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11.
Alan D. Potoff Bertrand L. Chamberland Lewis Katz 《Journal of solid state chemistry》1973,8(3):234-237
A single crystal study of hydrothermally prepared eight-layer BaMnO3 has been carried out which confirms the (Zhdanov notation) 121121 layer stacking scheme for the BaO3 layers. The MnO6 octahedra share faces in strings of four, and these strings are connected to each other by corner sharing. The compound has an hexagonal unit cell of dimensions a = 5.667 ± 0.003 and c = 18.738 ± 0.009 Å, probable space group . Its structure has been determined from 352 independent reflections, of which 242 were considered observed, collected manually by a counter technique and refined to a conventional R value of 0.079. 相似文献
12.
Studies on Alkyl Metal Alkoxides of Aluminium, Gallium, and Indium. III. Properties and Vibrational Spectra of Dialkylgallium- and Indium Alkoxides The preparation and the properties of dialkyl metal alkoxides R2MOR′ (with R = CH3, CD3, C2H5; R′ = CH3, CD3 and M = Ga, In) are described. The vibrational data (IR and Raman) of the trimeric methyl derivatives point to puckered six-membered M3O3-ring systems. 相似文献
13.
Alan R. Katritzky Scott A. Henderson Baozhen Yang 《Journal of heterocyclic chemistry》1998,35(5):1123-1159
Applications of benzotriazole methodology for the preparation of heterocyclic compounds are reviewed. The characteristic advantages of benzotriazole as a synthetic auxiliary are first briefly considered. This is followed by a summary of its use in ring synthesis in which the construction of small; five-membered; six-membered; and larger heterocyclic rings using benzotriazole methodology are each examined separately. Finally, consideration of the use of benzotriazole in the ring annulation - particularly benzannulation - of heterocycles. Subsequent sections deal with the introduction of substituents into aromatic heterocycles; the ring substitution of saturated heterocycles; and benzotriazole assisted modification of heterocyclic substituents. The present review supplements a recent comprehensive review of benzotriazole chemistry [1] which covers the literature through 1996. 相似文献
14.
Tetra-n-butylammonium hexachloroplatinate (IV) reacts with lithium methyl/lithium iodide in ether to give a solution containing lithium hexamethylplatinate (IV). With lithium methyl/lithium bromide in ether however, tetrabutylammonium hexamethylplatinate (IV) is precipitated together with lithium halides. Solid [Bu4N)2[Pt(Ch3)6] is stable under nitrogen at room temperature, but ether solutions of [Pt(Ch3)6]2- decompose in a few minutes at room temperature in the absence of excess lithium methyl. 相似文献
15.
Alan H. Cowley 《Journal of organometallic chemistry》2004,689(24):3866-3872
A survey of some recent developments and past achievements in low-valent main group chemistry is presented. Some emerging implications of this area of chemistry in materials science, catalysis and new reagent development are also discussed. 相似文献
16.
The mass spectra of 10 isomeric trimethylcyclohexanes and six cis–trans isomeric 1,2,3,5-tetramethylcyclohexanes are discussed. The thermochemically stable isomers show a higher abundance of the [M? CH3]+ ions and a lower abundance of the [M? C2H5]+ ions than the strained isomers. The log of the intensity ratio for loss of methyl and ethyl from the molecular ions correlates well with the strain energies and with the mean number of gauche arrangements of the stereoisomers. 相似文献
17.
The adhesive secreted by the barnacle, Balanus eburneus, has been demonstrated to contain two hexosamines, glucosamine and galactosamine. Degradation of the hexosamines during hydrolysis of the adhesive appears to be the reason why previous studies of the adhesive have indicated the absence of hexosamines, or the presence of only one hexosamine. 相似文献
18.
Alan S.F. BoydGraeme Cooke Florence M.A. DuclairoirVincent M. Rotello 《Tetrahedron letters》2003,44(2):303-306
We have investigated the electrochemically controlled hydrogen bonding interactions between tetrathiafulvalene host 3 and guests 4 or 5. Stabilisation of the 3+ state is dependent upon the nature of the guest species, whereas both guests prevent precipitation of the electrochemically generated 32+ species at the working electrode via hydrogen bonded molecular recognition processes. 相似文献
19.
A concise first total synthesis of the antitumour antibiotic belactosin A is reported, involving coupling of beta-lactone carboxylic acid 3 with N-Ala-aminocyclopropyl alanine 11. 相似文献
20.
Molybdenum-95 NMR spectra have been measured for a selection of molybdenum carbonyl compounds and Mo(Σ-C5H5)(η-C5H5)(NO)(S2CNMe2). A chemical shift range of more than 1500 ppm is found. The chemical shifts and linewidths are discussed. 相似文献