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71.
Abdul M. Rasheed Rambabu Namala Narendra Manne Sreelatha Vanjivaka Ravi Dhamjewar Gopalan Balasubramanian 《合成通讯》2013,43(2):162-169
Highly potent and selective DPP II inhibitors N′‐(4‐Chlorobenzyl)‐N′‐methyl‐4‐oxo‐4‐(1‐piperidinyl)‐1,3‐(S)‐butane‐diamine dihydrochloride 1 and N′‐(4‐chlorobenzyl)‐4‐oxo‐4‐(1‐piperidinyl)‐1,3‐(S)‐butanediamine dihydrochloride 2 have been efficiently synthesized starting from L‐glutamine. A short and high yielding route with simple isolation techniques has been disclosed. 相似文献
72.
Synthesis and Characterization of Donor–π‐Acceptor‐Based Porphyrin Sensitizers: Potential Application of Dye‐Sensitized Solar Cells 下载免费PDF全文
Mareedu Sreenivasu Akira Suzuki Dr. Mitsuhiro Adachi Challuri Vijay Kumar Dr. Bingi Srikanth S. Rajendar Dasa Rambabu Dr. Rangaraju Satish Kumar P. Mallesham Dr. N. Vijaya Bhaskar Rao Dr. M. Suresh Kumar Dr. P. Y. Reddy 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(43):14074-14083
New porphyrin sensitizers based on donor–π‐acceptor (D‐π‐A) approach have been designed, synthesized, characterized by various spectroscopic techniques and their photovoltaic properties explored. N,N′‐Diphenylamine acts as donor, the porphyrin is the π‐spacer, and either carboxylic acid or cyanoacryclic acid acts as acceptor. All compounds were characterized by using 1H NMR spectroscopy, ESI‐MS, UV–visible emission spectroscopies as well as electrochemical methods. The presence of aromatic groups between porphyrin π‐plane and acceptor group push the absorption of both Soret and Q‐bands of porphyrin towards the red region. The electrochemical properties suggests that LUMO of these sensitizers above the TiO2 conduction band. Finally, the device was fabricated using liquid redox electrolyte (I?/I3?) and its efficiency was compared with that of a leading sensitizer. 相似文献
73.
Pal M Dakarapu R Parasuraman K Subramanian V Yeleswarapu KR 《The Journal of organic chemistry》2005,70(18):7179-7187
[reaction: see text] A variety of 3-enynyl substituted flavones/thioflavones were synthesized via a sequential one-pot procedure using copper-free palladium-catalyzed cross coupling in a simple synthetic operation. The cross coupling between 3-iodo(thio)flavone and a broad range of terminal alkynes was carried out in the presence of Pd(PPh3)2Cl2 and triethylamine to afford the corresponding 3-enynyl derivatives in a regio- and stereoselective fashion. The best results are obtained by employing 3 equiv of the terminal alkynes. The process worked well irrespective of the substituents present on the (thio)flavone ring as well as in the terminal alkynes except arylalkynes. The reaction is quite regioselective, placing the substituent of the terminal alkyne at the far end of the double bond attached with the (thio)flavone ring. The orientation of the (thio)flavonyl and acetylenic moieties across the double bond was found to be syn in the products isolated. A tandem C-C bond-forming reaction in the presence of palladium catalyst rationalized the formation of coupled product. The catalytic process apparently involves heteroarylpalladium formation, regioselective addition to the C-C triple bond of the terminal alkyne, and subsequent displacement of palladium by another mole of alkyne. The present methodology is useful for the introduction of an enynyl moiety at the C-3 position of flavones and thioflavone rings to afford novel compounds of potential biological interest. In the presence of CuI the process afforded 3-alkynyl (thio)flavones in good yields. 相似文献
74.
Dikshitulu S. A. Lanka Rambabu Rallabandi Sridevi Nadimpalli 《Transition Metal Chemistry》1988,13(1):39-41
Summary The kinetics of oxidation of TeIV by CoIII have been studied in aqueous HClO4. A mechanism presuming [Co(OH2)5(OH)]2+ to be the reactive species has been proposed, which leads to the rate-equation shown. Rate=–d[CoIII]/dt=2kKK
h
2
[CoIII]
t
2
[TeIV]/[H+]2 Kb is the hydrolysis constant of CoIII, K is the formation constant of the complex between CoIII and TeIV and k is the rate of decomposition of that complex. Ea and S are 95.0±2.1 kJ mol–1 and 28.3±7.1 JK–1 mol–1, respectively. 相似文献
75.
Ravi D. Ashok K. Rambabu S. Sakram B. Shyam P. 《Russian Journal of General Chemistry》2018,88(6):1232-1237
Russian Journal of General Chemistry - An eco-friendly and highly efficient synthesis of substituted bis(3-aryl-1,8-naphthyridin-2-yl)-sulfanes and 2-(methylthio)-3-aryl-1,8-naphthyridines under... 相似文献
76.
A straightforward and highly efficient series of new substituted 3-aryl-1,8-naphthyridine derivatives 3a–e, 4a–e, and 6a–e were synthesized. Condensation dissimilar quantities of 2-chloro-3-aryl-1,8-naphthyridine 1a–e with benzene-1,4-diamine 2 and sodium ethoxide refluxing in ethanol solvent yielded the compounds 3a–e and 4a–e. The 2-(4-((3-aryl-1,8-naphthyridin-2-yl)amino)phenyl)isoindoline-1,3-diones 6a–e were obtained by treatment of compounds 3a–e with phthalic anhydride 5 in refluxing N,N-dimethylformamide is described. All synthesized compounds evaluated for their antimicrobial activity. The structures of the compounds have been proven on the established of spectral (IR, 1H NMR, and 13C NMR) data and elemental analyses. The reaction will be characterized by good efficacy, easy workup, simple purification of the products, and availability of catalyst. 相似文献
77.
P. Vani K. Krishna Kishore R. Rambabu L. S. A. Dikshitulu 《Journal of Chemical Sciences》2001,113(4):351-359
Kinetics and mechanism of oxidation of L-methionine by iron(III)-1,10-phenanthroline complex have been studied in perchloric
acid medium. The reaction is first order each in iron(III) and methionine. Increase in [phenanthroline] increases the rate
while increase in [HClO4] decreases it. While the reactive species of the substrate is the zwitterionic form, that of the oxidant is [Fe(phen)2(H2O)2]3+. The proposed mechanism leads to the rate law
相似文献
78.
The intramolecular protective group (benzylidene acetal) assisted syn-1,3-diol synthesis has been efficiently utilized in a short synthesis of 6-epiprelactone-V starting from (S)-malic acid. 相似文献
79.
A combination of "chiron" and "asymmetric" approaches is utilized to construct the southern (C 9-C 25) region of marine natural product spirastrellolide B. The key functionalities are derived from d-glucose and Sharpless asymmetric epoxidation and dihydroxylation. 相似文献
80.
Stereoselective total syntheses of the antiprotozoal natural product (+)-passifloricin A and its C-6 epimer have been achieved in ~5% overall yield. The strategy is based on Jacobsen epoxidation, Grubbs’ metathesis and an Evans’ intramolecular oxa-Michael reaction. 相似文献