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.

Pulse Radiolytic Formation of Solvated Electrons, Ion-pairs, and Alkali Metal Anions in Tetrahydrofuran

1974 ◽  
Vol 52 (18) ◽  
pp. 3259-3268 ◽  
Author(s):  
G. A. Salmon ◽  
W. A. Seddon ◽  
J. W. Fletcher
Keyword(s):  
Alkali Metal ◽  
Alkali Metals ◽  
Dissociation Constants ◽  
Alkali Metal Cation ◽  
Ion Pairs ◽  
Alkali Metal Cations ◽  
Solvated Electrons ◽  
Sodium Potassium ◽  
Sodium And Potassium ◽  
Metal Anions

Pulse radiolysis of solutions of alkali metal cations in tetrahydrofuran (THF) demonstrates the formation of solvated electrons es−, alkali metal cation-ion pairs (M+, es−), and alkali metal anions M−. This paper describes the spectra, extinction coefficients, and radiolytic yields of es−, lithium, sodium, potassium, and cesium species in THF. The reaction kinetics are complex but largely involve reactions A and B[Formula: see text]with the concomitant disappearance of all three species by reaction with radiolytically produced radicals. Rate constants and ion-pair dissociation constants for es− and the sodium and potassium species are presented and compared with data established from studies of blue solutions of alkali metals dissolved in THF.

Axle component separated ion-pair recognition by a neutral heteroditopic [2]rotaxane

2014 ◽  
Vol 50 (13) ◽  
pp. 1540-1542 ◽  
Author(s):  
Richard C. Knighton ◽  
Paul D. Beer
Keyword(s):  
Alkali Metal ◽  
Metal Cation ◽  
Alkali Metal Cation ◽  
Ion Pairs ◽  
Ion Pair ◽  
Sodium Cation ◽  
Halide Anion ◽  
Cooperative Recognition

A neutral heteroditopic pyridine N-oxide axle containing [2]rotaxane, synthesised via sodium cation templation, displays cooperative recognition of alkali metal cation-halide anion ion-pairs in an unprecedented axle component separated ion-pair binding fashion.

Correlation of optical and electron spin resonance spectra for alkali metal solutions in ethylamine and tetrahydrofuran

1976 ◽  
Vol 54 (19) ◽  
pp. 3110-3113 ◽  
Author(s):  
R. Catterall ◽  
J. Slater ◽  
W. A. Seddon ◽  
J. W. Fletcher
Keyword(s):  
Electron Spin Resonance ◽  
Optical Absorption ◽  
Alkali Metal ◽  
Electron Spin ◽  
Hyperfine Splitting ◽  
Pulse Radiolysis ◽  
Optical Absorption Spectra ◽  
Monomeric Species ◽  
Spin Resonance ◽  
Sodium Tetraphenylboron

The band maxima of transient optical absorption spectra observed by pulse radiolysis in ethylamine (EA)/tetrahydrofuran (THF) mixtures containing sodium tetraphenylboron are correlated with electron spin resonance (esr) hyperfine splitting constants obtained in potassium/EA/THF solutions. The data suggest that the optical spectra can be attributed to the same 'monomeric' species as observed by esr in alkali metal solutions.

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.

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