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Start Over Descriptor "Solvent effect" Publication Type Books
4 results on '"Solvent effect"'

1. Gulliver in the Country of Lilliput. An Interplay of Noncovalent Interactions.

Author

Shenderovich, Ilya and Shenderovich, Ilya

Subjects
Research & information: general, 31P NMR spectroscopy, Bader charge analysis, CPMD, DFT, IINS, IR, IR spectroscopy, Lewis acid-Lewis base interactions, NMR, QTAIM, Raman, Reaction mechanism, activation energy, adenine, aromaticity, azo dyes, benchmark, carboxyl group, computation of low-frequency Raman spectra, condensed matter, confinement, conventional and non-conventional H-bonds, crystal engineering, density functional theory, deuteration, dispersion, electron charge shifts, empirical Grimme corrections, external electric field, first-principle calculation, gas phase, halogen bond, halogen bonding, heavy drugs, histamine receptor, hydrogen bond, hydrogen bonding, hydrogen bonds, interfaces and surfaces, ketone-alcohol complexes, lattice energy of organic salts, molecular dynamics, molecular recognition, n/a, non-covalent interactions, phosphine oxide, pinacolone, pnicogen bond, polarizable continuum model, proton dynamics, proton transfer, reaction field, receptor activation, solid-state NMR, solvent effect, spectral correlations, substituent effect, tetrel bond, transition state structure, triel bond, vibrational spectroscopy
Abstract

Summary: Noncovalent interactions are the bridge between ideal gas abstraction and the real world. For a long time, they were covered by two terms: van der Waals interactions and hydrogen bonding. Both experimental and quantum chemical studies have contributed to our understanding of the nature of these interactions. In the last decade, great progress has been made in identifying, quantifying, and visualizing noncovalent interactions. New types of interactions have been classified-their energetic and spatial properties have been tabulated. In the past, most studies were limited to analyzing the single strongest interaction in the molecular system under consideration, which is responsible for the most important structural properties of the system. Despite this limitation, such an approach often results in satisfactory approximations of experimental data. However, this requires knowledge of the structure of the molecular system and the absence of other competing interactions. The current challenge is to go beyond this limitation. This Special Issue collects ideas on how to study the interplay of noncovalent interactions in complex molecular systems including the effects of cooperation and anti-cooperation, solvation, reaction field, steric hindrance, intermolecular dynamics, and other weak but numerous impacts on molecular conformation, chemical reactivity, and condensed matter structure.

2. Advances in Industrial Crystallization.

Author

Lorenz, Heike, Lorenz, Heike, and Temmel, Erik

Subjects
Technology: general issues, CA-LBM model, DTB crystallizer, K-MER zeolite, L-alanine, L-serine, PXRD, TRPXRD, amine, aryl glycerol ethers, asparagine monohydrate, aspect ratio, biocatalysis, catalyst, cellulose, chiral separation, chirality, continuous, continuous crystallization, crystal growth, crystal habit, crystal needles, crystal shape, crystal size measurement, crystallization, curcumin, cyanoethylation of methanol, dendritic growth, deracemization, dielectric property, enantiomer, enantiomers, enantioselective, enzyme, fine chemicals, fluidized bed, fluorescence, fluorescent-tagged polyacrylate, freeze crystallization (FC), grid scanning, gypsum scaling, hydrothermal synthesis, in situ data collection, inline probe, ionic liquid (IL), isomorphic miscibility, kinetics, melt crystallization, membrane fouling, microcrystals, microplate, modification, molecular dynamics (MD), morphology, multi-dendrite motion, n/a, nanocrystals, nanoscale TiO2 seed, natural convection, numerical simulation, optical measurement techniques, phase behavior, poly(butylene succinate), polymorphism, preferential crystallization, process design, process intensification, purification, racemate resolution, racemic conglomerate, recycling, reverse osmosis, scale inhibition mechanisms, scale up, solid-liquid equilibrium, solvent effect, spherical BaTiO3 nanoparticle, surface structure, synthesis parameter, ternary mixture of curcuminoids, thermal expansion
Abstract

Summary: This Special Issue is result of a call for papers of the Section Industrial Crystallization of MDPI's scientific journal Crystals. It addresses scientists and engineers active in research and process & product development in life-science industries (e.g. pharmaceuticals, fine chemicals and biotechnology products) and bulk chemical applications (e.g. desalination) as well. The contributions comprise several fundamental and application-oriented facets of crystallization providing an overview of industrially relevant subjects in the field. Main issues cover phase equilibria and solid-state behavior of crystalline compounds, crystal shape and size and related measurement techniques. Melt and solution crystallization are considered specifically addressing contemporary aspects of continuous crystallization and process intensification.

3. First Principle Study of the Anti– and Syn–Conformers of Thiophene–2–Carbonyl Fluoride and Selenophene–2–Carbonyl Fluoride in the Gas and Solution Phases.

Author

Abdallah, Hassan H. and Ramasami, Ponnadurai

Abstract

The anti- and syn-conformers of thiophene-2-carbonyl fluoride (A) and selenophene-2-carbonyl fluoride (B) have been studied in the gas phase. The transition states have also been obtained for the interconversion of the anti- and syn-conformers. The methods used are MP2 and DFT/B3LYP and the basis sets used for all atoms are 6-311++G(d,p). The optimized geometries, dipole moments, moment of inertia, energies, energy differences and rotational barriers are reported. This study has been extended to include solvent effect. Some of the vibrational frequencies of the conformers are reported with appropriate assignments. The results indicate that in the gas phase the syn conformer is more stable and the CCSD(T)//MP2 energy differences are 2.97 kJ/mol (A) and 3.02 kJ/mol (B) and barriers of rotation are 38.50 kJ/mol (A) and 36.89 kJ/mol (B). The structures and vibrational frequencies of (A) and (B) are not much affected by the solvents but the more polar conformer gets more stabilized. The major effect of the solvents is that energy difference decreases but rotational barrier increases. The peculiar characteristic of fluorine affecting conformational preference is not observed. [ABSTRACT FROM AUTHOR]

Published
2009
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4. Selective α-Sialylation.

Author

Ando, Hiromune and Kiso, Makoto

Abstract

Chemical construction of a α–glycoside of sialic acid is a demanding subject due to the structural disadvantages of sialic acid: the carboxylate group at C1, the deoxy moiety adjacent to the anomeric center, and the glycerol branch from C6. This chapter will provide an overview of sialic acid chemistry and show how the disadvantages can be surmounted and it will also cover the cutting–edge methodology used for α–selective sialylation. In this chapter, the forty–year history of sialylation is compartmentalized into three periods. The first period represents the use of 2–halogeno sialy donors. The second period covers the use of C3–appended sialyl donors and a set of thioglycoside donors, including also the acetonitrile effect, and third is the period of C5–modified sialy donors. While following this division, the chemistry of α–selective sialylation is discussed, and some examples of the stereoselective syntheses of sialyl oligosaccharides are described. Furthermore, the synthesis of the homopolymer of sialic acid and artificial sialyl S- and C–glycosides is discussed. [ABSTRACT FROM AUTHOR]

Published
2008
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