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1.
Nanoscale ; 12(4): 2345-2349, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31916555

RESUMO

Alloyed bimetallic Pd-Ru nanocatalysts prepared by in situ reduction of a mixture of a Ru(iii) source and a Pd(ii)@alkyne-PVA aerogel and characterized by TEM and XPS exhibit very highly catalytic activity towards hydrogen release from ammonia borane hydrolysis with a TOF value of 578.2 molH2 molcat-1 min-1.

2.
J Hazard Mater ; : 121761, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31796359

RESUMO

MXenes, as new members of the 2D materials group, are regarded as good candidates for heavy metal removal particularly for radioactive metal element because of their high irradiation stability. However, the small interlayer distance and lack of active sites on the surface limit their further application. In this report, nanoscale zero-valent iron has been introduced into the inter-layer structure of alkaline intercalated Ti3C2 (Alk-Ti3C2) and investigated to Cr(VI) removal. The XPS spectra, SEM images, TEM images, and N2 adsorption-desorption isotherms characterizations revealed that the OH groups on the Alk-Ti3C2 surface assisted the introducing of nZVI into the inter-layer of Alk-Ti3C2 and subsequently stabilized the nZVI. The increased active sites of nZVI and extended interlayer space of Alk-Ti3C2 could improve the uptake capacity of Cr(VI) (194.87 mg/g at pH = 2). The highly efficient removal of Cr(VI) was maintained even in the presence of coexisting cations, which showed great potential for real environment remediation. Mechanistic study indicated that the synergistic effects of nZVI and Alk-Ti3C2 nanosheet in nZVI-Alk-Ti3C2 composites are keys for Cr(VI) removal.

3.
Dalton Trans ; 48(5): 1595-1598, 2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30629050

RESUMO

Three (3,4)-connected uranyl-organic frameworks (UOFs) with pto and tbo topologies were synthesized. The UOF with a pto net possesses a 2-fold interpenetrating network and exhibits 2D interconnected channels. The UOF with a tbo net is constructed from two types of ultralarge nanocages. All these compounds can efficiently remove large cationic dye crystal violet (CV) through a cation exchange mechanism.

4.
Spectrochim Acta A Mol Biomol Spectrosc ; 202: 244-251, 2018 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-29793146

RESUMO

A novel tridentate ligand nitrilotris(methylene)tris(1,2,3-triazole)triacetate (NTTTA) has been synthesized by click reaction and followed with ester hydrolysis reaction. The silver nanoparticles (AgNPs) were then modified and stabilized by this ligand, and subsequently been employed for the highly selective and sensitive colorimetric detection of Mn2+ in aqueous solution. The presence of Mn2+ can cause the aggregation of AgNPs, which leads to the color change of the dispersion from yellow to brown, as well as the decrease and red-shift of the surface plasmon resonance absorption. The detection limit of Mn2+ was as approximately 0.5 µM by the naked eyes. UV-vis spectroscopy analysis showed a good linear relationship between the logarithm of the ratios (A550/A395) and the concentration of Mn2+over the range of 0.05 µM-10 µM, and the LOD was calculated to be 12.6 nM (S/N = 3). The present assay showed good simplicity without the need of adjusting the pH value. The feasibility of this technique was evaluated for successful detection of Mn2+ in tap water and lake water samples, with good recoveries.

5.
Angew Chem Int Ed Engl ; 53(7): 1837-40, 2014 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-24474595

RESUMO

The cladiellin family of natural products, which includes molecules with various biological activities, continues to invite new synthetic studies. A gold-catalyzed tandem reaction of 1,7-diynes to construct the 6-5-bicyclic ring systems that are present in a number of natural products was developed. This reaction was applied as the key step to realize the formal and total syntheses of nine members of the cladiellin family in an enantio- and diastereoselective manner. This modular and efficient approach could also be used for the construction of other cladiellins, as well as their analogues, for follow-up studies.

6.
J Org Chem ; 78(11): 5492-504, 2013 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-23672454

RESUMO

A total synthesis of the caribenol A (1), a novel natural product with an intriguing tetracyclic framework, has been achieved. The synthesis features an intramolecular Diels-Alder (IMDA) reaction for the facile construction of the tricyclic [5-7-6] skeleton of caribenol A (1) and a biomimetic oxidation reaction for the formation of the 2-hydroxyfuran-2(5H)-one motif of caribenol A (1) as key steps. This synthetic approach also reveals that the sp(2) carbon at C(2) in substrate 8 is a critical factor for the formation of the tricyclic [5-7-6] skeleton in 7.


Assuntos
Diterpenos/síntese química , Cristalografia por Raios X , Ciclização , Diterpenos/química , Modelos Moleculares , Conformação Molecular
8.
J Am Chem Soc ; 132(39): 13608-9, 2010 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-20831198

RESUMO

A unified strategy toward the asymmetric total synthesis of carbenol A is reported, featuring intramolecular Diels-Alder (IMDA) and biomimetic oxidation reactions as key steps.


Assuntos
Antibacterianos/síntese química , Diterpenos/síntese química , Antibacterianos/química , Cristalografia por Raios X , Diterpenos/química , Modelos Moleculares , Conformação Molecular , Estereoisomerismo
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