Unprecedented MoS cluster-catalyzed radical C-C cross-coupling reactions of aryl alkynes and acrylates.

A new method for the generation of benzyl radicals from terminal aromatic alkynes has been developed, which allows the direct cross coupling with acrylate derivatives. Our additive-free protocol employs air-stable diamino MoS cubane-type cluster catalysts in the presence of hydrogen. A sulfur-centered cluster catalysis mechanism for benzyl radical formation is proposed based on catalytic and stoichiometric experiments.

Heterogeneity of sensitization profiles and clinical phenotypes among patients with seasonal allergic rhinitis in Southern European countries-The @IT.2020 multicenter study.

Background: Pollen allergy poses a significant health and economic burden in Europe. Disease patterns are relatively homogeneous within Central and Northern European countries. However, no study broadly assessed the features of seasonal allergic rhinitis (SAR) across different Southern European countries with a standardized approach.

Spin-Crossing in the ()-Selective Alkyne Semihydrogenation Mechanism Catalyzed by MoS Clusters: A Density Functional Theory Exploration.

Semihydrogenation of internal alkynes catalyzed by the air-stable imidazolyl amino [MoSCl(ImNH)] cluster selectively affords the ()-alkene under soft conditions in excellent yields. Experimental results suggest a sulfur-based mechanism with the formation of a dithiolene adduct through interaction of the alkyne with the bridging sulfur atoms. However, computational studies indicate that this mechanism is unable to explain the experimental outcome: mild reaction conditions, excellent selectivity toward the ()-isomer, and complete deuteration of the vinylic positions in the presence of CDOD and CHOD.

Tuning the morphology to enhance the catalytic activity of α-AgWO through V-doping.

Here, we present the synthesis of a highly efficient V-doped α-AgWO catalyst for the oxidation of sulfides to sulfones, exhibiting a high degree of tolerance towards various sensitive functional groups. Remarkably, the catalysts with 0.01% V-doping content exhibited outstanding selectivity towards the oxidation process.

Disclosing the Biocide Activity of α-AgCuWO (0 ≤ ≤ 0.16) Solid Solutions.

In this work, α-AgCuWO (0 ≤ ≤ 0.16) solid solutions with enhanced antibacterial (against methicillin-resistant ) and antifungal (against ) activities are reported. A plethora of techniques (X-ray diffraction with Rietveld refinements, inductively coupled plasma atomic emission spectrometry, micro-Raman spectroscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, field emission scanning electron microscopy, ultraviolet-visible spectroscopy, photoluminescence emissions, and X-ray photoelectron spectroscopy) were employed to characterize the as-synthetized samples and determine the local coordination geometry of Cu cations at the orthorhombic lattice.

Heterogeneity of pollen food allergy syndrome in seven Southern European countries: The @IT.2020 multicenter study.

Background: Pollen food allergy syndrome (PFAS) is a frequently underdiagnosed disease due to diverse triggers, clinical presentations, and test results. This is especially relevant in geographic areas with a broad spectrum of pollen sensitization, such as Southern Europe.

Objectives: To elucidate similarities and differences of PFAS in nine Southern European centers and identify associated characteristics and unique markers of PFAS.

"Whole" vs. "fragmented" approach to EAACI pollen season definitions: A multicenter study in six Southern European cities.

Background: The adequate definition of pollen seasons is essential to facilitate a correct diagnosis, treatment choice, and outcome assessment in patients with seasonal allergic rhinitis. A position paper by the European Academy of Allergy and Clinical Immunology (EAACI) proposed season definitions for Northern and Middle Europe.

Objective: To test the pollen season definitions proposed by EAACI in six Mediterranean cities for seven pollen taxa.

On the catalytic transfer hydrogenation of nitroarenes by a cubane-type MoS cluster hydride: disentangling the nature of the reaction mechanism.

Cubane-type MoS cluster hydrides decorated with phosphine ligands are active catalysts for the transfer hydrogenation of nitroarenes to aniline derivatives in the presence of formic acid (HCOOH) and triethylamine (EtN). The process is highly selective and most of the cluster species involved in the catalytic cycle have been identified through reaction monitoring. Formation of a dihydrogen cluster intermediate has also been postulated based on previous kinetic and theoretical studies.

Efficient and Selective N-Methylation of Nitroarenes under Mild Reaction Conditions.

Herein, we report a straightforward protocol for the preparation of N,N-dimethylated amines from readily available nitro starting materials using formic acid as a renewable C source and silanes as reducing agents. This tandem process is efficiently accomplished in the presence of a cubane-type Mo PtS catalyst. For the preparation of the novel [Mo Pt(PPh )S Cl (dmen) ] (3 ) (dmen: N,N'-dimethylethylenediamine) compound we have followed a [3+1] building block strategy starting from the trinuclear [Mo S Cl (dmen) ] (1 ) and Pt(PPh ) (2) complexes.

Kinetics Aspects of the Reversible Assembly of Copper in Heterometallic MoCuS Clusters with 4,4'-Di-tert-butyl-2,2'-bipyridine.

Treatment of the triangular [MoSCl(dbbpy)]Cl cluster ([1]Cl) with CuCl produces a novel tetrametallic cuboidal cluster [Mo(CuCl)SCl(dbbpy)][CuCl] ([2][CuCl]), whose crystal structure was determined by X-ray diffraction (dbbpy = 4,4'-di-tert-butyl-2,2'-bipyridine). This species, which contains two distinct types of Cu(I), is the first example of a diimine-functionalized heterometallic MM'S cluster. Kinetics studies on both the formation of the cubane from the parent trinuclear cluster and its dissociation after treatment with halides, supported by NMR, electrospray ionization mass spectrometry, cyclic voltammetry, and density functional theory calculations, are provided.

C3-symmetry Mo3S4 aminophosphino clusters combining three sources of stereogenicity: stereocontrol directed by hydrogen bond interactions and ligand configuration.

A diastereoselective synthesis of proline containing aminophosphino cubane-type Mo3S4 clusters, (P)-[Mo3S4Cl3((1S,2R)-PPro)3]Cl (Cl) and (P)-[Mo3S4Cl3((1S,2S)-PPro)3]Cl (Cl), has been achieved in high yields by reacting the corresponding enantiomerically pure PPro ((R)- and (S)-2-[(diphenylphosphino)methyl]pyrrolidine) ligands with the Mo3S4Cl4(PPh3)3(H2O)2 complex. Circular dichroism, nuclear magnetic resonance and X-ray techniques confirm that the Cl and Cl cluster cations are diastereoisomers which combine three sources of stereogenicity provided by the cluster framework, one carbon atom of the aminophosphine ligand and the nitrogen stereogenic center. The higher stability of the (+) cation is due to stabilizing vicinal ClHN interactions as well as due to the cis-fused conformation of the bicyclic system formed upon coordination of the aminophosphine ligand.

Synthesis and characterization of metastable β-Ag2WO4: an experimental and theoretical approach.

Metastable silver tungstate (β-Ag2WO4) has attracted much attention lately because of its many potential applications. However, the synthesis of metastable phases of inorganic compounds is challenging because of the ease of transformation to the stable phase. We have overcome this challenge and have successfully synthesized β-Ag2WO4 microcrystals using a dropwise precipitation (DP) method in aqueous media at low temperature.

Synthesis and optical power limiting properties of heteroleptic Mo3S7 clusters.

Substitution of the halide ligands in (Bu4N)2[Mo3S7X6] (X = Cl, Br) by diimine ligands, such as 4,4'-dimethyl-2,2'-bipyridine (dmbpy), 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen), affords the neutral heteroleptic clusters Mo3S7Cl4(dmbpy) (), Mo3S7Br4(dmbpy) (), Mo3S7Br4(bpy) (), and Mo3S7Br4(phen) (). Further substitution of the halide ligands in Mo3S7Br4(diimine) clusters by dmit (1,3-dithiole-2-thione-4,5-dithiolate) allows the preparation of the mixed diimine-dithiolene neutral cluster complexes Mo3S7(dnbpy)(dmit)2 (, dnbpy = 4,4'-dinonyl-2,2'-bipyridine), Mo3S7(dcmbpy)(dmit)2 (, dcmbpy = 4,4'-dimethoxycarbonyl-2,2'-bipyridine), and Mo3S7(dcbpy)(dmit)2 (, dcbpy = 2,2'-bipyridine-4,4'-dicarboxylic acid). The optical limiting properties of complexes have been assessed by the open-aperture Z-scan technique at 570 nm, employing a nanosecond optical parametric oscillator.

Synthesis and structure of trinuclear W3S4 clusters bearing aminophosphine ligands and their reactivity toward halides and pseudohalides.

The aminophosphine ligand (2-aminoethyl)diphenylphosphine (edpp) has been coordinated to the W3(μ-S)(μ-S)3 cluster unit to afford trimetallic complex [W3S4Br3(edpp)3](+) (1(+)) in a one-step synthesis process with high yields. Related [W3S4X3(edpp)3](+) clusters (X = F(-), Cl(-), NCS(-); 2(+)-4(+)) have been isolated by treating 1(+) with the corresponding halide or pseudohalide salt. The structure of complexes 1(+) to 4(+) contains an incomplete W3S4 cubane-type cluster unit, and only one of the possible isomers is formed: the one with the phosphorus atoms trans to the capping sulfur and the amino groups trans to the bridging sulphurs.

Photogeneration of hydrogen from water by hybrid molybdenum sulfide clusters immobilized on titania.

Two new hybrid molybdenum(IV) Mo3 S7 cluster complexes derivatized with diimino ligands have been prepared by replacement of the two bromine atoms of [Mo3 S7 Br6 ](2-) by a substituted bipyridine ligand to afford heteroleptic molybdenum(IV) Mo3 S7 Br4 (diimino) complexes. Adsorption of the Mo3 S7 cores from sample solutions on TiO2 was only achieved from the diimino functionalized clusters. The adsorbed Mo3 S7 units were reduced on the TiO2 surface to generate an electrocatalyst that reduces the overpotential for the H2 evolution reaction by approximately 0.

New insights into the chemistry of di- and trimetallic iron dithiolene derivatives. Structural, Mössbauer, magnetic, electrochemical and theoretical studies.

Reaction of Fe3(CO)12 with 1,2-dithiolene HSC6H2Cl2SH affords a mixture of complexes [Fe2(CO)6(μ-SC6H2Cl2S)] 1, [Fe2(SC6H2Cl2S)4] 2 and [Fe3(CO)7(μ3-SC6H2Cl2S)2] 3. In the course of the reaction the trimetallic cluster 3 is first formed and then converted into the known dinuclear compound 1 to afford finally the neutral diiron tetrakis(dithiolato) derivative 2. Compounds 2 and 3 have been studied by Mössbauer spectroscopy, X-ray crystallography and theoretical calculations.

Effects of cigarette smoke on methacholine- and AMP-induced air trapping in asthmatics.

Unlabelled: Abstract Objective: No information is available on the effect of cigarette smoke on bronchoconstrictor-induced air trapping in asthma. The aim of this study was to evaluate the additional influence of smoking on methacholine- and adenosine 5'-monophosphate (AMP)-induced air trapping in subjects with asthma.

Methods: Airway responsiveness to methacholine and AMP, bronchial (J'awNO) and alveolar (CANO) nitric oxide (NO) and exhaled breath condensate pH were measured in 68 adults (23 current smokers with asthma, 23 non-smokers with asthma and 22 current or former smokers with chronic obstructive pulmonary disease; COPD).

Influence of the ligand alkyl chain length on the solubility, aqueous speciation, and kinetics of substitution reactions of water-soluble M3S4 (M = Mo, W) clusters bearing hydroxyalkyl diphosphines.

Water-soluble [M3S4X3(dhbupe)3](+) diphosphino complexes (dhbupe = 1,2-bis(bis(hydroxybutyl)phosphino)ethane), 1(+) (M = Mo, X = Cl) and 2(+) (M = W; X = Br), have been synthesized by extending the procedure used for the preparation of their hydroxypropyl analogues by reaction of the M3S4(PPh3)3X4(solvent)x molecular clusters with the corresponding 1,2-bis(bishydroxyalkyl)diphosphine. The solid state structure of the [M3S4X3(dhbupe)3](+) cation possesses a C3 symmetry with a cuboidal M3S4 unit, and the outer positions are occupied by one halogen and two phosphorus atoms of the diphosphine ligand. At a basic pH, the halide ligands are substituted by hydroxo groups to afford the corresponding [Mo3S4(OH)3(dhbupe)3](+) (1OH(+)) and [W3S4(OH)3(dhbupe)3](+) (2OH(+)) complexes.

Dithiolene dimetallic molybdenum(V) complexes displaying intraligand charge transfer (ILCT) emission.

Bifunctional dithiolene ligands have been coordinated to the Mo(V)(O)(μ-S2)Mo(V)(O) unit to afford [Mo2O2(μ-S)2(BPyDTS2)2](2-) (1(2-)) (BPyDTS2 (2-bis-(2-pyridyl)methylene-1,3-dithiolene) dianions. Reaction of the 1(2-) molybdenum dimer with pentacarbonylchlorothenium(i) affords a tetrametallic complex of formula [Mo2O2(μ-S)2(BPyDTS2)2{Re(CO)3Cl}2](2-) (2(2-)). The monomeric (CH3)2Sn(BPyDTS2) (3) tin complex has also been prepared for comparative purposes.

Cubane-type Mo3FeS4(4+,5+) complexes containing outer diphosphane ligands: ligand substitution reactions, spectroscopic studies, and electronic structure.

A general protocol to access Mo(3)FeS(4)(4+) clusters selectively modified at the Fe coordination site is presented starting from the all-chlorine Mo(3)(FeCl)S(4)(dmpe)(3)Cl(3) (1) [dmpe = 1,2-bis(dimethylphosphane-ethane)] cluster and tetrabutylammonium salts (n-Bu(4)NX) (X = CN(-), N(3)(-), and PhS(-)). Clusters Mo(3)(FeX)S(4)(dmpe)(3)Cl(3) [X = CN(-) (2), N(3)(-) (3), and PhS(-) (4)] are prepared in high yield, and comparison of geometric and redox features upon modification of the coordination environment at the Fe site at parity of ligands at the Mo sites is also presented. The existence of the cubane-type Mo(3)FeS(4)(4+,5+) redox couple is demonstrated by cyclic voltammetry and for compound 1 by cluster synthesis and X-ray structure determinations.

Synthesis and structure of a paramagnetic Mo3S4 incomplete cuboidal cluster with seven cluster skeletal electrons.

The electron precise incomplete cuboidal complex [Mo(3)S(4)(dppe)(3)Br(3)]Br (1a) with 6 cluster skeletal electrons (CSE) and its halogen-mixed analogue [Mo(3)S(4)(dppe)(3)(Br,Cl)(3)](Br,Cl) (1b) can be smoothly reduced to the paramagnetic [Mo(3)S(4)(dppe)(3)X(3)] clusters (2a, X = Br; 2b, X = Cl/Br) with 7 CSE by treatment with liquid Ga.

Chemoselective transfer hydrogenation to nitroarenes mediated by cubane-type Mo3S4 cluster catalysts.

Chemoselective cubes: Cubane-type [Mo(3)S(4)X(3)(dmpe)(3)](+) clusters (dmpe = 1,2-(bis)dimethylphosphinoethane), in combination with an azeotropic 5:2 mixture of HCOOH and NEt(3) as the reducing agent, act as selective cluster catalysts (X = H) or precatalysts (X = Cl) for the transfer hydrogenation of functionalized nitroarenes, without the formation of hazardous hydroxylamines.

Water-soluble Mo3S4 clusters bearing hydroxypropyl diphosphine ligands: synthesis, crystal structure, aqueous speciation, and kinetics of substitution reactions.

The [Mo(3)S(4)Cl(3)(dhprpe)(3)](+) (1(+)) cluster cation has been prepared by reaction between Mo(3)S(4)Cl(4)(PPh(3))(3) (solvent)(2) and the water-soluble 1,2-bis(bis(hydroxypropyl)phosphino)ethane (dhprpe, L) ligand. The crystal structure of [1](2)[Mo(6)Cl(14)] has been determined by X-ray diffraction methods and shows the typical incomplete cuboidal structure with a capping and three bridging sulfides. The octahedral coordination around each metal center is completed with a chlorine and two phosphorus atoms of the diphosphine ligand.