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X-ray absorption studies of graphite intercalates and metal-ammonia solutions. [AsF/sub 5/ and AsF/sub 6//sup -/ intercalates of graphite; Rb-NH/sub 3/]

Description: X-ray absorption spectroscopy (XAS) was used to study the arsenic fluorocomplexes, including the AsF/sub 5/ and AsF/sub 6//sup -/ intercalates of graphite, and rubidium metal-ammonia solutions. The As-F distances obtained for AsF/sub 3/ and AsF/sub 5/ gas are both in excellent agreement with electron diffraction data (within 0.004 A). A superior measurement which is significantly shorter than the accepted value of the bond distance in an undistorted AsF/sub 6//sup -/ octahedra is reported. Both… more
Date: September 1, 1979
Creator: Robertson, A. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The State of Manganese in the Photosynthetic Apparatus. Ii. X-Ray Absorption Edge Studies on Manganese in Photosynthetic Membranes

Description: X-ray absorption spectra at the Manganese K-edge are presented for spinach chloroplasts, and chloroplasts which have been Tris-treated and hence unable to evolve oxygen. A significant change in the electronic environment of manganese is observed and is attributed to the release of manganese from the thylakoid membranes with a concomitant change in oxidation state. A correlation of the K-edge energy, defined as the energy at the first inflection point, with coordination charge has been establish… more
Date: November 1, 1980
Creator: Kirby, J. A.; Goodin, D. B.; Wydrzynski, T.; Robertson, A. S. & Klein, M. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Novel Salts of Graphite and a Boron Nitride Salt

Description: Graphite is oxidized by O{sub 2}{sup +} AsF{sub 6}{sup -} and by OsF{sub 6} to give first-stage graphite salts C{sub 8}{sup +} MF{sub 6}{sup -} and S{sub 2}O{sub 6}F{sub 2} oxidizes both graphite and boron nitride to yield the salts C{sub 12}{sup +} SO{sub 3}F{sup -} and (BN){sub 4}{sup +} SO{sub 3}F{sup -}, the latter being the first example of a first-stage boron nitride salt.
Date: December 1, 1977
Creator: Bartlett, Neil; Biagioni, R. N.; McQuillan, B. W.; Robertson, A. S. & Thompson, A. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The State of Manganese in the Photosynthetic Apparatus. I. Exafs Studies on Chloroplasts and Di-U-Oxo Bridged Di-Manganese Model Compounds

Description: Extended X-ray Absorption Fine Structure (EXAFS) studies on the manganese contained in spinach chloroplasts and on certain di-u-oxo bridged manganese dimers of the form (X{sub 2}Mn)O{sub 2}(MnX{sub 2} (X=2,2'-bypyridine and 1,10-phenanthroline) are reported. From these studies, the manganese associated with photosynthetic oxygen evolution is suggested to occur as a bridged transition metal dimer with most likely another manganese. Extensive details on the analysis are included.
Date: November 1, 1980
Creator: Kirby, J. A.; Robertson, A. S.; Smith, J. P.; Thompson, A. C.; Thompson, A. C. & Klein, M. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The State of Manganese in the Photosynthetic Apparatus: First View of the Manganese Sites by X-Ray Absorption Spectroscopy

Description: Manganese atoms have long been implicated as essential ingredients in photosynthetic oxygen evolution. Heretofore they have eluded direct observation. We report the first direct observation, by X-ray Absorption Spectroscopy, of the Mn sites in chloroplasts isolated from Spinacia oleracea. The manganese in chlorplasts is commonly thought to exist in two pools. The major pool, corresponding to two-thirds of the manganese, can be reversibly released with concomitant loss of oxygen evolving capacit… more
Date: November 1, 1980
Creator: Kirby, Jon A.; Goodin, D. B.; Robertson, A. S.; Smith, J. P.; Thompson, A. C. & Klein, M. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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