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41.
Ilia A. Guzei Howard E. Zimmerman Sergey Shorunov Lara C. Spencer 《Journal of chemical crystallography》2009,39(6):399-406
Abstract 2,3-Diphenyl-1-naphthol (1) undergoes two unexpected reactions under different conditions. Compound (1) was heated in DMSO-d6 and underwent a Pummerer type thermal reaction to give two isomeric products, 1-(methylthio)methoxy-2,3-diphenyl naphthol-d5 which crystallized in the space group with a = 7.1610(9) ?, b = 11.2795(15) ?, c = 12.8905(17) ?, α = 114.049(2)°, β = 96.589(2)°, and γ = 102.945(2)°, and 2-(methylthio)methyl-2,3-diphenyl 1(2H)-naphthalenone-d5 which crystallized in the space group with a = 8.5981(5) ?, b = 10.4374(6) ?, c = 11.1078(6) ?, α = 78.748(2)°, β = 67.709(2)°, and γ = 83.184(2)°. Photolysis (254 nm) of (1) resulted in 2,2′,3,3′-tetraphenyl-1,1′-bi-2-naphthol which crystallized in the space group P21/c with a = 26.3616(11) ?, b = 10.1707(4) ?, c = 23.3376(9) ?, and β = 99.034(2)°.
Graphical Abstract When 2,3-diphenyl-1-naphthol was heated in DMSO-d6 two unexpected isomers, 1-(methylthio)methoxy-2,3-diphenyl naphthol-d5 and the racemate 2-(methylthio)methyl-2,3-diphenyl 1(2H)-naphthalenone-d5 were produced. Photolysis in THF at 254 nm led to the unexpected product 2,2′,3,3′-tetraphenyl-1,1′-bi-2-naphthol. All structures
were elucidated by X-ray crystallography.
相似文献
42.
《Analytical letters》2012,45(17):2673-2689
A high-performance liquid chromatography–UV/VIS detection–electrospray ionization single quadrupole mass spectrometry (HPLC–UV/VIS–ESI-MS) method was developed to separate oxidative and photolytic degradation products of aryldiamines, that is, para-phenylenediamine and para-toluenediamine. The separation was performed on a polar modified reversed phase-C18 column which provided superior chromatographic resolution compared to conventional columns. Gradient elution was used with the mobile phases of water and acetonitrile containing 10 mM ammonium acetate. Various compounds including aryldiamines, benzoquinones, aromatic nitro compounds, and azobenzenes were selected for an optimization of the ESI-MS operation and the chromatographic separation conditions. Highly linear calibrations (r2 > 0.999) were achieved for a subset of 5 standard substances. Using analyte-specific UV detection wavelengths, limits of detection and limits of quantitation of these substances ranged from 3.0 to 7.0 µg L?1 and from 10.0 to 23.3 µg L?1, respectively. The analysis of aqueous solutions of para-toluenediamine photolysis products confirmed the performance of the method. Up to 28 chromatographic signals were recorded and the change of their peak heights during the transformation process was monitored for 24 hours. The identities of the compounds were ascertained by means of MS detection correlations between molecular features and the chromatographic retention of the compounds. 相似文献
43.
Matthew J. Almond J. Pat Cannady Tracey A. Darling J. Steven Ogden Robin Walsh 《Journal of organometallic chemistry》2001,640(1-2):177-181
Irradiation using a low pressure mercury lamp (λ=ca. 250 nm) of argon matrices containing ca. 1% (Me2Si)6 and ca. 20% ethylene oxide (C2H4O) or nitrous oxide (N2O) for a period of ca. 20 h leads to the formation of the cyclic compound (Me2SiO)6. This has a 12-membered ring with alternating Si and O atoms. It is identified by comparison of its infrared spectrum with a spectrum of an authentic sample. The reaction appears to proceed by stepwise insertion of O atoms into Si---Si bonds. 相似文献
44.
链状双杂芳基乙烯化合物的合成与光化学性质研究 总被引:1,自引:0,他引:1
合成了1,n-双[4-[2-[2-(5-甲基苯并唑基)]乙烯基]苯氧基]烷烃(a:n=3;b:n=4;c:n=6)和2,2'-双[4-[2-[2-(5-甲基苯并唑基)]乙烯基]苯氧基]乙醚(d)4个新化合物.用元素分析、红外、紫外、核磁共振谱和质谱表征了其结构.用紫外吸收光谱跟踪研究了Ⅰa_Ⅰd在紫外灯照射下的变化,发现上述化合物在高压汞灯照射下可同时发生反顺异构化和[2+2]分子内光二聚两种反应,反顺异构化反应迅速可逆,而光二聚反应进行缓慢且不可逆.增加链长有助于提高分子内光二聚反应的速率.分子内光二聚反应不受空气中氧的影响的事实表明其是经激发单线态历程进行的.还发现分子内光二聚体在短波紫外光照射下容易进行逆[2+2]光解开环反应.上述化合物分子内光二聚和光解开环反应可以反复进行多次,表明该类化合物具有较高的光稳定性. 相似文献
45.
Under appropriate conditions, the photolysis of iodoaromatic compounds yields derivatives of biphenyl and phenanthrene, as well as organometallic compounds. Ring closures of o-terphenyls to triphenylenes and of benzanilides to phenanthridones are described. The formation of dehydrobenzene (benzyne) on photolysis of 1,2-diiodobenzene in solution has been established. The photolysis of various substituted iodoaromatic compounds or of substances such as CH3I, ICN, ICH3, COOH, or RC?CI, provides a general method for the generation of a large variety of free radicals in solution. The potential uses of photochemically initiated exchanges of iodine in ArI for 131I, Li, D, Cl, or Br are noted. 相似文献
46.
Tsunehisa Hirashita 《Tetrahedron letters》2005,46(2):289-292
Intramolecular cyclization of allylic radicals generated from allylindium compounds both by photolysis or by the reaction of radical initiators was examined. The photolysis of allylic indium compounds, prepared from 8-bromo- or 8-iodooct-1,6-dienes and powdered indium metal, led to the formation of the 5-exo-trig products. Benzoyl peroxide as a radical initiator was also effective for the cyclization. In contrast, the radical initiators with oxidizing nature, such as tert-butyl hypochlorite, induced iodocyclization producing iodomethylcyclopentane via an oxidation of the iodide on the indium atom. 相似文献
47.
William T. Murray Anne Pautard-cooper Nita A. Eskew Slayton A. Evans Jr 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):101-104
Abstract The kinetics of Lewis acid-mediated decomposition and definitions of the synthetic applicability of 1,3,2λ5-dioxaphospholanes for (i) the syntheses of highly-hindered epoxides, and (ii) the stereospecific functionalizations of stereocenters in 1,2-diol arrays are described. 相似文献
48.
We wish to report here a new and efficient partial synthesis of 3-oxa-5β-steroid, the first oxa steroid synthesized from cholic acid. 相似文献
49.
Yury A. Sayapin Vitaly N. Komissarov Nadezhda I. Makarova Valery V. Tkachev Sergey M. Aldoshin 《Tetrahedron》2010,66(45):8763-8771
A series of novel derivatives of the 1,3-tropolone (β-tropolone) system—2-(2-quinolyl)-5,6,7-trichloro-1,3-tropolones and 2-(2-quinolyl)-4,5,6,7-tetrachloro-1,3-tropolones have been prepared by the acid-catalyzed reaction of 2-methylquinolines with 3,4,5,6-tetrachloro-1,2-benzoquinone. The molecular structures of two compounds, 2-(4-chloro-6,8-dimethyl-5-nitro-2-quinolyl)-5,6,7-trichloro-1,3-tropolone 8 and 2-(4-chloro-7,8-dimethyl-5-nitro-2-quinolyl)-4,5,6,7-tetrachloro-1,3-tropolone 9, have been determined using X-ray crystallography. According to the performed DFT B3LYP/6-311++G∗∗ calculations the tautomeric (OH) and (NH) forms of β-tropolones 8 and 9 are nearly energy equivalent, the latter being more stabilized in polar media. Photolysis of 2-(2-quinolyl)-1,3-tropolones in heptane solution leads to the disrotatory electrocyclic rearrangement resulting in the formation of a mixture of E- and Z-isomers of 3-[2(1H)-quinolinylyden]-bicyclo[3.2.0]hept-6-en-2,4-dione derivatives. 相似文献
50.
Keitaro Ishii Takuya Sone Yukio Shimada Takahide Shigeyama Masahiro Noji Shigeo Sugiyama 《Tetrahedron》2004,60(48):10887-10898
The photochemical C,C-bond cleavage of N-benzyl β-aziridinylacrylonitrile 1 and acrylate 2 and the subsequent [3+2] cycloaddition with electron-deficient alkenes afforded head-to-head adducts selectively and efficiently. Irradiation of N-phenyl aziridine 3 with acrylonitrile gave adducts, but photoreaction of N-benzoyl aziridine 4 and thermal reactions of 3 and 4 with alkenes yielded C(γ),N-cleaved products instead of cycloadducts. N-trityl aziridine 5 also reacted with electron-deficient alkenes, affording 2,3-cis-pyrrolidine derivatives exclusively. A formal synthesis of a pyrrolizidine alkaloid, isoretronecanol (27), starting from 5 was achieved in a convenient manner. 相似文献