La metodologia per il recupero dei metalli nobili dai RAEE

Il progetto Recupero dell'oro da rifiuti elettrici ed elettronici aveva come finalità la dissoluzione e il recupero selettivo dei metalli preziosi dai RAEE mediante attacchi chimici poco aggressivi ed eco-compatibili. Le classi di RAEE selezionate sono state: simcards, cartucce ink-jet, schede elettroniche. Le classi di reagenti selezionate sono state: ditiossammidi cicliche epta-atomiche; ditiossammidi lineari 1e e 2e; dialchil (o morfolin) tiuram disolfuro. I reagenti selezionati accoppiano in un'unica molecola la capacità complessante del legante con quella ossidente dell'alogeno e: risultano altamente efficienti nell'ossidazione dell'oro; lavorano in condizioni sperimentali blande; sono di facile impiego; non sono citotossici.2007-03-05Sardegna Ricerche, Edificio 2, Località Piscinamanna 09010 Pula (CA) - ItaliaWorkshop - Recupero dell'oro da rifiuti elettrici ed elettronic

Near-IR Absorbers Based on Pt(II)-Dithiolene Donor–Acceptor Charge-Transfer (CT) Systems: A Structural Analysis to Highlight DA Interactions

The packing interactions of a series of electron donor (D) and electron acceptor (A) charge transfer (CT) near-IR absorbers based on platinum-dithiolene complexes are reinvestigated here as a case study also by using the Hirshfeld surface analysis. This analysis on systems, which exhibit the 1:1, 2:1 and 2:2 columnar stacking patterns between D and A, allows to point out that several inter-actions of atoms and fragments are involved in the stacking interactions but also that only a lim-ited fraction of these interactions, limited to the 1:1 D/A columnar stacking case, can be relatable to the absorption features of this class of compounds

chameleon behaviour of iodine in recovering noble metals from weee towards sustainability and zero waste

The peculiar properties of iodine and safe lixiviants for sustainable and effective noble-metal recovery from shredded WEEE

Structural changes in MII dithione/dithiolato complexes (M = Ni, Pd, Pt) on varying the dithione functionalization

The Ni triad [M(R2pipdt)(dmit)] based on donor/acceptor S,S′ ligands, where R2pipdt = 1,4-diisopropyl-piperazine-2,3-dithione (acceptor) and dmit = 2-thioxo-1,3-dithiole-4,5-dithiolato (donor), was completed by preparing and characterizing the Pd(2) and Pt(3) compounds in addition to the already known Ni(1) complex. The rationale behind the work was to compare the properties and structures inside the triad with those of the corresponding Ni(4), Pd(5) and Pt(6) complexes where R = Bz. Minor changes in the properties as redox active nonlinear second-order (NLO) chromophores were observed in solution for the two triads. Instead, different structural features, reflected by changes in the diffuse reflectance spectra, were observed in their crystals on changing R from Bz to Pri in the piperazine ring and also, more surprisingly, inside the triads. 2 (isostructural with 1) and 3 crystallized in monoclinic P21/n and orthorhombic Pbca space groups, respectively. The crystal packings of 2 and 3 are also markedly different. In particular 1 and 2 form head-to-tail dimers whereas 3 forms supramolecular layers characterized by a partial stack between the molecular planes. Large differences in the crystal structures, induced by the diverse number and types of interactions exchanged by the peripheral fragments of the ligands, were found in the Bz-triad. Indeed, the molecules are stacked in a head-to-head and in a head-to-tail fashion in 4 and in 5/6, respectively. Moreover, significantly different packings were observed. The Hirshfeld surface analysis was used to provide a detailed description of the main types of interactions involved in the crystal packing of the six complexes

Population Saturation in Trivalent Erbium Sensitized by Organic Molecular Antennae

We investigate sensitization efficiency of near-infrared emission and population saturation of trivalent erbium in erbium quincilinolato complexes photoexcited into the absorption band of the organic sensitizer. At low excitation levels, we find high (similar to 80%) sensitization efficiencies. We observe excited state population saturation at inversion threshold under subnanosecond pumping at the level of one injected photoexcitation per complex

Multi-Magnetic Properties of a Novel SCO [Fe(3-OMe-Sal2trien)]-[Fe(tdas)2]·CH3CN Salt

The multi‐magnetic salt [Fe(3‐OMe‐Sal2trien)][Fe(tdas)2]·CH3CN (1) has been prepared and fully characterized by a variety of methods. The crystal structure of 1, determined at 150, 297 and 350 K, consists of alternating layers composed by a parallel arrangement of the chains of isolated π–π coupled cation pairs of [Fe(3‐OMe‐Sal2trien)]+ and anion pairs of [Fe(tdas)2]–. The complex magnetic behavior of this salt is consistent with the sum of the contributions from spin‐crossover (SCO) cations and strong antiferromagnetically (AFM) coupled dimeric [Fe(tdas)2]22– anions. The observed gradual thermally induced spin transition (T1/2 = 195 K) is relatable to the cation exhibiting disordering of ethylene (–CH2–CH2–) groups between two conformers with a narrow thermal hysteresis of 6 K. The dc magnetization measurements and 57Fe Mössbauer spectroscopy at room temperature are in excellent agreement between γHS(%) value and ratio of disordering of ethylene groups obtained from X‐ray analysis. Mössbauer spectra at 80 K and 296 K indicate a spin transition between S = 1/2 and S = 5/2 for the iron(III) saltrien‐cation and confirms S = 3/2 for the [FeIII(tdas)2]– anion. The experimental results are supplemented with a theoretical Density Functional Theory (DFT) analysis

A chirality-induced alpha phase and a novel molecular magnetic metal in the BEDT-TTF/tris(croconate)ferrate(III) hybrid molecular system

The novel paramagnetic and chiral anion [Fe(C5O5)3]32 has been combined with the organic donor BEDT-TTF (= ET = bis(ethylenedithio)tetrathiafulvalene) to yield the first chirality- induced α phase and a paramagnetic metal.Gomez Garcia, Carlos, [email protected] ; Coronado Miralles, Eugenio, [email protected] ; Gimenez Saiz, Carlos, [email protected]

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe