Cross Sections and Rate Constants for Charge Transfer into Excited States

2006 ◽  
Vol 3 (2) ◽  
pp. 147-150 ◽  
Author(s):  
Krassimir A. Temelkov ◽  
Nikolay K. Vuchkov ◽  
Nikola V. Sabotinov
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Cross Sections ◽  
Rate Constants

Optische Anregung beim Ladungsaustausch von Edelgasionen für Stoßenergien von 5 bis 300 eVolt

1968 ◽  
Vol 23 (7) ◽  
pp. 970-978
Author(s):  
H. Schlumbohm
Keyword(s):  
Charge Transfer ◽  
Kinetic Energy ◽  
Internal Energy ◽  
Excited States ◽  
Cross Sections ◽  
Ground Level ◽  
High Rate ◽  
Transfer Processes ◽  
The Cross ◽  
Threshold Energies

Measurements of the photoemission caused by collisions of ground level He+- and Ne+-ions with Ar- and Kr-atoms have shown several multipletts of Ar II and Kr II within the investigated wavelength range of 3500 to 5500 A. At a high rate the charge transfer processes occur into excited states of Ar* and Kr*. The reactions are endothermic with a deficit of internal energy between 6 and 19 eV.The cross sections measured for several chosen transitions start at characteristic threshold energies between 10 and 25 eV. Above the threshold the cross sections rise slowly with increasing energy when Ne* is the colliding ion and very fast for He+. Above 50 to 100 eV the cross sections show nearly constant values. — The minimum kinetic energy values are calculated, which can just fill up the deficits of internal energy, and are shown to be equal to the measured threshold energies. Thus it follows that the pseudo-crossing of the potential energy curves of the quasimolecules occurs at an energy value equal to the asymptotic level of the above curve.

An experimental study of charge transfer in proton-atomic hydrogen collisions at impact energies above 40 keV

1966 ◽  
Vol 291 (1426) ◽  
pp. 438-443 ◽  
Keyword(s):  
Charge Transfer ◽  
Proton Beam ◽  
Excited States ◽  
Cross Section ◽  
Cross Sections ◽  
Atomic Hydrogen ◽  
Total Cross Sections ◽  
Charge Transfer Cross Section ◽  
Impact Energies ◽  
Beam Technique

The crossed beam technique has been used to study charge transfer in proton-atomic hydrogen collisions between 40 and 130 keV. A proton beam from a Van de Graaff accelerator was arranged to intersect a modulated beam of atomic hydrogen derived from a furnace source. The flux of fast neutral atoms produced by charge transfer in the beam intersection region was measured by a method based on double electrostatic deflexion of the proton beam. The ratio of the charge transfer cross section Q 1 in atomic hydrogen to that in molecular hydrogen Q 2 was determined by comparing the signals when the beam from the furnace was mainly atomic and when the beam was entirely molecular. Above 50 keV, measured ratios Q 1 / Q 2 were consistently less than ½. Absolute values of Q 1 , which represent total cross sections for capture into all states of atomic hydrogen, were obtained by reference to known values of Q 2 . Above 50 keV, the results agree fairly well with theoretical values due to Jackson & Schiff. When considered in conjunction with the low energy data of Fite and his collaborators, the results suggest that capture into excited states in the range 20 to 50 keV occurs to a greater extent than that predicted by Jackson & Schiff.

Charge transfer from low-lying excited states: effects on reactive thermal conductivity

1975 ◽  
Vol 14 (2) ◽  
pp. 365-371 ◽  
Author(s):  
M. Capitelli
Keyword(s):  
Thermal Conductivity ◽  
Charge Transfer ◽  
Excited States ◽  
Cross Sections ◽  
Nitrogen Plasma ◽  
Total Thermal Conductivity ◽  
A Minor ◽  
And Diffusion ◽  
Thermal Conductivity Λ ◽  
Minor Extent

Charge transfer and diffusion cross-sections of low-lying excited states are calculated usingab initioquantum-mechanical potential-energy curves. These data are used to calculate the reactive thermal conductivity λRof an atmospheric nitrogen plasma. Differences of up to 20 % are found between the present values of λRand the corresponding values obtained by increasing the cross-sections of excited states by a factor of 2. These differences propagate, to a minor extent (10 %), in the total thermal conductivity.

Theoretical Studies on Phosphorescent Materials: The Conjugation-Extended PtII Complexes

2014 ◽  
Vol 67 (10) ◽  
pp. 1522 ◽  
Author(s):  
Ai-Hua Liang ◽  
Fu-Quan Bai ◽  
Jian Wang ◽  
Jian-Bo Ma ◽  
Hong-Xing Zhang
Keyword(s):  
Charge Transfer ◽  
Decay Rate ◽  
Excited States ◽  
Rate Constants ◽  
Radiative Decay ◽  
Theoretical Study ◽  
Radiative Decay Rate ◽  
Ligand Charge Transfer ◽  
Emission Transition ◽  
Transfer Properties

A theoretical study on the PtII complex A based on a dimesitylboron (BMes2)-functionalized [Pt(C^N)(acac)] (C^N = 2-phenyl-pyridyl, acac = acetylaceton) complex, as well as three conjugation-extended analogues of the methylimidazole (C*) ligand BMes2-[Pt(C^C*)(acac)] complexes B–D is performed. Their theoretical geometries, electronic structures, emission properties, and the radiative decay rate constants (kr) were also investigated. The energy differences between the two highest occupied orbitals with dominant Pt d-orbital components (Δddocc) of D both at the ground and excited states are the smallest of all. Compared with B, the charge transfer in D possesses a marked trend towards the extended conjugated group, while C changed inconspicuously. The lowest-lying absorptions and the phosphorescence of them can be described as a mixed metal-to-ligand charge transfer (MLCT)/intra-ligand π→π* charge transfer (ILCT) and 3MLCT/3ILCT, respectively. The variation of charge transfer properties induced by extended conjugation and the radiative decay rate constants (kr) calculated revealed that D is a more efficient blue phosphorescence material with a 497 nm emission transition.

Synthesis and Photochemical Properties of Re(I) Tricarbonyl Complexes Bound to Thione and Thiazole-2-ylidene Ligands

2020 ◽  
Author(s):  
Matthew Stout ◽  
Brian Skelton ◽  
Alexandre N. Sobolev ◽  
Paolo Raiteri ◽  
Massimiliano Massi ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Ligand Exchange ◽  
Ligand Substitution ◽  
Bidentate Ligand ◽  
The Other ◽  
Ligand Exchange Reaction ◽  
Multiple Products ◽  
Ligand Charge Transfer ◽  
Photochemical Properties

<p>Three Re(I) tricarbonyl complexes, with general formulation Re(N^L)(CO)<sub>3</sub>X (where N^L is a bidentate ligand containing a pyridine functionalized in the position 2 with a thione or a thiazol-2-ylidene group and X is either chloro or bromo) were synthesized and their reactivity explored in terms of solvent-dependent ligand substitution, both in the ground and excited states. When dissolved in acetonitrile, the complexes bound to the thione ligand underwent ligand exchange with the solvent resulting in the formation of Re(NCMe)<sub>2</sub>(CO)<sub>3</sub>X. The exchange was found to be reversible, and the starting complex was reformed upon removal of the solvent. On the other hand, the complexes appeared inert in dichloromethane or acetone. Conversely, the complex bound to the thiazole-2-ylidene ligand did not display any ligand exchange reaction in the dark, but underwent photoactivated ligand substitution when excited to its lowest metal-to-ligand charge transfer manifold. Photolysis of this complex in acetonitrile generated multiple products, including Re(I) tricarbonyl and dicarbonyl solvato-complexes as well as free thiazole-2-ylidene ligand.</p>

Fluorescence Quenching of Aminodiphenylamines with Chloromethanes

2002 ◽  
Vol 67 (8) ◽  
pp. 1154-1164 ◽  
Author(s):  
Nachiappan Radha ◽  
Meenakshisundaram Swaminathan
Keyword(s):  
Charge Transfer ◽  
Fluorescence Quenching ◽  
Ground State ◽  
Rate Constants ◽  
Quenching Mechanism ◽  
Quenching Rate ◽  
Charge Transfer Interaction ◽  
Electronically Excited ◽  
A Charge

The fluorescence quenching of 2-aminodiphenylamine (2ADPA), 4-aminodiphenylamine (4ADPA) and 4,4'-diaminodiphenylamine (DADPA) with tetrachloromethane, chloroform and dichloromethane have been studied in hexane, dioxane, acetonitrile and methanol as solvents. The quenching rate constants for the process have also been obtained by measuring the lifetimes of the fluorophores. The quenching was found to be dynamic in all cases. For 2ADPA and 4ADPA, the quenching rate constants of CCl4 and CHCl3 depend on the viscosity, whereas in the case of CH2Cl2, kq depends on polarity. The quenching rate constants for DADPA with CCl4 are viscosity-dependent but the quenching with CHCl3 and CH2Cl2 depends on the polarity of the solvents. From the results, the quenching mechanism is explained by the formation of a non-emissive complex involving a charge-transfer interaction between the electronically excited fluorophores and ground-state chloromethanes.

Charge Transfer Between CO22+ and Ar or Ne at Collision Energies 3-10 eV

2003 ◽  
Vol 68 (1) ◽  
pp. 178-188 ◽  
Author(s):  
Libor Mrázek ◽  
Ján Žabka ◽  
Zdeněk Dolejšek ◽  
Zdeněk Herman
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Ground State ◽  
Scattering Method ◽  
Translational Energy ◽  
Centre Of Mass ◽  
Energy Distributions ◽  
Zener Model ◽  
Beam Scattering ◽  
Product Ions

The beam scattering method was used to investigate non-dissociative single-electron charge transfer between the molecular dication CO22+ and Ar or Ne at several collision energies between 3-10 eV (centre-of-mass, c.m.). Relative translational energy distributions of the product ions showed that in the reaction with Ar the CO2+ product was mainly formed in reactions of the ground state of the dication, CO22+(X3Σg-), leading to the excited states of the product CO2+(A2Πu) and CO2+(B2Σu+). In the reaction with Ne, the largest probability had the process from the reactant dication excited state CO22+(1Σg+) leading to the product ion ground state CO2+(X2Πg). Less probable were processes between the other excited states of the dication CO22+, (1∆g), (1Σu-), (3∆u), also leading to the product ion ground state CO2+(X2Πg). Using the Landau-Zener model of the reaction window, relative populations of the ground and excited states of the dication CO22+ in the reactant beam were roughly estimated as (X3Σg):(1∆g):(1Σg+):(1Σu-):(3∆u) = 1.0:0.6:0.5:0.25:0.25.

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