Proton tunneling dynamics and an isotopically dependent equilibrium geometry in the lowest excited π–π* singlet state of tropolone

1980 ◽  
Vol 73 (4) ◽  
pp. 1546-1550 ◽  
Author(s):  
R. Rossetti ◽  
L. E. Brus
Keyword(s):  
Singlet State ◽  
Equilibrium Geometry ◽  
Proton Tunneling ◽  
Tunneling Dynamics

Two-photon excitation fluorescence microscopy in living systems

1993 ◽  
Vol 51 ◽  
pp. 154-155 ◽  
Author(s):  
David W. Piston
Keyword(s):  
Confocal Microscopy ◽  
Fluorescence Microscopy ◽  
Singlet State ◽  
Excited Electronic State ◽  
Input Power ◽  
Two Photon ◽  
Simultaneous Absorption ◽  
Photon Excitation ◽  
Very High ◽  
Two Photon Excitation

Two-photon excitation fluorescence microscopy provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In our fluorescence experiments, the final excited state is the same singlet state that is populated during a conventional fluorescence experiment. Thus, the fluorophore exhibits the same emission properties (e.g. wavelength shifts, environmental sensitivity) used in typical biological microscopy studies. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10−5 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.

The Gold Porphyrin First Excited Singlet State¶

2002 ◽  
Vol 76 (1) ◽  
pp. 47 ◽  
Author(s):  
Joakim Andréasson ◽  
Gerdenis Kodis ◽  
Su Lin ◽  
Ana L. Moore ◽  
Thomas A. Moore ◽  
...  
Keyword(s):  
Singlet State ◽  
Excited Singlet State ◽  
Excited Singlet

Nickel(II)-Methyl Complexes Adopting Idealized Seesaw Geometries

2019 ◽  
Author(s):  
Ethan A. Hill ◽  
Norman Zhao ◽  
Alexander S. Filatov ◽  
John Anderson
Keyword(s):  
Singlet State ◽  
Strong Field ◽  
Structural Distortion ◽  
Computational Results ◽  
Threefold Symmetry ◽  
Chelating Ligand ◽  
Electronic Stabilization

We report four-coordinate nickel(II)-methyl complexes of tris-carbene borate ligands which adopt rare seesaw geometries. Experimental and computational results suggest the structural distortion from threefold symmetry results from a combination of electronic stabilization of the singlet state, strong field donors, and constrained angles from the chelating ligand.

Experimental evidence for proton tunneling in methylammonium lead triiodide perovskites

2017 ◽  
Author(s):  
Lionel Hirsch ◽  
Yan-Fang Chen ◽  
Yu-Tang Tsai ◽  
Dario M. Bassani
Keyword(s):  
Experimental Evidence ◽  
Proton Tunneling
Sign in / Sign up

Export Citation Format

Share Document