Synthetic Approaches for Accessing Rare-Earth Analogues of UiO-66

2021 ◽  
Author(s):  
Rafael P. Donnarumma ◽  
Sahara Frojmovic ◽  
Paola Marino ◽  
Hudson de Aguiar Bicalho ◽  
Hatem M. Titi ◽  
...  
Keyword(s):  
Rare Earth ◽  
Synthetic Approaches ◽  
First Time

Rare-earth (RE) analogues of UiO-66 with non-functionalised 1,4-benzenedicarboxylate linkers are synthesised for the first time, and a series of synthetic approaches is provided to troubleshoot the synthesis. RE-UiO-66 analogues are...

scholarly journals Synthetic Approaches for Accessing Rare-Earth Analogues of UiO-66

2021 ◽  
Author(s):  
P. Rafael Donnarumma ◽  
Sahara Frojmovic ◽  
Hudson de Aguiar Bicalho ◽  
Hatem M. Titi ◽  
Ashlee J Howarth
Keyword(s):  
Thermal Stability ◽  
Rare Earth ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Degree Of Crystallinity ◽  
Synthetic Approaches ◽  
High Degree ◽  
First Time

Rare-earth (RE) analogues of UiO-66 with non-functionalised 1,4-benzenedicarboxylate linkers are synthesised for the first time, and a series of synthetic approaches is provided to troubleshoot the synthesis. RE-UiO-66 analogues are fully characterised, and demonstrate a high degree of crystallinity, high surface area and thermal stability, consistent with the UiO-66 archetype.

scholarly journals Synthetic Approaches for Accessing Rare-Earth Analogues of UiO-66

2021 ◽  
Author(s):  
P. Rafael Donnarumma ◽  
Sahara Frojmovic ◽  
Hudson de Aguiar Bicalho ◽  
Hatem M. Titi ◽  
Ashlee J Howarth
Keyword(s):  
Thermal Stability ◽  
Rare Earth ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Degree Of Crystallinity ◽  
Synthetic Approaches ◽  
High Degree ◽  
First Time

Rare-earth (RE) analogues of UiO-66 with non-functionalised 1,4-benzenedicarboxylate linkers are synthesised for the first time, and a series of synthetic approaches is provided to troubleshoot the synthesis. RE-UiO-66 analogues are fully characterised, and demonstrate a high degree of crystallinity, high surface area and thermal stability, consistent with the UiO-66 archetype.

scholarly journals Synthetic Approaches to Organoselenium Derivatives with Antimicrobial and Anti-Biofilm Activity

2019 ◽  
Vol 16 (6) ◽  
pp. 589-601 ◽  
Author(s):  
Iris Di Leo ◽  
Federica Messina ◽  
Vanessa Nascimento ◽  
Francesca G. Nacca ◽  
Donatella Pietrella ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Biological Activities ◽  
Antimicrobial Activities ◽  
Pharmacological Properties ◽  
Organoselenium Compounds ◽  
Synthetic Approaches ◽  
First Time

In the recent years, an increasing attention has been given to the biological activities exerted by organoselenium compounds. In 1984, Sies reported for the first time the ability of ebselen to mimic the activity of glutathione peroxidase. From this milestone, several studies reported the pharmacological properties of selenium-containing compounds including their exploitation as antimicrobials. In this context, this minireview presents the most recent examples of seleno derivatives endowed with antimicrobial activities while discussing the most interesting and recent synthetic procedures used to obtain these compounds.

Condensed [Ru4Sn6] Units in the Stannides LnRu4Sn6 (Ln = La, Pr, Nd, Sm, Gd) - Synthesis, Structure, and Chemical Bonding

1999 ◽  
Vol 54 (7) ◽  
pp. 863-869 ◽  
Author(s):  
Markus F. Zumdick ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Single Crystals ◽  
Chemical Bonding ◽  
Melting Furnace ◽  
Structural Motif ◽  
X Ray Diffraction ◽  
X Ray ◽  
Arc Melting ◽  
First Time ◽  
Gadolinium Compound

The stannides LnRu4Sn6 (Ln = La, Pr, Nd, Sm, Gd) were prepared by reaction of the elements in an arc-melting furnace and subsequent annealing at 1120 K. The praseodymium, the neodymium, and the samarium stannide were obtained for the first time. The LnRu4Sn6 stannides were investigated by X-ray diffraction both on powders and single crystals. They adopt the YRu4Sn6 type structure which was refined from single crystal X-ray data for the samarium and the gadolinium compound: I4̄2m, a = 686.1 (1), c = 977.7(2) pm, wR2 = 0.0649, 483 F2 values for SmRu4Sn6, and a = 685.2(1), c = 977.6(3) pm, wR2 = 0.0629, 554 F2 values for GdRu4Sn6 with 19 variables for each refinement. The striking structural motif of these stannides are distorted RuSn6 octahedra with Ru-Sn distances ranging from 257 to 278 pm. Four of such octahedra are condensed via common edges and faces forming [Ru4Sn6] units which are packed in a tetragonal body-centered arrangement. The rare-earth atoms fill the voids between the [Ru4Sn6] units. Based on an extended Hückel calculation, strong bonding interactions were found for the Ru-Sn and the various Sn-Sn contacts.

scholarly journals New insights about the rare earth elements (REE) mobility in river waters

2002 ◽  
Vol 173 (2) ◽  
pp. 147-160 ◽  
Author(s):  
Samuel Deberdt ◽  
Jérôme Viers ◽  
Bernard Dupré
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
River Waters ◽  
Geological Processes ◽  
Ree Distribution ◽  
Colloidal Matter ◽  
Ree Mobility ◽  
First Time ◽  
Colloidal Fraction ◽  
The Rare Earth

Abstract While the rare earth elements (REE) have largely contributed to the understanding of some internal geological processes, their use as tracers of superficial mechanisms (i.e., weathering and elements transport) remains tricky. This results from the poor knowledge we have of the REE distribution in the different fractions of solutions. Up to recently, the studies carried out on the REE behavior in continental aquatic systems were mainly based on the “paniculate” and “solution” fractions separated by an arbitrary filtration through a 0.20 or 0.45 μm pore size membrane. Some recent work has shown, using ultrafiltration experiments, that REE are mainly contained in the colloidal fraction (i.e., 0.20 μm - 1 nm). However, studies devoted to the control of REE by the colloidal matter, have essentially focused on the organic pool (i.e., humic substances). By contrast, the mineral colloidal pool has received little attention. In order to model these processes, we have developed a combined approach that consider (1) ultrafiltration experiments performed on a series of rivers located in Africa (Cameroon) and south America (Brazil, Venezuela) and (2) speciation calculations. This quantitative approach reveals, for the first time, that more than 60 % of the total REE in the solution of river waters is controlled by the mineral colloidal pool.

Rare-earth-doped α′-Sialon ceramics with novel optical properties

1996 ◽  
Vol 11 (11) ◽  
pp. 2790-2794 ◽  
Author(s):  
B. S. B. Karunaratne ◽  
R. J. Lumby ◽  
M. H. Lewis
Keyword(s):  
Optical Properties ◽  
Thermal Properties ◽  
Rare Earth ◽  
Mechanical And Thermal Properties ◽  
Silicon Nitrides ◽  
Sintering Atmosphere ◽  
Oxidation Reduction ◽  
Reduction Mechanisms ◽  
First Time ◽  
Rare Earth Doped

A new phenomenon in the field of Sialon ceramics is reported which may lead to applications based on their optical or electronic properties in combination with their mechanical and thermal properties. For the first time a colored α′-Sialon ceramic has been synthesized, with relatively high optical transparency by careful control of the sintering atmosphere, and adding suitable rare earths as stabilizing cations. This compares with normal Sialons and silicon nitrides which are grey-black in color and are opaque. Oxidation/reduction mechanisms have been identified as an influence on the valence of the stabilizing cation, which is responsible for the unusual optical properties.

scholarly journals Rare-earth accessories and secondary minerals in plagiogneisses from the Stankuvatske Li-deposite

2020 ◽  
Vol 41 ◽  
pp. 54-67
Author(s):  
N.М. Lyzhachenkо ◽  
◽  
S.I. Kurylo ◽  
S. M. Bondarenko ◽  
◽  
...  
Keyword(s):  
Rare Earth ◽  
Microprobe Analysis ◽  
Metamorphic Rocks ◽  
Metasomatic Alteration ◽  
Accessory Minerals ◽  
Secondary Minerals ◽  
Fine Grained ◽  
Partial Redistribution ◽  
Bulk Chemical ◽  
First Time

The Stankuvatske Li deposit (SD) is situated at western flank of the Lypniazka structure (Ingul megablock of the Ukrainian Shield). Knowledge about REE content in host metamorphic rocks is based on the results of bulk chemical analysis, but their minerals have not been determined. For the first time rare-earth mineralization of the Stankuvatsky lithium deposit has been investigated in fine-grained gneiss with «augen» and schistose structure, porphiroblastic texture, formed as result of tectonical alteration. Our investigations were carried out using petrographic and microprobe analysis (EPMA). Mineralogically gneisses consist of quartz, plagioclase, zoizite, biotite, graphite, chlorite and abundant sulphides mainly represented by pyrite, arsenopyrite, sphalerite, molibdenite. Accessory minerals presented by titanite, apatite, monazite, zircon and coffinite. Gneisses have been subjected to deformation and hydrothermal — metasomatic alteration. An investigation of rock-forming and accessory minerals allows to revel low-temperature alterations of primary allanite by bastnäsiteand chlorite with formation of secondary bastnäsite-chlorite-coisite-pyrite association with «coronary» texture. The penetration of S, F, CO2, H2O enriched fluids were caused disintegration, partial redistribution and reprecipitation of rare earth elements. As result synhysite-chlorite-pyrite association was formed.

scholarly journals CONTENT OF RARE-EARTH ELEMENTS IN GROUNDWATERS OF UPPER JURASSIC SEDIMENTS OF THE VERKH-TARSK OIL FIELD (WESTERN SIBERIA)

2019 ◽  
Vol 2 (1) ◽  
pp. 141-148
Author(s):  
Dmitry Novikov ◽  
Anatoly Chernykh ◽  
Fedor Dultsev
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Western Siberia ◽  
Upper Jurassic ◽  
Oil Field ◽  
A Value ◽  
Free Ions ◽  
First Time ◽  
Rare Earth Elements Distribution

The results of the analysis of rare earth elements distribution in groundwater of J1 reservoir of the Verkh-Tarka oil field are reported for the first time. It was established that groundwater with Cl Na composition are predominate, with a value of total mineralization from 24.7 up to 48.9 g/dm3. The content of REE ranges from 3.72 to 30.49 µg/dm3 with an average of 13.61 µg/dm3. The highest concentrations are observed (µg/dm3) in La (up to 20.8), Eu (up to 7.9), Gd (up to 1.8) and Dy (up to 0.65). The level of dissolved REE is determined by their distribution in the water-bearing sandstones. Migration of rare-earth elements is carried out in the form of free ions and hydroxide complexes.

Synthetic Attempts Towards Eminent Anti-Viral Candidates of SARS-CoV

2021 ◽  
Vol 21 ◽  
Author(s):  
Subhradip Kundu ◽  
Debayan Sarkar
Keyword(s):  
Clinical Trials ◽  
Severe Acute Respiratory Syndrome ◽  
Southern China ◽  
World Health ◽  
The World ◽  
Entire World ◽  
Chemical Companies ◽  
Health Organization ◽  
Synthetic Approaches ◽  
First Time

: Severe Acute Respiratory Syndrome (SARS) aka SARS-CoV spread over southern China for the first time in 2002-2003 and history repeated again since last year and take away more than two million people so far. On March 11, 2020 COVID-19 outbreak was officially declared as pandemic by World Health Organization (WHO). Entire world united to fight back against this ultimate destruction. Around 90 vaccines are featured against SARS-CoV-2 and more than 300 active clinical trials are underway by several groups and individuals. So far, no drugs are currently approved that completely eliminates the deadly corona virus. The promising SARS-CoV-2 anti-viral drugs are favipiravir, remdesivir, lopinavir, ribavirin and avifavir. In this review, we have discussed the synthetic approaches elaborately made so far by different groups and chemical companies all around the world towards top three convincing anti-viral drugs against SARS-CoV-2 which are favipiravir, remdesivir and lopinavir.

Investigation of photophysical and photochemical properties of octa-substituted double-decker rare-earth metallophthalocyanine complexes

2012 ◽  
Vol 16 (07n08) ◽  
pp. 907-916 ◽  
Author(s):  
İlke Gürol ◽  
Mahmut Durmuş ◽  
Vefa Ahsen
Keyword(s):  
Rare Earth ◽  
Organic Solvents ◽  
Elemental Analysis ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Spectroscopic Techniques ◽  
Double Decker ◽  
Ft Ir ◽  
Photochemical Properties ◽  
First Time

For the first time, bis[octakis-(2,2,3,3-tetrafluoropropoxy)phthalocyaninato] rare-earth metal(III) double-decker phthalocyanine complexes (Pc2Sm, Pc2Eu, Pc2Gd, Pc2Dy and Pc2Lu) are synthesized. The new phthalocyanine complexes are characterized using mass, FT-IR and UV-vis spectroscopic techniques as well as elemental analysis. All these compounds exhibit excellent solubility in organic solvents. The photophysical and photochemical properties of the rare-earth metal(III) double-decker complexes are investigated and discussed.

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