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22.
O. A. Fedorova S. P. Gromov Yu. P. Strokach Yu. V. Pershina S. A. Sergeev V. A. Barachevskii G. Pepe A. Samat R. Guglielmetti M. A. Alfimov 《Russian Chemical Bulletin》1999,48(10):1950-1959
Methods for the synthesis of new spironaphthooxazines containing an aza-15-crown-5 fragment in two different positions (5′
and 9′) were developed. The spectral and photochemical properties of these compounds suggest that two competitive complexation
processes occur with alkaline-earth or rare-earth metal cations differing in efficiency and selectivity. A metal cation occupies
the optimum position in the crown-ether cavity with respect to the donor oxygen atom of the merocyanine form of the dye and
thus can affect more strongly its spectral and photochemical properties than in the case of intermolecular interaction.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1974–1983, October, 1999. 相似文献
23.
Strokach Yu. P. Fedorova O. A. Gromov S. P. Koshkin A. V. Valova T. M. Barachevsky V. A. Alfimov M. V. Lokshin V. A. Samat A. Guglielmetti R. 《Russian Chemical Bulletin》2002,51(1):58-66
Spironaphthoxazines linked with aza-15(18)-crown-5(6) fragments were synthesized and studied for the first time. Addition of alkaline-earth cations to solutions of crown-containing spironaphthoxazines causes a hypsochromic shift of the absorption band of the spiro form and a bathochromic shift of the absorption band of the merocyanine form, shifts the equilibrium to the merocyanine form, and changes the lifetime of the photoexcited merocyanine form. The spectral and kinetic data were used to propose a mechanism of complexation and calculate the stability constants of the resulting complexes. The complexation involves the crown fragment and the merocyanine oxygen atom. The type of the complex is determined by the cation nature and size. 相似文献
24.
Jean-Luc Pozzo Andr Samat Robert Guglielmetti Roger Dubest Jean Aubard 《Helvetica chimica acta》1997,80(3):725-738
New chromenes annulated with different six-membered azaheterocycles were prepared, i.e., the 3H-pyra-no[3,2-f]quinolines 9/10 and 14 , the 8H-pyrano[2,3-h]isoquinoline 11 , the 8H-pyrano[3,2-f]quinazolme 12 , the 8-H-pyrano[3,2-f]quinoxaline 13 , and the 2H-pyrano[2,3-f]isoquinoline 15. The synthesis was achieved using conveniently substituted α,β-unsaturated aldehydes and organotitanium intermediates arising from azaheterocyclic phenols. Their photochromic behaviour (photocolouration yield, UV/VIS spectrum of photomerocyanines, rate constant of thermal bleaching) were studied besides those of corresponding naphthopyrans. The heterocycle effect and the role of substituents in the pyran moiety were investigated quantitatively through the study of the photochromic properties and the solvent effects. Diaryl-substituted azino-fused chromenes, especially isoquinoline derivatives, exhibit increased colourabilities and bathochromically shifted spectra for photomerocyanines which open up new prospects for photochromic applications. 相似文献
25.
Synthesis of Thiophene-Substituted Spiropyrans and Spirooxazines,Precursors of Photochromic Polymers
Corinne Moustrou Andr Samat Robert Guglielmetti Roger Dubest Francis Garnier 《Helvetica chimica acta》1995,78(7):1887-1893
The synthesis of spiropyrans 11 and 12 and spirooxazines 13–17 containing a thiophene moiety is described. Two different synthetic approaches were used. The spectrokinetic properties of these new compounds are reported. 相似文献
26.
Efficient Access to Substituted Silafluorenes by Nickel‐Catalyzed Reactions of Biphenylenes with Et2SiH2 下载免费PDF全文
Jens Michael Breunig Puneet Gupta Dr. Animesh Das Dr. Samat Tussupbayev Dr. Martin Diefenbach Dr. Michael Bolte Prof. Dr. Matthias Wagner Prof. Dr. Max C. Holthausen Dr. Hans‐Wolfram Lerner 《化学:亚洲杂志》2014,9(11):3163-3173
The reaction of biphenylene ( 1 ) with Et2SiH2 in the presence of [Ni(PPhMe2)4] results in the formation of a mixture of 2‐diethylhydrosilylbiphenyl [ 2 (Et2HSi)] and 9,9,‐diethyl‐9‐silafluorene ( 3 ). Silafluorene 3 was isolated in 37.5 % and 2 (Et2HSi) in 36.9 % yield. The underlying reaction mechanism was elucidated by DFT calculations. 4‐Methyl‐9,9‐diethyl‐9‐silafluorene ( 7 ) was obtained selectively from the [Ni(PPhMe2)4]‐catalyzed reaction of Et2SiH2 and 1‐methylbiphenylene. By contrast, no selectivity could be found in the Ni‐catalyzed reaction between Et2SiH2 and the biphenylene derivative that bears tBu substituents in the 2‐ and 7‐positions. Therefore, two pairs of isomers of tBu‐substituted silafluorenes and of the related diethylhydrosilylbiphenyls were formed in this reaction. However, a subsequent dehydrogenation of the diethylhydrosilylbiphenyls with Wilkinson’s catalyst yielded a mixture of 2,7‐di‐tert‐butyl‐9,9‐diethyl‐9‐silafluorene ( 8 ) and 3,6‐di‐tert‐butyl‐9,9‐diethyl‐9‐silafluorene ( 9 ). Silafluorenes 8 and 9 were separated by column chromatography. 相似文献
27.
A synthetic and convenient pathway to phospha-crown ethers is presented involving the condensation of dichlorophenylphosphineoxide with polyethylene glycols under conditions that avoid polymerization. 相似文献
28.
Aloïse S Réhault J Moine B Poizat O Buntinx G Lokshin V Valès M Samat A 《The journal of physical chemistry. A》2007,111(10):1737-1745
For the two photochromic molecules, 3-benzoyl-2-benzyl-1-methyl-1H-quinolin-4-one (QC1) and 3-benzoyl-1,2-dibenzyl-1H-1,8-naphthyridin-4-one (QC18a) as well as the nonphotochromic 3-benzoyl-1-benzyl-2-methyl-1H-1,8-naphthyridin-4-one (QC18b), the full photochemical mechanism, which is based on the photoenolization process, has been elucidated using stationary and time-resolved spectroscopy techniques. After photoexcitation, the S1(n,pi*)-T1(n,pi*) ISC process involving the exocyclic carbonyl chromophore is demonstrated to occur. Subsequently, gamma-hydrogen transfer proceeds very rapidly to give rise to the triplet photoenol with a probable 1,4-biradical structure. For all three molecules, the biradical is clearly detected and proved quantitatively to be the direct precursor of the colored form (photochromic compounds) or ground state starting material (nonphotochromic compound). Solvent effects for the three molecules studied may suggest the existence of intramolecular hydrogen bonding in both biradical and colored form species. Structural effects on the gamma-hydrogen transfer rate and biradical decay are related to the photochromic performances. 相似文献
29.
Makarov AY Zhivonitko VV Makarov AG Zikirin SB Bagryanskaya IY Bagryansky VA Gatilov YV Irtegova IG Shakirov MM Zibarev AV 《Inorganic chemistry》2011,50(7):3017-3027
Interaction between Ph(3)P and 1,3,2,4-benzodithiadiazine (1); its 6,7-difluoro (2), 5,6,8-trifluoro (3) and 5,6,7,8-tetrafluoro (4) derivatives; and 5,6,8-trifluoro-3,1,2,4-benzothiaselenadiazine (5) proceeded via a 1:1 condensation to give Ph(3)P═N-R iminophosphoranes (1a-5a, R = corresponding 1,2,3-benzodichalcogenazol-2-yls), which are inaccessible by general approaches based on the Staudinger and Kirsanov reactions. In contrast, neither Ph(3)As nor Ph(3)Sb reacted with 1 and 4. Molecular structures of 1a-5a and 5 were confirmed by X-ray diffraction (XRD). The crystals formed by chiral molecules of 2a-5a were racemic, whereas the crystal of 1a was formed by a single enantiomer. In all of the Ph(3)P═N-R derivatives, one of the Ph rings is oriented face-to-face to the hetero ring, R. Upon heating to ~120 °C in squalane (1a, 3a, 4a) or dissolving in chloroform at ambient temperatures (1a, 2a, 4a), the Ph(3)P═N-R derivatives generated the 1,2,3-benzodithiazolyls (1b-4b, respectively) whose identity was confirmed by electron paramagnetic resonance (EPR). 2,1,3-Benzothiaselenazolyls 5b and 6b were detected by EPR as the main paramagnetic products of solution thermolysis of 5 and its 5,6,7,8-tetrafluoro congener (6), respectively. Passing a chloroform solution of 4a through silica column unexpectedly gave 5-6-6-6 tetracyclic (9) and 6-10-6 tricyclic (10) sulfur-nitrogen compounds, which were characterized by XRD. 相似文献
30.
Kamil Z. Tilyabaev Samat A. Talipov Bakhtiyar T. Ibragimov Michael K. Dowd Abdurasul M. Yuldashev 《Journal of chemical crystallography》2009,39(9):677-682
Abstract The crystal structures of di-ethylaminogossypol with ethyl acetate (DEAG-EA) and pyridine (DEAG-P) were studied by room-temperature
X-ray diffraction. The host-to-guest molecule ratio in these complexes is 2:1 for DEAG-EA and 2:5 for DEAG-P. The crystal
and cell parameters for DEAG-EA are C34H40N2O6·0.5(C4H8O2), M = 660.78, triclinic, space group P-1, a = 11.316(2) ?, b = 12.082(2) ?, c = 15.085(3) ?, α = 73.34(3)°, β = 73.32(3)°, γ = 73.61(3)°, V = 1,847.3(7) ?3, Z = 2, and d
calc. = 1.188 g/cm3 and for DEAG-P are C34H40N2O6·2.5(C5H5 N), M = 769.91, triclinic, space group P-1, a = 9.6090(19) ?, b = 14.894(3) ?, c = 16.038(3) ?, α = 90.66(3)°, β = 106.25(3)°, γ = 103.17(3)°, V = 2138.7(9) ?3, Z = 2, and d
calc. = 1.195 g/cm3. In both structures, the di-ethylaminogossypol molecules are in the enamine form, which is the same tautomer found for other
reported Schiff base gossypol derivatives. The enantiomeric gossypol molecules of each structure form different centrosymmetric
dimer assemblies. These assemblies pack differently in each solvate.
Index Abstract Crystal structures of the solvates of di-ethylaminogossypol with ethyl acetate and pyridine were determined by X-ray diffraction.
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