scholarly journals New Insights into the Chemistry of Oxovanadium(IV) Complexes with N4 Coordinating Ligands

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Ashok Kumar Yadava ◽  
Hardeo Singh Yadav ◽  
Uma Shanker Yadav ◽  
Devendra Pratap Rao
Keyword(s):  
Chelating Agents ◽  
Magnetic Moments ◽  
Molar Conductance ◽  
In Situ Method ◽  
Vanadyl Ion ◽  
Spin Resonance ◽  
Elemental Analyses ◽  
Resonance Data ◽  
Electron Spin Resonance Data

The syntheses of new oxovanadium(IV) complexes having general formula [VO(mac)]SO4 have been carried out by using in situ method of preparation where vanadyl ion acts as kinetic template for the ligands derived by condensation of 2,2′-pyridil with 1,2-diaminopropane and 1,3-diaminopropane. The complexes were characterized by elemental analyses, molar conductance, magnetic moments, and spectral (infrared, electronic, and electron spin resonance) data. All the oxovanadium(IV) complexes are five coordinate wherein derived ligands act as tetradentate chelating agents.

scholarly journals Synthesis of Oxovanadium(IV) Complexes with Tetraaza Coordinating Ligands

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Sanjay Singh ◽  
Hardeo S. Yadav ◽  
Ashok Kumar Yadava ◽  
Devendra Pratap Rao
Keyword(s):  
Magnetic Moments ◽  
Spectroscopic Studies ◽  
Molar Conductance ◽  
Pyramidal Geometry ◽  
Vanadyl Ion ◽  
Spin Resonance ◽  
Elemental Analyses ◽  
Resonance Data ◽  
Electron Spin Resonance Data ◽  
Square Pyramidal Geometry

Oxovanadium(IV) complexes of the type [VO(mac)]SO4(where mac = tetraaza macrocyclic ligands derived by condensation of thenil with 1,4-diaminobenzene or 3,4-diaminopyridine and their reaction withβ-diketones) have been prepared using vanadyl ion as kinetic template. The prepared macrocyclic complexes were characterized by elemental analyses, molar conductance, magnetic moments, and infrared, electronic, and electron spin resonance data. From the spectroscopic studies, five-coordinate square-pyramidal geometry for the VO2+complexes have been proposed wherein derived ligands act as tetradentate chelating agents.

Solvated electrons and the effect of coordination on the optical spectra of alkali metal cation – electron pairs in ethers

1977 ◽  
Vol 55 (19) ◽  
pp. 3356-3363 ◽  
Author(s):  
William Arthur Seddon ◽  
John Wallace Fletcher ◽  
Fred Charles Sopchyshyn ◽  
Ron Catterall
Keyword(s):  
Alkali Metal ◽  
Alkali Metal Cation ◽  
Ion Pairs ◽  
Alkali Metal Salts ◽  
Solvated Electrons ◽  
Electron Pairs ◽  
Monomeric Species ◽  
Spin Resonance ◽  
Resonance Data ◽  
Electron Spin Resonance Data

Pulse radiolysis of tetrahydrofuran (THF), dimethoxyethane (DME), diglyme (DG), and triglyme (TG), results in the formation of solvated electrons, es−, with optical band maxima λmax ≥ 1840 nm. In the presence of alkali metal salts transient optical bands are observed with λmax at ∼900 and ≥1600 nm. The latter bands are assigned to the formation of 'monomeric' species of stoichiometry M considered to be 'tight' and 'loose' ion-pairs, respectively. The proportion of 'loose' ion-pairs increases with decreasing temperature and increasing coordination of the solvent in the order [Formula: see text] These results demonstrate a good correlation with established electron spin resonance data in alkali metal solutions and substantiate the coexistence of at least two 'monomeric' species in DME and the glymes.

Stability in Amorphous Silicon

1987 ◽  
Vol 95 ◽  
Author(s):  
Z E. Smith ◽  
S. Wagner
Keyword(s):  
Electron Spin Resonance ◽  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Thermal Recovery ◽  
Defect States ◽  
Spin Resonance ◽  
Resonance Data ◽  
Electron Spin Resonance Data ◽  
Gap States ◽  
Hydrogenated Amorphous

AbstractThe experimental phenomena associated with light-induced degradation and thermal recovery of hydrogenated amorphous silicon (a-Si:H) films are reviewed, with special emphasis on the limitations of each experimental technique. When several techniques are used in concert, a fuller picture emerges. Recent experiments suggest different positions in the band-gap of the paramagnetic-associated defect states (the dangling bonds) for doped and undopedfilms; this information can be combined with conductivity, sub-bandgap optical absorption and electron spin resonance data to yield a model for the density of gap states (DOS) in a- Si:H, including how the DOS changes upon illumination and annealing.

Conducting and Antistatic Composites for Space Applications

2004 ◽  
Vol 851 ◽  
Author(s):  
Mircea Chipara ◽  
Jagannathan Sankar ◽  
Petre Notinger ◽  
Denis Panaitescu ◽  
David Hui ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Dc Conductivity ◽  
Filler Concentration ◽  
Space Applications ◽  
Polymeric Matrices ◽  
Spin Resonance ◽  
Resonance Data ◽  
Electron Spin Resonance Data ◽  
Polyaniline Composites

ABSTRACTThe percolative dependence of the DC conductivity on the volume concentration of fillers for composites obtained by dispersing conducting particles into polymeric matrices is studied in detail. An empirical Boltzmann like dependence is proposed for the modeling of the dependence of DC conductivity versus filler concentration. This expression allows for a more accurate determination of the percolation threshold in the case of broad percolations. It is shown that the loading of the polymeric matrices with conducting fillers produces percolative-like changes of various physical properties (such as the reciprocal of the tensile strength and the reciprocal of the double integral of the resonance spectrum). Experimental mechanical, electrical, and electron spin resonance data on polyvinylchloride-carbon, polyvinylchloride-polyaniline, and polyethylene-polyaniline composites are reported.

scholarly journals A new method for determining the concentration of vanadyl ions in clays

2011 ◽  
Vol 62 (2) ◽  
pp. 181-186 ◽  
Author(s):  
Pavle Premović ◽  
Budimir Ilić ◽  
Dragan Đorđević
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Room Temperature ◽  
Esr Spectra ◽  
New Method ◽  
Simple Method ◽  
Routine Work ◽  
Spin Resonance ◽  
Resonance Data ◽  
Electron Spin Resonance Data

A new method for determining the concentration of vanadyl ions in claysA novel and simple method for quantitatively determining the concentration of vanadyl ions in clays using electron spin resonance data has been developed. Several vanadyl standards with concentrations between 200-1000 ppm were prepared in a mixture of glycerol and kaolinite (KGa-2). The anisotropic electron spin resonance (ESR) spectra were recorded at room temperature, and the specific intensity of the line (attributed to nuclear spin m = -5/2||) was determined. For vanadyl concentrations between 50 ppm and 200 ppm, the standards must be prepared by mixing kaolinite with known vanadyl content (FBT2A-03) and kaolinite (GB1) containing no vanadyl. The method is applicable without modification to other clays and clay-rich sediments containing vanadyl ions. The whole procedure is very suitable for routine work.

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