AbstractThe predominant Charged silver Clusters formed in Ag ‐ Azeolite during mild (low‐temp.

Static magnetic susceptibility measurements have been carried out on autoreduced silver zeolite A to investigate the spin state of the principal silver cluster formed. This autoreduction procedure produces the so-called yellow form of silver zeolite A, where the color arises from an optical absorption in the neighborhood of 2.7–2.9 eV (previously assigned to a linear and paramagnetic Ag+23 cluster). Our static susceptibility data show unequivocally that this cluster is not paramagnetic and necessitate a reevaluation of the mechanism of autoreduction in silver zeolite A.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFormation of charged silver clusters and their reversible silver ion desorption in zeolite AJohn Texter, Richard Kellerman, and Thomas GonsiorowskiCite this: J. Phys. Chem. 1986, 90, 10, 2118–2124Publication Date (Print):May 1, 1986Publication History Published online1 May 2002Published inissue 1 May 1986https://pubs.acs.org/doi/10.1021/j100401a027https://doi.org/10.1021/j100401a027research-articleACS PublicationsRequest reuse permissionsArticle Views210Altmetric-Citations43LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

Interpretation of the temperature dependence of the magnetic moment of bare surface Cr(II) ions in Type A zeolite is given based on a model of thermally activated jumps between sites in which the orbital contribution to the magnetic moment is quenched and the trigonally coordinated sites has large orbital contributions within the Cr(II) ground state 5E′. This behavior contrasts with the temperature independent spin-only magnetic moment of the Cr(IV)-monooxygen complex which indicates a non-degenerate ground state 3A2 of the Cr(IV) ion tetrahedrally coordinated by its monooxygen ligand and three framework oxygens.

The optical absorption spectrum of anhydrous solid FeCl3 has been measured over the range 0.5–6 eV by diffuse reflectance spectroscopy. Features at 2.5, 3.65, and 5.25 eV are assigned to u→g charge transfer excitations. Other features at 1.1, 1.4, and 2.1 eV are assigned to g→g charge transfer (2.1 eV) and d–d (1.1, 1.4 eV) excitations. The contribution of FeCl3 to absorption in intercalated graphite compounds is indicated.

The state of adsorbed water in a dextran gel has been investigated by near-infrared gravimetric-adsoprtion techniques. Water-vapor adsorption (desorption) isotherms at three temperatures are reported. The calculated sorption heats are found to be markedly temperature-dependent as well as dependent on the coverage. The near-infrared spectrum (4650-9000 cm-minus 1) is reported, together with tentative assignments. The H2O combination (v+delta) band at 5184 cm-minus 1 has been examined as a function of relative humidity. The line-shapes of this band have been analyzed by a recently established, Fourier-inversion technique, and information on the microdynamics of the absorbed water molecules has been resolved on the picosecond time-scale. At low and intermediate degrees of hydration, reorientational jumps take place with periods from four to six times longer than those for free water. The onset of saturation is then accompanied by the sudden removal of the reorientational jumps. A comparison of microdynamical and thermodynamic data indicates the hydration mechanism to be highly cooperative at all relative humidities.

A series of polycrystalline iron films (1 < t < 100 nm) was prepared and examined under ultrahigh vacuum conditions. The effect of oxygen on the ferromagnetic resonance response was investigated, and a thickness-dependent, transient increase in the perpendicular mode resonance field was attributed to the formation of Fem+ cations in a reconstructed surface layer. A subsequent decrease in the resonance field was consistent with the loss of ∼1.5 nm of ferromagnetic iron at large oxygen exposures. Information on the structure of the films was obtained from transmission electron microscopy of ultrahigh vacuum deposited films coated in situ with silicon monoxide.

A reinvestigation of the esr spectra of ammonia precipitated, oxygen dried, TiO2 powders has revealed that at least two of the triplets observed and previously assigned to some form of adsorbed oxygen (O2+), are caused by species resulting from the photochemical or thermal oxidation of traces of ammonia firmly held by the material. Confirmation for this view is provided in esr studies on relatively pure TiO2 following (1) contamination with 14NH3 and 15NH3 prior to drying in oxygen and (2) adsorption of oxides of nitrogen (14NO, 15NO2, 14NO2, and 15NO2). The nature of the species responsible for the triplets is discussed.