Results 31 to 40 of about 26,157 (280)

Influence of Swelling Media on the Crystallinity and Accessibility of Lyocell Fibers: An FTIR and 13C NMR Analysis

open access: yesJournal of Natural Fibers, 2022
Cellulose swelling using different protic, aprotic and alkaline solvents, which are capable of penetrating crystalline parts of cellulose is one of the important methods to enhance the accessibility and, as a result, the reactivity of cellulose in ...
Fereshteh Fadavi   +3 more
doaj   +1 more source

Polarity-Dependent Twisted Intramolecular Charge Transfer in Diethylamino Coumarin Revealed by Ultrafast Spectroscopy

open access: yesChemosensors, 2022
Twisting intramolecular charge transfer (TICT) is a common nonradiative relaxation pathway for a molecule with a flexible substituent, effectively reducing the fluorescence quantum yield (FQY) by swift twisting motions.
Jiawei Liu, Cheng Chen, Chong Fang
doaj   +1 more source

Synthesis of pyrrolizines by intramolecular capture of 1,4-dipolar intermediates in reactions of enamines with dimethyl acetylenedicarboxylate [PDF]

open access: yes, 1981
Solvent polarity and reaction temperature strongly influence the reactions of dimethyl acetylenedicar-boxylate (DMAD) with 1-pyrrolidinyl enamines of acyclic and cyclic ketones. Whereas DMAD and 1-[1-phenyl-2-(phenylthio)ethenyl]pyrrolidine (3) give only
Harkema, S.   +5 more
core   +3 more sources

Localization of dexamethasone within dendritic core-multishell (CMS) nanoparticles and skin penetration properties studied by multi-frequency electron paramagnetic resonance (EPR) spectroscopy [PDF]

open access: yes, 2016
The skin and especially the stratum corneum (SC) act as a barrier and protect epidermal cells and thus the whole body against xenobiotica of the external environment. Topical skin treatment requires an efficient drug delivery system (DDS).
Anske, M.   +8 more
core   +1 more source

Cooperative catalysis by silica-supported organic functional groups [PDF]

open access: yes, 2008
Hybrid inorganic–organic materials comprising organic functional groups tethered from silica surfaces are versatile, heterogeneous catalysts. Recent advances have led to the preparation of silica materials containing multiple, different functional groups
Davis, Mark E.   +2 more
core   +1 more source

Assisted dipeptide bond formation: glycine as a case study

open access: yesHeliyon, 2021
Peptide bond formation is a crucial chemical process that dominates most biological mechanisms and is claimed to be a governing factor in the origin of life.
Sofiene Achour   +3 more
doaj   +1 more source

Investigating the antiparasitic potential of the marine sesquiterpene avarone, its reduced form avarol, and the novel semisynthetic thiazinoquinone analogue thiazoavarone [PDF]

open access: yes, 2020
The chemical analysis of the sponge Dysidea avara afforded the known sesquiterpene quinone avarone, along with its reduced form avarol. To further explore the role of the thiazinoquinone scaffold as an antiplasmodial, antileishmanial and antischistosomal
AIELLO, ANNA   +13 more
core   +1 more source

Evaluation of solvents’ effect on solubility, intermolecular interaction energies and habit of ascorbic acid crystals

open access: yesJournal of Saudi Chemical Society, 2019
Solubility of active pharmaceutical ingredient (API) in solvents is very important for drug development and manufacturing. Solubility data may provide further information such as thermochemical properties and intermolecular interactions that may lead to ...
S. Hassan   +3 more
doaj   +1 more source

Investigations of the reactivity of pyridine carboxylic acids with diazodiphenylmethane in protic and aprotic solvents. [PDF]

open access: yesJournal of the Serbian Chemical Society, 2005
Rate constants for the reaction of diazodiphenylmethane with isomeric pyridine carboxylic acids were determined in chosen protic and aprotic solvents at 30 °C, using the well known UV spectrophotometric method.
ALEKSANDAR D. MARINKOVIC   +3 more
doaj  

Proton-Electron Hyperfine Coupling Constants of the Chlorophyll a Cation Radical by ENDOR Spectroscopy [PDF]

open access: yes, 1977
In this paper we describe the assignment of the major coupling constants in monomer chlorophyll a cation free radical by ENDOR spectroscopy. To facilitate chemical manipulation methylpyrochlorophyllide a has been used as a stand-in, and a suite of six ...
Katz, J. J., Norris, J. R., Scheer, Hugo
core   +1 more source

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