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Molecular Magnetism of Lanthanides Complexes and Networks

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ISBN: 9783038429876 9783038429883 Year: Pages: VI, 110 Language: Englisch
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Biochemistry --- Biology --- Environmental Sciences
Added to DOAB on : 2018-08-20 16:50:33
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Over the last ten years a fresh air has been blowing in the field of molecular magnetism with the re-introduction of lanthanides ions as spin carriers in magnetic molecules. The strong magnetic moment and huge magnetic anisotropy of lanthanide ions has enabled significant breakthroughs in magnetic blocking temperature and related phenomena. The chemical versatility of these ions is also a strong asset as easy substitution among the lanthanides series enables isotropic, anisotropic or solid-solutions of magnetic molecules. Additionally, their outstanding luminescent properties are key features in rationalizing the single-molecule magnet (SMM) behavior and paving the way toward production of multifunctional materials. In this book, selected examples of research on molecular magnetism of lanthanides complexes and networks are presented illustrating the current dynamism of this research field.

Enzyme-Mediated Stereoselective Synthesis

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ISBN: 9783039219360 / 9783039219377 Year: Pages: 116 DOI: 10.3390/books978-3-03921-937-7 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General) --- Inorganic Chemistry
Added to DOAB on : 2020-01-07 09:08:26
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This book is a collection of studies focused on the exploitation of enzyme stereoselectivity for the synthesis of relevant chemicals, such as innovative materials, chiral building blocks, natural products, and flavor and fragrance compounds. Different catalytic approaches are reported. The first study describes a resolution-based process for the stereoselective synthesis of the enantiomeric forms of the flavor compound linaloyl oxide, whereas other enantiomeric enriched aroma compounds were obtained through a novel microbial approach based on solid-state fermentation. Two relevant works exploit the potential of the biocatalyzed reduction reactions. The first of these contributions describes the enantioselective synthesis of ?-nitroalcohols by enzyme-mediated reduction of ?-nitroketones, whereas a second contribution reports the preparation of chiral 1,4-diaryl-1,4-diols through ADH-catalyzed bioreduction of the corresponding diketones. Concerning enantioenriched alcohol derivatives, natural hydroxy fatty acids are prepared by means of the biocatalytic hydration reaction of natural fatty acids using the probiotic bacterium Lactobacillus rhamnosus as a whole-cell biocatalyst. Further studies describe the use of modified pullulan polysaccharide for lipase immobilization and the recent advances in synthetic applications of ?-transaminases for the production of chiral amines.

Enzymes and Their Biotechnological Applications

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ISBN: 9783038421481 9783038421474 Year: Pages: 468 DOI: 10.3390/books978-3-03842-147-4 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Added to DOAB on : 2016-05-12 12:11:22
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Catalyzed Synthesis of Natural Products

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ISBN: 9783039219483 / 9783039219490 Year: Pages: 82 DOI: 10.3390/books978-3-03921-949-0 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General) --- Organic Chemistry
Added to DOAB on : 2020-01-07 09:08:26
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Natural products have been a source of inspiration for chemists and chemical biologists for many years, and have a special relevance in the chemical space. In recent years, several novel synthetic strategies have appeared, such as diversity-oriented synthesis (DOS), biological-oriented synthesis (BiOS), and function-oriented synthesis (FOS), for accessing complex and functionally diverse molecules. In this manner, the synthesis of natural products has evolved towards simpler and ecological methods using biotransformation, combinatorial chemistry, or organocatalysts. In this issue, Prof. Chojnacka shows demonstrates the use of immobilized lipases as catalysts to aid in the synthesis of phosphatidylcholine enriched with myristic acid. Profs. Vila and Pedro used catalysts derived from (S)-mandelic acid to achieve the catalytic enantioselective addition of dimethylzinc to isatins. Prof. Diez shows the possibility of the obtention of 7,8-carvone epoxides in a diastereoselective manner using proline, quinidine, and diphenylprolinol as organocatalysts. A cheap, simple, clean, and scalable method involves the use of deep eutectic mixtures as reaction media, and Profs. Alonso and Guillena describe the use of this methodology for the enantioselective, organocatalyzed ?-amination of 1,3-dicarbonyl compounds. Biotransformations have been one of the methodologies for more efficient synthesis of natural products. Prof. Wu transforms ergostane triterpenoid antcin K using Psychrobacillus sp. Ak 187. Finally, Prof. Kovayashi reviews the total synthesis and biological evaluation of phaeosphaerides. The reader, through this issue, could gain an idea of the new directions that the synthesis of natural products using catalysts will have in the years to come.

Possible Scenarios for Homochirality on Earth

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ISBN: 9783039217229 / 9783039217236 Year: Pages: 318 DOI: 10.3390/books978-3-03921-723-6 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General)
Added to DOAB on : 2019-12-09 11:49:16
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In 1978, Fred Hoyle proposed that interstellar comets carrying several viruses landed on Earth as part of the panspermia hypotheses. With respect to life, the origin of homochirality on Earth has been the greatest mystery because life cannot exist without molecular asymmetry. Many scientists have proposed several possible hypotheses to answer this long-standing L-D question. Previously, Martin Gardner raised the question about mirror symmetry and broken mirror symmetry in terms of the homochirality question in his monographs (1964 and 1990). Possible scenarios for the L-D issue can be categorized into (i) Earth and exoterrestrial origins, (ii) by-chance and necessity mechanisms, and (iii) mirror-symmetrical and non-mirror-symmetrical forces as physical and chemical origins. These scenarios should involve further great amplification mechanisms, enabling a pure L- or D-world.

Keywords

chirogenesis --- enantiomorphism --- nepheline --- magmatic flow --- etch figures --- origin of life --- biological homochirality --- deracemization --- super-high-velocity impact --- plasma reactor --- absolute asymmetric synthesis --- amino acids --- origin of life --- amino acid handedness --- nucleus–molecular coupling --- chirality --- circularly polarized luminescence --- circular dichroism --- symmetry breaking --- parity violation --- weak neutral current --- tunneling --- Z0 boson --- homochirality --- precision measurement --- homochirality --- circularly polarized light --- asymmetric reaction --- polymer --- ?-strand --- hidden chirality --- two-fold helix --- multi-point approximation --- tilt-chirality --- high dimensional chirality --- spin polarized electrons --- homochirality --- magnetism --- prebiotic --- environmental chirality --- C1- and C2-symmetric catalysts --- chiral field (memory) --- racemic field --- Viedma ripening effect --- Wallach’s rule --- heat capacity --- metal-organic framework --- triethylenediamine (DABCO) molecules --- racemate --- Salam hypothesis --- homochirality --- parity violation --- neutrinos --- gravitation --- enantiomer self-disproportionation --- SDE --- achiral stationary phase --- homochiral and heterochiral aggregates --- chiral separation --- chirality --- genesis of life chirality --- asymmetric autocatalysis --- homochirality --- chirality --- asymmetric synthesis --- Soai reaction --- biological homochirality --- enantioselective reaction --- autocatalysis --- origin of life --- replicators --- bioorganic homochirality --- circularly polarized photon --- spin-polarized lepton --- parity violation in the weak interaction --- symmetry breaking --- assemblies --- supramolecular chirality --- homochirality --- self-assembly --- vortex --- lipid --- supramolecular assembly --- symmetry breaking --- homochirality

Solid Phase Extraction: State of the Art and Future Perspectives

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ISBN: 9783039211586 / 9783039211593 Year: Pages: 176 DOI: 10.3390/books978-3-03921-159-3 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Chemistry (General)
Added to DOAB on : 2019-08-28 11:21:27
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This book is a collection of 13 innovative papers describing the state of the art and the future perspectives in solid-phase extraction covering several analytical fields prior to the use of gas or liquid chromatographic analysis. New sorptive materials are presented including carbon nanohorn suprastructures on paper support, melamine sponge functionalized with urea–formaldehyde co-oligomers, chiral metal–organic frameworks, UiO-66-based metal–organic frameworks, and fabric phase sorptive media for various applications. Solid-phase extraction can be applied in several formats aside from the conventional cartridges or mini-column approach, e.g., online solid-phase extraction, dispersive solid-phase microextraction, and in-syringe micro-solid-phase extraction can be very helpful for analyte pre-concentration and sample clean-up. Polycyclic musks in aqueous samples, 8-Nitroguanine in DNA by chemical derivatization antibacterial diterpenes from the roots of salvia prattii, perfluoroalkyl substances (PFASs) in aater samples by bamboo charcoal-based SPE, parabens in environmental water samples, benzotriazoles as environmental pollutants, organochlorine pesticide residues in various fruit juices and water samples and synthetic peptide purification are among the applications cited in this collection. All these outstanding contributions highlight the necessity of this analytical step, present the advantages and disadvantages of each method and focus on the green analytical chemistry guidelines that have to be fulfilled in current analytical practices.

Advances in Food Analysis

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ISBN: 9783039217427 / 9783039217434 Year: Pages: 488 DOI: 10.3390/books978-3-03921-743-4 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Mathematics
Added to DOAB on : 2019-12-09 11:49:16
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This Topical Collection of Molecules provides the most recent advancements and trends within the framework of food analysis, confirming the growing public, academic, and industrial interest in this field. The articles broach topics related to sample preparation, separation science, spectroscopic techniques, sensors and biosensors, as well as investigations dealing with the characterization of macronutrients, micronutrients, and other biomolecules. It offers the latest updates regarding alternative food sources (e.g., algae), functional foods, effects of processing, chiral or achiral bioactive compounds, contaminants, and every topic related to food science that is appealing to readers. Nowadays, the increasing awareness of the close relation among diet, health, and social development is stimulating demands for high levels of quality and safety in agro-food production, as well as new studies to fill gaps in the actual body of knowledge about food composition. For these reasons, modern research in food science and human nutrition is moving from classical methodologies to advanced instrumental platforms for comprehensive characterization. Nondestructive spectroscopic and imaging technologies are also proposed for food process monitoring and quality control in real time.

Keywords

cuprous oxide nanoparticles --- reduced graphene oxide --- modified electrode --- sunset yellow --- second-derivative linear sweep voltammetry --- clenbuterol --- systematic evolution of ligands by exponential enrichment --- real-time quantitative PCR --- high-throughput sequencing technology --- aptamers --- gold nanoparticles biosensor --- carbamates --- multiple reaction monitoring (MRM) --- enhanced product ion (EPI) --- mass fragmentation --- confirmatory method --- pesticide residues --- Croatian wines --- biogenic amines --- HPLC --- geographical origin --- polyelectrolyte composite film --- nitrite detection --- differential pulse voltammetry --- cyclic voltammetry --- mycotoxin --- dimerization --- HRMS --- NMR --- fruit jams --- food security --- phenolic acids --- quercetin --- agro-biodiversity --- HPLC fingerprint --- Polygonatum cyrtonema --- saccharides --- oligosaccharides --- fructose --- HPLC–QTOF–MS/MS --- steaming --- essential oil --- extraction techniques --- hops extracts --- hydrodistillation --- Marynka strain --- microwave-assisted hydrodistillation --- anthocyanins --- bioactive compounds --- Box–Behnken design --- microwave-assisted extraction --- myrtle --- Myrtus communis --- phenolic compounds --- Chia seed oil --- polyunsaturated fatty acid --- antioxidant --- lipid-lowering effect --- collagen peptide --- HPLC fingerprint --- antioxidant --- anti-inflammatory --- spectrum-effect relationship --- amino acids --- carbohydrates --- acidity --- polarity --- molecular weight --- Tricholoma matsutake --- Pol gene --- qualitative and quantitative PCR --- DNA extraction --- ?-blockers --- metabolites --- milk powder --- Q-Orbitrap --- rosé wines --- white wines --- bottle aging --- flavor profile --- closures --- anthocyanins --- bioactive compounds --- Box–Behnken design --- ultrasound-assisted extraction --- myrtle --- Myrtus communis L. --- phenolic compounds --- food safety --- kiwifruit (Actinidia chinensis) --- molecular identification --- phylogeny --- DNA barcode --- hard clams --- Meretrix lyrata --- lipid classes --- fatty acids --- phospholipids --- molecular species of phospholipid --- high resolution mass spectrometry --- impedimetric aptasensor --- screen-printed interface --- bifunctional polymer arms --- PAT detection --- apple juice --- chiral --- chiral stationary phases --- enantiomers --- food --- review --- Piper methysticum (kava) --- kavalactones --- flavokavains --- UHPLC-UV --- mass spectra --- isomerization --- single-laboratory validation --- quality control --- Lactarius deliciosus --- chemical composition --- antioxidant --- antihyperglycemic --- ?13C-IRMS --- fatty acids composition --- 1H-NMR --- walnut varieties --- poultry eggs --- thiamphenicol --- florfenicol --- florfenicol amine --- ASE --- UPLC-FLD --- Sojae semen praeparatum (SSP) --- fermentation --- conversion --- ultra-fast liquid chromatography (UFLC)–TripleTOF MS --- principal component analysis (PCA) --- microalgae --- Scenedesmus --- supercritical fluid extraction --- carotenoids --- fat-soluble vitamins --- antioxidants --- fruit juice --- blends --- adulteration --- 1H NMR --- PLS --- chemometrics --- natural mature honey --- immature honey --- chemometric analysis --- multi-physicochemical parameters --- food quality --- IMS --- food composition --- food process control --- food authentication --- food adulteration --- food safety --- antibiotics --- liquid chromatography mass spectrometry --- milk --- muscle --- validation

SPIG2018

Authors: --- --- ---
ISBN: 9783038978503 9783038978510 Year: Pages: 288 DOI: 10.3390/books978-3-03897-851-0 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Physics (General) --- Nuclear Physics
Added to DOAB on : 2019-04-25 16:37:17
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This Special Issue covers a wide range of topics from fundamental studies to applications of ionized gases. It is dedicated to four topics of interest: 1. ATOMIC COLLISION PROCESSES (electron and photon interactions with atomic particles, heavy particle collisions, swarms, and transport phenomena); 2. PARTICLE AND LASER BEAM INTERACTION WITH SOLIDS (atomic collisions in solids, sputtering and deposition, and laser and plasma interactions with surfaces); 3. LOW TEMPERATURE PLASMAS (plasma spectroscopy and other diagnostic methods, gas discharges, and plasma applications and devices); 4. GENERAL PLASMAS (fusion plasmas, astrophysical plasmas, and collective phenomena). This Special Issue of Atoms will highlight the need for continued research on ionized gas physics in different topics ranging from fundamental studies to applications, and will review current investigations.

Keywords

strong-field physics --- attoscience --- bicircular field --- high-order harmonic generation --- above-threshold ionization --- spin-polarized electrons --- capacitively-coupled discharge --- oxygen --- particle-in-cell/Monte Carlo collision --- electron heating --- secondary electron emission --- Large Helical Device (LHD) --- deuterium experiment --- ion temperature of 10 keV --- plasma research --- spectroscopic study --- dispersion interferometer --- modified theories of gravity --- methods: analytical --- methods: numerical --- galaxies: elliptical --- galaxies: fundamental parameters --- non-equilibrium --- collisions --- radiation --- planetary atmospheric entry --- laser matter interaction --- laser-induced breakdown --- plasma --- spectroscopy --- streak camera --- plasma --- spectral lines --- Stark broadening --- oxygen --- silicon --- spectroscopy --- gas discharges --- plasma applications --- databases --- virtual observatory --- cross sections --- rate coefficients --- runway electron --- plasma current --- fusion plasma --- tokamak --- glow discharge --- argon --- nitrogen admixture --- discharge voltage --- diffuse discharge --- constricted discharge --- electrical theory of DBDs --- QV-plot --- instantaneous power --- rainbow scattering --- positron channeling effect --- time-dependent Schrödinger equation --- chiral single wall carbon nanotubes --- black hole physics --- cosmology --- quasar spectroscopy --- cosmological parameters --- ionized gas --- broad line region --- Rydberg atoms --- dynamic instability --- control of atomic states --- Förster resonance --- plasma spectroscopy --- Stark broadening --- plasma diagnostics --- line shape modeling --- Zeeman-Doppler broadening --- Balmer line series --- radiative recombination --- photoacoustic --- photothermal --- inverse problem --- thermal memory --- minimum volume cell --- neural networks --- thermal diffusivity --- conductivity --- linear coefficient of thermal extension --- AGN --- black holes --- gravitational waves --- binary black holes --- quasars --- photodetachment --- magnetically confined fusion --- neutral beam injection --- plasma heating --- optical cavity amplification --- low-energy electrons --- electron–molecule interactions --- astrochemistry --- laboratory plasma --- astrophysical plasma --- fusion plasma --- lasers --- stars --- extragalactic objects --- spectra --- spectroscopy --- scaling laws

Synthesis and Applications of New Spin Crossover Compounds

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ISBN: 9783039213610 / 9783039213627 Year: Pages: 254 DOI: 10.3390/books978-3-03921-362-7 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Physics (General)
Added to DOAB on : 2019-12-09 11:49:15
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The crystal chemistry of spin crossover (SCO) behavior in coordination compounds can potentially be in association with smart materials—promising materials for applications as components of memory devices, displays, sensors and mechanical devices and, especially, actuators, such as artificial muscles. This Special Issue is devoted to various aspects of SCO and related research, comprising 18 interesting original papers on valuable and important SCO topics. Significant and fundamental scientific attention has been focused on the SCO phenomena in a wide research range of fields of fundamental chemical and physical and related sciences, containing the interdisciplinary regions of chemical and physical sciences related to the SCO phenomena. Coordination materials with bistable systems between the LS and the HS states are usually triggered by external stimuli, such as temperature, light, pressure, guest molecule inclusion, soft X-ray, and nuclear decay. Since the first Hofmann-like spin crossover (SCO) behavior in {Fe(py)2[Ni(CN)4]}n (py = pyridine) was demonstrated, this crystal chemistry motif has been frequently used to design Fe(II) SCO materials to enable determination of the correlations between structural features and magnetic properties.

Keywords

spin crossover --- spin transition --- cobalt(II) ion --- paramagnetic ligand --- aminoxyl --- switch --- mosaicity --- spin crossover --- X-ray diffraction --- fatigability --- single crystal --- phase transition --- structural disorder --- spin-crossover --- dinuclear triple helicate --- Fe(II) --- solvent effects --- metal dithiolene complexes --- [Au(dmit)2]?, [Au(dddt)2]? --- ion-pair crystals --- [Fe(III)(3-OMesal2-trien)]+ --- coordination complexes --- crystal structure --- magnetic properties --- magnetic susceptibility --- magnetization --- spin-crossover transition --- Fe(II) complex --- dipyridyl-N-alkylamine ligands --- high spin (HS) --- low spin (LS) --- spin cross-over (SCO) --- magnetic transition --- cobalt oxide --- spin polaron --- impurity effect --- spin-state crossover --- coordination polymer --- supramolecular isomerism --- spin crossover --- crystal engineering --- spin crossover --- X-ray absorption spectroscopy --- soft X-ray induced excited spin state trapping --- high spin --- spin-crossover --- LIESST effect --- hydrogen bonding --- ?-? interactions --- charge-transfer phase transition --- iron mixed-valence complex --- hetero metal complex --- dithiooxalato ligand --- substitution of 3d transition metal ion --- ferromagnetism --- dielectric response --- 57Fe Mössbauer spectroscopy --- Fe(III) coordination complexes --- hexadentate ligand --- Schiff base --- spin crossover --- UV-Vis spectroscopy --- SQUID --- EPR spectroscopy --- spin-crossover --- optical microscopy --- reaction diffusion --- spin crossover --- Fe(III) complex --- qsal ligand --- thermal hysteresis --- structure phase transition --- counter-anion --- solvate --- lattice energy --- optical conductivity spectrum --- spiral structure --- 1,2-bis(4-pyridyl)ethane --- supramolecular coordination polymer --- chiral propeller structure --- atropisomerism --- spin crossover --- iron(II) complexes --- C–H···? interactions --- magnetic properties --- thermochromism --- spin crossover --- linear pentadentate ligand --- iron(II) --- mononuclear --- 1,2,3-triazole --- crystal structure --- magnetic properties --- DFT calculation --- intermolecular interactions --- amorphous --- spin crossover --- Cu(II) complexes --- nitroxides --- phase transitions --- magnetostructural correlations --- iron (II), spin crossover --- X-ray diffraction --- coordination polymers --- n/a

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