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11.
A variety of alcoholic TBDMS (t-butyldimethylsilyl) ethers are easily removed in excellent yields by treatment with a catalytic amount of N-iodosuccinimide (NIS, 5 mol %) in methanol. This method is able to deprotect TBDMS ethers of alcohols in the presence of TBDMS ethers of phenols. 相似文献
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A simple, efficient, and new method has been developed for the synthesis of thiiranes from epoxides through a one-pot reaction of epoxides with diethyl phosphite in the presence of ammonium acetate or ammonium hydrogen carbonate/sulfur/ and acidic alumina under solvent-free conditions using microwave irradiation. 相似文献
13.
Baptiste Demoulin Margherita Maiuri Tetyana Berbasova Prof. James H. Geiger Prof. Babak Borhan Prof. Marco Garavelli Prof. Giulio Cerullo Prof. Ivan Rivalta 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(66):16389-16400
Artificial biomimetic chromophore-protein complexes inspired by natural visual pigments can feature color tunability across the full visible spectrum. However, control of excited state dynamics of the retinal chromophore, which is of paramount importance for technological applications, is lacking due to its complex and subtle photophysics/photochemistry. Here, ultrafast transient absorption spectroscopy and quantum mechanics/molecular mechanics simulations are combined for the study of highly tunable rhodopsin mimics, as compared to retinal chromophores in solution. Conical intersections and transient fluorescent intermediates are identified with atomistic resolution, providing unambiguous assignment of their ultrafast excited state absorption features. The results point out that the electrostatic environment of the chromophore, modified by protein point mutations, affects its excited state properties allowing control of its photophysics with same power of chemical modifications of the chromophore. The complex nature of such fine control is a fundamental knowledge for the design of bio-mimetic opto-electronic and photonic devices. 相似文献
14.
Host–Guest Assembly of a Molecular Reporter with Chiral Cyanohydrins for Assignment of Absolute Stereochemistry
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Hadi Gholami Dr. Mercy Anyika Jun Zhang Dr. Chrysoula Vasileiou Prof. Dr. Babak Borhan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(27):9235-9239
The absolute stereochemistry of cyanohydrins, derived from ketones and aldehydes, is obtained routinely, in a microscale and derivatization‐free manner, upon their complexation with Zn‐MAPOL, a zincated porphyrin host with a binding pocket comprised of a biphenol core. The host–guest complex leads to observable exciton‐coupled circular dichroism (ECCD), the sign of which is easily correlated to the absolute stereochemistry of the bound cyanohydrin. A working model, based on the ECCD signal of cyanohydrins with known configuration, is proposed. 相似文献
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Atieh Khosravi Mohammad Reza Khani Elham Dejban Goy Babak Shokri 《Plasma Chemistry and Plasma Processing》2018,38(2):365-378
In present paper, an atmospheric-pressure low-temperature plasma treatment of pyrolysis fuel oil (PFO) was investigated in dielectric barrier discharge plasma torch reactor. The effect of the applied voltage and the volume of feedstock, as the main parameters, on the cracking of PFO were studied. By increasing the applied voltage from 10 to 16 kV, the production rate of hydrocarbons containing methane, ethylene, acetylene, propane, propylene, and C4 rise 18 times. In this case, the production rate of hydrogen increases by approximately 14 times and reaches 7.27 × 10?3 mol/min for 16 kV. In the feedstock volume investigation, based on limitation of reactor volume, the production rate of hydrocarbons decreased from 0.44 × 10?3 to 0.15 × 10?3 mol/min by increasing volume of feedstock from 1 to 5 cc. 相似文献
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19.
Near-eutectic Sn-Ag-Cu samples were produced in different sizes and geometries, with different solidification temperatures.
The Sn grain morphologies of samples were characterized and found to be correlated with the sample solidification temperature;
the lower the solidification temperature, the higher the degree of interlacing observed. These Sn grain morphologies were
observed to be consistent with a simple model that envisions the nucleus in an undercooled Sn-Ag-Cu liquid to be Sn atoms
clustered around a Ag atom in a hexagonal configuration that allows Sn to grow epitaxially on each of its surfaces. At intermediate
degrees of undercooling, a mixed Sn grain morphology is observed, with the interlaced portion associated with the region closer
to Sn nucleation in these samples. 相似文献
20.
Various types of trimethylsilyl and tert-butyldimethylsilyl ethers of primary and secondary benzylic alcohols could be selectively converted to their corresponding carbonyl compounds with MnO2 in the presence of AlCl3 in good to excellent yields. 相似文献