scholarly journals Yb to Tb Cooperative Upconversion in Supramolecularly Assembled Complexes in a Solution

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 1037-1046
Author(s):  
Lohona K. Soro ◽  
Cyrille Charpentier ◽  
Frédéric Przybilla ◽  
Yves Mély ◽  
Aline M. Nonat ◽  
...  
Keyword(s):  
Excited State ◽  
Laser Power ◽  
Hydration Number ◽  
Laser Power Density ◽  
Water Molecules ◽  
Acidic Ph ◽  
Excited State Lifetime ◽  
Cooperative Upconversion ◽  
Hydrated Complexes ◽  
Assembled Complexes

The podand-type ligand L, based on a tertiary amine substituted by three pyridyl-6-phosphonic acid functions, forms hydrated complexes with Ln3+ cations. The luminescence properties of the YbL complex were studied in D2O as a function of the pD and temperature. In basic conditions, increases in the luminescence quantum yield and the excited state lifetime of the Yb centered emission associated with the 2F5/2 → 2F7/2 transition were observed and attributed to a change in the hydration number from two water molecules in the first coordination sphere of Yb at acidic pH to a single one in basic conditions. Upon the addition of TbCl3 salts to a solution containing the YbL complex in D2O, heteropolynuclear Yb/Tb species formed, and excitation of the Yb at 980 nm resulted in the observation of the typical visible emission of Tb as a result of a cooperative upconversion (UC) photosensitization process. The UC was further evidenced by the quadratic dependence of the UC emission as a function of the laser power density.

scholarly journals Elucidating Cooperative Luminescence and Cooperative Sensitisation Upconversion of Nonanuclear Lanthanide Complexes in Solution

2021 ◽  
Author(s):  
Richard Knighton ◽  
Lohona Soro ◽  
Laura Frances-Soriano ◽  
Aurora Rodriguez-Rodriguez ◽  
Guillaume Pilet ◽  
...  
Keyword(s):  
Excited State ◽  
Quantum Yield ◽  
Solar Energy ◽  
Power Density ◽  
Laser Power ◽  
Lanthanide Complexes ◽  
Laser Power Density ◽  
Upconversion Nanoparticles ◽  
Molecular Scale ◽  
First Time

Upconversion nanoparticles have led to various breakthrough applications in solar energy conversion, imaging, and biomedicine. One key impediment is the facilitation of such processes at the molecular scale in solution where quenching effects are much more pronounced. In this work we explore, for the first time, molecular solution-state cooperative luminescence (CL) upconversion arising from a Yb excited state and investigate the mechanistic origin behind cooperative sensitisation (CS) upconversion in Yb/ Tb systems. Counterintuitively, the best UC performances were obtained for Yb/Tb ratios close to parity, resulting in the brightest molecular upconversion complexes with an unprecedented quantum yield of 2.8 × 10-6 at a low laser power density of 2.86 W/cm2.

scholarly journals Impact of the Dynamic Electron Correlation on the Unusually Long Excited-State Lifetime of Thymine

2021 ◽  
pp. 4339-4346
Author(s):  
Woojin Park ◽  
Seunghoon Lee ◽  
Miquel Huix-Rotllant ◽  
Michael Filatov ◽  
Cheol Ho Choi
Keyword(s):  
Excited State ◽  
Electron Correlation ◽  
Excited State Lifetime

Measurement of excited-state lifetime using two-pulse photon echoes in rubidium vapor

2007 ◽  
Vol 24 (3) ◽  
pp. 671 ◽  
Author(s):  
E. A. Rotberg ◽  
B. Barrett ◽  
S. Beattie ◽  
S. Chudasama ◽  
M. Weel ◽  
...  
Keyword(s):  
Excited State ◽  
Excited State Lifetime ◽  
Rubidium Vapor ◽  
Photon Echoes ◽  
Pulse Photon

scholarly journals Influence of Saturation Phenomena on Laser-Excited Atomic Fluorescence Flame Spectrometry

1973 ◽  
Vol 28 (2) ◽  
pp. 273-279
Author(s):  
J. Kühl ◽  
S. Neumann ◽  
M. Kriese
Keyword(s):  
Power Density ◽  
Laser Power ◽  
Atomic Emission ◽  
Equation Model ◽  
Laser Power Density ◽  
Atomic Level ◽  
Dye Laser ◽  
Atomic Fluorescence ◽  
Emission Flame ◽  
Flame Spectrometry

Using a simple rate equation model, the laser power density Ic necessary to reach 50% of the saturation limited population of the excited atomic level under typical flame conditions is calculated. For Na atoms aspirated into the flame a saturating power density for irradiation with a narrow dye laser line (bandwidth 0.033 Å) of Ic ~ 0.4 kW/cm2 was determined. With the aid of a dye laser with an appropriate laser power density, analytical curves for Na were measured yielding a detection limit of 0.2 ng/ml. This sensitivity is comparable with the best results obtained by atomic emission flame spectrometry.

scholarly journals Excited State Lifetime Measurements in Rare Earth Nuclei with Fast Electronics

2011 ◽  
Vol 312 (9) ◽  
pp. 092062 ◽  
Author(s):  
V Werner ◽  
N Cooper ◽  
M Bonett-Matiz ◽  
E Williams ◽  
J-M Régis ◽  
...  
Keyword(s):  
Rare Earth ◽  
Excited State ◽  
Excited State Lifetime ◽  
Lifetime Measurements ◽  
Rare Earth Nuclei

Prolonged Excited-State Lifetime of Porphyrin Due to the Addition of Colloidal SiO2to Triton X-100 Micelles

Langmuir ◽  
2004 ◽  
Vol 20 (5) ◽  
pp. 1582-1586 ◽  
Author(s):  
Junhua Yu ◽  
Xuesong Wang ◽  
Baowen Zhang ◽  
Yuxiang Weng ◽  
Lei Zhang
Keyword(s):  
Excited State ◽  
Excited State Lifetime ◽  
Triton X

Experimental Study on Testing Ni-Containing Stainless Steel Protective Coatings by Pulsed Laser Scratching

2010 ◽  
Vol 43 ◽  
pp. 651-656
Author(s):  
Ai Xin Feng ◽  
Yu Peng Cao ◽  
Chuan Chao Xu ◽  
Huai Yang Sun ◽  
Gui Fen Ni ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Power Density ◽  
Laser Power ◽  
Protective Coatings ◽  
Three Dimensional ◽  
Pulsed Laser ◽  
Laser Power Density ◽  
The Matrix ◽  
The Impact

In the experiment, we use pulsed laser to conduct discrete scratching on Ni-containing stainless steel protective coatings to test residual stress situation after the matrix is scratched; then to analyze the the impact of the impact stress wave on coating - substrate bonding strength according to the test results, finally to infer the laser power density range within which it occurs coating failure. The study shows that: after laser discrete scratching, the residual stress of the center of the laser-loaded point on matrix surface gradually reduces when the pulsed laser power density increases. The matrix produces a corresponding residual compressive stress under the laser power density reaches a certain value. The actual failure threshold values are 12.006 GW/cm2, 11.829GW/cm2 and 12.193GW/cm2 measured by the three-dimensional topography instrument testing the discrete scratch point of three groups of samples and verified by using a microscope

scholarly journals Chemical Energetics and Atomic Charges Distribution of Variably Sized Hydrated Sulfate Clusters in the light of Density Functional Theory

2021 ◽  
Vol 25 (1) ◽  
pp. 595
Author(s):  
Anant Babu Marahatta
Keyword(s):  
Structural Stability ◽  
Density Functional ◽  
Hydration Number ◽  
Binding Energies ◽  
Dynamics Simulation ◽  
Water Molecules ◽  
Atomic Charges ◽  
Electronic Interactions ◽  
Hydrogen Bond Formation ◽  
Depth Analysis

Among the ions classified in the Hofmeister series, the firstly ranked divalent sulfate anion has the strongest hydrating and water-structure making propensity. This unique characteristic actually makes it kosmotropic which causes water molecules to interact each other and contributes to gain structural stability of its hydrated clusters [SO42−(H2O)n]n = 1−40. In this study, few variably sized microhydrated sulfate clusters [SO42−(H2O)n]n = 1−4, 16 are considered separately, and inquired their chemical energetics and atomic charge distributions through ab initio based theoretical model. The main objective of this insight is to specify and interpret their thermodynamic stabilities, binding energies, and specific bonding and electronic interactions quantum mechanically. An in-depth analysis of their change in relative ground state electronic energy with respect to hydration number indicates stronger affinity of the sulfate ion towards water molecules while attaining structural stability in any aqueous type solutions. The mathematically determined values of their binding energy (DE) almost holds up the same with this structural stability order: [SO42−(H2O)16] > [SO42−(H2O)4] > [SO42−(H2O)3] > [SO42−(H2O)2] > [SO42−(H2O)], as reliable as experimentally and molecular dynamics simulation predicted trend. Moreover, the Mulliken derived partial atomic charges feature qualitative charge distribution in them which not only depicts electronic interactions between the specific atoms but also exemplifies the involvement of central sulfate units in hydrogen bond formation with surrounding water molecules.

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