First Chemical Profile Analysis of Acacia Pods.

This study intended to evaluate the potential industrial applications of various Acacia species (Acacia melanoxylon, Acacia longifolia, Acacia cyclops, Acacia retinodes, Acacia pycnantha, Acacia mearnsii, and Acacia dealbata) by examining their chemical composition, antioxidant, and antimicrobial properties. Using high-resolution mass spectrometry, a comprehensive analysis successfully identified targeted compounds, including flavonoids (flavonols/flavones) and phenolic acids, such as 4-hydroxybenzoic acid, p-coumaric acid, and ellagic acid. Additionally, p-coumaric acid was specifically identified and quantified within the hydroxycinnamic aldehydes. This comprehensive characterization provides valuable insights into the chemical profiles of the studied species. Among the studied species, A. pycnantha exhibited a higher concentration of total phenolic compounds, including catechin, myricetin, quercetin, and coniferaldehyde. Furthermore, A. pycnantha displayed notable antibacterial activity against K. pneumoniae, E. coli, S. Typhimurium, and B. cereus. The identified compounds in Acacia pods and their shown antibacterial activities exhibit promising potential for future applications. Moreover, vibrational spectroscopy was a reliable method for distinguishing between species. These significant findings enhance our understanding of Acacia species and their potential for various industrial applications.

Shedding Light on Metals Release from Chestnut Wood to Wine Spirit Using ICP-MS.

Possible effects caused by mineral elements during wine spirit ageing are diverse. In this study, the evolution of the mineral composition of wine spirit during ageing with chestnut (Castanea sativa Mill.) wood was investigated. A wine distillate was aged in 250 L wooden barrels (traditional ageing) and in 50 L glass demijohns with wood staves and micro-oxygenation (alternative ageing). Sampling was performed after 21, 60, 180, 270, and 365 days of ageing. The elemental composition of the wine spirits, including alkaline, alkaline earth metals, and heavy metals, was assessed by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS). For most of the elements, no significant differences between wine spirits from distinct ageing modalities were observed. Ageing time had significant effect on most of them, with different trends and distinct magnitude of changes, depending on each specific element. The concentrations of the mineral elements found in the wine spirits were very low, especially those of heavy metals, which is quite positive in terms of quality and food safety. Novel information on metals released from chestnut wood to wine spirits confirms its appropriateness for ageing this beverage.

Hybrid Silver(I)-Doped Soybean Oil and Potato Starch Biopolymer Films to Combat Bacterial Biofilms.

This study describes the preparation, characterization, and antimicrobial properties of novel hybrid biopolymer materials doped with bioactive silver(I) coordination polymers (bioCPs). Two new bioCPs, [Ag2(µ6-hfa)]n (1) and [Ag2(µ4-nda)(H2O)2]n (2), were assembled from Ag2O and homophthalic (H2hfa) or 2,6-naphthalenedicarboxylic (H2nda) acids as unexplored building blocks. Their structures feature 2D metal-organic and supramolecular networks with 3,6L64 or sql topology. Both compounds act as active antimicrobial agents for producing bioCP-doped biopolymer films based on epoxidized soybean oil acrylate (SBO) or potato starch (PS) as model biopolymer materials with a different rate of degradability and silver release. BioCPs and their hybrid biopolymer films (1@[SBO]n, 2@[SBO]n, 1@[PS]n, and 2@[PS]n) with a very low loading of coordination polymer (0.05-0.5 wt %) show remarkable antimicrobial activity against Staphylococcus aureus and Staphylococcus epidermidis (Gram-positive) and Escherichia coli and Pseudomonas aeruginosa (Gram-negative) bacteria. Biopolymer films also effectively impair the formation of bacterial biofilms, allowing total biofilm inhibition in several cases. By reporting on new bioCPs and biopolymer films obtained from renewable biofeedstocks (soybean oil and PS), this study blends highly important research directions and widens a limited antimicrobial application of bioCPs and derived functional materials. This research thus opens up the perspectives for designing hybrid biopolymer films with outstanding bioactivity against bacterial biofilms.

Identification of gallotannins and ellagitannins in aged wine spirits: A new perspective using alternative ageing technology and high-resolution mass spectrometry.

This research was focused on identifying gallotannins and ellagitannins degradation pathways to better understand their behavior in complex media such as wine spirits (WS). A WS was aged with chestnut wood staves with three levels of micro-oxygenation, nitrogen, and using wooden barrels. Gallotannins and ellagitannins were identified by LC-ESI-HRMS/MS using a Q-TOF in samples collected at 8, 21, 60, 180, 270, and 365 days of ageing, allowed comparing their relative abundances according to the ageing technology. It was established for the first time, the importance of oxygen in gallotannins and ellagitannins formation/degradation pathways in WS and shading light into the explanation for the steady increase of gallic and ellagic acid contents on WS during ageing. The results also highlighted the presence of penta-O-galloyl-ß-d-glucose, tetra-O-galloyl-ß-d-glucose, tri-O-galloyl-ß-d-glucose, di-O-galloyl-ß-d-glucose, and mono-O-galloyl-ß-d-glucose, 2,3-(S)-hexahydroxydiphenoyl-ß-d-glucose, pedunculagin, isomers vescalagin/castalagin and two products stemming from ethanol-promoted oxidation of castalagin/vescalagin and vescalin/castalin, in the composition WS aged with chestnut wood.

Time-Dependent Self-Assembly of Copper(II) Coordination Polymers and Tetranuclear Rings: Catalysts for Oxidative Functionalization of Saturated Hydrocarbons.

This study describes a time-dependent self-assembly generation of new copper(II) coordination compounds from an aqueous-medium reaction mixture composed of copper(II) nitrate, H3bes biobuffer (N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid), ammonium hydroxide, and benzenecarboxylic acid, namely, 4-methoxybenzoic (Hfmba) or 4-chlorobenzoic (Hfcba) acid. Two products were isolated from each reaction, namely, 1D coordination polymers [Cu3(µ3-OH)2(µ-fmba)2(fmba)2(H2O)2]n (1) or [Cu2(µ-OH)2(µ-fcba)2]n (2) and discrete tetracopper(II) rings [Cu4(µ-Hbes)3(µ-H2bes)(µ-fmba)]·2H2O (3) or [Cu4(µ-Hbes)3(µ-H2bes)(µ-fcba)]·4H2O (4), respectively. These four compounds were obtained as microcrystalline air-stable solids and characterized by standard methods, including the single-crystal X-ray diffraction. The structures of 1 and 2 feature distinct types of metal-organic chains driven by the µ3- or µ-OH- ligands along with the µ-benzenecarboxylate linkers. The structures of 3 and 4 disclose the chairlike Cu4 rings assembled from four µ-bridging and chelating aminoalcoholate ligands along with µ-benzenecarboxylate moieties playing a core-stabilizing role. Catalytic activity of 1-4 was investigated in two model reactions, namely, (a) the mild oxidation of saturated hydrocarbons with hydrogen peroxide to form alcohols and ketones and (b) the mild carboxylation of alkanes with carbon monoxide, water, and peroxodisulfate to generate carboxylic acids. Cyclohexane and propane were used as model cyclic and gaseous alkanes, while the substrate scope also included cyclopentane, cycloheptane, and cyclooctane. Different reaction parameters were investigated, including an effect of the acid cocatalyst and various selectivity parameters. The obtained total product yields (up to 34% based on C3H8 or up to 47% based on C6H12) in the carboxylation of propane and cyclohexane are remarkable taking into account an inertness of these saturated hydrocarbons and low reaction temperatures (50-60 °C). Apart from notable catalytic activity, this study showcases a novel time-dependent synthetic strategy for the self-assembly of two different Cu(II) compounds from the same reaction mixture.

Silver(I) Coordination Polymers Immobilized into Biopolymer Films for Antimicrobial Applications.

This study describes a template-mediated self-assembly synthesis, full characterization, and structural features of two new silver-based bioactive coordination polymers (CPs) and their immobilization into acrylated epoxidized soybean oil (ESOA) biopolymer films for antimicrobial applications. The 3D silver(I) CPs [Ag4(µ8-H2pma)2]n·4nH2O (1) and [Ag5(µ6-H0.5tma)2(H2O)4]n·2nH2O (2) were generated from AgNO3 and pyromellitic (H4pma) or trimesic (H3tma) acid, also using N,N'-dimethylethanolamine (Hdmea) as a template. Both 1 and 2 feature the intricate 3D layer-pillared structures driven by distinct polycarboxylate blocks. Topological analysis revealed binodal nets with the flu and tcj/hc topology in 1 and 2, respectively. These CPs were used for fabricating new hybrid materials, namely, by doping the [ESOA]n biopolymer films with very low amounts of 1 and 2 (0.05, 0.1, and 0.5%). Their antimicrobial activity and ability to impair bacterial biofilm formation were investigated in detail against both Gram-positive (Staphylococcus epidermidis and Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria. Both silver(I) CPs and derived biopolymer films showed activity against all the tested bacteria in a concentration-dependent manner. Compound 1 exhibited a more pronounced activity, especially in preventing biofilm growth, with mean bacterial load reductions ranging from 3.7 to 4.3 log against the four bacteria (99.99% bacterial eradication). The present work thus opens up antibiofilm applications of CP-doped biopolymers, providing new perspectives and very promising results for the design of functional biomaterials.

Photocatalytic degradation of acetaminophen and caffeine using magnetite-hematite combined nanoparticles: kinetics and mechanisms.

The increased use of pharmaceutical and personal care products (PPCPs) has contributed to the contamination of water systems and put pressure on the development of new techniques to deal with this problem. Acetaminophen (paracetamol), a common analgesic and antipyretic drug, and caffeine, a known central nervous system stimulant, are being used frequently by many people and found in large amounts in wastewater systems. In this work, their removal, by photocatalytic degradation, was promoted using magnetic nanoparticles (NPs) based on iron oxides. Besides being obtained from cheap and plentiful source, the magnetic properties of these NPs provide an easy way to separate them from the solution when the reaction is complete. Three types of hematite-based NPs, one pure (1) and two of them composed by a magnetite core partially (2) or completely (3) covered by a hematite shell, were synthesized and characterized. Sample 2 was the best photocatalyst for both pollutants' photo-assisted degradation. Under UV-vis irradiation and using a 0.13 g catalyst/L solution, the total acetaminophen and caffeine degradation (20 ppm/150 mL) was achieved in 45 min and 60 min, respectively. The identification of some of the intermediate products was carried out by liquid chromatography in combination with electrospray ionization mass spectrometry. A complementary Density Functional Theory (DFT) study revealed the relative stability of several species formed during the acetaminophen and caffeine degradation processes and gave some insight about the most favorable degradation pathways.

Influence of the Storage in Bottle on the Antioxidant Activities and Related Chemical Characteristics of Wine Spirits Aged with Chestnut Staves and Micro-Oxygenation.

Different ageing technology of wine spirits (WSs) has been investigated, but little has been published on the chemical evolution of aged WS during storage in bottle. The purpose of this study was to examine how 12 months of storage in bottle affected the evolution of antioxidant activity (DPPH, FRAP and ABTS assays), total phenolic index (TPI) and low molecular weight (LMW) compounds content of the WSs aged through alternative technology using three micro-oxygenation levels (MOX) and nitrogen control (N). Results revealed the ability of phenolic compounds from aged WSs to scavenge free radicals during storage in bottle. Among the in vitro antioxidant-activity methods, FRAP assay was the more effective to differentiate WSs according to the ageing technology. Concerning the overall influence of storage in bottle on antioxidant activity, and TPI and LMW compounds content, the higher results were obtained for the MOX modalities (O15, O30 and O60), which showed a similar evolution. In summary, this study provides innovative information, demonstrating that the differences between the aged WSs imparted throughout the ageing process (resulting from different MOX levels) were mostly retained, and only slight modifications during storage in bottle were found.

PLS-R Calibration Models for Wine Spirit Volatile Phenols Prediction by Near-Infrared Spectroscopy.

Near-infrared spectroscopic (NIR) technique was used, for the first time, to predict volatile phenols content, namely guaiacol, 4-methyl-guaiacol, eugenol, syringol, 4-methyl-syringol and 4-allyl-syringol, of aged wine spirits (AWS). This study aimed to develop calibration models for the volatile phenol's quantification in AWS, by NIR, faster and without sample preparation. Partial least square regression (PLS-R) models were developed with NIR spectra in the near-IR region (12,500-4000 cm-1) and those obtained from GC-FID quantification after liquid-liquid extraction. In the PLS-R developed method, cross-validation with 50% of the samples along a validation test set with 50% of the remaining samples. The final calibration was performed with 100% of the data. PLS-R models with a good accuracy were obtained for guaiacol (r2 = 96.34; RPD = 5.23), 4-methyl-guaiacol (r2 = 96.1; RPD = 5.07), eugenol (r2 = 96.06; RPD = 5.04), syringol (r2 = 97.32; RPD = 6.11), 4-methyl-syringol (r2 = 95.79; RPD = 4.88) and 4-allyl-syringol (r2 = 95.97; RPD = 4.98). These results reveal that NIR is a valuable technique for the quality control of wine spirits and to predict the volatile phenols content, which contributes to the sensory quality of the spirit beverages.

Behaviour of Low Molecular Weight Compounds, Iron and Copper of Wine Spirit Aged with Chestnut Staves under Different Levels of Micro-Oxygenation.

Alternative technologies for a more sustainable wine spirits' ageing have been studied but a lack of knowledge on the effect of oxygenation level remains. This work examined the behaviour of low molecular weight compounds, iron and copper of a wine spirit aged in 50 L demijohns with chestnut wood staves combined with three levels of micro-oxygenation or nitrogen. Compounds and mineral elements were quantified by HPLC and FAAS, respectively, in samples collected at 8, 21, 60, 180, 270 and 365 days of ageing. Results showed that most of the compounds underwent significant changes in their content over time and behave differently depending on the wine spirit's oxygenation level: higher contents of gallic acid, syringic acid and vanillin were associated with lower micro-oxygenation level while higher contents of ellagic acid, syringaldehyde, coniferaldehyde and sinapaldehyde resulted from higher one; lowest contents of these compounds were found in the nitrogen modality. Weak correlation between copper and the studied compounds was evidenced whereas closer relationship between iron, vanillin, gallic, syringic and ellagic acids at end of ageing was observed. This study provides innovative information on the role of oxygen in wine spirit's ageing, and on chestnut wood effect on wine spirit's mineral composition.

Age and calving time affects production efficiency of beef cows and their calves.

The aim of this study was to evaluate the influence of two sub-periods of the calving season and two cow maturity stages on the efficiency of beef cows and their calves. A total of 159 cow-calf pairs were divided by calving time (early or late) within the calving season and maturity stage (young or adult). Calves were weaned at 42 or 63 days after birth and evaluated until 210 days of age. Cows and calves had their development examined based on their weight and body condition score at calving, at weaning, and at 210 days. Reproductive performance was evaluated on the basis of time to become pregnant again. Milk yield was assessed by the direct method on three occasions spaced 21 days apart. Adult cows were heavier than young cows, at calving (398.5 vs 327.5 kg, respectively), weaning (397.3 vs 324.1 kg, respectively) at the end breeding season (424.1 vs 342.1 kg, respectively). Reproductive performance was influenced by calving time. Adult cows had higher pregnancy rates (83.75 and 69.17%, for early and for late calving, respectively) than young cows (57.03 and 35.01% for early and for late-calving, respectively). Calves from early-calving young cows weighed 158.8 kg at 210 days of age vs. 123.7 kg for those born from late-calving adult cows. However, late-calving cows produced 10.7% more milk than those that calved early in the season (227.0 vs 205.0 liters, respectively). Early calving associated with non-requirement of growth determine higher productivity efficiency in beef cows.

Phosphonate Decomposition-Induced Polyoxomolybdate Dumbbell-Type Cluster Formation: Structural Analysis, Proton Conduction, and Catalytic Sulfoxide Reduction.

The reaction of MoO42- with a number of phosphonic acids [bis(phosphonomethyl)glycine, R,S-hydroxyphosphonoacetic acid, 1-hydroxyethane-1,1-diphosphonic acid, phenylphosphonic acid, aminotris(methylene phosphonic acid), and 1,2-ethylenediphosphonic acid] under oxidizing (H2O2) hydrothermal conditions at low pH leads to rupture of the P-C bond, release of orthophosphate ions, and generation of the octanuclear, phosphate-bridged, polyoxometalate molybdenum cluster (NH4)5[Mo8(OH)2O24(µ8-PO4)](H2O)2 (POMPhos). This cluster has been fully characterized and its structure determined. It was studied as a proton conductor, giving moderate values of σ = 2.13 × 10-5 S·cm-1 (25 °C) and 1.17 × 10-4 S·cm-1 (80 °C) at 95% relative humidity, with Ea = 0.27 eV. The POMPhos cluster was then thermally treated at 310 °C, yielding (NH4)2.6(H3O)0.4(PO4Mo12O36) together with an amorphous impurity containing phosphate and molybdenum oxide. This product was also studied for its proton conductivity properties, giving rise to an impressively high value of σ = 2.43 × 10-3 S·cm-1 (25 °C) and 6.67 × 10-3 S·cm-1 (80 °C) at 95% relative humidity, 2 orders of magnitude higher than those corresponding to the "as-synthesized" solid. The utilization of POMPhos in catalytic reduction of different sulfoxides was also evaluated. POMPhos acts as an efficient homogeneous catalyst for the reduction of diphenyl sulfoxide to diphenyl sulfide, as a model reaction. Pinacol was used as a low-cost, environmentally friendly, and highly efficient reducing agent. The effects of different reaction parameters were investigated, namely the type of solvent and reducing agent, presence of acid promoter, reaction time and temperature, loading of catalyst and pinacol, allowing to achieve up to 84-99% yields of sulfide products under optimized conditions. Substrate scope was tested on the examples of diaryl, alkylaryl, dibenzyl, and dialkyl sulfoxides and excellent product yields were obtained.

Mild C-H functionalization of alkanes catalyzed by bioinspired copper(ii) cores.

Three new copper(ii) coordination compounds formulated as [Cu(H1.5bdea)2](hba)·2H2O (1), [Cu2(µ-Hbdea)2(aca)2]·4H2O (2), and [Cu2(µ-Hbdea)2(µ-bdca)]n (3) were generated by aqueous medium self-assembly synthesis from Cu(NO3)2, N-butyldiethanolamine (H2bdea) as a main N,O-chelating building block and different carboxylic acids [4-hydroxybenzoic (Hhba), 9-anthracenecarboxylic (Haca), or 4,4'-biphenyldicarboxylic (H2bdca) acid] as supporting carboxylate ligands. The structures of products range from discrete mono- (1) or dicopper(ii) (2) cores to a 1D coordination polymer (3), and widen a family of copper(ii) coordination compounds derived from H2bdea. The obtained compounds were applied as bioinspired homogeneous catalysts for the mild C-H functionalization of saturated hydrocarbons (cyclic and linear C5-C8 alkanes). Two model catalytic reactions were explored, namely the oxidation of hydrocarbons with H2O2 to a mixture of alcohols and ketones, and the carboxylation of alkanes with CO/S2O82- to carboxylic acids. Both processes proceed under mild conditions with a high efficiency and the effects of different parameters (e.g., reaction time and presence of acid promoter, amount of catalyst and solvent composition, substrate scope and selectivity features) were studied and discussed in detail. In particular, an interesting promoting effect of water was unveiled in the oxidation of cyclohexane that is especially remarkable in the reaction catalyzed by 3, thus allowing a potential use of diluted, in situ generated solutions of hydrogen peroxide. Moreover, the obtained values of product yields (up to 41% based on alkane substrate) are very high when dealing with the C-H functionalization of saturated hydrocarbons and the mild conditions of these catalytic reactions (50-60 °C, H2O/CH3CN medium). This study thus contributes to an important field of alkane functionalization and provides a notable example of new Cu-based catalytic systems that can be easily generated by self-assembly from simple and low-cost chemicals.

New Copper(II) Coordination Compounds Assembled from Multifunctional Pyridine-Carboxylate Blocks: Synthesis, Structures, and Catalytic Activity in Cycloalkane Oxidation.

Two new copper(II) coordination compounds, namely a 1D coordination polymer [Cu(µ-cpna)(phen)(H2O)]n (1) and a discrete tetracopper(II) derivative [Cu(phen)2(H2O)]2[Cu2(µ-Hdppa)2(Hdppa)2] (2), were hydrothermally synthesized from copper(II) chloride as a metal source, 5-(4-carboxyphenoxy)nicotinic acid (H2cpna) or 5-(3,4-dicarboxylphenyl)picolinic acid (H3dppa) as a principal building block, and 1,10-phenanthroline (phen) as a crystallization mediator. Compounds 1 and 2 were isolated as air-stable microcrystalline solids and fully characterized by elemental and thermogravimetric analyses, IR spectroscopy, powder and single-crystal X-ray diffraction. In the solid state, the structure of 1 discloses the linear interdigitated 1D coordination polymer chains with the 2C1 topology. The crystal structure of an ionic derivative 2 shows that the mono- and dicopper(II) units are extended into the intricate 1D hydrogen-bonded chains with the SP 1-periodic net (4,4)(0,2) topology. Thermal stability and catalytic properties of 1 and 2 were also investigated. In fact, both Cu derivatives act as efficient homogeneous catalysts (catalyst precursors) for the mild oxidation of cycloalkanes by hydrogen peroxide to give the corresponding alcohols and ketones; the substrate scope and the effects of type and amount of acid promoter as well as bond-, regio-, and stereo-selectivity features were investigated.

Interplay between H-bonding and interpenetration in an aqueous copper(ii)-aminoalcohol-pyromellitic acid system: self-assembly synthesis, structural features and catalysis.

Two new copper(ii) coordination compounds, [Cu(H1.5mdea)2]2(H2pma) (1a) and [{Cu2(µ-Hmdea)2}2(µ4-pma)]n·2nH2O (1b), were self-assembled at different temperatures from the same multicomponent reaction system, comprising copper(ii) nitrate, N-methyldiethanolamine (H2mdea), pyromellitic acid (H4pma), and potassium hydroxide. Products 1a and 1b were isolated as microcrystalline solids and fully characterized and their structures were established by single-crystal X-ray diffraction. Compound 1a features the bis-aminoalcohol(ate) monocopper(ii) units and H2pma2- anions that are multiply interconnected by strong H-bonds into a firm 2D H-bonded layer. Compound 1b reveals the bis-aminoalcoholate dicopper(ii) motifs that are interlinked by the µ4-pma4- spacers into a 3D + 3D interpenetrated metal-organic framework. From a topological perspective, both networks of 1a and 1b are uninodal and driven by similar 4-connected H2pma2- or pma4- nodes, but result in distinct sql and dia topologies, respectively. Compound 1a was applied as an efficient catalyst for two model cycloalkane functionalization reactions: (1) oxidation by H2O2 to form cyclic alcohols and ketones and (2) hydrocarboxylation by CO/H2O and S2O82- to form cycloalkanecarboxylic acids. The substrate scope, effects of various reaction parameters, selectivity and mechanistic features were also investigated.

Copper(II) Coordination Polymers Self-Assembled from Aminoalcohols and Pyromellitic Acid: Highly Active Precatalysts for the Mild Water-Promoted Oxidation of Alkanes.

Three novel water-soluble 2D copper(II) coordination polymers-[{Cu2(µ2-dmea)2(H2O)}2(µ4-pma)]n·4nH2O (1), [{Cu2(µ2-Hedea)2}2(µ4-pma)]n·4nH2O (2), and [{Cu(bea)(Hbea)}4(µ4-pma)]n·2nH2O (3)-were generated by an aqueous medium self-assembly method from copper(II) nitrate, pyromellitic acid (H4pma), and different aminoalcohols [N,N-dimethylethanolamine (Hdmea), N-ethyldiethanolamine (H2edea), and N-benzylethanolamine (Hbea)]. Compounds 2 and 3 represent the first coordination polymers derived from H2edea and Hbea. All the products were characterized by infrared (IR), electron paramagnetic resonance (EPR), and ultraviolet-visible light (UV-vis) spectroscopy, electrospray ionization-mass spectroscopy (ESI-MS(±)), thermogravimetric and elemental analysis, and single-crystal X-ray diffraction (XRD), which revealed that their two-dimensional (2D) metal-organic networks are composed of distinct dicopper(II) or monocopper(II) aminoalcoholate units and µ4-pyromellitate spacers. From the topological viewpoint, the underlying 2D nets of 1-3 can be classified as uninodal 4-connected layers with the sql topology. The structures of 1 and 2 are further extended by multiple intermolecular hydrogen bonds, resulting in three-dimensional (3D) hydrogen-bonded networks with rare or unique topologies. The obtained compounds also act as highly efficient precatalysts for the mild homogeneous oxidation, by aqueous H2O2 in acidic MeCN/H2O medium, of various cycloalkanes to the corresponding alcohols and ketones. Overall product yields up to 45% (based on cycloalkane) were attained and the effects of various reaction parameters were investigated, including the type of precatalyst and acid promoter, influence of water, and substrate scope. Although water usually strongly inhibits the alkane oxidations, a very pronounced promoting behavior of H2O was detected when using the precatalyst 1, resulting in a 15-fold growth of an initial reaction rate in the cyclohexane oxidation on increasing the amount of H2O from ∼4 M to 17 M in the reaction mixture, followed by a 2-fold product yield growth.

Synthesis of phosphinoferrocene amides and thioamides from carbamoyl chlorides and the structural chemistry of Group 11 metal complexes with these mixed-donor ligands.

The reaction of in situ generated 1'-(diphenylphosphino)-1-lithioferrocene with carbamoyl chlorides, ClC(E)NMe2, affords the corresponding (thio)amides, Ph2PfcC(E)NMe2 (E = O (), S (); fc = ferrocene-1,1'-diyl). These compounds as well as their analogues, Ph2PfcC(O)NHMe () and Ph2PfcC(O)NH2 (), prepared from 1'-(diphenylphosphino)ferrocene-1-carboxylic acid (Hdpf) were studied as ligands for the Group 11 metal ions. In the reactions with [Cu(MeCN)4][BF4], the amides give rise to bis-chelate complexes of the type [Cu(L-κ(2)O,P)2][BF4]. Similar products, [Ag(L-κ(2)O,P)2]ClO4, are obtained from silver(i) perchlorate and , or . In contrast, the reaction of AgClO4 with produces a unique molecular dimer [Ag()(ClO4-κO)]2, where the metal centres are bridged by the sulfur atoms of the P,S-chelating thioamides. The reactions of with [AuCl(tht)] (tht = tetrahydrothiophene) afford the expected gold(i)-phosphine complexes, [AuCl(L-κP)], containing uncoordinated (thio)amide moieties. Hemilabile coordination of the phosphinoamide ligands in complexes with the soft Group 11 metal ions is established by the crystal structure of a solvento complex, [Cu(-κ(2)O,P)(-κP)(CHCl3-κCl)][BF4], which was isolated serendipitously during an attempted crystallisation of [Cu(-κ(2)O,P)2][BF4]. All of the compounds are characterised by spectroscopic methods, and the structures of several representatives of both the free phosphinoamides and their complexes are determined by X-ray diffraction analysis and further studied by DFT calculations and cyclic voltammetry.

Evolution of phenolic composition of red wine during vinification and storage and its contribution to wine sensory properties and antioxidant activity.

The objective of this work was to study the evolution of the phenolic composition of red wine during vinification and storage and its relationship with some sensory properties (astringency and bitterness) and antioxidant activities. Thus, red wine was made by a classic vinification method with Castelão and Tinta Miúda grapes (Vitis vinifera L.) harvested at maturity (3:2; w/w). Samples were taken at 2 and 7 days of maceration, at second racking, at the time of bottling and at 6 and 14 months after bottling. The total polyphenols extract (TPx) in each sample was isolated by column chromatography. The phenolic composition (anthocyanins and proanthocyanidins), in vitro antioxidant activity, and sensory property (astringency, bitterness) of the isolated TPx from different winemaking stages were evaluated through high-performance liquid chromatography-diode array detection, 1,1-diphenyl-2-picrylhidrazyl radical test, ferric reducing antioxidant power assay, total phenolic index, MWI (polyphenol molecular weight index), TSA (tannin specific activity), and sensory panel tasting. The results showed that the phenolic composition of red wine varied significantly during winemaking. The intensity of astringency (IA) and the intensity bitterness (IB) of the isolated TPx from different winemaking stages increased from 2 days of maceration until second racking and then decreased. Furthermore, MWI and TSA are positively correlated with IA and IB. The in vitro antioxidant activity of the isolated TPx from different winemaking stages maintained unchanged after alcoholic fermentation, which was independent of the variation of phenolic composition and sensory properties.

Pathway from chain to dimer in Cu(I) camphor hydrazone complexes.

The chemical reactivity, molecular structure, and surface characteristics of Cu(I) camphor hydrazone compounds indicate that exist a structural pathway for conversion of coordination polymers into dimers and vice versa. By X-ray diffraction analysis two polymorphic forms of the chain compound [{CuCl}(2)(Me(2)NNC(10)H(14)O)](n) were identified that essentially differ in the structural arrangement and geometry of the non-linear copper atom. The characterization of the dimer complexes [{Cu(Me(2)NNC(10)H(14)O)}(2)(µ-X)(2)] (X = Cl or Br) was also achieved by X-ray diffraction analysis showing the unusual arrangement of the camphor hydrazone ligands that occupy the same side of the molecule. Bond lengths and torsion angles show that one of the polymorphic forms is structurally close to the related dimer. The surface composition of the coordination polymers [{CuX}(2)(YNC(10)H(14)O)](n) (X = Cl, Y = NMe(2), NH(2); X = Br, Y = NH(2)) and dimers [{Cu(Me(2)NNC(10)H(14)O)}(2)(µ-X)(2)] (X = Cl or Br) studied by X-ray Photoelectron Spectroscopy corroborate the molecular properties and the reactivity trend.

A new class of anthocyanin-procyanidin condensation products detected in red wine by electrospray ionization multi-stage mass spectrometry analysis.

In our previous work, we have identified, in a model wine solution containing malvidin 3-glucoside, epicatechin and acetaldehyde, a new condensation product--hydroxylethyl-malvidin-3-glucoside-ethyl-epicatechin. The objective of this work was to verify the presence of such new condensation products in red wine. For this purpose, red wine was fractionated into various fractions by column chromatography on LiChroprep RP 18 and on Toyopearl 40 (F). The phenolic composition of each fraction was verified by HPLC-DAD and direct-infusion ESI-MS(n) analysis. In addition to the well-known anthocyanins and their acetyl and coumaroyl derivatives, and several direct and indirect anthocyanin-(epi)catechin condensation products, a new class of pigmented products, namely hydroxyethyl-anthocyanin-ethyl-flavanol compounds, have been detected in red wine. The new class of pigmented products would be expected to be the major pigments responsible for the color of aged red wine.