Convert Harm into Benefit: The Role of the AlCaFe Phase in Al-Ca Wrought Aluminum Alloys Having High Compatibility with Fe.

The compatibility of the wrought Al-Ca alloy with the element Fe was investigated in the present study. In this work, both the Al-Ca alloy and Al-Ca-Fe alloy were synthesized through melting, casting, heat treatment, and rolling. A new ternary Al-Ca-Fe eutectic phase, identified as AlCaFe with an orthorhombic structure, demonstrated enhanced performance, as revealed by nanoindentation tests.

Effect of Chain Structure on the Various Properties of the Copolymers of Fluorinated Norbornenes with Cyclooctene.

Fluorinated polymers are attractive due to their special thermal, surface, gas separation, and other properties. In this study, new diblock, multiblock, and random copolymers of cyclooctene with two fluorinated norbornenes, 5-perfluorobutyl-2-norbornene and N-pentafluorophenyl-exo-endo-norbornene-5,6-dicarboximide, are synthesized by ring-opening metathesis copolymerization and macromolecular cross-metathesis in the presence of the first- to third-generation Grubbs' Ru-catalysts. Their thermal, surface, bulk, and solution characteristics are investigated and compared using differential scanning calorimetry, water contact angle measurements, gas permeation, and light scattering, respectively.

Surface and Structural Characterization of PVTMS Films Treated by Elemental Fluorine in Liquid Perfluorodecalin.

Poly(vinyl trimethylsilane) (PVTMS) films were subjected to direct surface fluorination in liquid medium (perfluorodecalin). The samples were investigated using several techniques: SEM-XEDS, XPS, ATR-IR, and contact angle measurement. The methods used allowed us to estimate chemical changes occurring because of the treatment.

Effect of Radial-Shear Rolling on the Structure and Hardening of an Al-8%Zn-3.3%Mg-0.8%Ca-1.1%Fe Alloy Manufactured by Electromagnetic Casting.

Aluminum alloys are one of the most common structural materials. To improve the mechanical properties, an alloy of the Al-Zn-Mg-Ca-Fe system was proposed. In this alloy, when Fe and Ca are added, compact particles of the AlCaFe compound are formed, which significantly reduces the negative effect of Fe on the mechanical properties.

Hydrophobic-Hydrophilic Properties and Characterization of PIM-1 Films Treated by Elemental Fluorine in Liquid Perfluorodecalin.

A direct fluorination technique was applied for the surface treatment of PIM-1 films in a liquid phase (perfluorodecalin). The fluorinated samples were analyzed by various instrumental techniques. ATR-IR spectroscopy showed that the fluorination predominantly takes place in methylene- and methyl-groups.

The Physicochemical Characterization of New "Green" Epoxy-Resin Hardener Made from PET Waste.

"Green" thermally stable hardener was synthesized from a PET waste. The rigid molecular linear structure of the new hardener suggests that it will provide the polymer matrix with the necessary physical and mechanical characteristics. It also allows the expectation that cured matrix based on this hardener can provide increased toughness.

Difluoromethylenation of fullerene C provides isomeric diversity and availability of equatorial [5,6]-homofullerene C(CF).

We report synthesis, isolation, and spectroscopic characterization of the novel [5,6]-open C(CF) isomer III along with the already known [6,6]-closed and [6,6]-open C(CF) isomers I and II. The compounds were obtained in a ratio of I : II : III = 4 : 6 : 1 by means of thermal treatment of C fullerene with sodium chlorodifluoroacetate. This product composition is explained with the use of quantum chemical calculations that identify the reaction pathway as a two-stage nucleophilic cyclopropanation rather than the previously postulated carbene addition.

Olefin-Metathesis-Derived Norbornene-Ethylene-Vinyl Acetate/Vinyl Alcohol Multiblock Copolymers: Impact of the Copolymer Structure on the Gas Permeation Properties.

Commercial metathesis polynorbornene is used for the fabrication of high-damping coatings and bulk materials that dissipate vibration and impact energies. Functionalization of this non-polar polymer can improve its adhesive, gas barrier, and other properties, thereby potentially expanding its application area. With this aim, the post-modification of polynorbornene was carried out by inserting ethylene-vinyl acetate-vinyl alcohol blocks into its backbone via the cross-metathesis of polynorbornene with poly(5-acetoxy-1-octenylene) and subsequent deacetylation and hydrogenation of the obtained multiblock copolymers.

Features of the Gas-Permeable Crystalline Phase of Poly-2,6-dimethylphenylene Oxide.

Poly-2,6-dimethylphenylene oxide (PPO) film samples with varying degrees of crystallinity (from 0 to 69%) were obtained by means of different techniques. The films were studied by various physicochemical methods (Fourier-transform infrared spectroscopy, positron annihilation lifetime spectroscopy, X-ray diffraction, and H nuclear magnetic resonance relaxation). Solubility coefficients of gases in the PPO samples were measured via sorption isotherms of gases by volumetric technique with chromatographic detection.

Changes in Antioxidative Compounds and Enzymes in Small-Leaved Linden ( Mill.) in Response to Mistletoe ( L.) Infestation.

Mistletoe infestation leads to a decrease in the growth of woody plants, their longevity, and partial or complete drying of the top, as well as premature death. Various environmental stress factors, both abiotic and biotic, stimulate the formation of reactive oxygen species and the development of oxidative stress in plant tissues. This study aimed to investigate the effect of mistletoe ( L.

Effect of Direct Fluorination on the Transport Properties and Swelling of Polymeric Materials: A Review.

Fluorine-containing polymers occupy a peculiar niche among conventional polymers due to the unique combination of physicochemical properties. Direct surface fluorination of the polymeric materials is one of the approaches for the introduction of fluorine into the chemical structure that allows one to implement advantages of fluorinated polymers in a thin layer. Current review considers the influence of the surface interaction of the polymeric materials and membranes with elemental fluorine on gas, vapor and liquid transport as well as swelling and related phenomena.

Structure-Property Relationship on the Example of Gas Separation Characteristics of Poly(Arylene Ether Ketone)s and Poly(Diphenylene Phtalide).

Three poly(arylene ether ketone)s (PAEKs) with propylidene (C1, C2) and phtalide (C3) fragments, and one phtalide-containing polyarylene (C4), were synthesized. Their chemical structures were confirmed via H NMR, C NMR and F NMR spectroscopy. The polymers have shown a high glass transition temperature (>155 °C), excellent film-forming properties, and a high free volume for this polymer type.

Electrochemically Induced Dimerization of -C(CF) Trifluoromethylated Fullerene.

We report a comprehensive study of a novel isomer of C(CF), -C(CF), whose electrochemical behavior differs from most of the other trifluoromethylated fullerenes. The addition pattern of -C(CF) is established by means of F-F COSY NMR spectroscopy and DFT calculations. Like -C(CF), the new isomer -C(CF) undergoes dimerization to the [C(CF)] upon single-electron reduction.

Stereochemistries and Biological Properties of Oligomycin A Diels-Alder Adducts.

Oligomycin A is a potent antibiotic and antitumor agent. However, its applications are restricted by its high toxicity and low bioavailability. In this study, we obtained Oligomycin A Diels-Alder adducts with benzoquinone and -benzylmaleimide and determined their absolute configurations by combining H and ROESY NMR data with molecular mechanics conformational analysis and quantum chemical reaction modeling.

Mindfulness related changes in grey matter: a systematic review and meta-analysis.

Knowing target regions undergoing strfuncti changes caused by behavioural interventions is paramount in evaluating the effectiveness of such practices. Here, using a systematic review approach, we identified 25 peer-reviewed magnetic resonance imaging (MRI) studies demonstrating grey matter changes related to mindfulness meditation. An activation likelihood estimation (ALE) analysis (n = 16) revealed the right anterior ventral insula as the only significant region with consistent effect across studies, whilst an additional functional connectivity analysis indicates that both left and right insulae, and the anterior cingulate gyrus with adjacent paracingulate gyri should also be considered in future studies.

Direct Fluorination as Method of Improvement of Operational Properties of Polymeric Materials.

Direct fluorination of polymers is a widely utilized technique for chemical modification. Such introduction of fluorine into the chemical structure of polymeric materials leads to laminates with highly fluorinated surface layer. The physicochemical properties of this layer are similar to those of perfluorinated polymers that differ by a unique combination of chemical resistance, weak adhesion, low cohesion, and permittivity, often barrier properties, etc.

Regioselective Mono- and Dialkylation of [6,6]-open C (CF ): Synthetic and Kinetic Aspects.

Alkylation of homofullerene [6,6]-C (CF ) dianion with the set of alkyl halides, RX, was established to demonstrate an effect of RX nature on the conversion, product composition, and regioselectivity. The respective C (CF )RH, C (CF )R and C (CF )R'R'' compounds were obtained in the reaction with sterically unhindered RX, isolated by HPLC and unequivocally characterized. The kinetic studies evidenced S 2 mechanism for both alkylation steps, yielding mono- and dialkylated C (CF ), respectively, and indicated the negative charge localization at the bridgehead carbon atoms as well as a steric hindrance of the CF moiety likely to be a key factors for the S 2 reaction mechanism and observed regioselectivity.

Ecological and Landscape Factors Affecting the Spread of European Mistletoe ( L.) in Urban Areas (A Case Study of the Kaliningrad City, Russia).

Green spaces are very important for an urban environment. Trees in cities develop under more stressful conditions and are, therefore, more susceptible to parasite including mistletoe infestation. The aim of this study was to investigate the ecological, microclimatic, and landscape factors causing the spread of European mistletoe ( L.

Tightly Bound Double-Caged [60]Fullerene Derivatives with Enhanced Solubility: Structural Features and Application in Solar Cells.

A series of novel highly soluble double-caged [60]fullerene derivatives were prepared by means of lithium-salt-assisted [2+3] cycloaddition. The bispheric molecules feature rigid linking of the fullerene spheres through a four-membered cycle and a pyrrolizidine bridge with an ester function CO R (R=n-decyl, n-octadecyl, benzyl, and n-butyl; compounds 1 a-d, respectively), as demonstrated by NMR spectroscopy and X-ray diffraction. Cyclic voltammetry studies revealed three closely overlapping pairs of reversible peaks owing to consecutive one-electron reductions of fullerene cages, as well as an irreversible oxidation peak attributed to abstraction of an electron from the nitrogen lone-electron pair.

Stepwise Regioselective Hydrogenation of cis-2-C (CF ) Homofullerene with [6,6]-Open/Closed Valence Tautomerism.

The homofullerene compound cis-2-C (CF ) , which has an unusual kind of open/closed valence tautomerism undergoes consecutive regioselective hydrogenation at bridgehead carbon atoms upon reduction with Zn/Cu couple in H O-toluene mixture. The tautomerism barrier in cis-2-C (CF ) is negligible in the neutral state, whereas negative charging both impedes tautomeric transformation and promotes regioselective addition of electrophilic species at the bridgehead carbon atoms. In light of this observation, two novel homofullerene derivatives, mixed [6,6]-open/closed C (CF ) H and [6,6]-open cis-2-C (CF ) H , were synthesized and their structures were unambiguously determined by means of single crystal X-ray crystallography and NMR spectroscopy.

Reductive Hydrogenation of Cs -C70 (CF3 )8 and C1 -C70 (CF3 )10.

CF3 -derivatized fullerenes prove once again to be promising scaffolds for regioselective fullerene functionalization: now with the smallest possible addends-hydrogen atoms. Hydrogenation of Cs -C70 (CF3 )8 and C1 -C70 (CF3 )10 by means of reduction with Zn/Cu couple in the presence of water proceeds regioselectively, yielding only one major isomer of C70 (CF3 )8 H2 and only two for C70 (CF3 )10 H2 , whose addition patterns are combined in the only abundant isomer of C70 (CF3 )10 H4 . The observed selectivity is governed by the electronic structure of trifluoromethylated substrates.

Orienting Effect of the Cage Addends: The Case of Nucleophilic Cyclopropanation of C2 -C70 (CF3 )8.

C2 -C70 (CF3 )8 was found to be a very promising substrate in the Bingel and the Bingel-Hirsch reactions combining perfect regioselectivity with much higher reactivity compared to its analogs. The reactions with diethyl malonate yield a single isomer of the monoadduct C70 (CF3 )8 [C(CO2 Et)2 ] and a single C2 -symmetrical bisadduct C70 (CF3 )8 [C(CO2 Et)2 ]2 . The Bingel-Hirsch variation is particularly interesting in that it additionally affords, in a similar regioselective manner, the unexpected alkylated derivatives C70 (CF3 )8 [CH(CO2 Et)2 ]H and C70 (CF3 )8 [C(CO2 Et)2 ][CH(CO2 Et)2 ]H.

Alkali-metal trichloroacetates for dichloromethylenation of fullerenes: nucleophilic addition-substitution route.

The first experimental evidence that fullerenes react with alkali-metal trichloroacetates through a nucleophilic addition-substitution route, yielding dichloromethylenefullerenes as the final products, is reported. The intermediates, C60 (CCl3 )(-) and C70 (CCl3 )(-) anions, have been isolated in their protonated forms as ortho-C60 (CCl3 )H, as well as three ortho and one para isomer of C70 (CCl3 )H. The structures were unambiguously determined by means of (1) H, (13) C, and (1) H-(13) C HMBC NMR spectroscopy along with UV/Vis spectroscopy.

Transalkylation of higher trifluoromethylated fullerenes with C70: a pathway to new addition patterns of C70(CF3)8.

We report three new isomers of C70(CF3)8, structurally related to p(7)mp-C70(CF3)10, that are inaccessible by direct trifluoromethylation, but can be easily identified among the products of the transalkylation of higher trifluoromethylfullerenes with C70. The reported compounds are characterized by UV/Vis, 1 D and 2 D COSY (19)F NMR spectroscopy, and DFT calculations. A rather unusual addition pattern is observed in p(6),i-C70(CF3)8 in which one addend is attached remotely from the others; polarization of the adjacent unsaturated bonds by the addend makes the molecule readily oxidizable.