Search results for "Sulfonate"
showing 10 items of 447 documents
CCDC 1824417: Experimental Crystal Structure Determination
2020
Related Article: Lucia Volbach, Niklas Struch, Fabian Bohle, Filip Topić, Gregor Schnakenburg, Andreas Schneider, Kari Rissanen, Stefan Grimme, Arne Lützen|2020|Chem.-Eur.J.|26|3335|doi:10.1002/chem.201905070
CCDC 1955601: Experimental Crystal Structure Determination
2020
Related Article: Lucia Volbach, Niklas Struch, Fabian Bohle, Filip Topić, Gregor Schnakenburg, Andreas Schneider, Kari Rissanen, Stefan Grimme, Arne Lützen|2020|Chem.-Eur.J.|26|3335|doi:10.1002/chem.201905070
CCDC 987655: Experimental Crystal Structure Determination
2014
Related Article: José J. Baldoví, Eugenio Coronado, Alejandro Gaita-Ariño, Christoph Gamer, Mónica Giménez-Marqués, Guillermo Mínguez Espallargas|2014|Chem.-Eur.J.|20|10695|doi:10.1002/chem.201402255
CCDC 987656: Experimental Crystal Structure Determination
2014
Related Article: José J. Baldoví, Eugenio Coronado, Alejandro Gaita-Ariño, Christoph Gamer, Mónica Giménez-Marqués, Guillermo Mínguez Espallargas|2014|Chem.-Eur.J.|20|10695|doi:10.1002/chem.201402255
Electrospray ion mobility mass spectrometry of positively and negatively charged (1R,2S)-dodecyl(2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium br…
2015
Rationale Self-assembling processes of surfactants in the gas phase constitute a developing research field of interest since they allow information to be gained on the peculiar structural organization of these aggregates, on their ability to incorporate from small molecules up to proteins and on their possible use as carriers of drugs in the gas phase or as cleaning agents and exotic reaction media. Methods The mass spectra of charged aggregates of the chiral surfactant (1R,2S)-dodecyl(2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium bromide (DMEB) in the gas phase have been recorded using a Synapt G2-Si mass spectrometer in the positive and negative ion mode. For comparison purposes, the …
Polyelectrolytes: Intrinsic Viscosities in the Absence and in the Presence of Salt
2008
Intrinsic viscosities were determined at 25 °C for 10 samples of narrowly distributed sodium polystyrene sulfonate (the molecular weights M ranging from 0.9 to 1000 kg/mol) in pure water and in aqueous solutions containing 0.9 wt % NaCl from the slope of ln ηrel versus polymer concentration. In the middle range of M, the [η] values are in the former case almost 2 orders of magnitude larger than in the latter case. In the absence of salt, the plot of log [η] as a function of log M exhibits a sigmoidal shape, which can be approximated within the interval 3 < M (in kg mol-1) < 30 by log[η] = −0.17 + 2.1 log M. In the presence of salt, the following relation holds true in the entire regime: lo…
Polyelectrolyte Complexes: Phase Diagram and Intrinsic Viscosities of the System Water/Poly(2-vinylpyridinium-Br)/Poly(styrene sulfonate-Na)
2012
In contrast to all earlier work on that subject, measurements are performed at high dilution up to total polymer concentrations wpol of 0.5 wt%. Aqueous solutions of poly(2-vinylpyridinium-Br) and of poly(styrene sulfonate-Na) are only fully miscible if wpol < 0.02 wt%. Decomposition into two liquid phases is observed upon an increase in wpol, where the extension of the miscibility gap is considerably larger at 60 than at 25 °C. Viscosity measurements demonstrate that the formation of the polyelectrolyte complexes may take hours. The intrinsic viscosity of the polyanion turns out to be 20 times larger than that of the polycation and to be much more sensitive toward the addition of extra sal…
Coil overlap in moderately concentrated polyelectrolyte solutions: effects of self-shielding as compared with salt-shielding as a function of chain l…
2016
The generalized intrinsic viscosity {η} (hydrodynamic volume of the solute at arbitrary polymer concentration c) – introduced by analogy to the intrinsic viscosity [η] – provides access to the degree of coil overlap Ω for polyelectrolyte solutions in pure water or in saline water. The experimental basis of this investigation consists in viscosity measurements as a function of c for a large number of sodium polystyrene sulfonate (Na-PSS) samples covering the molecular weight range from 0.91 to 1000 kg mol−1. The accurate modeling of these dependencies with a maximum of three parameters yields detailed information on Ω as a function of (c[η]) in the absence and in the presence of extra salt. …
Concave π-prismand hydrocarbon [2.2.2]cyclophanes and their crystalline Ag-triflate complexes
1999
New small concave hydrocarbon cyclophanes were prepared via the well-known HD-2SO2-method. The cyclophanes obtained are isomers of the very well-known [2.2.2]p,p,p-cyclophane, C24H24, a π-prismand efficiently complexing Ag+-ion. X-ray crystal structure determinations showed the bis-sulfide 7 (1,10-dithia[3.3.2]m,p,p-cyclophane) to be helically chiral and that the conformation of the parent hydrocarbon cyclophane 13 ([2.2.2]m,p,p-cyclophane) does not change dramatically upon complexation with the Ag+-ion. The 16- and 17-membered [2.2.2]m,m,p- and [2.2.2]m,p,p-cyclophane (15 and 16) also act as π-prismands and form surprisingly similar crystalline 1:1 Ag-triflate complexes (π-prismates) as th…
Homochiral self-assembly of biocoordination polymers: anion-triggered helicity and absolute configuration inversion
2015
The different natures of the weakly coordinating anions – triflate or perchlorate – in the Cu2+-mediated self-assembly of cytidine monophosphate nucleotide play a fundamental role in the homochiral resolution process, yielding one-dimensional copper(II) coordination polymers of opposite helicity that can be easily inverted, in a reversible way, by changing the nature of the anion as revealed by circular dichroism experiments both in solution and in the solid state.