Download or read book The Photophysics of Pyridinium Betaines Studied by Ultrafast Transient Absorption Spectroscopy written by Zuzanna Pawlowska and published by . This book was released on 2011 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work deals with the photophysics, in solution, of Pyridinium betaine, 2-Pyridin-1-yl-1H-benzimidazole (SBPa), and two derivatives substituted by mono- or bi-thiophene groups. It is based on a combination of steady-state and time-resolved absorption spectroscopic measurements, supported by PCM-(TD)DFT calculations. SBPa was found to undergo ultrafast intramolecular charge transfer (ICT) upon light excitation, with a drastic change in dipole moment. Stationary absorption and emission as well as TDDFT results revealed a strongly solvatochromic CT absorption due to a S0→S2(CT) transition and a non-solvatochromic emission due to S1→S0 transition. Comprehensive band shape analysis and innovative solvatochromic data treatment considering protic and aprotic solvents separately led to a detailed knowledge of the solvent effects and allowed estimating four relevant dipole moments. From extensive femtosecond transient absorption experiments, the overall photophysics of SBPa could be discussed in terms of two distinct CT states and a complete photophysical scheme was proposed: a subpicosecond ICT process occurs from the initially populated S2(CT) state to a charge transfer S1(CT) state, in parallel to the ultrafast production (t
Download or read book PYRIDINIUM SALTS AS ELECTRON TRAPS written by Ilnur Khubaibullin and published by . This book was released on 2016 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two pyridinium salts capture an electron in a concerted fashion and retain it for tens of picoseconds. This process has been studied by ultrafast transient absorption spectroscopy. Further studies with other pyridinium salts and donors have been conducted in effort to determine the optimum geometry for electron capture and complex stabilization.
Download or read book Ultrafast Spectroscopic Studies of the Photophysics of Phenyl substituted Butadienes in Liquids written by Rebecca Lynn Hoff and published by . This book was released on 1991 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2734 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiconfigurational Quantum Chemistry written by Björn O. Roos and published by John Wiley & Sons. This book was released on 2016-08-08 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book to aid in the understanding of multiconfigurational quantum chemistry, Multiconfigurational Quantum Chemistry demystifies a subject that has historically been considered difficult to learn. Accessible to any reader with a background in quantum mechanics and quantum chemistry, the book contains illustrative examples showing how these methods can be used in various areas of chemistry, such as chemical reactions in ground and excited states, transition metal and other heavy element systems. The authors detail the drawbacks and limitations of DFT and coupled-cluster based methods and offer alternative, wavefunction-based methods more suitable for smaller molecules.
Download or read book Conical Intersections Electronic Structure Dynamics Spectroscopy written by Wolfgang Domcke and published by World Scientific. This book was released on 2004-07-14 with total page 857 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is widely recognized nowadays that conical intersections of molecular potential-energy surfaces play a key mechanistic role in the spectroscopy of polyatomic molecules, photochemistry and chemical kinetics. This invaluable book presents a systematic exposition of the current state of knowledge about conical intersections, which has been elaborated in research papers scattered throughout the chemical physics literature.Section I of the book provides a comprehensive analysis of the electronic-structure aspects of conical intersections. Section II shows the importance of conical intersections in chemical reaction dynamics and gives an overview of the computational techniques employed to describe the dynamics at conical intersections. Finally, Section III deals with the role of conical intersections in the fields of molecular spectroscopy and laser control of chemical reaction dynamics.This book has been selected for coverage in:• CC / Physical, Chemical & Earth Sciences• Chemistry Citation Index(tm)• Index to Scientific Book Contents® (ISBC)
Download or read book Proceedings of the First International Workshop on Optical Power Limiting written by Francois Kajzar and published by CRC Press. This book was released on 1999 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Advances in Density Functional Methods written by Delano Pun Chong and published by World Scientific. This book was released on 1995 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Of all the different areas in computational chemistry, density functional theory (DFT) enjoys the most rapid development. Even at the level of the local density approximation (LDA), which is computationally less demanding, DFT can usually provide better answers than Hartree-Fock formalism for large systems such as clusters and solids. For atoms and molecules, the results from DFT often rival those obtained by ab initio quantum chemistry, partly because larger basis sets can be used. Such encouraging results have in turn stimulated workers to further investigate the formal theory as well as the computational methodology of DFT.This Part II expands on the methodology and applications of DFT. Some of the chapters report on the latest developments (since the publication of Part I in 1995), while others extend the applications to wider range of molecules and their environments. Together, this and other recent review volumes on DFT show that DFT provides an efficient and accurate alternative to traditional quantum chemical methods. Such demonstration should hopefully stimulate frutiful developments in formal theory, better exchange-correlation functionals, and linear scaling methodology.
Download or read book Fluorescent Analogs of Biomolecular Building Blocks written by Marcus Wilhelmsson and published by John Wiley & Sons. This book was released on 2016-04-04 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluorescent Analogs of Biomolecular Building Blocks focuses on the design of fluorescent probes for the four major families of macromolecular building blocks. Compiling the expertise of multiple authors, this book moves from introductory chapters to an exploration of the design, synthesis, and implementation of new fluorescent analogues of biomolecular building blocks, including examples of small-molecule fluorophores and sensors that are part of biomolecular assemblies.
Download or read book Time Dependent Density Functional Theory written by Carsten Ullrich and published by Oxford University Press. This book was released on 2012 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: Time-dependent density-functional theory (TDDFT) is a quantum mechanical approach for the dynamical properties of electrons in matter. It's widely used in (bio)chemistry and physics to calculate molecular excitation energies and optical properties of materials. This is the first graduate-level text on the formal framework and applications of TDDFT.
Download or read book Intramolecular Charge Transfer written by Ramprasad Misra and published by John Wiley & Sons. This book was released on 2018-02-27 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Pyrene written by Petr Ruzicka and published by Nova Science Publishers. This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pyrene (Py) and various metabolites with a Py chromophore are powerful probes often used in biophysical and biochemical sciences due to their high fluorescent quantum yields and relatively long fluorescence lifetimes. In this book, the authors present current research in the study of the chemical properties, biochemistry applications and toxic effects of pyrene. Topics include the biological effects induced by benzyprene in soil and plants; benzo(a)pyrene and colonic cancer; bacterial metabolism of pyrene; low-temperature laser-induced fluorescence studies of various biological systems with pyrene chromophore; photo-energy and electron donating ability of pyrene; and synthesis of novel silylated pyrene units and their application as a fluorescent labeling agent for bioactive components such as oligodna and cholesterol.
Download or read book Olefin Polymerization written by Walter Kaminsky and published by Wiley-VCH. This book was released on 2006-08-18 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: With an enormous velocity, olefin polymerization has expanded to one of the most significant fields in polymers since the first industrial use about 50 years ago. In 2005, 100 million tons of polyolefins were produced - the biggest part was catalyzed by metallorganic compounds. The Hamburg Macromolecular Symposium 2005 with the title "Olefin Polymerization" involved topics such as new catalysts and cocatalysts, kinetics, mechanism and polymer reaction engineering, synthesis of special polymers, and characterization of polyolefins. The conference combined scientists from different disciplines to discuss latest research results of polymers and to offer each other the possibility of cooperation. This is reflected in this volume, which contains invited lectures and selected posters presented at the symposium.
Download or read book QM MM Studies of Light responsive Biological Systems written by Tadeusz Andruniów and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, a consecutive contribution to the series Challenges and Advances in Computational Chemistry and Physics, focuses on understanding the photoinduced processes in biological systems. Understanding and fine control of light fate in molecules is vital for the progress of society and environmental safety. Light induced changes of various physico-chemical and spectroscopic properties in nucleic acids and proteins is the basis of fundamental biological events such as vision, DNA photodamage or photosensing. The investigation of these processes is challenging to both theoretical and experimental studies. This volume encompasses the quantum mechanics/molecular mechanics theory in several subfields, including: advanced computational methods for nucleic acids and proteins systems; dynamics, spectroscopic and physico-chemical properties of biological photoreceptors; DNA photodamage. This book is of interest to readers in both fundamental and application-oriented research by overviewing recent achievements in computational modeling of excited states in nucleic acids and proteins.
Download or read book Non Linear Optical Properties of Matter written by Manthos G. Papadopoulos and published by Springer Science & Business Media. This book was released on 2007-05-03 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book assembles both theory and application in this field, to interest experimentalists and theoreticians alike. Part 1 is concerned with the theory and computing of non-linear optical (NLO) properties while Part 2 reviews the latest developments in experimentation. This book will be invaluable to researchers and students in academia and industry, particularlrly to anyone involved in materials science, theoretical and computational chemistry, chemical physics, and molecular physics.
Download or read book Coherent Vibrational Dynamics written by Guglielmo Lanzani and published by CRC Press. This book was released on 2007-11-29 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Remarkable developments in the spectroscopy field regarding ultrashort pulse generation have led to the possibility of producing light pulses ranging from 50 to5 fs and frequency tunable from the near infrared to the ultraviolet range. Such pulses enable us to follow the coupling of vibrational motion to the electronic transitions in molecules and
Download or read book Advances in Spectroscopy Molecules to Materials written by Dheeraj Kumar Singh and published by Springer. This book was released on 2020-10-26 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents and discusses recent developments in the broad field of spectroscopy, providing the reader with an updated overview. The main objective is to introduce them to recent innovations and current trends in spectroscopy applied to molecules and materials. The book also brings together experimentalists and theoreticians to highlight the multidimensional aspects of spectroscopy and discuss the latest issues. Accordingly, it provides insights not only into the general goals of spectroscopy, but also into how the various spectroscopic techniques represent a toolbox that can be used to gain a more detailed understanding of molecular systems and complex chemical problems. Besides technical aspects, basic theoretical interpretations of spectroscopic results are also presented. The spectroscopy techniques discussed include UV-visible absorption spectroscopy, Raman spectroscopy, IR absorption spectroscopy, fluorescence spectroscopy, and time-resolved spectroscopy. In turn, basic tools like lasers and theoretical modeling approaches are also presented. Lastly, applications for the characterization of fundamental properties of molecules (environmental aspects, biomolecules, pharmaceutical drugs, hazardous molecules, etc.) and materials (nanomaterials, nuclear chemistry materials, biomaterials, etc.) are discussed. Given its scope, the book offers a valuable resource for researchers from various branches of science, and presents new techniques that can be applied to their specific problems.
