Core photoelectron emission study of binary and ternary indium chlorides. Metal binding energy as a function of oxidation state and other parameters

1984 ◽  
Vol 23 (17) ◽  
pp. 2625-2632 ◽  
Author(s):  
John D. Corbett ◽  
Gerd Meyer ◽  
James W. Anderegg
Keyword(s):  
Binding Energy ◽  
Oxidation State ◽  
Metal Binding ◽  
Photoelectron Emission ◽  
Emission Study

scholarly journals The Biochemical Properties of Manganese in Plants

Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 381 ◽  
Author(s):  
Schmidt ◽  
Husted
Keyword(s):  
Metal Ions ◽  
Oxidation State ◽  
Metal Binding ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Biochemical Properties ◽  
Oxygen Evolving Complex ◽  
Functional Roles ◽  
Catalyzed Reactions ◽  
Enzyme Catalyzed Reactions

Manganese (Mn) is an essential micronutrient with many functional roles in plant metabolism. Manganese acts as an activator and co-factor of hundreds of metalloenzymes in plants. Because of its ability to readily change oxidation state in biological systems, Mn plays and important role in a broad range of enzyme-catalyzed reactions, including redox reactions, phosphorylation, decarboxylation, and hydrolysis. Manganese(II) is the prevalent oxidation state of Mn in plants and exhibits fast ligand exchange kinetics, which means that Mn can often be substituted by other metal ions, such as Mg(II), which has similar ion characteristics and requirements to the ligand environment of the metal binding sites. Knowledge of the molecular mechanisms catalyzed by Mn and regulation of Mn insertion into the active site of Mn-dependent enzymes, in the presence of other metals, is gradually evolving. This review presents an overview of the chemistry and biochemistry of Mn in plants, including an updated list of known Mn-dependent enzymes, together with enzymes where Mn has been shown to exchange with other metal ions. Furthermore, the current knowledge of the structure and functional role of the three most well characterized Mn-containing metalloenzymes in plants; the oxygen evolving complex of photosystem II, Mn superoxide dismutase, and oxalate oxidase is summarized.

Photoelectron Emission Study of Hydrogenated Amorphous Carbon Films Prepared by RF Plasma Chemical Vapor Deposition

1991 ◽  
Vol 30 (Part 2, No. 5B) ◽  
pp. L924-L926 ◽  
Author(s):  
Masatoshi Nakayama ◽  
Kunihiro Ueda ◽  
Masanori Shibahara ◽  
Kazunori Maruyama ◽  
Kiichiro Kamata
Keyword(s):  
Vapor Deposition ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Rf Plasma ◽  
Photoelectron Emission ◽  
Plasma Chemical ◽  
Amorphous Carbon Films ◽  
Plasma Chemical Vapor Deposition ◽  
Emission Study ◽  
Hydrogenated Amorphous

Examination of the proposition that Cu(II) can be required for charge neutrality in a sulfide lattice — Cu in tetrahedrites and sphalerite

2007 ◽  
Vol 85 (10) ◽  
pp. 767-781 ◽  
Author(s):  
Alan N Buckley ◽  
William M Skinner ◽  
Sarah L Harmer ◽  
Allan Pring ◽  
Robert N Lamb ◽  
...  
Keyword(s):  
Binding Energy ◽  
Oxidation State ◽  
Spectroscopic Data ◽  
High Binding Energy ◽  
Surface Species ◽  
Copper Uptake ◽  
Charge Neutrality ◽  
Outermost Layer ◽  
Formal Oxidation State ◽  
Energy Components

Synchrotron XPS and Cu L2,3-edge NEXAFS spectroscopic data for a natural tetrahedrite surface prepared by fracture under UHV were in accord with the composition of the mineral and its expected semiconductivity. The 2p binding energy for the 6-coordinate S atoms was found to be not detectably greater than that for the 4-coordinate S atoms, and surface species were not clearly discernible in either surface-optimized S 2p or Cu 2p spectra. The Cu 2p and Cu L2,3-edge spectra indicated that all Cu in the mineral was indisputably Cu(I). The Cu L2,3-edge spectra of relatively pure natural sphalerite treated with mildly acidic aqueous cupric solution revealed the presence of Cu(II) in the outermost layer of the fracture surfaces, but it was concluded that most of the Cu near the surface of the mineral was in formal oxidation state Cu(I), albeit with higher than normal d9 character. The Cu(I) absorption peak was at an energy much lower than for the tetrahedrite absorption edge, but still consistent with Cu(I) in 4-fold coordination by S. The Cu(II) was consistent with Cu bonded both to S atoms in the outermost layer of the sphalerite and to O atoms in chemisorbed water. S 2p spectra determined at different photon energies revealed high binding energy components arising from oligosulfide-like environments in the outermost layers, but not necessarily in a completely restructured lattice and not in a Cu oligosulfide only. The data indicated some loss of Zn in addition to the Zn that had been replaced by Cu in the outermost layers of the sulfide lattice. The presence of these oligosulfide-like environments precluded the detection of S with formal oxidation state greater than (-II) that might have arisen only from Cu(I) in the S lattice. No evidence was obtained for the presence of Cu(II) in a sulfide lattice, but it was not possible to exclude the possibility of a very low concentration because of the presence of the Cu(II) bonded to both S and O at the surface of the treated sphalerite.Key words: tetrahedrite, sphalerite, copper uptake, XPS, NEXAFS.

Synchrotron Radiation Photoelectron Emission Study of SiO2Film Formed by Hyperthermal O-Atom Beam at Room Temperature

2005 ◽  
Vol 44 (12) ◽  
pp. 8300-8304 ◽  
Author(s):  
Masahito Tagawa ◽  
Chie Sogo ◽  
Kumiko Yokota ◽  
Syunsuke Hachiue ◽  
Akitaka Yoshigoe ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Room Temperature ◽  
Atom Beam ◽  
Photoelectron Emission ◽  
Emission Study

A photoelectron emission study of conducting polymer/metal interfaces

1999 ◽  
Vol 102 (1-3) ◽  
pp. 975 ◽  
Author(s):  
Mitsuyoshi Onoda ◽  
Kazuya Tada ◽  
Hiroshi Nakayama
Keyword(s):  
Conducting Polymer ◽  
Photoelectron Emission ◽  
Polymer Metal ◽  
Metal Interfaces ◽  
Emission Study
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