Two fundamental halocarbon ions, CHsub.2Clsup.+ and CHsub.3ClHsup.+, were studied in the gas phase using the FELion 22-pole ion trap apparatus and the Free Electron Laser for Infrared eXperiments ...(FELIX) at Radboud University, Nijmegen (the Netherlands). The vibrational bands of a total of four isotopologs, CHsub.2 sup.35,37Clsup.+ and CHsub.3 sup.35,37ClHsup.+, were observed in selected wavenumber regions between 500 and 2900 cmsup.−1 and then spectroscopically assigned based on the results of anharmonic force field calculations performed at the CCSD(T) level of theory. As the infrared photodissociation spectroscopy scheme employed probes singly Ne-tagged weakly bound complexes, complementary quantum-chemical calculations of selected species were also performed. The impact of tagging on the vibrational spectra of CHsub.2Clsup.+ and CHsub.3ClHsup.+ is found to be virtually negligible for most bands; for CHsub.3ClHsup.+–Ne, the observations suggest a proton-bound structural arrangement. The experimental band positions as well as the best estimate rotational molecular parameters given in this work provide a solid basis for future spectroscopic studies at high spectral resolutions.
Computational spectroscopy is a rapidly evolving field that is becoming a versatile and widespread tool for the assignment of experimental spectra and their interpretation as related to chemical ...physical effects. This book is devoted to the most significant methodological contributions in the field, and to the computation of IR, UV-VIS, NMR and EPR spectral parameters with reference to the underlying vibronic and environmental effects. Each section starts with a chapter written by an experimental spectroscopist dealing with present challenges in the different fields; comprehensive coverage of conventional and advanced spectroscopic techniques is provided by means of dedicated chapters written by experts. Computational chemists, analytical chemists and spectroscopists, physicists, materials scientists, and graduate students will benefit from this thorough resource.
Raman spectroscopy is increasingly being used in biology, forensics, diagnostics, pharmaceutics and food science applications. This growth is triggered not only by improvements in the computational ...and experimental setups but also by the development of chemometric techniques. Chemometric techniques are the analytical processes used to detect and extract information from subtle differences in Raman spectra obtained from related samples. This information could be used to find out, for example, whether a mixture of bacterial cells contains different species, or whether a mammalian cell is healthy or not. Chemometric techniques include spectral processing (ensuring that the spectra used for the subsequent computational processes are as clean as possible) as well as the statistical analysis of the data required for finding the spectral differences that are most useful for differentiation between, for example, different cell types. For Raman spectra, this analysis process is not yet standardized, and there are many confounding pitfalls. This protocol provides guidance on how to perform a Raman spectral analysis: how to avoid these pitfalls, and strategies to circumvent problematic issues. The protocol is divided into four parts: experimental design, data preprocessing, data learning and model transfer. We exemplify our workflow using three example datasets where the spectra from individual cells were collected in single-cell mode, and one dataset where the data were collected from a raster scanning-based Raman spectral imaging experiment of mice tissue. Our aim is to help move Raman-based technologies from proof-of-concept studies toward real-world applications.
Theory Theory of Coherent Raman Scattering, Eric Olaf Potma and Shaul MukamelCoherent Raman Scattering under Tightly Focused Conditions, Eric Olaf Potma, Xiaoliang Sunney Xie, Andreas Volkmer, and ...Ji-Xin ChengPlatformsConstruction of a Coherent Raman Microscope, Brian G. Sarr and Xiaoliang Sunney XieStimulated Raman Scattering Microscopy, Christian Freudiger and Xiaoliang Sunney XieFemtosecond versus Picosecond Pulses for Coherent Raman Microscopy, Mikhail N. Slipchenko, Delong Zhang, and Ji-Xin ChengWide-Field CARS Microscopy, Alexander Jesacher, Gregor Thalhammer, Stefan Bernet, and Monika Ritsch-MarteVibrational Spectromicroscopy by Coupling Coherent Raman Imaging with Spontaneous Raman Spectral Analysis, Mikhail N. Slipchenko and Ji-Xin ChengCoherent Control in CARS, Jonathan M. Levitt, Ori Katz, and Yaron SilberbergFourier Transform CARS Microscopy, Jennifer P. OgilvieCRS with Alternative Beam Profiles, Varun Raghunathan, Hyunmin Kim, Stephan Stranick, and Eric Olaf PotmaVibrational Phase Microscopy, Martin Jurna, Cees Otto, and Herman L. OfferhausMultiplex CARS Microscopy, James P.R. Day, Katrin F. Domke, Gianluca Rago, Erik M. Vartiainen, and Mischa BonnInterferometric Multiplex CARS, Sang-Hyun LimPhotonic Crystal Fiber-Based Broadband CARS Microscopy, Marcus T. Cicerone, Young Jong Lee, Sapun H. Parekh, and Khaled A. AamerMultiplex Stimulated Raman Scattering Microscopy, Dan Fu and Xiaoliang Sunney XieApplicationsImaging Myelin Sheath Ex Vivo and In Vivo by CARS Microscopy, Yan Fu, Yunzhou (Sophia) Shi, and Ji-Xin ChengImaging Lipid Metabolism in Caenorhabditis elegans and Other Model Organisms, Helen Fink, Christian Brackmann, and Annika EnejderLipid-Droplet Biology and Obesity-Related Health Risks, Thuc T. LeWhite Matter Injury: Cellular-Level Myelin Damage Quantification in Live Animals, Erik Bélanger, F.P. Henry, R. Vallée, M.A.
Randolph, I.E. Kochevar, J.M. Winograd, Charles P. Lin, and Daniel CôtéCARS Microscopy Study of Liquid Crystals, Heung-Shik Park and Oleg D. LavrentovichLive Cell Imaging by Multiplex CARS Microspectroscopy, Hideaki Kano Coherent Raman Scattering Imaging of Drug Delivery Systems, Ling Tong and Ji-Xin ChengApplications of Stimulated Raman Scattering Microscopy, Christian Freudiger, Daniel A. Orringer, and Xiaoliang Sunney XieApplications of Coherent Anti-Stokes Raman Spectroscopy Imaging to Cardiovascular Diseases, Han-Wei Wang, Michael Sturek, and Ji-Xin ChengApplications of CARS Microscopy to Tissue Engineering, Annika Enejder and Christian BrackmannDietary Fat Absorption Visualized by CARS Microscopy, Kimberly K. BuhmanIndex.
Vibrational spectroscopy is an essential tool in chemical analyses, biological assays, and studies of functional materials. Over the past decade, various coherent nonlinear vibrational spectroscopic ...techniques have been developed and enabled researchers to study time-correlations of the fluctuating frequencies that are directly related to solute-solvent dynamics, dynamical changes in molecular conformations and local electrostatic environments, chemical and biochemical reactions, protein structural dynamics and functions, characteristic processes of functional materials, and so on. In order to gain incisive and quantitative information on the local electrostatic environment, molecular conformation, protein structure and interprotein contacts, ligand binding kinetics, and electric and optical properties of functional materials, a variety of vibrational probes have been developed and site-specifically incorporated into molecular, biological, and material systems for time-resolved vibrational spectroscopic investigation. However, still, an all-encompassing theory that describes the vibrational solvatochromism, electrochromism, and dynamic fluctuation of vibrational frequencies has not been completely established mainly due to the intrinsic complexity of intermolecular interactions in condensed phases. In particular, the amount of data obtained from the linear and nonlinear vibrational spectroscopic experiments has been rapidly increasing, but the lack of a quantitative method to interpret these measurements has been one major obstacle in broadening the applications of these methods. Among various theoretical models, one of the most successful approaches is a semiempirical model generally referred to as the vibrational spectroscopic map that is based on a rigorous theory of intermolecular interactions. Recently, genetic algorithm, neural network, and machine learning approaches have been applied to the development of vibrational solvatochromism theory. In this review, we provide comprehensive descriptions of the theoretical foundation and various examples showing its extraordinary successes in the interpretations of experimental observations. In addition, a brief introduction to a newly created repository Web site (http://frequencymap.org) for vibrational spectroscopic maps is presented. We anticipate that a combination of the vibrational frequency map approach and state-of-the-art multidimensional vibrational spectroscopy will be one of the most fruitful ways to study the structure and dynamics of chemical, biological, and functional molecular systems in the future.
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