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71.
Mohammad Salim Hidenori UbukataTakao Kimura Michinori Karikomi 《Tetrahedron letters》2011,52(49):6591-6593
The reaction of helical quinone with alcohols in the presence of Brønsted acid such as para-toluenesulfonic acid (pTSA) or HCl proceeded smoothly to produce the corresponding alkoxy substituted oxa[9]helicenes in good yields. 相似文献
72.
Liu B Nakata K Sakai M Saito H Ochiai T Murakami T Takagi K Fujishima A 《Langmuir : the ACS journal of surfaces and colloids》2011,27(13):8500-8508
A facile new method that combines electrospray and hydrothermal treatment is used to prepare mesoporous core-shell TiO(2) spheres with high specific surface areas and high pore volumes. Interestingly, the resulting TiO(2) spheres are composed of anatase TiO(2) nanocrystals with exposed step-like {001} and smooth {010} facets. The percentage of exposed {001} facets can be adjusted by changing the experimental parameters used in the electrospray and hydrothermal treatment processes, such as the contents of poly(N-vinyl-2-pyrrolidone) and acetic acid. The combination of high specific surface area (>100 m(2) g(-1)), high pore volume (>0.30 cm(3) g(-1)), useful pore size (10-15 nm), spherical core-shell structure, and exposed high energy facets makes these TiO(2) spheres an important candidate for use in many photoelectrochemical applications. The formation mechanism of the mesoporous TiO(2) spheres is also studied. The great advantage of this method is that interesting and complicated mesoporous superstructures can be prepared using electrospray technology. 相似文献
73.
Cimpoesu F Ito S Shimotani H Takagi H Dragoe N 《Physical chemistry chemical physics : PCCP》2011,13(20):9609-9615
Analysis of IR and Raman spectra of Ar@C(60) and Kr@C(60) shows that the incorporation of noble gas atoms causes a blue shift of low energy vibrations, which have radial character, and a red shift of higher energy ones which have a tangential character movement. The mechanism of these phenomena is explained on the basis of ab initio numerical experiments with DFT and MP2 procedures. Methodological discussions are advanced, altogether with a scheme for the estimation of the van der Waals interaction between fullerene and noble gas, based on the frequency shifts. 相似文献
74.
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76.
Anthony H. Jackson K. R. Nagaraja Rao N. Sim Ooi Esther Adelakun 《Tetrahedron letters》1984,25(52):6049-6050
Treatment of α-methylpyrroles with thallium (III) nitrate/Montmorillonite clay affords the corresponding α-formylpyrroles in excellent yields. 相似文献
77.
Nickel(II) complexes of N3O2 donor macrocycles incorporating 17- to 19-membered macrocyclic rings have been prepared. Physical measurements ind 相似文献
78.
The aqueous solution chemistry of niobium is rather unexplored, and well characterized aqua complexes are scarce. In this work, a new niobium aqua ion is obtained upon treatment of Zn-reduced ethanolic solutions of NbCl5 with HCl in the presence of a sulfide source. The red aqua ion, obtained upon cation-exchange chromatography, forms readily the thiocyanate complex which has been crystallized as Cs(4.26)Na(1.74)[Nb4SO5(NCS)10] . 0.33H2O. X-ray crystallography revealed an unprecedented metal-metal bonded tetranuclear Nb4(mu4-S)(mu2-O)5(4+) core with a capping mu4-S ligand. 相似文献
79.
Stains CI Porter JR Ooi AT Segal DJ Ghosh I 《Journal of the American Chemical Society》2005,127(31):10782-10783
We describe a general methodology for the direct detection of DNA by the design of a split-protein system that reassembles to form an active complex only in the presence of a targeted DNA sequence. This approach, called SEquence Enabled Reassembly (SEER) of proteins, combines the ability to rationally dissect proteins to construct oligomerization-dependent protein reassembly systems and the availability of DNA binding Cys2-His2 zinc-finger motifs for the recognition of specific DNA sequences. We demonstrate the feasibility of the SEER approach utilizing the split green fluorescent protein appended to appropriate zinc fingers, such that chromophore formation is only catalyzed in the presence of DNA sequences that incorporate binding sites for both zinc fingers. 相似文献
80.