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81.
Rituraj Borah Rajeshreddy Ninakanti Gert Nuyts Hannelore Peeters Adrián Pedrazo-Tardajos Silvia Nuti Prof. Christophe Vande Velde Prof. Karolien De Wael Prof. Silvia Lenaerts Prof. Sara Bals Prof. Sammy W. Verbruggen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(35):9011-9021
The functionalization of photocatalytic metal oxide nanoparticles of TiO2, ZnO, WO3 and CuO with amine-terminated (oleylamine) and thiol-terminated (dodecane-1-thiol) alkyl-chain ligands was studied under ambient conditions. A high selectivity was observed in the binding specificity of a ligand towards nanoparticles of these different oxides. It was observed that oleylamine binds stably to only TiO2 and WO3, whereas dodecane-1-thiol binds stably only to ZnO and CuO. Similarly, polar-to-nonpolar solvent phase transfer of TiO2 and WO3 nanoparticles could be achieved by using oleylamine, but not dodecane-1-thiol, whereas the opposite holds for ZnO and CuO. The surface chemistry of ligand-functionalized nanoparticles was probed by attenuated total reflectance (ATR)-FTIR spectroscopy, which enabled the occupation of the ligands at the active sites to be elucidated. The photostability of the ligands on the nanoparticle surface was determined by the photocatalytic self-cleaning properties of the material. Although TiO2 and WO3 degrade the ligands within 24 h under both UV and visible light, ligands on ZnO and CuO remain unaffected. The gathered insights are also highly relevant from an application point of view. As an example, because the ligand-functionalized nanoparticles are hydrophobic in nature, they can be self-assembled at the air-water interface to give nanoparticle films with demonstrated photocatalytic as well as anti-fogging properties. 相似文献
82.
Veera Reddy Arava Srinivasulu Reddy Amasa Bharat Kumar Goud Bhatthula Laxmi Srinivas Kompella Venkata Prasad Matta M. C. S. Subha 《合成通讯》2013,43(21):2892-2897
An efficient and enantioselective hydrogenation of N-acetylamino phenyl acrylic acids was successfully developed by using ruthenium catalyst. This methodology is important in the field of pharmaceuticals and provides a new process for the preparation of unnatural amino acids and tamsulosin chiral intermediate. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.] 相似文献
83.
Borah P Ma X Nguyen KT Zhao Y 《Angewandte Chemie (International ed. in English)》2012,51(31):7756-7761
Selective benzene hydroxylation: A periodic mesoporous organosilica embedded with a vanadyl(IV) acetylacetonate complex has been synthesized through a co-condensation method. This system is a catalyst for direct hydroxylation of benzene to phenol, presenting a selectivity of 100?% towards the phenol formation as well as an excellent catalytic recyclability (see scheme). 相似文献
84.
The reaction of [Fe3(CO)12] with bis[2‐(diphenylphosphino)phenyl]ether (DPEphos) in refluxing THF afforded a mononuclear complex, [Fe(CO)4(η1‐P‐DPEphos)] (1), as major product and a binuclear complex, [Fe2(CO)6(μ‐CO)(μ‐P,P‐DPEphos)] (2), as minor product respectively. The DPEphos ligand acts as a terminal P‐donor in complex 1 and a bridging P,P‐donor in complex 2. Complexes 1 and 2 were characterized by elemental analysis, fast atom bombardment mass spectrometry, FT‐IR, 1H and 31P{1H} NMR spectroscopy. The structure of complex 1 has been tentatively assigned by density functional theory calculations and its analogy with reported complexes. Combination of complex 1 and PdCl2 furnished an active catalyst for the Suzuki–Miyaura cross‐coupling reactions of various aryl halides with arylboronic acids. Interestingly, under the same experimental condition, complex 1/PdCl2 as catalyst showed superior activity over the DPEphos/PdCl2 system. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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86.
Addition reactions of allyl stannanes to an indolo[2′,3′:3,4]pyrido[1,2‐b]isoquinoline imminium salt
Paul C. Unangst Larry D. Bratton David T. Connor Bruce D. Roth J. Ronald Rubin Bharat K. Trivedi 《Journal of heterocyclic chemistry》2000,37(5):1081-1087
The addition of organometallic reagents to the 13b‐position of the indolo[2′,3′:3,4]pyrido[1,2‐b]isoquinoline imminium salt 4 is described. Reaction of 4 with tetraallyl tin in 2‐methoxyethanol gave the allyl adduct 7 in moderate yield. Further elaboration of 7 yielded the pentacyclic benzylidene alcohols 13 and 14 . Structure elucidation of the compounds prepared was achieved by a combination of 1H nmr spec troscopy and X‐ray crystallography. 相似文献
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89.
Shailendra K. Saxena Rupnayan Borah Vivek Kumar Hari Mohan Rai Ravikiran Late V.G. Sathe Ashisha Kumar Pankaj R. Sagdeo Rajesh Kumar 《Journal of Raman spectroscopy : JRS》2016,47(3):283-288
A combined effect of doping (type and species) and size on Raman scattering from silicon (Si) nanowires (NWs) has been presented here to study interplay between quantum confinement and Fano effects. The SiNWs prepared from low doping Si wafers show only confinement effect, as evident from the asymmetry in the Raman line‐shape, irrespective of the doping type. On the other hand SiNWs prepared from wafer with high doping shows the presence of electron–phonon interaction in addition to the phonon confinement effect as revealed from the presence of asymmetry and antiresonence in the corresponding Raman spectra. This combined effect induces an extra asymmetry in the lower energy side of Raman peak for n‐type SiNWs whereas the asymmetry flips from lower energy side to the higher energy side of the Raman peak in p‐type SiNWs. Such an interplay can be represented by considering a general Fano‐Raman line‐shape equation to take care of the combined effect in SiNWs. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
90.
Study of electron drift velocity caused by Etimes B motion is done with the help of a Mach probe in a dc cylindrical magnetron sputtering system at different plasma discharge parameters like discharge voltage, gas pressure and applied magnetic field strength. The interplay of the electron drift with the different discharge parameters has been investigated. Strong radial variation of the electron drift velocity is observed and is found to be maximum near the cathode and it decreases slowly with the increase of radial distance from the cathode. The sheath electric field, E measured experimentally from potential profile curve using an emissive probe is contributed to the observed radial variation of the electron drift velocity. The measured values of the drift velocities are also compared with the values from the conventional theory using the experimental values of electric and magnetic fields. This study of the drift velocity variation is helpful in providing a useful insight for determining the discharge conditions and parameters for sputter deposition of thin film. 相似文献