Charge-transfer excited states of osmium(II) complexes. 1. Assignment of the visible absorption bands

Three Re(I) tricarbonyl complexes, with general formulation Re(N^L)(CO)3X (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)2(CO)3X. 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.

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

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20030178 ◽

2003 ◽

Vol 68 (1) ◽

pp. 178-188 ◽

Cited By ~ 3

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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Global double hybrids do not work for charge transfer: A comment on “Double hybrids and time‐dependent density functional theory: An implementation and benchmark on charge transfer excited states”

Journal of Computational Chemistry ◽

10.1002/jcc.26478 ◽

2021 ◽

Vol 42 (8) ◽

pp. 528-533

Author(s):

Marcos Casanova‐Páez ◽

Lars Goerigk

Keyword(s):

Density Functional Theory ◽

Charge Transfer ◽

Excited States ◽

Density Functional ◽

Time Dependent ◽

Functional Theory ◽

Dependent Density

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A SERS Study of Charge Transfer Process in Au Nanorod–MBA@Cu2O Assemblies: Effect of Length to Diameter Ratio of Au Nanorods

Nanomaterials ◽

10.3390/nano11040867 ◽

2021 ◽

Vol 11 (4) ◽

pp. 867

Author(s):

Lin Guo ◽

Zhu Mao ◽

Sila Jin ◽

Lin Zhu ◽

Junqi Zhao ◽

...

Keyword(s):

Charge Transfer ◽

Shell Structure ◽

Shell Structures ◽

Core Shell ◽

Absorption Bands ◽

Au Nanorods ◽

The Core ◽

Band Position ◽

Surface Enhanced Raman ◽

Core Shell Structure

Surface-enhanced Raman scattering (SERS) is a powerful tool in charge transfer (CT) process research. By analyzing the relative intensity of the characteristic bands in the bridging molecules, one can obtain detailed information about the CT between two materials. Herein, we synthesized a series of Au nanorods (NRs) with different length-to-diameter ratios (L/Ds) and used these Au NRs to prepare a series of core–shell structures with the same Cu2O thicknesses to form Au NR–4-mercaptobenzoic acid (MBA)@Cu2O core–shell structures. Surface plasmon resonance (SPR) absorption bands were adjusted by tuning the L/Ds of Au NR cores in these assemblies. SERS spectra of the core-shell structure were obtained under 633 and 785 nm laser excitations, and on the basis of the differences in the relative band strengths of these SERS spectra detected with the as-synthesized assemblies, we calculated the CT degree of the core–shell structure. We explored whether the Cu2O conduction band and valence band position and the SPR absorption band position together affect the CT process in the core–shell structure. In this work, we found that the specific surface area of the Au NRs could influence the CT process in Au NR–MBA@Cu2O core–shell structures, which has rarely been discussed before.

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