scholarly journals Mononuclear Copper(I) 3-(2-pyridyl)pyrazole Complexes: The Crucial Role of Phosphine on Photoluminescence

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6869
Author(s):  
Kristina F. Baranova ◽  
Aleksei A. Titov ◽  
Alexander F. Smol’yakov ◽  
Andrey Yu. Chernyadyev ◽  
Oleg A. Filippov ◽  
...  
Keyword(s):  
Excited States ◽  
Theoretical Calculations ◽  
Green Emission ◽  
Emission Efficiency ◽  
Bright Yellow ◽  
Ligand Type ◽  
Wide Range ◽  
Emission Behavior ◽  
Triplet Excited States

A series of emissive Cu(I) cationic complexes with 3-(2-pyridyl)-5-phenyl-pyrazole and various phosphines: dppbz (1), Xantphos (2), DPEPhos (3), PPh3 (4), and BINAP (5) were designed and characterized. Complexes obtained exhibit bright yellow-green emission (ca. 520–650 nm) in the solid state with a wide range of QYs (1–78%) and lifetimes (19–119 µs) at 298 K. The photoluminescence efficiency dramatically depends on the phosphine ligand type. The theoretical calculations of buried volumes and excited states explained the emission behavior for 1–5 as well as their lifetimes. The bulky and rigid phosphines promote emission efficiency through the stabilization of singlet and triplet excited states.

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

Nanomaterials ◽  
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.

The role of singlet and triplet excited states in the photochemistry of 3,5-cycloheptadienone

1968 ◽  
Vol 90 (5) ◽  
pp. 1300-1307 ◽  
Author(s):  
David I. Schuster ◽  
Bruce R. Sckolnick ◽  
Tui-Tseng H. Lee
Keyword(s):  
Excited States ◽  
Triplet Excited States

The Role of Hydrogen In The Structure of γ-Alumina

1998 ◽  
Vol 549 ◽  
Author(s):  
Karl Sohlberg ◽  
Stephen J. Pennycook ◽  
Sokrates T. Pantelides
Keyword(s):  
Spinel Structure ◽  
Systematic Approach ◽  
Theoretical Calculations ◽  
Unique Form ◽  
Material Density ◽  
Hexagonal Close Packed ◽  
Wide Range ◽  
The Subject ◽  
Contradictory Data

AbstractThe structure of a-alumina (α-A12O3) is well known to be hexagonal close packed. In contrast, the structures of the so-called transition aluminas (-γ-alumina, η-alumina,…) are the subject of controversy. We report theoretical calculations which show that -γ-alumina is actually a sequence of compounds with the general formula H3mAl2−mO3. (0 ≤ m ≤ ⅓). m = ⅛ is a unique form, HAl5O8, with a perfect spinel structure. For m > 8, there are interstitial H atoms whereas for m < ⅛. there are vacancies. This picture is supported m > ⅛ by calculations of material density and proton vibrational frequencies. The results are in excellent agreement with measured values. The present new systematic approach accounts for a wide range of seemingly contradictory data and leads to the conclusion that γ-alumina behaves as a “reactive sponge” by storing and releasing water in a novel reactive way.

Picosecond dynamics of an IR sensitive squaraine dye. Role of singlet and triplet excited states in the photosensitization of TiO2 nanoclusters

1997 ◽  
Vol 106 (15) ◽  
pp. 6404-6411 ◽  
Author(s):  
Di Liu ◽  
Prashant V. Kamat ◽  
K. George Thomas ◽  
K. J. Thomas ◽  
Suresh Das ◽  
...  
Keyword(s):  
Excited States ◽  
Squaraine Dye ◽  
Triplet Excited States

Electron Energy Loss and DFT/SCI Study of the Singlet and Triplet Excited States of Aminobenzonitriles and Benzoquinuclidines:  Role of the Amino Group Twist Angle

1999 ◽  
Vol 103 (39) ◽  
pp. 7766-7772 ◽  
Author(s):  
Christophe Bulliard ◽  
Michael Allan ◽  
Gabriele Wirtz ◽  
Edwin Haselbach ◽  
Klaas A. Zachariasse ◽  
...  
Keyword(s):  
Energy Loss ◽  
Excited States ◽  
Electron Energy ◽  
Twist Angle ◽  
Amino Group ◽  
Triplet Excited States ◽  
Electron Energy Loss

scholarly journals The Role of Local Triplet Excited States and D-A Relative Orientation in Thermally Activated Delayed Fluorescence: Photophysics and Devices

2016 ◽  
Vol 3 (12) ◽  
pp. 1600080 ◽  
Author(s):  
Fernando B. Dias ◽  
Jose Santos ◽  
David R. Graves ◽  
Przemyslaw Data ◽  
Roberto S. Nobuyasu ◽  
...  
Keyword(s):  
Excited States ◽  
Delayed Fluorescence ◽  
Relative Orientation ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Triplet Excited States
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