Experimental and Theoretical Approaches to Redox Innocence of Ligands in Uranyl Complexes: What Is Formal Oxidation State of Uranium in Reductant of Uranyl(VI)?

2014 ◽  
Vol 53 (11) ◽  
pp. 5772-5780 ◽  
Author(s):  
Koichiro Takao ◽  
Satoru Tsushima ◽  
Toshinari Ogura ◽  
Taro Tsubomura ◽  
Yasuhisa Ikeda
Keyword(s):  
Oxidation State ◽  
Uranyl Complexes ◽  
Formal Oxidation State ◽  
Theoretical Approaches

scholarly journals Selenium– and tellurium–halogen reagents

2018 ◽  
Vol 3 (12) ◽  
Author(s):  
Tristram Chivers ◽  
Risto S. Laitinen
Keyword(s):  
Oxidation State ◽  
Halogen Bond ◽  
The Other ◽  
Oxidation States ◽  
Alkyl Aryl ◽  
Organic Selenium ◽  
Formal Oxidation State ◽  
Wide Range ◽  
Inorganic And Organic

Abstract Selenium and tellurium form binary halides in which the chalcogen can be in formal oxidation states (IV), (II) or (I). They are versatile reagents for the preparation of a wide range of inorganic and organic selenium and tellurium compounds taking advantage of the reactivity of the chalcogen–halogen bond. With the exception of the tetrafluorides, the tetrahalides are either commercially available or readily prepared. On the other hand, the low-valent species, EX2 (E = Se, Te; X = Cl, Br) and E2X2 (E = Se, Te; X = Cl, Br) are unstable with respect to disproportionation and must be used as in situ reagents. Organoselenium and tellurium halides are well-known in oxidation states (IV) and (II), as exemplified by REX3, R2EX2 and REX (R = alkyl, aryl; E = Se, Te; X = F, Cl, Br, I); mixed-valent (IV/II) compounds of the type RTeX2TeR are also known. This chapter surveys the availability and/or preparative methods for these widely used reagents followed by examples of their applications in synthetic inorganic and organic selenium and tellurium chemistry. For both the binary halides and their organic derivatives, the discussion is subdivided according to the formal oxidation state of the chalcogen.

Über Derivate des Hydrazins, VII Zur Reaktivität von Bis(trimethylsilyl)aminoisocyanid / On Derivatives of Hydrazine, VII Reactivity of Bis(trimethylsilyl)aminoisocyanide

1977 ◽  
Vol 32 (9) ◽  
pp. 1003-1009 ◽  
Author(s):  
Nils Wiberg ◽  
Gerhard Hübler
Keyword(s):  
Double Bond ◽  
Oxidation State ◽  
Ring Cleavage ◽  
Reaction Paths ◽  
Stable Compound ◽  
Oxidizing Agents ◽  
Formal Oxidation State ◽  
Double Bond System ◽  
Bond System ◽  
Derivatives Of

The chemistry of bis(trimethylsilyl)aminoisocyanide (1) is determined by three reactive centres of the system : the hydrolyzable Si–N-bond, the oxidizable carbon in the formal oxidation state two, the additionable double bond system. Reactions of the oxygen stable compound 1 with halogens X2 or sulfenyl halides RSX as oxidizing agents gives compounds of type (Me3Si)2NNCX2 or (Me3Si)2NNCX(SR). Heterocumulenes such as CO2, CS2, RNCS (R = (Me3Si)2N), SO2 add to 1, leading to heterocycles, which decompose at higher temperatures by ring cleavage. With other heterocumulenes such as PhNCO, Me3SiNSO, Me3SiNSNSiMe3 products are found, the formation of which could be explained by reaction paths including the building and cleavage of heterocycles.

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.

Formal Oxidation State versus Partial Charge—A Comment

1995 ◽  
Vol 34 (9) ◽  
pp. 986-986 ◽  
Author(s):  
Martin Kaupp ◽  
Hans Georg von Schnering
Keyword(s):  
Oxidation State ◽  
Partial Charge ◽  
Formal Oxidation State

Is rhodium tetroxide in the formal oxidation state VIII stable? a quantum chemical and matrix isolation investigation of rhodium oxides

2011 ◽  
Vol 129 (3-5) ◽  
pp. 667-676 ◽  
Author(s):  
Yu Gong ◽  
Mingfei Zhou ◽  
Lester Andrews ◽  
Tobias Schlöder ◽  
Sebastian Riedel
Keyword(s):  
Oxidation State ◽  
Quantum Chemical ◽  
Matrix Isolation ◽  
Formal Oxidation State ◽  
Rhodium Oxides
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