Single rotational level fluorescence quantum yields, radiative lifetimes, and nonradiative decay rates of S1 D2CO and H2CO(Ã 1A2, 41): Rotational dependence

1981 ◽  
Vol 75 (7) ◽  
pp. 3397-3406 ◽  
Author(s):  
Kazuhiko Shibuya ◽  
Paul W. Fairchild ◽  
Edward K. C. Lee
Keyword(s):  
Rotational Level ◽  
Decay Rates ◽  
Quantum Yields ◽  
Radiative Lifetimes ◽  
Nonradiative Decay ◽  
Fluorescence Quantum Yields

scholarly journals Inverted energy gap law for the nonradiative decay in fluorescent floppy molecules: larger fluorescence quantum yields for smaller energy gaps

2019 ◽  
Vol 6 (12) ◽  
pp. 1948-1954 ◽  
Author(s):  
Junqing Shi ◽  
Maria A. Izquierdo ◽  
Sangyoon Oh ◽  
Soo Young Park ◽  
Begoña Milián-Medina ◽  
...  
Keyword(s):  
Radiative Decay ◽  
Energy Gap ◽  
Quantum Yields ◽  
Nonradiative Decay ◽  
Fluorescence Quantum Yields ◽  
Energy Gaps ◽  
Energy Gap Law ◽  
Solution Increase ◽  
Floppy Molecules ◽  
Franck Condon

The non-radiative decay of substituted dicyano-distyrylbenzenes in solution increase with the Franck–Condon energy, being opposite to the conventional energy gap law.

Regioselective Oxidative Cross-Coupling Reaction: Synthesis of Imidazo[1,2-a]pyridine Fluorophores

Synthesis ◽  
2021 ◽  
Author(s):  
Xianglong Chu ◽  
Yadi Niu ◽  
Chen Ma ◽  
Xiaodong Wang ◽  
Yunliang Lin ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Cross Coupling Reaction ◽  
Color Tunable ◽  
Palladium Catalyzed ◽  
Structure Relationship ◽  
High Fluorescence

AbstractA rapid access to a series of N-heteroarene fluorophores has been developed on the basis of the palladium-catalyzed direct oxidative C–H/C–H coupling of imidazo[1,2-a]pyridines with thiophenes/furans. The photophysical properties–structure relationship was systematically investigated. The resulting N-heteroarene fluorophores present color-tunable emissions (λem: 431–507 nm in CH2Cl2) and high fluorescence quantum yields (up to 91% in CH2Cl2).

scholarly journals Indenopyrans – synthesis and photoluminescence properties

2016 ◽  
Vol 12 ◽  
pp. 825-834 ◽  
Author(s):  
Andreea Petronela Diac ◽  
Ana-Maria Ţepeş ◽  
Albert Soran ◽  
Ion Grosu ◽  
Anamaria Terec ◽  
...  
Keyword(s):  
Solid State ◽  
Emission Band ◽  
Fluorescence Spectra ◽  
Photophysical Properties ◽  
Quantum Yields ◽  
Band Broadening ◽  
Photoluminescence Properties ◽  
Fluorescence Quantum Yields ◽  
Blue Emitters ◽  
Solid State Fluorescence

New indeno[1,2-c]pyran-3-ones bearing different substituents at the pyran moiety were synthesized and their photophysical properties were investigated. In solution all compounds were found to be blue emitters and the trans isomers exhibited significantly higher fluorescence quantum yields (relative to 9,10-diphenylanthracene) as compared to the corresponding cis isomers. The solid-state fluorescence spectra revealed an important red shift of λmax due to intermolecular interactions in the lattice, along with an emission-band broadening, as compared to the solution fluorescence spectra.

Mechanistic studies of aromatic ketone-sensitized photoreduction of bis(acetylacetonato)copper(II)

1983 ◽  
Vol 61 (5) ◽  
pp. 801-808 ◽  
Author(s):  
Yuan L. Chow ◽  
Gonzalo E. Buono-Core ◽  
Bronislaw Marciniak ◽  
Carol Beddard
Keyword(s):  
Rate Constant ◽  
Rate Constants ◽  
Flash Photolysis ◽  
Decay Rates ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Aromatic Ketone ◽  
Quantum Yields ◽  
Triplet States ◽  
Quenching Rate ◽  
Triplet Energy

Bis(acetylacetonato)copper(II), Cu(acac)2, quenches triplet excited states of ketones and polynuclear aromatic hydrocarbons efficiently, but only aromatic ketones with high triplet energy successfully sensitize photoreduction of Cu(acac)2 in alcohols under nitrogen to give derivatives of aeetylacetonatocopper(I), Cu(acac). For the triplet state benzophenone-sensitized photoreduction of Cu(acac)2, the quantum yields of photoreduction (ΦC) and those of benzophenone disappearance (ΦB) were determined in methanol with various concentrations of Cu(acac)2. The values of the quenching rate constant, kq, determined from these two types of monitors on the basis of the proposed mechanism were in good agreement (6.89 ~ 7.35 × 109 M−1 s−1). This value was higher, by a factor of about two, than that obtained from the monitor of the benzophenone triplet decay rates generated by flash photolysis in the presence of Cu(acac)2. The quenching rate constants of various aromatic ketone and hydrocarbon triplet states by Cu(acac)2 were determined by flash photolysis to be in the order of the diffusion rate constant and the quantum yields of these photoreductions were found to be far from unity. Paramagnetic quenching, with contributions of electron exchange and charge transfer, was proposed as a possible quenching mechanism. For a series of aromatic ketone sensitizers with higher triplet energy, this mechanism was used to rationalize the observed high quenching rate constants in contrast to the low quantum yields of photoreduction.

Radiative and nonradiative decay rates in chromium-related centers in nanodiamonds

2011 ◽  
Vol 36 (21) ◽  
pp. 4224 ◽  
Author(s):  
S. Castelletto ◽  
A. Boretti
Keyword(s):  
Decay Rates ◽  
Nonradiative Decay

Impact of cyclic topology: odd–even glass transition temperatures and fluorescence quantum yields in molecularly-defined macrocycles

2017 ◽  
Vol 8 (17) ◽  
pp. 2686-2692 ◽  
Author(s):  
Kun Li ◽  
Ganquan Jiang ◽  
Feng Zhou ◽  
Lishan Li ◽  
Zhengbiao Zhang ◽  
...  
Keyword(s):  
Glass Transition ◽  
Intermolecular Interactions ◽  
Topological Structure ◽  
Quantum Yields ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Fluorescence Quantum Yields

The topological structure of cyclic-TPEn+1 (n = 1–6) induces odd–even effects on the Tg and AIE behavior, arising from the alternation of intermolecular interactions.

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