Search results for " Lanthanides"

White light emitting silsesquioxane based materials: the importance of a ligand with rigid and directional arms

2022

The synthesis of a novel polyhedral oligomeric silsesquioxane functionalized with eight rigid and directional terpyridine-based arms (Ter-POSS) was successfully achieved via a Sonogashira reaction. The POSS based ligand was extensively characterized using different techniques including 1H, 13C and 29Si NMR as well as UV-Vis and fluorescence spectroscopies. The assembly of these nano-caged units in the presence of different transition metal ions (Fe2+, Zn2+ and Cu2+) as well as of a cation from the lanthanides (Eu3+) was investigated using absorption and emission spectroscopies. The final materials display an evident emission in different regions of the visible spectrum as a function of the …

An anthropic soil transformation fingerprinted by REY patterns

2009

Abstract This Focus article deals intentionally with modern soil disturbance in situ . This is of interest to archaeologists as after disturbances, both short- and long-term, pedogenesis (re-)starts obliterating previous signs. Soil modifications induced by human activity may be linked to pedogenetic evidence for disturbance with archaeological evidence for the cultural activities. We contrasted two 750-m 3 soil pedons, an Anthrosol and a Kastanozem, from which the Anthrosol is derived, using 77 descriptors of soil properties which have been utilized in archaeological studies (pedo-morphological, routine laboratory, biochemical, metals and rare earth elements plus yttrium, REY) with the aim…

NMR and μ+SR detection of unconventional spin dynamics in Er(trensal) and Dy(trensal) molecular magnets

2019

SOURCE RECOGNITION OF INHALED ATMOSPHERIC PARTICLES ACCORDING TO GEOCHEMICAL AND STATISTICAL EVALUATIONS OF TRACE ELEMENT SIGNATURES

2011

During 2001 the Mount Etna had a large eruption producing a large amount of pyroclastic products consisting of a mixture of glass, minerals and soluble salt materials (SAF) encrusting solid particles. Inhalation of the finest of these materials induced pulmonary diseases in people living in subjected areas and gave us the possibility to collect bronchoalveolar lavages (BAL) from people in care in Catania hospitals. Concentrations of several trace elements measured in these BAL fluids (BALF) evidence strong enrichments in several trace elements compared to reference values. Related enrichments factors, calculated with respect to composition of volcanic ejecta (EFASH), show similar values in …

Direct detection of 17O NMR in [Gd(DOTA)]- by NMR Spectroscopy

2015

The 17O NMR spectrum of the non-coordinated carboxyl oxygen in the GdIII-DOTA (DOTA = tetraazacyclododecanetetraacetic acid) complex has been observed experimentally. Its line width is essentially unaffected by paramagnetic relaxation due to gadolinium, and is only affected by the quadrupole pathway. The results are supported by the relevant parameters (hyperfine and quadrupole coupling constants) calculated by relativistic DFT methods. This finding opens up new avenues for investigating the structure and reactivity of paramagnetic GdIII complexes used as contrast agents in magnetic resonance imaging.

Combining organocatalysis and lanthanide catalysis: a sequential one-pot quadruple reaction sequence/hetero-Diels-Alder asymmetric synthesis of funct…

2016

A stereoselective one-pot synthesis of functionalized complex tricyclic polyethers has been achieved using the combination of secondary amine and lanthanide catalysis. This one-pot quadruple reaction/Hetero-Diels–Alder sequence gave good yields (per step) as well as excellent diastereo- and enantioselectivities. Furthermore, the particular combination of lanthanide complexes with organocatalysis is one of the first examples described for sequential catalysis.

Effect of pyroclastic atmospheric fallout on YREE distribution in human bronchial washing solutions

2009

Self-assembly and intra-cluster reactions of erbium and ytterbium bis(2-ethylhexyl)sulfosuccinates in the gas phase.

2014

RATIONALE: The study of surfactant organization in vacuum allows surfactant–surfactant interaction to be unveiled in the absence of surrounding solvent molecules. Knowledge on their chemical-physical properties may also lead to the definition of more efficient gas-phase carriers, air-cleaning agents and nanoreactors. In addition, the presence of lanthanide-group ions adds unique photochemical properties to surfactants. METHODS: The structural features, stability and fragmentation patterns of charged aggregates formed by lanthanide- functionalized surfactants, ytterbium and erbium bis(2-ethylhexyl)sulfosuccinate ((AOT) 3 Yb and (AOT) 3 Er), have been investigated by electrospray ionization m…

Simultaneous determinations of zirconium, hafnium, yttrium and lanthanides in seawater according to a co-precipitation technique onto iron-hydroxide

2013

Very low concentrations (pg mL 1 or sub-pg mL 1 level) along with the high salinity are the main problems in determining trace metal contents in seawater. This problem is mainly considered for investigations of naturally occurring YLOID (Y and Lanthanides) and Zr and Hf in order to provide precise and accurate results. The inductively coupled plasma mass spectrometry (ICP-MS), both in high and low resolution, offers many advantages including simultaneous analyses of all elements and their quantitative determination with detection limits of the order of pg mL 1. However in the analysis of YLOID in seawater, a better determination needs an efficient combination of ICP-MS measurement with a pr…

Toxicological Impact of Rare Earth Elements (REEs) on the Reproduction and Development of Aquatic Organisms Using Sea Urchins as Biological Models

2022

The growing presence of lanthanides in the environment has drawn the attention of the scientific community on their safety and toxicity. The sources of lanthanides in the environment include diagnostic medicine, electronic devices, permanent magnets, etc. Their exponential use and the poor management of waste disposal raise serious concerns about the quality and safety of the ecosystems at a global level. This review focused on the impact of lanthanides in marine organisms on reproductive fitness, fertilization and embryonic development, using the sea urchin as a biological model system. Scientific evidence shows that exposure to lanthanides triggers a wide variety of toxic insults, includi…