Optical study of electrons and positive ions in pulse-irradiated liquid 3-methyloctane at low temperatures

1977 ◽  
Vol 55 (11) ◽  
pp. 2022-2029 ◽  
Author(s):  
Hugh A. Gillis ◽  
Norman V. Klassen ◽  
Robert J. Woods
Keyword(s):  
Charge Transfer ◽  
Decay Rate ◽  
Radical Cation ◽  
Low Temperatures ◽  
Optical Study ◽  
Solvated Electron ◽  
Positive Ions ◽  
Higher Hydrocarbons ◽  
Resonance Charge ◽  
Positive Ion

The spectrum of pulse-irradiated liquid 3-methyloctane at 127 K has maxima around 625 and 2100 nm. The latter is well-known as being due to the solvated electron (es−). The former is attributed to a positive ion because it is eliminated by the addition of triethylamine, but remains in solutions of electron scavengers, and is very similar to bands observed earlier by Louwrier and Hamill in glassy solutions at 77 K of higher hydrocarbons in CCl4 or CO2-bubbled 3-methylpentane. At temperatures of 127 K and less the initial decay rate of es− is greatly decreased by the addition of ∼6mol% triethylamine. The result is interpreted as indicating that at low temperatures the mobility of the initial hydrocarbon positive ion is much greater than that of either es− or the positive ion in triethylamine solutions, and therefore the initial hydrocarbon positive ion must be the parent radical cation which moves by resonance charge transfer. As the temperature of pure 3-methyloctane is raised from 103 to 153 K, the initial Gε650 decreases by about 30% while initial Gε2100 almost doubles; because of these and other observations it is tentatively suggested that a second solvated electron is also produced.

scholarly journals New Radical Cation Salts Based on BDH-TTP Donor: Two Stable Molecular Metals with a Magnetic [ReF6]2− Anion and a Semiconductor with a [ReO4]− Anion

2021 ◽  
Vol 7 (4) ◽  
pp. 54
Author(s):  
Nataliya D. Kushch ◽  
Gennady V. Shilov ◽  
Lev I. Buravov ◽  
Eduard B. Yagubskii ◽  
Vladimir N. Zverev ◽  
...  
Keyword(s):  
Radical Cation ◽  
Low Temperatures ◽  
Ac Susceptibility ◽  
Slow Relaxation ◽  
Organic Radical ◽  
Inorganic Anion ◽  
Distinctive Features ◽  
Metallic Character ◽  
Radical Cation Salts ◽  
Partial Population

Three radical cation salts of BDH-TTP with the paramagnetic [ReF6]2− and diamagnetic [ReO4]− anions have been synthesized: κ-(BDH-TTP)4ReF6 (1), κ-(BDH-TTP)4ReF6·4.8H2O (2) and pseudo-κ″-(BDH-TTP)3(ReO4)2 (3). The crystal and band structures, as well as the conducting properties of the salts, have been studied. The structures of the three salts are layered and characterized by alternating κ-(1, 2) and κ″-(3) type organic radical cation layers with inorganic anion sheets. Similar to other κ-salts, the conducting layers in the crystals of 1 and 2 are formed by BDH-TTP dimers. The partial population of positions of Re atoms and disorder in the anionic layers of 1–3 are their distinctive features. Compounds 1 and 2 show the metallic character of conductivity down to low temperatures, while 3 is a semiconductor. The ac susceptibility of crystals 1 was investigated in order to test the possible slow relaxation of magnetization associated with the [ReF6]2− anion.

Optical Study of the Fe3+-Related Emission at 0.5 eV in InP:Fe

1992 ◽  
Vol 262 ◽  
Author(s):  
Klaus Pressel ◽  
G. Bohnert ◽  
A. Dörnen ◽  
K. Thonke
Keyword(s):  
Fourier Transform ◽  
Fine Structure ◽  
Charge Transfer ◽  
Transfer Process ◽  
Decay Time ◽  
Optical Study ◽  
Charge Transfer Process ◽  
Excitation Mechanism ◽  
Different Temperatures ◽  
A Charge

ABSTRACTThe 0.5 eV (2.5 μm 4000 cm1) emission band in InP has been studied by optical spectroscopy. By the use of Fourier-transform-infrared photoluminescence we have been able to observe at least a three-fold fine structure in the zero-phonon transitions at ∼ 4300 cm−1 which are studied at different temperatures. Based on the fine structure and the long decay time of 1.1 ms we ascribe the 0.5 eV emission to the 4T1 → 6A1 spin-flip transition of Fe3+. The excitation spectrum of this Fe3+-related emission shows a characteristic fine structure at ∼ 1.13 eV which belongs to a charge-transfer process of the type: Fe3+ + hv (1.13 eV) → [Fe2+, bound hole]. We discuss the excitation mechanism of the 0.5 eV emission by charge-transfer states and compare the results with an emission at 3057 cm1 in GaAs, which we attribute to the same Fe3+ transition (decay time: 1.9 ms).

Note on radiationless transitions involving three-body collisions

1936 ◽  
Vol 32 (3) ◽  
pp. 482-485 ◽  
Author(s):  
R. A. Smith
Keyword(s):  
Continuous Spectrum ◽  
Negative Ions ◽  
Bound State ◽  
Excess Energy ◽  
Negative Ion ◽  
Positive Ions ◽  
Continuous State ◽  
Direct Formation ◽  
Three Body ◽  
Positive Ion

When an electron makes a transition from a continuous state to a bound state, for example in the case of neutralization of a positive ion or formation of a negative ion, its excess energy must be disposed of in some way. It is usually given off as radiation. In the case of neutralization of positive ions the radiation forms the well-known continuous spectrum. No such spectrum due to the direct formation of negative ions has, however, been observed. This process has been fully discussed in a recent paper by Massey and Smith. It is shown that in this case the spectrum would be difficult to observe.

Dissociation chemistry of the hydrogen-bridged radical cation [CH2O ⋯ H ⋯ OC–OCH3]·+: proton transport catalysis and charge transfer

2000 ◽  
Vol 195-196 ◽  
pp. 85-99 ◽  
Author(s):  
Lorne M Fell ◽  
Paul J.A Ruttink ◽  
Peter C Burgers ◽  
Moschoula A Trikoupis ◽  
Johan K Terlouw
Keyword(s):  
Charge Transfer ◽  
Radical Cation ◽  
Proton Transport ◽  
Dissociation Chemistry

scholarly journals Effects of the Distributions of Energy or Charge Transfer Rates on Spectral Hole Burning in Pigment–Protein Complexes at Low Temperatures

2011 ◽  
Vol 115 (50) ◽  
pp. 15098-15109 ◽  
Author(s):  
Nicoleta Herascu ◽  
Somaya Ahmouda ◽  
Rafael Picorel ◽  
Michael Seibert ◽  
Ryszard Jankowiak ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Low Temperatures ◽  
Protein Complexes ◽  
Hole Burning ◽  
Spectral Hole Burning ◽  
Transfer Rates ◽  
Spectral Hole ◽  
Pigment Protein Complexes

scholarly journals An overview of the cycloaddition chemistry of fulvenes and emerging applications

2019 ◽  
Vol 15 ◽  
pp. 2113-2132
Author(s):  
Ellen Swan ◽  
Kirsten Platts ◽  
Anton Blencowe
Keyword(s):  
Natural Products ◽  
Charge Transfer ◽  
Electronic Properties ◽  
Combinatorial Chemistry ◽  
Low Temperatures ◽  
Charge Transfer Complexes ◽  
Reference Source ◽  
Materials Chemistry ◽  
Dynamic Combinatorial Chemistry ◽  
Cyclic Adducts

The unusual electronic properties and unique reactivity of fulvenes have interested researchers for over a century. The propensity to form dipolar structures at relatively low temperatures and to participate as various components in cycloaddition reactions, often highly selectively, makes them ideal for the synthesis of complex polycyclic carbon scaffolds. As a result, fulvene cycloaddition chemistry has been employed extensively for the synthesis of natural products. More recently, fulvene cycloaddition chemistry has also found application to other areas including materials chemistry and dynamic combinatorial chemistry. This highlight article discusses the unusual properties of fulvenes and their varied cycloaddition chemistry, focussing on applications in organic and natural synthesis, dynamic combinatorial chemistry and materials chemistry, including dynamers, hydrogels and charge transfer complexes. Tables providing comprehensive directories of fulvene cycloaddition chemistry are provided, including fulvene intramolecular and intermolecular cycloadditions complete with reactant partners and their resulting cyclic adducts, which provide a useful reference source for synthetic chemists working with fulvenes and complex polycyclic scaffolds.

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