Materials, organometallic

Topics in Organometallic Chemistry Volume 28 Molecular Organometallic Materials for Optics... 

Finally, the combination of dendrimers and organometallic entities as fundamental building blocks affords an opportunity to construct an infinite variety of organometallic starburst polymeric superstructures of nanoscopic, microscopic, and even macroscopic dimensions. These may represent a promising class of organometallic materials due to their specific properties, and potential applications as magnetic ceramic precursors, nonlinear optical materials, and liquid crystal devices in nanoscale technology. 

Lehrstuhl filr Anorganische Chemie II Organometallics Materials Science Ruhr-Universitat Bochum 44780 Bochum, Germany roland.fischer rub.de... 

Antireflective (AR) coatings are required on optics to reduce the reflective surface losses. Vitreous silica coatings in the form of porous or multilayer films are used extensively in this application. Antireflective coatings have been developed which employ colloidal fused silica sol—gel particles made from organometallic materials (253). 

Many other organic and some organometallic materials have been examined by the powder SHG method and/or tested by EFISH techniques. They will not be discussed in detail here but are listed by structural classes for completeness. Several compendia of materials responses have been published. (38,54,55) Clearly, the largest single class of second order materials consists of donor-acceptor substituted aromatics. The class has been extended to stilbenes and diarylacetylenes and... 

The same kinds of concepts may be applied to organometallic materials, where the presence of organometallic moieties such as metal carbonyls and metallocenes offers a great deal of scope for synthetic and electronic versatility. Metallocene derivatives such as 11.73 exhibit NLO properties as shown in Table 11.2. The (3 values are comparable to organic species of the same type, but do show additional behaviour due to mixing with metal states.73... 

The resulting chiral organometallic materials were used as catalysts in the Michael addition reaction of methyl vinyl ketone to (R/S)-ethyl a-iso-cyanopropionate, and after 24 h a conversion of 63% was obtained as compared to 80% conversion observed for the covalently immobilized [PtI(NCN-COOK)]. As for the latter, no chirality transfer was observed (see Sect. 2). 

An additional family of organometallic materials is the cyanometallates, which are Prussian blue analogues. These are microporous materials, similar to zeolites, with relatively large adsorption space and small access windows [237-241], These Prussian blue analogues develop zeolite-like structures based upon a simple cubic (T[M(CN)6]) framework, in which octahedral [M(CN)6]" complexes are linked via octahedrally coordinated, nitrogen-bound Tm+ ions [237], In the prototypic compound, that is, Prussian blue, specifically (Fe4[Fe(CN)6]3 14H20), charge balance with the Fe3+ ions conducts to vacancies at one-quarter of the [Fe(CN)6]4 complexes [242],... 

It is not recommended for metallic compounds (e.g., metals, metal salts, and organometallic materials) and high-molecular weight proteins. 

Bohm, M. C. One-Dimensional Organometallic Materials An Analysis of Electronic Structure Effects. Lecture Notes in Chemistry, no. 45. New York Springer-Verlag, 1987. 

Marder, S.R., Beratan, D.N., Tiemann, B.G., Cheng, L.T., Tam, W. Structure/property relationships for organic and organometallic materials with second-order optical nonhnearities, Spec. Publ. -R.S.C. 91, 165-175 (1991)... 

Heck, J.. Dabek, S., Meyer-Friedrichsen, T., Wong, H. Mono- and dinuclear sesquifulvalene complexes, organometallic materials with large nonlinear optical properties. Coord. Chem. Rev. 190-192, 1217-1254(1999)... 

Mechanical mixing via high-energy ball-milling is a sustainable experimental technique, which is generally used for the preparation of metal hydrides and other organometallic materials.Recently, it has also been used in organic synthesis and some important transformations are reviewed in this section. 

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