Photodynamics of extended molecular systems. I. A theoretical approach for strongly coupled primary and secondary regions

1991 ◽  
Vol 94 (7) ◽  
pp. 4900-4912 ◽  
Author(s):  
Deepak Srivastava ◽  
David A. Micha
Keyword(s):  
Theoretical Approach ◽  
Strongly Coupled ◽  
Molecular Systems

scholarly journals Two-dimensional electronic–vibrational sum frequency spectroscopy for interactions of electronic and nuclear motions at interfaces

2021 ◽  
Vol 118 (34) ◽  
pp. e2100608118
Author(s):  
Gang-Hua Deng ◽  
Yuqin Qian ◽  
Tong Zhang ◽  
Jian Han ◽  
Hanning Chen ◽  
...  
Keyword(s):  
Excited State ◽  
Excited States ◽  
Degrees Of Freedom ◽  
Two Dimensional ◽  
Strongly Coupled ◽  
Molecular Systems ◽  
Sum Frequency ◽  
Quantum Chemistry Calculations ◽  
Vibrational Sum Frequency Spectroscopy ◽  
Vibronic Couplings

Interactions of electronic and vibrational degrees of freedom are essential for understanding excited-states relaxation pathways of molecular systems at interfaces and surfaces. Here, we present the development of interface-specific two-dimensional electronic–vibrational sum frequency generation (2D-EVSFG) spectroscopy for electronic–vibrational couplings for excited states at interfaces and surfaces. We demonstrate this 2D-EVSFG technique by investigating photoexcited interface-active (E)-4-((4-(dihexylamino) phenyl)diazinyl)-1-methylpyridin-1- lum (AP3) molecules at the air–water interface as an example. Our 2D-EVSFG experiments show strong vibronic couplings of interfacial AP3 molecules upon photoexcitation and subsequent relaxation of a locally excited (LE) state. Time-dependent 2D-EVSFG experiments indicate that the relaxation of the LE state, S2, is strongly coupled with two high-frequency modes of 1,529.1 and 1,568.1 cm−1. Quantum chemistry calculations further verify that the strong vibronic couplings of the two vibrations promote the transition from the S2 state to the lower excited state S1. We believe that this development of 2D-EVSFG opens up an avenue of understanding excited-state dynamics related to interfaces and surfaces.

Differential polarization imaging of sickled cells

1988 ◽  
Vol 46 ◽  
pp. 62-63
Author(s):  
Marcos F. Maestre
Keyword(s):  
Optical Properties ◽  
Theoretical Approach ◽  
Polarized Light ◽  
Polarization Microscopy ◽  
Spectroscopic Techniques ◽  
Polarization Imaging ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Microscopic Scale ◽  
Chiral Structures

Recently we have developed a form of polarization microscopy that forms images using optical properties that have previously been limited to macroscopic samples. This has given us a new window into the distribution of structure on a microscopic scale. We have coined the name differential polarization microscopy to identify the images obtained that are due to certain polarization dependent effects. Differential polarization microscopy has its origins in various spectroscopic techniques that have been used to study longer range structures in solution as well as solids. The differential scattering of circularly polarized light has been shown to be dependent on the long range chiral order, both theoretically and experimentally. The same theoretical approach was used to show that images due to differential scattering of circularly polarized light will give images dependent on chiral structures. With large helices (greater than the wavelength of light) the pitch and radius of the helix could be measured directly from these images.

A new classical method for dynamical calculation in molecular systems

1997 ◽  
Vol 90 (4) ◽  
pp. 599-609 ◽  
Author(s):  
NAĐA DOSLIC ◽  
S.DANKO BOSANAC
Keyword(s):  
Classical Method ◽  
Molecular Systems ◽  
Dynamical Calculation
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