Preparation, reactivity and photoluminescence of copper(I) borohydride complexes with bis[(2-diphenylphosphino)phenyl] ether as chelating ligand

Bis[(2-diphenylphosphino)phenyl] ether (DPEphos) was used as chelating ligand to prepare the corresponding borohydride complex [Cu(2–BH4)(DPEphos)], whose structure was ascertained spectroscopically and by means of X-ray diffraction. The spectroscopic assignments related to the coordinated borohydride were confirmed by preparing the isotopologue [Cu(2–BD4)(DPEphos)]. Reaction of [Cu(2–BH4)(DPEphos)] with triflic acid afforded the dimer [Cu2(–BH4)(DPEphos)2][OTf] (OTf = triflate). The borohydride complexes exhibited appreciable blue emission upon excitation with UV light at room temperature. [Cu(2–BH4)(DPEphos)] revealed to be a suitable precursor for the preparation of luminescent heteroleptic copper(I) complexes having general formula [Cu(N^N)(DPEphos)]+ (N^N = 1,10-phenantroline, 2,9-dimethyl-1,10-phenantroline, 2,2’-bypiridine, 4,4’-dimethyl-2,2’bipyridine)

Designing Ln3+-doped BiF3 particles for luminescent primary thermometry and molecular logic

The design of molecular materials suitable for disparate fields could lead to new advances in engineering applications. In this work, a series of Ln3+-doped BiF3 sub-microparticles were synthesized through microwave-assisted synthesis. The effects of doping are evaluated from the structural and morphological viewpoint. In general, increasing the Ln3+ concentration the octahedral habitus is distorted to a spheric one, and some aggregates are visible without any differences in the crystalline phase. The optical response of the samples confirms that the BiF3 materials are suitable hosts for the luminescence of the tested trivalent lanthanide (Ln3+) ions (Ln = Eu, Tb, Tm, Ho, Er, Yb). A Yb3+/ Er3+ co-doped sample is presented as an illustrative example of all-photonic molecular logic operations and primary luminescent thermometry.publishe

Energy transfer in color-tunable water-dispersible Tb-Eu codoped CaF2 nanocrystals

The development of highly luminescent water-dispersible biocompatible nanoparticles is a hot topic in biomedical research. Here, we report about the study of the energy transfer process between Tb3+ and Eu3+ in calcium fluoride nanoparticles. Water-dispersible RE-doped nanoparticles were prepared by means of a simple synthesis route without the need for high temperature, pressure or additional surface functionalization. The structural and morphological properties were investigated by means of XRPD and TEM analysis. Optical analysis led to information about both the RE ion site symmetry in the crystalline host and the Tb3+ and Eu3+ excited state lifetimes, whose remarkable duration is suitable for biosensing applications. Concerning the energy transfer process, dipole-dipole interaction, with a donor-activator critical distance of about 13 Å, was identified as the most probable mechanism.The development of highly luminescent water-dispersible biocompatible nanoparticles is a hot topic in biomedical research. Here, we report about the study of the energy transfer process between Tb3+ and Eu3+ in calcium fluoride nanoparticles. Water-dispersible RE-doped nanoparticles were prepared by means of a simple synthesis route without the need for high temperature, pressure or additional surface functionalization. The structural and morphological properties were investigated by means of XRPD and TEM analysis. Optical analysis led to information about both the RE ion site symmetry in the crystalline host and the Tb3+ and Eu3+ excited state lifetimes, whose remarkable duration is suitable for biosensing applications. Concerning the energy transfer process, dipole-dipole interaction, with a donor-activator critical distance of about 13 angstrom, was identified as the most probable mechanism

Silver doping of silica-hafnia waveguides containing Tb3+/Yb3+ rare earths for downconversion in PV solar cells

The aim of this paper is to study the possibility to obtain an efficient downconverting waveguide which combines the quantum cutting properties of Tb3+/Yb3+ codoped materials with the optical sensitizing effects provided by silver doping. The preparation of 70SiO(2)-30HfO(2) glass and glass-ceramic waveguides by sol-gel route, followed by Ag doping by immersion in molten salt bath is reported. The films were subsequently annealed in air to induce the migration and/or aggregation of the metal ions. Results of compositional and optical characterization are given, providing evidence for the successful introduction of Ag in the films, while the photoluminescence emission is strongly dependent on the annealing conditions. These films could find potential applications as downshifting layers to increase the efficiency of PV solar cells. (C) 2016 Elsevier B.V. All rights reserved

Ag-Sensitized Yb3+ Emission in Glass-Ceramics

Rare earth doped materials play a very important role in the development of many photonic devices, such as optical amplifiers and lasers, frequency converters, solar concentrators, up to quantum information storage devices. Among the rare earth ions, ytterbium is certainly one of the most frequently investigated and employed. The absorption and emission properties of Yb3+ ions are related to transitions between the two energy levels 2F7/2 (ground state) and 2F5/2 (excited state), involving photon energies around 1.26 eV (980 nm). Therefore, Yb3+ cannot directly absorb UV or visible light, and it is often used in combination with other rare earth ions like Pr3+, Tm3+, and Tb3+, which act as energy transfer centres. Nevertheless, even in those co-doped materials, the absorption bandwidth can be limited, and the cross section is small. In this paper, we report a broadband and efficient energy transfer process between Ag dimers/multimers and Yb3+ ions, which results in a strong PL emission around 980 nm under UV light excitation. Silica-zirconia (70% SiO2-30% ZrO2) glass-ceramic films doped by 4 mol.% Yb3+ ions and an additional 5 mol.% of Na2O were prepared by sol-gel synthesis followed by a thermal annealing at 1000 °C. Ag introduction was then obtained by ion-exchange in a molten salt bath and the samples were subsequently annealed in air at 430 °C to induce the migration and aggregation of the metal. The structural, compositional, and optical properties were investigated, providing evidence for efficient broadband sensitization of the rare earth ions by energy transfer from Ag dimers/multimers, which could have important applications in different fields, such as PV solar cells and light-emitting near-infrared (NIR) devices

Ceftolozane/Tazobactam for Treatment of Severe ESBL-Producing Enterobacterales Infections: A Multicenter Nationwide Clinical Experience (CEFTABUSE II Study)

Background. Few data are reported in the literature about the outcome of patients with severe extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) infections treated with ceftolozane/tazobactam (C/T), in empiric or definitive therapy.Methods. A multicenter retrospective study was performed in Italy (June 2016-June 2019). Successful clinical outcome was defined as complete resolution of clinical signs/symptoms related to ESBL-E infection and lack of microbiological evidence of infection. The primary end point was to identify predictors of clinical failure of C/T therapy.Results. C/T treatment was documented in 153 patients: pneumonia was the most common diagnosis (n = 46, 30%), followed by 34 cases of complicated urinary tract infections (22.2%). Septic shock was observed in 42 (27.5%) patients. C/T was used as empiric therapy in 46 (30%) patients and as monotherapy in 127 (83%) patients. Favorable clinical outcome was observed in 128 (83.7%) patients; 25 patients were considered to have failed C/T therapy. Overall, 30-day mortality was reported for 15 (9.8%) patients. At multivariate analysis, Charlson comorbidity index >4 (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.9-3.5; P = .02), septic shock (OR, 6.2; 95% CI, 3.8-7.9; P < .001), and continuous renal replacement therapy (OR, 3.1; 95% CI, 1.9-5.3; P = .001) were independently associated with clinical failure, whereas empiric therapy displaying in vitro activity (OR, 0.12; 95% CI, 0.01-0.34; P < .001) and adequate source control of infection (OR, 0.42; 95% CI, 0.14-0.55; P < .001) were associated with clinical success.Conclusions. Data show that C/T could be a valid option in empiric and/or targeted therapy in patients with severe infections caused by ESBL-producing Enterobacterales. Clinicians should be aware of the risk of clinical failure with standard-dose C/T therapy in septic patients receiving CRRT

Ratiometric Optical Thermometer Based on Dual Near-Infrared Emission in Cr3+-Doped Bismuth-Based Gallate Host

Detailed spectroscopic analysis of the electronic configuration of Cr3+ in Bi2Ga4O9 is reported. The material exhibits unique luminescent properties arising from the crystal field experienced by Cr3+, with simultaneous strong sharp and broadband near-infrared emissions from the E-2 and T-4(2) excited states, in a wide range of temperature. The system displays dual near-infrared emission characterized by a remarkable thermal sensitivity over the whole explored range of temperatures, reaching a value of 0.7%.K-1 in the physiological range. Moreover, the possibility to absorb and emit in the first biological window, allows one to consider the system as a new promising candidate for ratiometric fluorescent thermal sensing in biotechnological applications

Preparation, reactivity and photoluminescence of copper(I) borohydride complexes with bis[(2-diphenylphosphino)phenyl] ether as chelating ligand

Bis[(2-diphenylphosphino)phenyl] ether (DPEphos) was used as chelating ligand to prepare the corresponding borohydride complex [Cu(κ2–BH4)(DPEphos)], whose structure was ascertained spectroscopically and by means of X-ray diffraction. The spectroscopic assignments related to the coordinated borohydride were confirmed by preparing the isotopologue [Cu(κ2–BD4)(DPEphos)]. Reaction of [Cu(κ2–BH4)(DPEphos)] with triflic acid afforded the dimer [Cu2(μ–BH4)(DPEphos)2][OTf] (OTf = triflate). The borohydride complexes exhibited appreciable blue emission upon excitation with UV light at room temperature. [Cu(κ2–BH4)(DPEphos)] revealed to be a suitable precursor for the preparation of luminescent heteroleptic copper(I) complexes having general formula [Cu(N^N)(DPEphos)]+ (N^N = 1,10-phenantroline, 2,9-dimethyl-1,10-phenantroline, 2,2’-bypiridine, 4,4’-dimethyl-2,2’bipyridine)