Origin of the diffuse interstellar absorption bands - Transition metal ions in oxide grains

1979 ◽  
Vol 227 ◽  
pp. 824 ◽  
Author(s):  
W. W. Duley
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
Absorption Bands ◽  
Interstellar Absorption

Calculation of crystal field splittings in distorted coordination polyhedra: spectra and thermodynamic properties of minerals

1972 ◽  
Vol 38 (300) ◽  
pp. 909-917 ◽  
Author(s):  
Bernard J. Wood ◽  
R. G. J. Strens
Keyword(s):  
Charge Transfer ◽  
Transition Metal ◽  
Metal Ions ◽  
Crystal Field ◽  
Transition Metal Ions ◽  
Orbital Energy ◽  
Absorption Bands ◽  
Simple Method ◽  
Coordination Polyhedra ◽  
Metal Metal

SummaryA simple method has been developed for calculating the d-orbital energy levels of transition-metal ions in coordination polyhedra with both orthogonal and non-orthogonal distortions, using equations based on those derived by Ballhausen (1954). The input data are atomic coordinates, a standard value of the crystal field splitting parameter Δ at known metal-ligand distance, and the ratio of radial integrals B2/B4, which is approximately constant for a given ion. The method can be applied to polyhedra containing different ligands.Application of the equations to the Mn3+ (M3) site in piemontite and the Fe2+ (M2) site in orthopyroxene gives calculated transition energies in good agreement with the observed band energies.The calculations permit definite assignment of the great majority of d-d absorption bands even in multi-site phases, and enable discrimination of crystal-field and charge-transfer bands in mineral spectra. They also throw light on the fine structures of both oxygen → metal and metal → metal charge-transfer bands, and allow the calculation of crystal-field stabilization enthalpy and electronic entropy. The latter is a previously neglected energy term that contributes significantly to the energetics of reactions within and between phases containing transition-metal ions.

High-energy optical-absorption bands of transition-metal ions in fluoride host crystals

1975 ◽  
Vol 11 (10) ◽  
pp. 3832-3841 ◽  
Author(s):  
Joseph F. Sabatini ◽  
Arthur E. Salwin ◽  
Donald S. McClure
Keyword(s):  
Transition Metal ◽  
Optical Absorption ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
High Energy ◽  
Absorption Bands

scholarly journals Selective Chromogenic Recognition of Copper(II) Ion by Thiacalix[4]arene Tetrasulfonate and Mechanism

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 612 ◽  
Author(s):  
Shufang Zhu ◽  
Lilin Lu
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Density Functional ◽  
Color Change ◽  
Bathochromic Shift ◽  
Transition Metal Ions ◽  
Water Soluble ◽  
Ion Concentration ◽  
Absorption Bands ◽  
Simple Method

Detection of biologically important transition metal ions such as copper by using a simple method is desirable and of great importance. In this work, we firstly reported that water-soluble thiacalix[4]arene tetrasulfonate (TCAS) exhibited selective chromogenic recognition towards copper(II) ion over other transition metal ions. Color change from colorless to salmon pink was observed in TCAS solution, weak bathochromic shift was induced in UV absorption spectrum of TCAS upon addition of copper(II) ion, and the absorbance of characteristic absorption band at 312 nm increased linearly with copper(II) ion concentration. The recognition mechanism of TCAS to copper(II) ion was investigated by a comparative study with calix[4]arene tetrasulfonate (CAS) and time-dependent density functional theory(TD-DFT) study, and the absorption bands were assigned based on transition orbital analysis.

HREM Study of electron-induced surface radiation damage in ReO3

1991 ◽  
Vol 49 ◽  
pp. 636-637
Author(s):  
R. Ai ◽  
H.-J. Fan ◽  
L. D. Marks
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Oxides ◽  
Electron Irradiation ◽  
Transition Metal Oxides ◽  
Carbon Film ◽  
Transition Metal Ions ◽  
Surface Radiation ◽  
Valence Transition ◽  
Electron Microscopes

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.

Binary and ternary complexes of some inner transition metal ions with amino acids and acetyl acetone

1998 ◽  
Vol 95 (5) ◽  
pp. 1068-1090 ◽  
Author(s):  
R. H. Abu-Eittah ◽  
M. M. Abdou ◽  
M. B. Salem
Keyword(s):  
Amino Acids ◽  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
Ternary Complexes ◽  
Binary And Ternary Complexes ◽  
Acetyl Acetone

EPR of Transition-Metal Ions on the Surfaces ofγ-Al2O3, ZnO and Mg(OH)2

1990 ◽  
Vol 166 (Part_2) ◽  
pp. 233-248 ◽  
Author(s):  
T. Böttjer ◽  
G. Lehmann
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions

Synthesis, Spectral and Antimicrobial Investigation of 2-(Naphthalenel-ylamino)-2- Phenylacetonitrile and 1, 10-Phenanthroline with Five Divalent Transition Metal Ions

2019 ◽  
Vol 10 (01) ◽  
Author(s):  
Mohammed Al-Amery1 ◽  
Ashraf Saad Rasheed ◽  
Dina A. Najeeb
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
Molar Conductance ◽  
Octahedral Geometry ◽  
Mixed Ligand ◽  
Gram Negative Bacteria ◽  
Magnetic Studies ◽  
Gram Positive Bacteria

Five new mixed ligand metal complexes have been synthesized by the reaction of divalent transition metal ions (Hg, Ni, Zn, Cu and Cd) with 2-(naphthalen-l-ylamino)-2-phenylacetonitrile (L1 ) and 1,10-phenanthroline (L2). The coordination likelihood of the two ligands toward metal ions has been suggested in the light of elemental analysis, UV-Vis spectra, FTIR, 1H-NMR, flam atomic absorption, molar conductance and magnetic studies. Results data suggest that the octahedral geometry for all the prepared complexes. Antibacterial examination of synthesized complexes in vitro was performed against four bacterias. Firstly, Gram-negative bacteria namely, Pseudomonas aerugin and Escherichia. Secondly, Gram-positive bacteria namely, Bacillus subtilis, Staphylococcuaurouss. Results data exhibit that the synthesized complexes exhibited more biological activity than tetracycline pharmaceutical.

Bond-length distributions for ions bonded to oxygen: Metalloids and post-transition metals

2017 ◽  
Author(s):  
Olivier Charles Gagné ◽  
Frank Christopher Hawthorne
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Metal Ions ◽  
Bond Length ◽  
Lone Pair ◽  
Transition Metal Ions ◽  
Oxygen Lone Pair

Bond-length distributions are examined for thirty-three configurations of the metalloid ions and fifty-six configurations of the post-transition-metal ions bonded to oxygen. Lone-pair stereoactivity is discussed.

Bond-length distributions for ions bonded to oxygen: Metalloids and post-transition metals

2017 ◽  
Author(s):  
Olivier Charles Gagné ◽  
Frank Christopher Hawthorne
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Metal Ions ◽  
Bond Length ◽  
Lone Pair ◽  
Transition Metal Ions ◽  
Oxygen Lone Pair

Bond-length distributions are examined for thirty-three configurations of the metalloid ions and fifty-six configurations of the post-transition-metal ions bonded to oxygen. Lone-pair stereoactivity is discussed.

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