Electron Spin Echo Modulation Analysis Research Articles

ChemInform Abstract: ELECTRON SPIN RESONANCE AND ELECTRON SPIN ECHO STUDIES OF THE PHOTOIONIZATION OF TETRAMETHYLBENZIDINE IN FROZEN AQUEOUS ANIONIC, CATIONIC, AND NONIONIC MICELLAR SOLUTIONS. EFFECT OF MICELLE TYPE AND ANIONIC MICELLE SIZE

AbstractFeste Lösungen der Titelverbindung (TMB) in wäßrigen anionischen Micellen der Sulfate (I) ergeben nach einer Lichteinwirkung bei 77 K ESR‐Spektren, die auf eine Intensität der Kationen TMB+ schließen lassen, die mit steigender Kettenlänge abnimmt.

Determination of the coordination geometry of supported vanadium catalysts by electron spin echo modulation analysis

Electron spin echo modulation analysis was used to characterize the coordination geometry of the paramagnetic vanadium species formed in the 0.25% V 2O 5 in SiO 2 with D 2O adsorbate. The deuterium modulation indicates one deuteron at 0.23 nm and four deuterons at 0.26 nm. The four farther deuterons are interpreted as due to two-coordinated water molecules.

Electron spin echo study of neodymium(3+) solvation geometry in ethanol glasses. Disorientation of molecular dipoles in the first solvation shell

Electron spin echo modulation (ESEM) studies have been carried out for Nd/sup 3 +/ in ethanol glasses at 4.2/sup 0/K. ESEM analysis of Nd/sup 3 +/ in CH/sub 3/CH/sub 2/OD indicates ninefold coordination of ethanol in the first solvation shell. By using the specifically deuterated ethanols CH/sub 3/CH/sub 2/OD, CH/sub 3/CD/sub 2/OH, and CD/sub 3/CH/sub 2/OH, ESEM analysis of deuterium modulation in three-pulse electron spin echo decay curves gives the distances to the various deuteron groups. These distances establish that the molecular dipole of ethanol is disoriented from Nd/sup 3 +/ by about 35/sup 0/. This contrasts with methanol solvation of Nd/sup 3 +/ where the methanol moleculr dipole is oriented toward Nd/sup 3 +/. The difference between methanol and ethanol solvation is attributed to steric interactions. 4 figures.

Location and movement on dehydration of Cu2+ in Cs7Na5A zeolite from electron spin echo modulation analysis

It is shown that paramagnetic ions like Cu2+ can be located and that their motion upon dehydration in zeolites can be monitored by electron spin echo modulation analysis. In Cs7Na5A zeolite, Cu2+ is located inside the β cage about 0.1 nm below a hexagonal window between the β and α cages. The Cu2+ is coordinated to three lattice oxygens and one water molecule. On dehydration Cu2+ moves out of the β cage along the threefold axis of the hexagonal window to about 0.1 nm above the hexagonal window into the α cage.

ChemInform Abstract: GEOMETRICAL STRUCTURE OF SOLVATED ELECTRONS IN ETHANOL GLASS DETERMINED FROM ELECTRON SPIN ECHO MODULATION ANALYSES

Chemischer InformationsdienstVolume 12, Issue 28 Preparative Organic Chemistry ChemInform Abstract: GEOMETRICAL STRUCTURE OF SOLVATED ELECTRONS IN ETHANOL GLASS DETERMINED FROM ELECTRON SPIN ECHO MODULATION ANALYSES M. NARAYANA, M. NARAYANASearch for more papers by this authorL. KEVAN, L. KEVANSearch for more papers by this author M. NARAYANA, M. NARAYANASearch for more papers by this authorL. KEVAN, L. KEVANSearch for more papers by this author First published: July 14, 1981 https://doi.org/10.1002/chin.198128134AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume12, Issue28July 14, 1981 RelatedInformation

Electron spin echo studies of solvation structure

The development and application of electron spin echo modulation analysis for deducing detailed geometrical information about the solvation shell structure of paramagnetic species is described. This technique makes it possible to measure weaker hyperfine interactions in disordered systems such as frozen solutions and surfaces than is normally possible. The number, distance, and orientation of first solvation shell molecules can then be determined. Applications of this technique to silver atom solvation, electron solvation, anion solvation, cation solvation, and cation solvation on surfaces are described.

Geometrical structure of solvated electrons in ethanol glass determined from electron spin echo modulation analyses

Two-pulse and three-pulse electron spin echo deuterium modulation patterns have been analyzed for radiation-produced solvated electrons in the following specifically deuterated ethanol glasses: CH/sub 3/CH/sub 2/OD, CH/sub 3/CD/sub 2/OH, and CD/sub 3/CH/sub 2/OH. The analyses are all consistent with four first-solvation-shell molecules around the electron with the CD/sub 3/ deuterons at 0.38 nm, the CD/sub 2/ deuterons at 0.33 nm, and the OD deuteron at 0.22 nm from the electron. The distances are compatible only with a molecular dipole orientation of the ethanol molecules with the bisector of the COD bond angle approximately oriented toward the electron. This contrasts with the OD bond dipole orientation found for solvated electrons in aqueous matrices.

Solvation-shell geometry of copper ion in methanol and in acetone and a molecular picture of preferential solvation of copper ion by methanol in methanol-acetone mixed solvent determined by electron spin-echo modulation analysis

Electron spin-echo modulation studies have been carried out for Cu/sup 2 +/ in CD/sub 3/OH, CH/sub 3/OD, and CD/sub 3/COCD/sub 3/ to deduce the cation solvation-shell geometry in these solvents. The results indicate that the Cu/sup 2 +/ is solvated by six molecules in both methanol and acetone with the molecular dipoles of these molecules oriented toward Cu/sup 2 +/. The Cu/sup 2 +/ to nearest solvent molecule oxygen distance is 2.1 A for both solvents. In mixed solvents the basic solvation-shell geometry does not change, but methanol preferentially solvates Cu/sup 2 +/ in comparison with acetone. A quantitative study shows that the probability of finding methanol in the first solvation shell of Cu/sup 2 +/ is 78% more than statistical over the range of 9 to 40 mol % methanol in acetone. This constant probability suggests the absence of cooperative effects in the solvation process.

Analysis of three-pulse electron spin-echo modulation: Phase reversal

Abstract Three-pulse electron spin-echo modulation patterns are analyzed with particular attention paid to the phase reversal of the modulation. For zero isotropic hyperfine coupling a simple expression is derived which relates the time of phase reversal to the dipolar distance to the interacting magnetic nuclei. However, even a small isotrophc hyperfine coupling dramatically affects the time of phase reversal. The absence of phase reversal in the three-pulse echo modulation from trapped electrons in methyltetrahydrofuran glass is shown to be consistent with the results obtained from two-pulse echo modulation studies.