Download or read book Conformational Vibrational Rotational and Molecular Structural Studies of Several Molecules with Low Frequency Modes written by Patricia Ann Brletic and published by . This book was released on 1982 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structures and Conformations of Non Rigid Molecules written by J. Laane and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the beginnings of modern chemistry, molecular structure has been a lively area of research and speculation. For more than half a century spectroscopy and other methods have been available to characterize the structures and shapes of molecules, particularly those that are rigid. However, most molecules are at least to some degree non-rigid and this non-rigidity plays an important role in such diverse areas as biological activity, energy transfer, and chemical reactivity. In addition, the large-amplitude vibrations present in non-rigid molecules give rise to unusual low-energy vibrational level patterns which have a dramatic effect on the thermodynamic properties of these systems. Only in recent years has a coherent picture of the energetics and dynamics of the conformational changes inherent in non-rigid (and semi-rigid) molecules begun to emerge. Advances have been made in a number of different experimental areas: vibrational (infrared and Raman) spectroscopy, rotational (microwave) spectroscopy, electron diffraction, and, most recently, laser techniques probing both the ground and excited electronic states. Theoretically, the proliferation of powerful computers coupled with scientific insight has allowed both empirical and ab initio methods to increase our understanding of the forces responsible for the structures and energies of non-rigid systems. The development of theory (group theoretical methods and potential energy surfaces) to understand the unique characteristics of the spectra of these floppy molecules has also been necessary to reach our present level of understanding. The thirty chapters in this volume contributed by the key speakers at the Workshop are divided over the various areas. Both vibrational and rotational spectroscopy have been effective at determining the potential energy surfaces for non-rigid molecules, often in a complementary manner. Recent laser fluorescence work has extended these types of studies to electronic excited states. Electronic diffraction methods provide radial distribution functions from which both molecular structures and compositions of conformational mixtures can be found. Ab initio calculations have progressed substantially over the past few years, and, when carried out at a sufficiently high level, can accurately reproduce (or predict ahead of time) experimental findings. Much of the controversy of the ARW related to the question of when an ab initio is reliable. Since the computer programs are readily available, many poor calculations have been carried out. However, excellent results can be obtained from computations when properly done. A similar situation exists for experimental analyses. The complexities of non-rigid molecules are many, but major strides have been taken to understand their structures and conformational processes.
Download or read book Normal Mode Analysis written by Qiang Cui and published by CRC Press. This book was released on 2005-12-12 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rapid developments in experimental techniques continue to push back the limits in the resolution, size, and complexity of the chemical and biological systems that can be investigated. This challenges the theoretical community to develop innovative methods for better interpreting experimental results. Normal Mode Analysis (NMA) is one such technique
Download or read book Vibrational Dynamics Of Molecules written by Joel M Bowman and published by World Scientific. This book was released on 2022-06-14 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vibrational Dynamics of Molecules represents the definitive concise text on the cutting-edge field of vibrational molecular chemistry. The chapter contributors are a Who's Who of world leaders in the field. The editor, Joel Bowman, is widely considered as one of the founding fathers of theoretical reaction dynamics. The included topics span the field, from fundamental theory such as collocation methods and vibrational CI methods, to interesting applications such as astrochemistry, supramolecular systems and virtual computational spectroscopy. This is a useful reference for theoretical chemists, spectroscopists, physicists, undergraduate and graduate students, lecturers and software developers.
Download or read book Vibrational rotational Spectroscopy And Molecular Dynamics written by Dusan Papousek and published by World Scientific. This book was released on 1997-10-31 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book reviews the results of vibration-rotational spectroscopy of molecules obtained recently by combining modern computational methods of quantum chemistry with the new techniques of high-resolution rotational and vibration-rotational spectroscopy. It shows for example that the tunneling vibration-rotational spectroscopy of the van der Waals complexes provides a new look at intermolecular forces while the high precision and sensitivity of the submillimeter-wave and Fourier transform microwave spectroscopy make it possible to study complex rotational spectra of molecules in excited vibrational states. New results of high level ab initio quantum chemical computations of vibrational and rotational energy levels and dipole moment functions of unusual molecules will be discussed together with the recent discovery of clustering of energy levels in asymmetric tops. Group theoretical analysis of floppy molecules, especially the tunneling effects in nonrigid molecules, will also be discussed.
Download or read book Conformational and Structural Analyses of Some Alcohols and Amines of Molecules with Low Frequency Large Amplitude Anharmonic Vibrations written by Arindam Ganguly and published by . This book was released on 2010 with total page 876 pages. Available in PDF, EPUB and Kindle. Book excerpt: The infrared and Raman spectra of compounds with hydroxyl and amino functional groups, as well as some with cyclic skeletal structures have been recorded of the gas and in condensed phases. Temperature dependent infrared spectra in xenon and krypton solutions were also recorded. A complete vibrational assignment, conformational stability determination and adjusted r0 parameters have been obtained for each of the most stable conformers and in some cases for lesser stable conformers. The results of these investigations were supported by ab initio predicted infrared intensities and depolarization ratios, band contours an conformational stabilities. Normal coordinate calculations were carried out for all of the molecules. From these calculations potential energy distributions for all the fundamentals were predicted for each molecules from which approximate descriptions of the vibrations were ascertained. Cyclobutanes substituted with asymmetric rotor such as hydroxyl and amine groups have four possible conformers. In case of cyclobutanol two of the four possible stable conformers have been confidently identified and their order of stabilities has been experimentally determined whereas three out of the four conformers were experimentally determined for cyclobutylamine. For halogen substituted cyclobutanes only two possible determined for cyclobutylamine. For halogen substituted cyclobutanes only two possible conformers exist and the enthalpy difference between the more stable equatorial conformer and the axial form has been determined for fluoro-, chloro-, and bromocyclobutane. For fluorocyclopentane only a single twist conformer was found which is at a variance to previously reported structures of both envelope-equatorial and envelope-axial conformers or only a single envelope-equatorial conformer. Thus, fluorocyclopentane provides a unique example of pseudorotation for five member rings. However for cyanocyclopentane both the equatorial and axial forms were observed. The conformational stabilities, adjusted R0 structural parameters and other scientific information are discussed and compared to the corresponding properties of some similar molecules based upon their functional groups and molecular structure.
Download or read book Molecular Structures and Vibrations written by Sven Josef Cyvin and published by . This book was released on 1972 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1990 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rotational Spectra and Molecular Structure written by James E. Wollrab and published by Academic Press. This book was released on 2013-10-22 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physical Chemistry, A Series of Monographs: Rotational Spectra and Molecular Structure covers the energy levels and rotational transitions. This book is divided into nine chapters that evaluate the rigid asymmetric top molecules and the nuclear spin statistics for asymmetric tops. Some of the topics covered in the book are the asymmetric rotor functions; rotational transition intensities; classes of molecules; nuclear spin statistics for linear molecules and symmetric tops; and classical appearance of centrifugal and coriolis forces. Other chapters deal with the energy levels and effects of centrifugal distortion, as well as the internuclear distance and moments of inertia. The discussion then shifts to the coriolis coupling effects on rotational constants and the perturbation treatment of vibration-rotational Hamiltonian. The last chapter is devoted to the examination of origin of the quadrupole interaction. The book can provide useful information to chemists, physicists, electrical engineers, students, and researchers.
Download or read book Vibrational Spectra Molecular Structure and Conformational Analysis of Some Molecules with Anharmonic Vibrations written by Dennis Jay Gerson and published by . This book was released on 1980 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Dissertation Index Chemistry P Z written by and published by . This book was released on 1984 with total page 844 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1989 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low Frequency Vibrations of Inorganic and Coordination Compounds written by John R. Ferraro and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the course of far-infrared investigations of inorganic and coordina tion compounds at Argonne National Laboratory in the years 1962-1966, it became apparent that no suitable book existed which correlated and dis cussed the important vibrations occurring in this region for these molecules. Early in 1967 the initial steps were taken to write such a book. Then, in 1968, an excellent text by Professor David M. Adams entitled Metal-Ligand and Related Vibrations was published. At this point serious consideration was given to discontinuing work on this book. However, upon examination of Adams' book, it became clear that the references covered only the period to 1966. This field of research is accelerating so tremendously, and the period 1966-1969 has seen so many new studies, that upon reconsideration it was decided to continue writing this text. The references in this book, particularly in the last several chapters, include many papers published in 1969. However, the proliferation of the far-infrared literature has made it impossible to present all the published material that has any bearing on the subject. Many titles do not pertain primarily to the far-infrared region as such, and some of this research has been omitted for this reason. Organometallic compounds have been neglected since the author feels that adequate reviews of that subject are available. Other studies may be missing simply because, owing to space limitations, only the more important researches could be considered. Of course, "importance" may, in this case, reflect the author's interest and prejudices.
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 Low Temperature Molecular Spectroscopy written by Rui Fausto and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular spectroscopy has achieved rapid and significant progress in recent years, the low temperature techniques in particular having proved very useful for the study of reactive species, phase transitions, molecular clusters and crystals, superconductors and semiconductors, biochemical systems, astrophysical problems, etc. The widening range of applications has been accompanied by significant improvements in experimental methods, and low temperature molecular spectroscopy has been revealed as the best technique, in many cases, to establish the connection between experiment and theoretical calculations. This, in turn, has led to a rapidly increasing ability to predict molecular spectroscopic properties. The combination of an advanced tutorial standpoint with an emphasis on recent advances and new perspectives in both experimental and theoretical molecular spectroscopy contained in this book offers the reader insight into a wide range of techniques, particular emphasis being given to supersonic jet and matrix isolation techniques, spectroscopy in cryogenic solutions (including liquid noble gases), and in both crystalline and amorphous states. Suitable quantum chemical methods are also considered, as are empirically based force field methods for calculating spectra of large molecular systems. The wide range of topics covered includes: molecular dynamics and reactivity, time-resolved and high-resolution spectroscopy, conformational analysis, hydrogen bonding and solvent effects, structure and dynamics of weakly bound complexes, transition metal and organic photochemistry, spectroscopy of excited states, ab initio prediction of molecular spectra, and biochemical and astrophysical applications.
Download or read book Structure of Molecules and Internal Rotation written by San-Ichiro Mizushima and published by Academic Press. This book was released on 2013-10-22 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structure of Molecules and Internal Rotation reviews early studies on dihalogenoethanes. This book is organized into two parts encompassing 8 chapters that evaluate the Raman effect in ethane derivatives, the energy difference between rotational isomers, and the infrared absorption of ethane derivatives. Some of the topics covered in the book are the potential barrier to internal rotation; nature of the hindering potential; entropy difference between the rotational isomers; internal rotation in butane, pentane, and hexane; and internal rotation in long chain n-paraffins. Other chapters deal with the configuration of a polypeptide chain, as well as the sum rule and the product rule for rotational isomers. The normal vibrations of the 1,2-dihalogenoethanes are presented. The last chapters are devoted to the examination of the Raman effect, dielectric constant, and electron diffraction. The book can provide useful information to chemists, physicists, students, and researchers.
Download or read book Frontiers of Molecular Spectroscopy written by Jaan Laane and published by Elsevier. This book was released on 2011-08-11 with total page 741 pages. Available in PDF, EPUB and Kindle. Book excerpt: Much of what we know about atoms, molecules, and the nature of matter has been obtained using spectroscopy over the last one hundred years or so. In this book we have collected together twenty chapters by eminent scientists from around the world to describe their work at the cutting edge of molecular spectroscopy. These chapters describe new methodology and applications, instrumental developments, and theory which is taking spectroscopy into new frontiers. The range of topics is broad. Lasers are utilized in much of the research, but their applications range from sub-femtosecond spectroscopy to the study of viruses and also to the investigation of art and archeological artifacts. Three chapters discuss work on biological systems and three others represent laser physics. The recent advances in cavity ringdown spectroscopy (CRDS), surface enhanced Raman spectroscopy (SERS), two-dimensional correlation spectroscopy (2D-COS), and microwave techniques are all covered. Chapters on electronic excited states, molecular dynamics, symmetry applications, and neutron scattering are also included and demonstrate the wide utility of spectroscopic techniques. - Provides comprehensive coverage of present spectroscopic investigations - Features 20 chapters written by leading researchers in the field - Covers the important role of molecular spectroscopy in research concerned with chemistry, physics, and biology
