Role of the Porphyrin Excited States in their Interactions with DNA and DNA — Model Compounds in Aqueous Solutions

Using semiempirical MNDO method of quantum chemistry the optimal geometries and corresponding electronic structures of [Pb3(OH)n]6-n model systems as well as of their hydrated [Pb3(OH)n(H2O)8-n]6-n analogues (n = 4, 5) are investigated. The most stable trinuclear lead(II) complexes present in aqueous solutions correspond to cyclo-(μ3-OH)(μ2-OH)3Pb32+, Pb(μ-OH)2Pb(μ-OH)2Pb2+, cyclo-(μ3-OH)2(μ2-OH)3Pb3+, Pb(OH)(μ-OH)2Pb(μ-OH)Pb(OH)+ and Pb(OH)(μ-OH)2Pb(μ-OH)2Pb+ systems. The key role of OH bridges (by vanishing direct Pb-Pb bonds) on the stability of individual isomers is discussed.

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The role of zero-field splitting and π-stacking interaction of different nitrogen-donor ligands on the optical properties of luminescent rhenium tricarbonyl complexes

New Journal of Chemistry ◽

10.1039/d1nj01544c ◽

2021 ◽

Author(s):

Plinio Cantero-López ◽

Yoan Hidalgo-Rosa ◽

Zoraida Sandoval-Olivares ◽

Julián Santoyo-Flores ◽

Pablo Mella ◽

...

Keyword(s):

Excited States ◽

Coordination Compounds ◽

Donor Ligands ◽

Zero Field ◽

Zero Field Splitting ◽

Nitrogen Donor Ligands ◽

Nitrogen Donor ◽

Π Stacking Interaction ◽

Rhenium Tricarbonyl

Rhenium tricarbonyl complexes are one of the most important classes of coordination compounds in inorganic chemistry. Exploring their luminescent excited states, lowest singlet (S1), and the lowest triplet (T1), is...

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Influence of TOPO and TOPO-CdSe/ZnS Quantum Dots on Luminescence Photodynamics of InP/InAsP/InPHeterostructure Nanowires

Nanomaterials ◽

10.3390/nano11030640 ◽

2021 ◽

Vol 11 (3) ◽

pp. 640

Author(s):

Artem I. Khrebtov ◽

Vladimir V. Danilov ◽

Anastasia S. Kulagina ◽

Rodion R. Reznik ◽

Ivan D. Skurlov ◽

...

Keyword(s):

Quantum Dots ◽

Excited States ◽

Molecular Beam ◽

Surface Passivation ◽

Low Energy ◽

Trioctylphosphine Oxide ◽

Reverse Transfer ◽

Semiconductor Heterostructure ◽

Ligand Type

The passivation influence by ligands coverage with trioctylphosphine oxide (TOPO) and TOPO including colloidal CdSe/ZnS quantum dots (QDs) on optical properties of the semiconductor heterostructure, namely an array of InP nanowires (NWs) with InAsP nanoinsertion grown by Au-assisted molecular beam epitaxy on Si (111) substrates, was investigated. A significant dependence of the photoluminescence (PL) dynamics of the InAsP insertions on the ligand type was shown, which was associated with the changes in the excitation translation channels in the heterostructure. This change was caused by a different interaction of the ligand shells with the surface of InP NWs, which led to the formation of different interfacial low-energy states at the NW-ligand boundary, such as surface-localized antibonding orbitals and hybridized states that were energetically close to the radiating state and participate in the transfer of excitation. It was shown that the quenching of excited states associated with the capture of excitation to interfacial low-energy traps was compensated by the increasing role of the “reverse transfer” mechanism. As a result, the effectiveness of TOPO-CdSe/ZnS QDs as a novel surface passivation coating was demonstrated.

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