Intramolecular Charge Transfer

Intramolecular Charge Transfer
Author: Ramprasad Misra
Publisher: John Wiley & Sons
Total Pages: 257
Release: 2018-02-27
Genre: Science
ISBN: 3527801944

Bridging the gap between the multitude of advanced research articles and the knowledge newcomers to the field are looking for, this is a timely and comprehensive monograph covering the interdisciplinary topic of intramolecular charge transfer (ICT). The book not only covers the fundamentals and physico-chemical background of the ICT process, but also places a special emphasis on the latest experimental and theoretical studies that have been undertaken to understand this process and discusses key technological applications. After outlining the discovery of ICT molecules, the authors go on to discuss several important substance classes. They present the latest techniques for studying the underlying processes and show the interplay between charge transfer and the surrounding medium. Examples taken from nonlinear optics, viscosity and polarity sensors, and organic electronics testify to the vast range of applications. The result is a unique information source for experimentalists as well as theoreticians, from postgraduate students to researchers.

Ultrafast Photoinduced Electron Transfer Reactions in Supramolecular Arrays

Ultrafast Photoinduced Electron Transfer Reactions in Supramolecular Arrays
Author:
Publisher:
Total Pages: 5
Release: 1993
Genre:
ISBN:

Research in our laboratory focuses on developing supramolecular arrays that produce long-lived charge separation by limiting the electronic coupling between the separated charges, and on the role of solvation in determining the rates and energetics of photoinitiated electron transfer reactions. Arrays have been developed that closely mimic the electronic coupling that was observed only for long-lived radical pairs produced in photosynthetic glassy solids. A series of 36 fixed-distance donor-acceptor molecules using porphyrin donors, triptycene spacers, and 9 different acceptors has been prepared; these are used to probe the dependence of photoinduced charge separation rates on free energy of reaction as a function of solvent both in liquid and solid solution. Data were obtained on rates of charge separation in dioxane, MTHF, butyronitrile, toluene, chlorobenzene, and benzonitrile.

Ultrafast Photophysics and Photochemistry After Excited State Intramolecular Charge Transfer in the Liquid Phase

Ultrafast Photophysics and Photochemistry After Excited State Intramolecular Charge Transfer in the Liquid Phase
Author: Hanna A. Ernst
Publisher:
Total Pages: 0
Release: 2015
Genre: Charge transfer
ISBN: 9783832539849

The ultrafast excited state dynamics of the small donor-acceptor molecules ortho-, meta- and para-nitrophenol, their corresponding phenolates as well as selected type-I photoinitiators have been studied by means of steady state UV-Vis and femtosecond time-resolved transient absorption spectroscopy in the liquid phase. The investigated compounds are characterized by intramolecular charge transfer in the ultra violet. The experimental findings were assisted by ab initio calculations at the (TD)-DFT and the CASSCF level of theory.

New Trends in Fluorescence Spectroscopy

New Trends in Fluorescence Spectroscopy
Author: Bernard Valeur
Publisher: Springer Science & Business Media
Total Pages: 496
Release: 2012-12-06
Genre: Science
ISBN: 364256853X

This first volume in the new Springer Series on Fluorescence brings together fundamental and applied research from this highly interdisciplinary and field, ranging from chemistry and physics to biology and medicine. Special attention is given to supramolecular systems, sensor applications, confocal microscopy and protein-protein interactions. This carefully edited collection of articles is an invaluable tool for practitioners and novices.

Ultrafast Infrared Vibrational Spectroscopy

Ultrafast Infrared Vibrational Spectroscopy
Author: Michael D. Fayer
Publisher: CRC Press
Total Pages: 475
Release: 2013-03-04
Genre: Science
ISBN: 1466510145

The advent of laser-based sources of ultrafast infrared pulses has extended the study of very fast molecular dynamics to the observation of processes manifested through their effects on the vibrations of molecules. In addition, non-linear infrared spectroscopic techniques make it possible to examine intra- and intermolecular interactions and how su

Ultrafast Phenomena XIX

Ultrafast Phenomena XIX
Author: Kaoru Yamanouchi
Publisher: Springer
Total Pages: 892
Release: 2015-01-24
Genre: Science
ISBN: 3319132423

This book presents the latest advances in ultrafast science, including both ultrafast optical technology and the study of ultrafast phenomena. It covers picosecond, femtosecond, and attosecond processes relevant to applications in physics, chemistry, biology, and engineering. Ultrafast technology has a profound impact in a wide range of applications, amongst them biomedical imaging, chemical dynamics, frequency standards, material processing, and ultrahigh-speed communications. This book summarizes the results presented at the 19th International Conference on Ultrafast Phenomena and provides an up-to-date view of this important and rapidly advancing field.

Ultrafast Photoinduced Energy and Electron Transfer Studies in Closely Bound Molecular and Nanocarbon Donor-Acceptor Systems

Ultrafast Photoinduced Energy and Electron Transfer Studies in Closely Bound Molecular and Nanocarbon Donor-Acceptor Systems
Author: Habtom Berhane Gobeze
Publisher:
Total Pages: 306
Release: 2018
Genre: Charge exchange
ISBN:

As part of the study, photosynthetic system constructs based on BF2-chelated dipyrromethene (BODIPY), BF2-chelated azadipyrromethene (AzaBODIPY), porphyrin, phthalocyanine, oxasmaragdyrin, polythiophene, fullerene (C60), single-walled carbon nanotube and graphene are investigated. Antenna systems of BODIPY dyads and oligomers having BODIPY as an excitation energy donor connected to different acceptors including BODIPY, azaBODIPY, oxasmaragdyrin and aluminum porphyrin are studied. Different synthetic methodologies are used to afford donor-acceptor systems either directly linked with no spacer or with short spacers of varying length and orientation. The effect of donor orientation, donor optical gap as well as nature of donor-acceptor coupling on the donor-acceptor spectral overlap and hence the rate of excitation energy transfer is investigated. In all these systems, an ultrafast energy transfer followed by electron transfer is observed. In particular, in a directly connected BODIPY-azaBODIPY dyad an unusually ultrafast energy transfer (̃ 150−200 f̧ ' ) via F©œrster mechanism is observed. The observation of energy transfer via F©œrster instead of Dexter mechanism in such closely coupled donor-acceptor systems shows the balance between spatial and electronic coupling achieved in the donor-acceptor system. Moreover, in donor-acceptor systems involving semiconducting 1D and 2D materials, covalently functionalized single-walled carbon nanotubes via charge stabilizing (TPA)3ZnP and noncovalently hybridized exfoliated graphene via polythiophene chromophores are studied for their charge transportation functions. In both cases, not only an ultrafast charge transfer in the range of (̃ 2−5 p̧ ' ) is observed but also the charge-separated states were long lived implying the potential of these functionalized materials as efficient charge transporting substrates with organic chromophores for photovoltaic and optoelectronic applications where ultrafast intercomponent charge transfer is vital. In addition, as a final part of this dissertation, the mechanisms of electron injection and back electron transfer in heterogeneous systems involving supramolecularly anchored high potential chromophores on TiO2 film are studied by femtosecond transient absorption spectroscopy. In this study, not only are important insights gained on the utilization of supramolecular anchoring of chromophores such as porphyrins, phthalocyanines, and their perflorinated high potential analogues, chromophores currently showing promise as highly efficient sensitizers in dye sensitized solar cells, on TiO2 film but also on the effect of anchor length and sensitizer orientation on the rates of electron injection and back electron transfer at the sensitizer-TiO2 interface.

Electron Transfer

Electron Transfer
Author: Joshua Jortner
Publisher: John Wiley & Sons
Total Pages: 759
Release: 2009-09-09
Genre: Science
ISBN: 0470142197

an integrated approach to electron transfer phenomena This two-part stand-alone volume in the prestigious Advances in Chemical Physics series provides the most comprehensive overview of electron transfer science today. It draws on cutting-edge research from diverse areas of chemistry, physics, and biology-covering the most recent developments in the field, and pointing to important future trends. This second volume offers the following sections: * Solvent control, including ultrafast solvation dynamics and related topics * Ultrafast electron transfer and coherence effects * Molecular electronics * Electron transfer and exciplex chemistry * Biomolecules-from electron transfer tubes to kinetics in a DNA environment Part One addresses the historical perspective, electron transfer phenomena in isolated molecules and clusters, general theory, and electron transfer kinetics in bridged compounds. Electron transfer science has seen tremendous progress in recent years. Technological innovations, most notably the advent of femtosecond lasers, now permit the real-time investigation of intramolecular and intermolecular electron transfer processes on a time scale of nuclear motion. New scientific information abounds, illuminating the processes of energy acquisition, storage, and disposal in large molecules, clusters, condensed phase, and biophysical systems. Electron Transfer: From Isolated Molecules to Biomolecules is the first book devoted to the exciting work being done in nonradiative electron transfer dynamics today. This two-part edited volume emphasizes the interdisciplinary nature of the field, bringing together the contributions of pioneers in chemistry, physics, and biology. Both theoretical and experimental topics are featured. The authors describe modern approaches to the exploration of different systems, including supersonic beam techniques, femtosecond laser spectroscopy, chemical syntheses, and methods in genetic and chemical engineering. They examine applications in such areas as supersonic jets, solvents, electrodes, semi- conductors, respiratory and enzymatic protein systems, photosynthesis, and more. They also relate electron transfer and radiationless transitions theory to pertinent physical phenomena, and provide a conceptual framework for the different processes. Complete with over two hundred illustrations, Part Two opens with solvent control issues, including electron transfer reactions and ultrafast solvation dynamics. Other topics include ultrafast electron transfer and coherence effects, molecular electronics, and electron transfer in exciplex chemistry. This volume concludes with a section on biomolecules-from electron transfer tubes to experimental electron transfer and transport in DNA. Timely, comprehensive, and authoritative, Electron Transfer: From Isolated Molecules to Biomolecules is an essential resource for physical chemists, molecular physicists, and researchers working in nonradiative dynamics today.