- and nanostructures and on the nature and extent of the O–I interfaces Consequently, predictable mechanical properties for hybrids still represent a major challenge for hybrid materials science Industrial attraction for hybrid materials has been emphasized by the development of new functional coatings An important issue is the interface between the film and the substrate since strong adhesion can be tailored and ensures that delamination of the film will be limited

Mechanical properties of hybrid organic–inorganic materials

The three-dimensional framework of [Gd(H2O)3]3[GdMo12O42]vdt·3H2O, which was synthesized from hydrothermal reaction, is built up from Silverton-type anions linked by nine coordinated gadolinium(III...

Hydrothermal Assembly of a Novel Three-Dimensional Framework Formed by [GdMo12O42]9- Anions and Nine Coordinated GdIII Cations

The chemical modification of titanium alkoxides by alkoxy- and aminoalcohols, s-diketones, s-ketoesters, carboxylic and phosphonic acids, and related compounds, and the hydrolysis behavior of the organically modified precursors are reviewed Special focus is put on structural aspects and on the possibility to introduce functional organic groups Such precursors have a high potential for innovative materials syntheses because they permit control of the precursor reactivity in sol–gel processes and the preparation of titania-based inorganic–organic hybrid materials Coordination, solvation, aggregation and redistribution equilibria play an important role in the chemistry of the modified titanium alkoxides, and organic side reactions have to be taken into account

Chemical modification of titanium alkoxides for sol–gel processing

The remarkably large cluster Sc4(μ3-O)2 has been obtained trapped inside an Ih-C80 cage by conducting the vaporization of graphite rods doped with copper(II) nitrate and scandium(III) oxide in an electric arc under a low pressure helium atmosphere with an added flow of air. The product has been isolated by chromatography and identified by high-resolution mass spectrometry. The structure of Sc4(μ3-O)2@Ih-C80 has been determined by X-ray crystallography on a crystal of Sc4(μ3-O)2@Ih-C80·NiII(OEP)·2(C6H6). The Sc4(μ3-O)2 unit consists of a distorted tetrahedron of scandium atoms with oxygen atoms bridging two of its faces. The Sc−Sc distances range from 2.946(7) to 3.379(7) A.

A Distorted Tetrahedral Metal Oxide Cluster inside an Icosahedral Carbon Cage. Synthesis, Isolation, and Structural Characterization of Sc4(μ3-O)2@Ih-C80

Organometallic Aggregates. 1. Structural Data Anne Harrison-Marchand*,† and Florence Mongin*,‡ †Laboratoire COBRA de l′Universite ́ de Rouen, INSA de Rouen, CNRS, UMR 6014 & FR 3038, IRCOF, Rue Tesnier̀e, 76821 Mont St Aignan Ced́ex, France ‡Équipe Chimie et Photonique Molećulaires, Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Universite ́ de Rennes 1, Bat̂iment 10A, case 1003, Avenue du Geńeŕal Leclerc, 35042 Rennes Ced́ex, France

Mixed AggregAte (MAA): A Single Concept for All Dipolar Organometallic Aggregates. 1. Structural Data

Physicochemical Approach to the Studies of Metal Alkoxides

The authors study the formation of polycrystalline films of LiNbO/sub 3/ and NaNbO/sub 3/ obtained by the hydrolysis of alcoholic solutions of alkoxides. To determine the optimum conditions for the formation of the coatings the effect is discussed of the following process parameters: the concentration of the initial solution; the film growth method; and the moisture content and aging of the solution. The crystallization, quality and thickness of the films were monitored with X-ray diffraction, scanning electron microscopy, and ellipsometry. Quartz and platinum were used as the substrates. A table lists the preparation conditions, including annealing and storage time, for the films; photographs show their morphology. The method presented is found to be suitable for preparing continuous oxide films. To obtain films with a thickness greater than 500 angstroms, it is recommended that layered application be used, in which each layer is annealed at the crystallization temperature of the given oxide phase.

Nataliya Ya. Turova

Papers

Physicochemical Approach to the Studies of Metal Alkoxides

Preparation of polycrystalline films of sodium and lithium niobates from solutions of the metal alkoxides

Niobium, Tantalum, Protactinium

On the structure of heterometallic methoxide Li2(WO)2(OMe)10·MeOH