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281.
282.
The interaction of 2,6-disubstituted bicyclo[3.3.1]nonanes with - and -cyclodextrins has been investigated by1H NMR spectroscopy and the formation of (11) host—guest complexes has been established.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2523–2525, December, 1995. 相似文献
283.
Eugenius Butkus José C. Martins Ulf Berg 《Journal of inclusion phenomena and macrocyclic chemistry》1996,26(4):209-218
The formation and structure of inclusion complexes of 2,6- and 2,9-substituted bicyclo[3.3.1]nonanes with- and-cyclodextrin (CD) has been investigated by high-resolution1H NMR spectroscopy.- and-CD were found to form 1:1 inclusion complexes and the binding constants were estimated from titration studies. 2D ROESY experiments provided insight into the structure of the complexes.Presented in part at the 8th International Cyclodextrin Symposium, Budapest, March 30–April 2, 1996. 相似文献
284.
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286.
Antonio E. Mauro Paula S. Haddad Henrique E. Zorel Jr. Regina H. A. Santos Sandra R. Ananias Fabiane R. Martins Laura H. R. Tarrasqui 《Transition Metal Chemistry》2004,29(8):893-899
The compounds [Cu(N3)(NSC)(tmen)]n (1), [Cu(N3)(NCO)(tmen)]n (2) and [Cu(N3)(NCO)(tmen)]2 (3) (tmen=N,N,N′,N′-tetramethylethylenediamine) were synthesized and studied by i.r. spectroscopy. Single crystals of compounds (1) and (3) were obtained and characterized by X-ray diffraction. The structure of compound (1) consists of neutral chains of copper(II) ions bridged by a single azido ligand showing the asymmetric end-to-end coordination fashion. Each copper ion is also surrounded by the other three nitrogen atoms; two from one N,N,N′,N′-tetramethylethylenediamine and one from a terminal bonded thiocyanate group. Compound (2) decomposes slowly in acetone and the product formed [Cu(N3)(NCO)(tmen)]2 (3) crystallizes in the monoclinic system (P21). The structure of (3) consists of dimeric units in which the Cu atoms are penta-coordinated and connected by μ(1,3) bridging azido and cyanate ligands. In both cases the five coordinated atoms give rise to a slightly distorted square-based pyramid coordination geometry at each copper ion. The thermal behavior of [Cu(N3)(NSC)(tmen)]n (1) and [Cu(N3)(NCO)(tmen)]n (2) were investigated and the final decomposition products were identified by X-ray powder diagrams. 相似文献
287.
Pentacyclo[5.4.0.02,6.03,10.05,9]undecan-8-one 1 is readily sulfurated into pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8-thione 2 with Lawesson’s reagent in dry THF. Upon standing at ambient temperature the thione 2 formed the corresponding thio-dimer 3 within 10 days. When the thio-dimer 3 was exposed to oxygen and ultraviolet light an unexpected photochemical oxidation and rearrangement took place to form the stable disulfenate 5. 相似文献
288.
M.E. Martins C. Castellano A.J. Calandra A.J. Arvía 《Journal of Electroanalytical Chemistry》1977,81(2):291-300
Gold dissolves anodically in acetonitrile solutions containing dissolved NaSCN, at 25°C. The reaction yields Au(I) and Au(III) complex ion species which can be cathodically electroplated. The voltammetric experiments indicate that the anodic dissolution is preceded by a partial surface saturation with the intermediate initially discharged, followed by a diffusion controlled process which depends on the SCN? ion concentration. The electrochemical behaviour of the anodic and cathodic processes is comparable to that of gold in aqueous solutions containing Au-complex ions. 相似文献
289.
Nilo Zanatta Fabio M. da Silva Luciana S. da Rosa Louíse Jank Helio G. Bonacorso Marcos A.P. Martins 《Tetrahedron letters》2007,48(37):6531-6534
A simple one-pot procedure to obtain a series of new 3-alkoxy-3-cyanocarboxylic acids from the reaction of 4-alkoxy-1,1,1-trichloro-but-3-en-2-ones with sodium cyanide is described. 相似文献
290.
S. Baier M. Martins B. R. Müller P. Zimmermann 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1988,10(4):445-449
Using a combination of collisional and laser excitation the lifetimes of 17 autoionizing Cu I states in the configurations 3d 9 4s 6s and 3d 9 4s4d were measured. The lifetimes are in the range of 1–50 ps and depend strongly on the coupling properties, the mixing with different configurations, and the radial integrals of the discrete with the continuum states. For the level 3d 9 4s 4d 4 S 3/2 the influence of an electric field via Stark mixing of 3d 9 4s 5p 4 P 1/2 on the autoionizing rate was investigated. The experimental values are compared with theoretical results which follow from ab initio calculations for the transition probabilities and least square fit values deduced from the experimental positions. Good agreement is found only for theJ=3/2 levels of both configurations 3d 9 4s 4d and 3d 9 4s 6s. 相似文献