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Nuclear Magnetic Resonance (NMR) is an analytical technique extensively used in almost every chemical laboratory for structural identification. This technique provides statistically equivalent signals in spite of using spectrometer with different hardware features and is successfully used for the traceability and quantification of analytes in food samples. Nevertheless, to date only a few internationally agreed guidelines have been reported on the use of NMR for quantitative analysis. The main goal of the present study is to provide a methodological pipeline to assess the reproducibility of NMR data produced for a given matrix by spectrometers from different manufacturers, with different magnetic field strengths, age and hardware configurations. The results have been analyzed through a sequence of chemometric tests to generate a community-built calibration system which was used to verify the performance of the spectrometers and the reproducibility of the predicted sample concentrations.

The Champenoise method for the obtainment of sparkling wines is based on “in bottle” re-fermentation driven by few commercial strains belonging to the Saccharomyces cerevisiae species and their exclusive use can cause a flattening of the sensorial profile. In this work, the impact of native selected yeast strains on the chemical profile of sparkling wines has been evaluated through non-targeted metabolomic approach based on HPLC-HRMS and GC-MS techniques. Results showed that yeast strain affects the levels of i) some fermentative compounds as well as of ii) polysaccharides, organic acids, phenolic acids and lipids. Moreover, a HPLC-HRMS/GC-MS correlation analysis permitted to draw a map that constitutes a useful tool to monitor the different patterns of aroma release. Finally, the present work provide original information to modulate positively the quality of regional sparkling wines from minor autochthonous grape varieties using selected microbial resources.

The one-pot stepwise reductive amination of arylaldehydes with nitroarenes is described, using reusable nickel nanoparticles (Ni-pol) as catalyst and NaBH4 as mild, inexpensive, and safe reducing agent. The proposed catalytic system holds several advantages such as the use of a non-precious and earth-abundant metal, the facile separation of the catalyst from the reaction mixture by centrifugation, excellent stability towards air and moisture, very mild reaction conditions, good recyclability, broad substrate scope with good to excellent yields, and easy scalability (up to 1.0 g). FESEM analyses indicate that the active species are cubic nanocrystals of Ni in the average cross section value of 35 nm with a quite narrow (25–45 nm) and monomodal distribution, which becomes bimodal with the recycling reactions but without agglomeration.

31P and 195Pt solid state NMR spectra of anti-[(PHCy)ClPt(μ-PCy2)2Pt(PHCy)Cl] (3) and [(PHCy2)Pt(μ-PCy2)(κ2P,O-μ-POCy2)Pt(PHCy2)] (Pt-Pt) (4) were recorded under cross polarization/magic-angle spinning conditions (31P) or with the cross polarization/Carr-Purcell-Meiboom-Gill pulse sequence (195Pt) and compared to the data obtained by relativistic DFT calculations of 31P and 195Pt CS tensors and isotropic shielding at the ZORA spin-orbit level. A good agreement with the experimental results was found and it was possible to rationalize the chemical shift differences of 195Pt and 31P nuclei between compounds 3 and 4 as mostly due to a change (in opposite directions for 195Pt and 31P) of the principal component of the shielding tensor perpendicular to the molecular plane defined by the Pt and P atoms. Paramagnetic and spin-orbit terms were found to be the most important contributions to 195Pt and 31P shielding.

An insight into the nano- and micro-structural morphology of a polymer supported Pd catalyst employed in different catalytic reactions under green conditions is reported. The pre-catalyst was obtained by copolymerization of the metal-containing monomer Pd(AAEMA)2 [AAEMA− = deprotonated form of 2-(acetoacetoxy) ethyl methacrylate] with ethyl methacrylate as co-monomer, and ethylene glycol dimethacrylate as cross-linker. This material was used in water for the Suzuki-Miyaura cross-coupling of aryl bromides, and for the reduction of nitroarenes and quinolines using NaBH4 or H2, as reductants. TEM analyses showed that in all cases the pristine Pd(II) species were reduced in situ to Pd(0), which formed metal nanoparticles (NPs, the real active species). The dependence of their average size (2–10 nm) and morphology on different parameters (temperature, reducing agent, presence of a phase transfer agent) is discussed. TEM and micro-IR analyses showed that the polymeric support retained its porosity and stability for several catalytic cycles in all reactions and Pd NPs did not aggregate after reuse. The metal nanoparticle distribution throughout the polymer matrix after several recycles provided precious information about the catalytic mechanism, which was truly heterogeneous in the hydrogenation reactions and of the so-called “release and catch” type in the Suzuki coupling.

A polymer supported palladium catalyst, obtained by copolymerization of Pd(AAEMA) 2 [AAEMA − = deprotonated form of 2-(acetoacetoxy) ethyl methacrylate] with ethyl methacrylate (co-monomer) and ethylene glycol dimethacrylate (cross-linker), exhibited excellent activity and selectivity for the hydrogenation of quinolines to 1,2,3,4-tetrahydroquinolines in the presence of NaBH 4 as hydrogen donor in water. Both the activity and selectivity could be maintained for at least seven reaction runs. No metal leaching into solution occurred during recycles. TEM analyzes carried out on the catalyst showed that the active species were supported palladium nanoparticles having a mean size of 3 nm, which did not aggregate with the recycles.

Composites based on a commercial grade polystyrene (PS) resin containing non commercial perovskite particles were prepared by melt mixing and analyzed in terms of mechanical properties, dynamic-mechanical behavior and morphology. In particular, with the aim to study the influence of the filler size on the ultimate properties of PS based composites micro- and nano-sized perovskite La0.5Sr0.5MnO3 crystal particles, synthesized by using an efficient and rapid microwave-assisted hydrothermal route, were considered. Measurements of flexural parameters such as modulus and strength by static tests and storage modulus and damping factor by dynamic-mechanical evaluations showed better performance for nanofilled systems with respect to the ones containing micro particles, with the same filler content. Mechanical evidences were explained also by morphological observations from which a different level of filler dispersion seems to be obtained with the organization of perovskite nanosized crystals in superstructures able to support viscoelastic results.

Olivine-type LiFePO4 is nowadays one of the most important cathode materials of choice for highenergy lithium ion batteries. Its intrinsic defectivity, and chiefly the so-called lithium iron anti-site, is one of the most critical issues when envisaging electrochemical applications. This paper reports a combined diffractometric (Synchrotron Radiation XRD with Rietveld and PDF analyses) and spectroscopic (Moessbauer) approach able to give a thorough characterization of the material defectivity. Such analytical procedure has been applied to a sample prepared following an innovative microwave-assisted hydrothermal synthesis route that, in a few minutes, allowed us to obtain a well crystallized material. PDF analysis, which is applied for the first time to this type of battery material, reveals the presence of disorder possibly due to Li/Fe exchange or to a local symmetry lowering. A 5% amount of iron on the lithium site has been detected both by PDF as well as by Moessbauer spectroscopy, which revealed a small percentage of Fe3+ on the regular sites.

Magnetite (Fe3O4) nanoparticles prepared by microwave-assisted hydrothermal synthesis have been characterized in terms of morphological and structural features. Electron micrographs collected in both scanning (SEM) and transmission (TEM) modes and evaluations of X-ray powder diffraction (XRD) patterns have indicated the achievement of a monodispersed crystallite structure with particles having an average size around 15–20 nm. Structural investigations by Micro-Raman spectroscopy highlighted the obtainment of magnetite nanocrystals with a partial surface oxidation to maghemite (γ-Fe3O4). Preliminary attention has been also paid to the use of these magnetite nanoparticles as filler for a commercial polymethylmethacrylate resin. Hybrid formulations containing up to 3 wt% of nanoparticles were prepared by melt blending and characterized by calorimetric and thermogravimetric tests. For sake of comparison, same formulations containing commercial Fe3O4nanoparticles are also reported. Calorimetric characterization indicates an increase of both glass transition temperature and thermal stability of the nanocomposite systems when loaded with the synthesized magnetite nanoparticles rather then loaded with the same amount of commercial Fe3O4. This first observation represents just one aspect of the promising potentiality offered by the novel magnetic nanoparticles when mixed with PMMA.

Based on the principle of stability of geopolymer gel as refractory binder, a geopolymeric paste in the K2O–Al2O3–SiO2 system was developed and used to produce refractory concretes by adding various amount of α-quartz sand (grain size in the range 0.1 μm to 1 mm) and fine powder alumina (grain size in the range 0.1–100 μm). The consolidated samples were characterized before and after sintering using optical dilatometer, DSC, XRD and SEM. The total shrinkage in the range of 25–900 °C was less than 3%, reduced with respect to the most diffused potassium or sodium based geopolymer systems, which generally records a >5% shrinkage. The maximum shrinkage of the basic geopolymer composition was recorded at 1000 °C with a 17% shrinkage which is reduced to 12% by alumina addition. The temperature of maximum densification was shifted from 1000 °C to 1150 or 1200 °C by adding 75 wt% α-quartz sand or fine powder alumina respectively. The sequences of sintering of geopolymer concretes could be resumed as dehydration, dehydroxylation, densification and finally plastic deformation due to the importance of liquid phase. The geopolymer formulations developed in this study appeared as promising candidates for high-temperature applications: refractory, fire resistant or insulating materials.

In this work the advantage of the use of the microwave technology was exploited for the preparation of perovskite ceramics. Microwave-assisted hydrothermal method has been applied to the preparation of strontium-doped lanthanum manganites with different stoichiometric ratio of the three oxides, La1-x SrxMnO3 (x = 0.3, 0.5, 0.6). In particular, pure black narrow dispersed crystallites of La0.5Sr0.5MnO3 of 0.68?0.18 ?m were prepared in only 45 minutes at 240?C and a KOH concentration of 21 M. The complete chemical, mineralogical and microstructural characterization of the powders reveal the same structural properties of the perovskite powders previously synthesised by ceramic and conventional hydrothermal routes. .

The effect of intense electromagnetic fields, generated inside a multimode microwave applicators, on the crystallization of calcium carbonate polymorphs starting from calcium bicarbonate solutions has been investigated. The identification and quantitative analysis of the calcium carbonate polymorphs has been made by X-ray diffraction using Rietveld-Reference Intensity Ratio (RIR) method. Scanning Electron Microscopy analysis has also been performed to study the morphology of calcium carbonate samples. Crystallization tests have been conducted at atmospheric pressure while adjusting microwave power to maintain solution temperature between 80 °C and 90 °C. For the sake of comparison, calcium carbonate powders have also been prepared using conventional heating either in a oven or on a hot plate with a magnetic stirrer. The experiments conducted using microwave radiation gave in a high percentage yield of aragonite (99%) which has been favoured by increasing microwave exposure times. Low microwave exposure times, on the other hand, favours vaterite formation which crystallized in an unusual flower-like morphology.

A simple and fast microwave-assisted hydrothermal method is proposed for the synthesis of magnetite nanoparticles. The addition of different surfactants (polyvinylpyrrolidone, oleic acid, or trisodium citrate) was studied to investigate the effect on size distribution, morphology, and functionalization of the magnetite nanoparticles. Microwave irradiation at 150 °C for 2 h of aqueous ferrous chloride and hydrazine without additives resulted in hexagonal magnetite nanoplatelets with a facet-to-facet distance of 116 nm and a thickness of 40 nm having a saturation magnetization of ~65 Am2 kg−1. The use of polyvinylpyrrolidone led to hexagonal nanoparticles with a facet-to-facet distance of 120 nm and a thickness of 53 nm with a saturation magnetization of ~54 Am2 kg−1. Additives such as oleic acid and trisodium citrate yielded quasi-spherical nanoparticles of 25 nm in size with a saturation magnetization of ~70 Am2 kg−1 and spheroidal nanoparticles of 60 nm in size with a saturation magnetization up to ~82 Am2 kg−1, respectively. A kinetic control of the crystal growth is believed to be responsible for the hexagonal habit of the nanoparticles obtained without additive. Conversely, a thermodynamic control of the crystal growth, leading to spheroidal nanoparticles, seems to occur when additives which strongly interact with the nanoparticle surface are used. A thorough characterization of the materials was performed. Magnetic properties were investigated by Superconducting Quantum Interference Device and Vibrating Sample magnetometers. Based on the observed magnetic properties, the magnetite obtained using citrate appears to be a promising support for magnetically transportable catalysts.

An interlaboratory comparison (ILC) was organized with the aim to set up quality control indicators suitable for multicomponent quantitative analysis by nuclear magnetic resonance (NMR) spectroscopy. A total of 36 NMR data sets (corresponding to 1260 NMR spectra) were produced by 30 participants using 34 NMR spectrometers. The calibration line method was chosen for the quantification of a five-component model mixture. Results show that quantitative NMR is a robust quantification tool and that 26 out of 36 data sets resulted in statistically equivalent calibration lines for all considered NMR signals. The performance of each laboratory was assessed by means of a new performance index (named Qp-score) which is related to the difference between the experimental and the consensus values of the slope of the calibration lines. Laboratories endowed with a Qp-score falling within the suitable acceptability range are qualified to produce NMR spectra that can be considered statistically equivalent in terms of relative intensities of the signals. In addition, the specific response of nuclei to the experimental excitation/relaxation conditions was addressed by means of the parameter named NR. NR is related to the difference between the theoretical and the consensus slopes of the calibration lines and is specific for each signal produced by a well-defined set of acquisition parameters. (Graph Presented).

The carbonylation of the solvento species [(PHCy2)(L)Pt(-PCy2)(-H)Pt(PHCy2){P-P(OH)Cy-2}][BF4](2)(Pt-Pt) ([1-L](2+), L = CH2Cl2, thf, CH3CN) led to the formation of a singly bridged dicarbonyl Pt-I compound syn-[(PHCy2)(CO)Pt(-PCy2)Pt{P-P(OH)Cy-2}(CO)](+)(Pt-Pt) (2(+)). The reaction proceeded in two steps: 1) Substitution of L by CO to give the intermediate syn-[(PHCy2)(CO)Pt(-PCy2)(-H)Pt(PHCy2){P-P(OH)Cy-2}](2+)(Pt-Pt) ([1-CO](2+)) and 2) uptake of a second molecule of CO and elimination of [PH2Cy2](+) (as the BF4- salt) to give 2(+). The dicarbonyl complex [2][BF4] was also synthesized starting from the dicyclohexylphosphanido-bridged complex [(PHCy2)Pt(-PCy2){P-2,O--P(O)Cy-2}Pt(PHCy2)](Pt-Pt) (5). In this case the first step consisted of the carbonylation of 5 to give [(PHCy2)(2)Pt(-PCy2)Pt{P-P(O)Cy-2}(CO)](Pt-Pt) (6), which was transformed into 2(+) by protonation with HBF4 under an atmosphere of CO. Prolonged reaction times for the carbonylation of [1-L](2+) in halogenated solvents resulted in the formation of the symmetrical dicarbonyl compound syn-[(CO)(PHCy2)Pt(-PCy2)Pt(PHCy2)(CO)](+)(Pt-Pt) (3(+)) along with Cy2P(H)OBF3. Complexes 6 and [1-L][BF4](2) were also formed by the carbonylation of 5 and [1-OMe2][BF4](2) in the solid state.

The guarantee of the origin and quality of raw material is essential for the protection and valorization of Campana buffalo mozzarella cheese. The risk of utilization of semifinished products and stored milk in substitution for fresh milk is increasing, due to the continuous desire to reduce production costs. A proteomics approach and electrophoresis survey of retail mozzarella cheeses indicated different rates of proteolysis in the production of dairy industries. The use of fresh milk and correct cheesemaking protocol yielded only γ-caseins, which are derived from β-casein by plasmin, and para-κ-casein, which is derived from κ-casein by chymosin. The detection of abnormal hydrolysis resulting in β- and αS1-casein fragments, identified by mass spectrometry, indicates the use of stored milk or stored and pressed curd, or the reuse of unsold mozzarella cheese, to produce mozzarella. The formation of γ-caseins and other fragments during a long storage of raw materials at room or refrigeration temperature was ascribed to plasmin (endogenous milk enzyme), whereas formation of αS1-casein fragments, mainly αS1-I(6P)- and αS1-I(7P)-casein during the storage of curd was ascribed to the action of chymosin (exogenous enzyme) from rennet. Sodium dodecyl sulfate-PAGE and alkaline urea-PAGE permitted us to evaluate the freshness of the raw materials used in the manufacturing of buffalo mozzarella cheese and to reveal possible inappropriate preservation.

The synthesis of the first polyacetylenes bearing chiral fluorene-based pendant groups is described. Poly{9,9-bis[(S)-3,7-dimethyloctyl]fluoren-2-ylacetylene} (PFA1), poly{9,9-bis[(S)-2-methylbutyl]fluoren-2-ylacetylene} (PFA2), and poly{9,9,9',9',9'',9''-hexakis[(S)-2-methylbutyl]-7,2';7',2''-terfluoren-2-ylacetylene} (PFA3) have been obtained by Rh(I)-catalyzed polymn. of the corresponding terminal acetylene monomers 2-ethynyl-9,9-bis[(S)-3,7-dimethyloctyl]fluorene , 2-ethynyl-9,9-bis[(S)-2-methylbutyl]fluorene, and 2-ethynyl-9,9,9',9',9'',9''-hexakis[(S)-2-methylbutyl]-7,2';7',2''-terfluorene. The effect of the alkyl chain length at the C-9 position of fluorene on the structural and conformational aspects of the polymers PFA1 and PFA2 as well as on their chiroptical properties was studied by XRD, DSC, TGA, GPC, UV-vis, and CD. A more planar conformation of the polyenic backbone of PFA1 with respect to PFA2 can be inferred by a red shift of the Ĉ-Ĉ* transition in the UV-vis spectra. Their photoluminescence properties are those typical of fluorene systems. CD measurements evidenced Cotton effects of opposite signs in correspondence of the backbone absorption region, ascribable to an excess of a screw sense of the helical conformations assumed by the two polymers. PFA3 revealed an amorphous structure and exhibited peculiar thermal stability features (as indicated by TGA and DSC). Its emission spectra interest the violet-blue region and do not show any substantial red shift passing from soln. to solid state, thus pointing out an aggregation prevention of terfluorene groups by means of the polyacetylene backbone.

The polymerizable rhodium complex [(+)-diopRh(AAEMA)] (AAEMA − : deprotonated form of the ligand 2-(acetoacetoxy)-ethylmethacrylate) was obtained by reaction of (cod)Rh(AAEMA) with (+)-diop at −80 °C. Supported chiral complexes have been obtained by copolymerization of [(+)-diopRh(AAEMA)] with N , N -dimethylacrylamide and N , N ′-methylenebisacrylamide or by reaction of [(+)-diopRhCl] 2 with an opportunely prepared poly(β-ketoesterate). Catalytic tests carried out with the homogeneous catalyst or with both its heterogeneous analogues proved to be active in the enantioselective hydrogenation of methyl-( Z )-α- N -acetamidocinnamate yielding ( S )-phenylalanine methylester with ee’s up to 67%.

The effect of 2-chloroethylphosphonic acid (Ethephon, in the following ETH) as abscising agent on cv. Crimson Seedless table grape was investigated by means of Fruit Detachment Force (FDF) and Fruit Drop (FD) analyses combined with a metabolomic study carried out by High Resolution Mass Spectrometry (HRMS) and Nuclear Magnetic Resonance (NMR) spectroscopy. The effectiveness of ETH as abscising agent was ascertained with ETH concentration ranging from 1.4 to 4.0 g/L in a two-year study. The ETH treatments caused berry drops higher than 40% and induced an increase of tartaric acid, procyanidin P2, terpenoid derivatives and peonidin-3-glucoside as well as a decrease of catechin and epicatechin. HRMS–NMR covariance analysis was carried out to correlate the fluctuations of tartaric acid NMR signals to those of MS peaks of the secondary metabolites affected by ETH treatments.

Polymer supported palladium nanoparticles, generated in situ by Pd(II) reduction under reaction conditions, catalyzed the hydrogenation of nitroarenes to anilines with high efficiency in water at room temperature in the presence of NaBH4. The protocol proved to be highly selective and generally favored the formation of the desired aniline as single product in high yields with short reaction times. TEM analyses revealed that the size distribution of the formed Pd nanocrystals was regulated by the reductant agent. In details, when 1 atm H2 was used as the nitroarene reductant, the in situ generated polymer supported palladium nanoparticles were crystallites with diameters ranging from 6 to 10 nm. On the contrary, when the reaction was carried out in the presence of NaBH4 in water under N2 or air, the formation of Pd nanocrystallites was observed as well, but this time they were smaller (mean size diameter ca. 3 nm) and catalytically more active compared to the palladium nanoparticles formed under 1 atm H2 in the absence of NaBH4. The catalyst displayed excellent recyclability over twelve cycles and no leaching of metal into solution occurred, which made the overall system eco-friendly and economic.

The reactions of [(cod)RhCl] 2 (cod=1,5-cyclooctadiene) and Na 2 PdCl 4 with the anion of 2-(acetoacetoxy)ethyl methacrylate (AAEMA − ) afforded (cod)Rh(AAEMA) ( 1 ) and Pd(AAEMA) 2 ( 2 ). Thermal copolymerization of 1 and 2 with suitable comonomers and cross-linkers yielded insoluble resins that have been characterised by elemental analyses, IR, UV–Vis, XPS and SEM techniques and successfully used in the hydrogenation of 1-heptene under mild conditions.

Suzuki couplings of aryl bromides were efficiently performed by a polymer supported palladium catalyst under air in water at 100 degrees C without additives. In the case of activated aryl chlorides the reactions proceeded smoothly in the presence of a suitable phase transfer agent. The catalyst was active and recyclable for at least five times. Atomic absorption analyses revealed that the metal content in the polymeric support did not significantly decrease with the cycles while inductively coupled plasma analyses revealed that the palladium amount both in the mother liquors and in the organic products after reactions was lower than 500 ppb. The activity of the mother liquors has been investigated in detail. A transmission electron microscopy study of the supported catalyst before, during and after duty is also described. (c) 2012 Elsevier B.V. All rights reserved.

The reactivity of the phosphinito bridged Pt(I) complex [(PHCy(2))Pt(1)(μ-PCy(2)){κ(2)P,O-μ-P(O)Cy(2)}Pt(2)(PHCy(2))](Pt-Pt) (1) towards Au(I) and Ag(I) electrophiles was explored. Treatment of 1 with AuCl yielded the dichloro Pt(II) complex [(Cl)(PHCy(2))Pt(μ-PCy(2)){κ(2)P,O-μ-P(O)Cy(2)}Pt(Cl)(PHCy(2))] (4), while [Au(PPh(3))Cl] in thf (or toluene) caused ligand exchange resulting in the formation of [(PPh(3))Pt(μ-PCy(2)){κ(2)P,O-μ-P(O)Cy(2)}Pt(PHCy(2))](Pt-Pt) (7) and [(PPh(3))Pt(μ-PCy(2)){κ(2)P,O-μ-P(O)Cy(2)}Pt(PPh(3))](Pt-Pt) (8). With [Au(PPh(3))OTf] (independently from the solvent) or with [Au(PPh(3))Cl] (only in dichloromethane), reaction with 1 gave [(PHCy(2))Pt(1)(μ-PCy(2)){κ(2)P,O-μ-P(O)Cy(2)}Pt(2){μ-Au(PPh(3))}(PHCy(2))]X(Pt-Pt) ([6]X, X = OTf, Cl) clusters in which the [Au(PPh(3))] moiety bridges the μP-Pt(2) bond. The [Ag(PPh(3))](+) electrophile attacks complex 1 selectively at the Pt(2)-μP bond to afford, at low T, the cationic cluster [(PHCy(2))Pt(1)(μ-PCy(2)){κ(2)P,O-μ-P(O)Cy(2)}Pt(2){μ-Ag(PPh(3))}(PHCy(2))](+)(Pt-Pt) (10(+)) in which the [Ag(PPh(3))](+) moiety bridges the μP-Pt(2) bond. Clusters analogous to 10(+), but without PPh(3) bonded to Ag, are obtained from reactions of 1 with AgOTf, AgBF(4), AgClO(4) and AgCl.

X-ray powder diffraction was combined, for the first time, with Nuclear Magnetic Resonance spectroscopy and direct infusion mass spectrometry to characterise fresh and brined grape leaves. Covariance analysis of data generated by the three techniques was performed with the aim to correlate information deriving from the solid part with those obtained for soluble metabolites. The results obtained indicate that crystalline components can be correlated to the metabolites contained in the grape leaves, paving the way to the use of X-ray diffraction analysis for food fingerprinting purposes. Moreover it was ascertained that, differently from most of the metabolites present in the fresh vine leaves, linolenic acid (an omega-3-fatty acid) and quercetin-3-O-glucuronide (a polyphenol metabolite) do not undergo sensible degradation during the brining process, which is used as preservative method for the grape leaves. (C) 2013 Elsevier Ltd. All rights reserved.

This work describes the one-pot direct reductive amination of carbonyl compounds with nitroarenes promoted by a polymer supported palladium catalyst, in the presence of molecular hydrogen as the reductant. This methodology is applicable, with slight differences, to both aliphatic and aromatic aldehydes. The operational simplicity, the mild reaction conditions, the high yields and the good recyclability of the supported catalyst are major advantages of this method. TEM observations of the catalyst showed that the active species are palladium nanoparticles having a size distribution centered at 5 nm within the polymeric support.

This study is focused on the synthesis of zirconia nanopowders stabilized by 6%mol calcia prepared under hydrothermal conditions using microwave technology. Sodium hydroxide-based hydrolysis of zirconyl chloride solution containing calcium nitrate followed by microwave irradiation at the temperature of 220 °C for 30 min was sufficient to obtain white powders of crystalline calcia stabilized zirconia. By means of X-ray diffraction and transmission electron microscopy, it was shown that tetragonal zirconia nanocrystallites with a size of ca 7 nm and diameter/standard deviation ratio of 0.10 were formed. The effects of the [Ca2+] and [NaOH] as well as temperature and time of microwave irradiation on the density and specific surface area were evaluated. Sintering test of the tetragonal nanopowders at 1,300 °C in air was performed in a monomode microwave applicator. The sample was sintered to the density of 95% and the grain size, analyzed by field emission scanning electron microscopy, was in the range from 90 to 170 nm.

Based on the principle of stability of geopolymer gel as refractory binder, a geopolymeric paste in the K 2 O-Al 2 O 3 -SiO 2 system was developed and used to produce refractory concretes by adding various amount of α-quartz sand (grain size in the range 0.1μm-1mm) and fine powder alumina (grain size in the range 0.1-100 μm). The consolidated samples were characterized before and after sintering using optical dilatometer, DSC, XRD and SEM. The total shrinkage in the range of 25-900°C was less than 3%, reduced with respect to the most diffused potassium or sodium based systems, which generally records a >5% shrinkage. The maximum shrinkage of the base geopolymer was recorded at 1000°C with a 17% shrinkage which is reduced to 12% by alumina addition. The maximum densification temperature was shifted from 1000°C to 1150°C or 1200°C by adding 75 wt% α-quartz sand or fine powder alumina respectively. The sequences of sintering of geopolymer concretes could be resumed as dehydration, dehydroxylation, densification and finally plastic deformation due to liquid phase appearance. The geopolymer formulations developed in this study appeared as promising candidates for high temperature applications.

In this work attempts to prepare strontium-doped lanthanum manganites La1-xSrxMnO3 using microwave-assisted hydrothermal synthesis were undertaken from a mixture of lanthanum nitrate, strontium nitrate, manganese(II) nitrate, potassium permanganate and potassium hydroxide as a mineralizer. For x = 0.3, and x = 0.5, the perovskite obtained is not defined since both La0.7Sr0.3MnO3 and La0.5Sr0.5MnO3 phases are consistent with XRD spectra. While with x = 1.0, for the first time, hexagonal strontium manganite was prepared as blade-shaped crystallites with a narrow particle length distribution (range 3.75-7.75 μm) at 210°C using a treatment time of only 1 hour. Conventional hydrothermal synthetic routes require at least 24 hrs treatment time.

A novel approach to the synthesis of pyrazole derivatives from tosylhydrazones of alpha,beta-unsaturated carbonyl compounds possessing a beta-hydrogen is proposed, exploiting microwave (MW) activation coupled with solvent free reaction conditions. The cycloaddition was studied on three ketones (trans-4-phenyl-3-buten-2-one, beta-ionone and trans-chalcone). The corresponding 3,5-disubstituted-1H-pyrazoles were obtained in high yields and after short reaction times. In order to simplify and point out the green chemistry features of the method, a further improvement was achieved under the same catalytic conditions with a "one pot" synthesis of these heterocyclic compounds, starting directly from their carbonyl precursors via tosylhydrazones generated in situ. For an exhaustive study, the dielectric properties of the solid reaction mixtures were also measured, in order to obtain input data for the numerical simulation of their heating behaviour in the single mode MW cavity which was used for experimental work. In order to supply a valid methodology and tool for measuring the environmental impact, a comparative study between the synthetic route proposed and the classical synthetic route has been carried out.

The catalytic activity of the cross-linked polymer obtained by reaction of Rh(cod)(AAEMA) [AAEMA − =deprotonated form of 2-(acetoacetoxy)ethyl methacrylate] and suitable acrylamides as comonomers and cross-linkers was investigated in the hydrogenation reactions of substrates such as olefins, unsaturated aldehydes and ketones, nitrobenzene and nitriles.