Controlling the Excited-State Relaxation for Tunable Single-Molecule Dual Fluorescence in Both the Solution and Film States

2022 ◽  
Author(s):  
Gang Wang ◽  
Nannan Ding ◽  
Hongxing Hao ◽  
Qingwei Jiang ◽  
Qianqian Feng ◽  
...  
Keyword(s):  
Excited State ◽  
Single Molecule ◽  
Dual Fluorescence

Realizing single-molecule dual fluorescence with facile tunability in both the solution and film states through manipulating the excited-state relaxation pathways is highly desirable but challenging. Herein, three synthesized fluorophores emit...

Influence of solvent polarity on the dual fluorescence of p-N,N-dimethylaminobenzonitrile: An AM1 theoretical study

1990 ◽  
Vol 55 (8) ◽  
pp. 1891-1895 ◽  
Author(s):  
Peter Ertl
Keyword(s):  
Excited State ◽  
Theoretical Study ◽  
Solvent Polarity ◽  
Semiempirical Method ◽  
Dual Fluorescence ◽  
Long Wavelength ◽  
Polar Media ◽  
Wavelength Emission ◽  
Ground State Geometry ◽  
Influence Of Solvent

Twisting of the NMe2 group in p-N,N-dimethylaminobenzonitrile (DMABN) was investigated using AM1 semiempirical method with configuration interaction. Effect of polar media was considered by placing + and - charge centers ("sparkles") at appropriate places opposite the molecule. Optimized ground state geometry of DMABN is slightly twisted with the lowest vertical excited state of 1B character. As the polarity of media increases and/or the - NMe2 group twists, the symmetric 1A excited state having considerable charge separation becomes energetically favorable. Anomalous long-wavelength emission of DMABN comes from this state.

Dual fluorescence and excited-state intramolecular proton transfer in jet-cooled 3,4-benzotropolone

1993 ◽  
Vol 215 (6) ◽  
pp. 641-648 ◽  
Author(s):  
Hiroshi Sekiya ◽  
Mariko Habu ◽  
Hiroki Ujita ◽  
Takeshi Tsuji ◽  
Akira Mori ◽  
...  
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Intramolecular Proton Transfer ◽  
Dual Fluorescence

scholarly journals Ultrafast stimulated emission microscopy of single nanocrystals

Science ◽  
2019 ◽  
Vol 366 (6470) ◽  
pp. 1240-1243 ◽  
Author(s):  
Lukasz Piatkowski ◽  
Nicolò Accanto ◽  
Gaëtan Calbris ◽  
Sotirios Christodoulou ◽  
Iwan Moreels ◽  
...  
Keyword(s):  
Excited State ◽  
Spontaneous Emission ◽  
Single Molecule ◽  
Room Temperature ◽  
Direct Detection ◽  
Excited State Absorption ◽  
Stimulated Emission ◽  
Detection Capability ◽  
Emission Signal ◽  
Carrier Population

Single-molecule detection is a powerful method used to distinguish different species and follow time trajectories within the ensemble average. However, such detection capability requires efficient emitters and is prone to photobleaching, and the slow, nanosecond spontaneous emission process only reports on the lowest excited state. We demonstrate direct detection of stimulated emission from individual colloidal nanocrystals at room temperature while simultaneously recording the depleted spontaneous emission, enabling us to trace the carrier population through the entire photocycle. By capturing the femtosecond evolution of the stimulated emission signal, together with the nanosecond fluorescence, we can disentangle the ultrafast charge trajectories in the excited state and determine the populations that experience stimulated emission, spontaneous emission, and excited-state absorption processes.

Regulating the femtosecond excited-state lifetime of a single molecule

Science ◽  
2018 ◽  
Vol 361 (6406) ◽  
pp. 1012-1016 ◽  
Author(s):  
K. R. Rusimova ◽  
R. M. Purkiss ◽  
R. Howes ◽  
F. Lee ◽  
S. Crampin ◽  
...  
Keyword(s):  
Excited State ◽  
Single Molecule ◽  
Scanning Tunneling Microscope ◽  
Scanning Tunneling ◽  
Initial Condition ◽  
Excited State Lifetime ◽  
Invariant Surface ◽  
Ionic State ◽  
Tunneling Microscope ◽  
Excited State Dynamics

The key to controlling reactions of molecules induced with the current of a scanning tunneling microscope (STM) tip is the ultrashort intermediate excited ionic state. The initial condition of the excited state is set by the energy and position of the injected current; thereafter, its dynamics determines the reaction outcome. We show that a STM can directly and controllably influence the excited-state dynamics. For the STM-induced desorption of toluene molecules from the Si(111)-7x7 surface, as the tip approaches the molecule, the probability of manipulation drops by two orders of magnitude. A two-channel quenching of the excited state is proposed, consisting of an invariant surface channel and a tip height–dependent channel. We conclude that picometer tip proximity regulates the lifetime of the excited state from 10 femtoseconds to less than 0.1 femtoseconds.

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