Optical characterization of a two-dimensional BODIPY-based polymer material and its related chromophores

2019 ◽  
Vol 7 (26) ◽  
pp. 7872-7884 ◽  
Author(s):  
P. Piatkowski ◽  
M. Moreno ◽  
M. Liras ◽  
F. Sánchez ◽  
A. Douhal
Keyword(s):  
Charge Transfer ◽  
Polymer Material ◽  
Intramolecular Charge Transfer ◽  
Optical Characterization ◽  
Two Dimensional

Elucidating the ultrafast photoevents happening in an excited BODIPY 2-D-material and its parent units: relevance of intramolecular-charge transfer and interunit interactions to their photoresponse.

Optical Characterization of Silica Aerogel

1988 ◽  
Vol 121 ◽  
Author(s):  
Lawrence W. Hrubesh ◽  
Cynthia T. Alviso
Keyword(s):  
Silica Aerogel ◽  
Porous Silica ◽  
Optical Characterization ◽  
Optical Methods ◽  
Gradient Index ◽  
Two Dimensional ◽  
Two Dimensional Image ◽  
The Third ◽  
Third Dimension

ABSTRACTTwo optical methods are described for mapping the local variations of refractive index within monoliths of porous silica aerogel. One is an interferometrie measurement that produces “iso-index” fringes in a two dimensional image; an orthogonal view gives the third dimension information. The other method uses the deflection of a He-Ne laser beam to map the gradient index within a sample. The quantification of the measurements is described and the accuracy of the results is discussed.

Optical characterization of graphene-f-o-phenylenediamine and charge transfer interaction with organic dyes

Carbon ◽  
2020 ◽  
Vol 166 ◽  
pp. 15-25
Author(s):  
Vijay Kumar Sagar ◽  
Shubhayan Bhattacharya ◽  
Soumyodeep Dey ◽  
Prem Ballabh Bisht
Keyword(s):  
Charge Transfer ◽  
Organic Dyes ◽  
Optical Characterization ◽  
Charge Transfer Interaction

scholarly journals Synergistic Approach of Ultrafast Spectroscopy and Molecular Simulations in the Characterization of Intramolecular Charge Transfer in Push-Pull Molecules

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 430 ◽  
Author(s):  
Barbara Patrizi ◽  
Concetta Cozza ◽  
Adriana Pietropaolo ◽  
Paolo Foggi ◽  
Mario Siciliani de Cumis
Keyword(s):  
Charge Transfer ◽  
Density Functional ◽  
Ultrafast Spectroscopy ◽  
Intramolecular Charge Transfer ◽  
Molecular Simulations ◽  
System Size ◽  
Significant Information ◽  
Electronic Density ◽  
Complex Molecules

The comprehensive characterization of Intramolecular Charge Transfer (ICT) stemming in push-pull molecules with a delocalized π-system of electrons is noteworthy for a bespoke design of organic materials, spanning widespread applications from photovoltaics to nanomedicine imaging devices. Photo-induced ICT is characterized by structural reorganizations, which allows the molecule to adapt to the new electronic density distribution. Herein, we discuss recent photophysical advances combined with recent progresses in the computational chemistry of photoactive molecular ensembles. We focus the discussion on femtosecond Transient Absorption Spectroscopy (TAS) enabling us to follow the transition from a Locally Excited (LE) state to the ICT and to understand how the environment polarity influences radiative and non-radiative decay mechanisms. In many cases, the charge transfer transition is accompanied by structural rearrangements, such as the twisting or molecule planarization. The possibility of an accurate prediction of the charge-transfer occurring in complex molecules and molecular materials represents an enormous advantage in guiding new molecular and materials design. We briefly report on recent advances in ultrafast multidimensional spectroscopy, in particular, Two-Dimensional Electronic Spectroscopy (2DES), in unraveling the ICT nature of push-pull molecular systems. A theoretical description at the atomistic level of photo-induced molecular transitions can predict with reasonable accuracy the properties of photoactive molecules. In this framework, the review includes a discussion on the advances from simulation and modeling, which have provided, over the years, significant information on photoexcitation, emission, charge-transport, and decay pathways. Density Functional Theory (DFT) coupled with the Time-Dependent (TD) framework can describe electronic properties and dynamics for a limited system size. More recently, Machine Learning (ML) or deep learning approaches, as well as free-energy simulations containing excited state potentials, can speed up the calculations with transferable accuracy to more complex molecules with extended system size. A perspective on combining ultrafast spectroscopy with molecular simulations is foreseen for optimizing the design of photoactive compounds with tunable properties.

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