Download or read book The Study of Nitrogen containing Molecules of Astrochemical Importance Using Rotational Spectroscopy and Computational Chemistry written by Maria Zdanovskaia and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proper analysis of rotational spectra can provide insight into a variety of molecular properties, such as its structure, energy separations between vibrational states, and quantum-mechanical phenomena, such as coupling, to a high degree of accuracy and precision. Data acquired from the analysis can be used as benchmarks for computational chemistry, as well as in the experimental determination of related molecular properties. At the same time, high-level calculations can be used to support the experimental analysis. Additionally, most extraterrestrial molecular identifications are achieved using radioastronomy and require precise laboratory rotational spectroscopy measurements. The work presented in this dissertation details the gas-phase rotational spectral analysis of several molecules containing nitrogen (e.g., 1,2,3-triazole, benzonitrile, phenyl isocyanide, cyanobutadiene) and two nitrogen-less molecules. Some of these species' rotational spectra are studied for the first time and all works provide improved data for use with observational extraterrestrial data. Molecular properties gleaned include highly accurate and precise semi-experimental equilibrium structures, structural comparisons between benzonitrile and phenyl isocyanide, highly precise energy separations between vibrational states, vibrational-state term energies, coupling terms, and anharmonicity constants.
Download or read book Computational and Spectroscopic Investigations of Species of Astrochemical Relevance written by and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work focuses on several research projects that apply computational or spectroscopic techniques to study molecules of astrochemical relevance. Chapters 1 and 2 discuss computational projects relevant to carbon condensation and fullerene formation as proposed by the coalescence and annealing model. We find that alkynyl substitution of cyclobutadiene provides stabilization of the antiaromatic species which provides support of the proposed poly-alkynl cyclobutadiene intermediate. Further theoretical investigation reveals that the cyclization of the poly-alkynyl cyclobutadiene to form a para diradical via a Bergman cyclization may not be a viable step in fullerene formation and does not lead to the necessary 6-membered rings. This work calls into question the coalescence and annealing model of carbon condensation and fullerene formation. Chapter 3 details a computational investigation of the decomposition of carbonyl diazide into diazirinone. This builds upon previous work refuting the original reports of diazirinone generation and our subsequent work synthesizing carbonyl diazide as a potential precursor. While incomplete, this work shows how the conformers of carbonyl diazide can interconvert and, by loss of nitrogen, can form 3nitreno-carbonylazide or azidoisocyanate. Higher-level, multi-reference calculations, such as SF-EOM-CCSD are likely needed to obtain a more definitive decomposition pathway that leads to diazirinone. Chapters 4 and 5 describe the type of laboratory rotational spectroscopy typically used by radio astronomers to detect molecules in the interstellar medium. Chapter 4 describes the reconstruction and programming of the millimeter-wave spectrometer used to make these measurements. This instrument allowed us to complete an investigation of the rotational spectrum of pyridazine. We have observed several thousand transitions of pyridazine, its isotopomers, and its vibrationally-excited states. This work provides the spectroscopic data that are needed to search for this important 6-membered aromatic heterocycles in the interstellar medium by radioastronomy. Chapter 6 describes an authentic use of computational chemistry to support the experiments completed in an undergraduate organic chemistry laboratory course. As a result of the curriculum redevelopment project, undergraduates are using WebMO and Gaussian to calculate conformers, transition states, reaction intermediates, molecular orbitals, and natural bond orbitals.
Download or read book Active Nitrogen written by A. Nelson Wright and published by Elsevier. This book was released on 2012-12-02 with total page 615 pages. Available in PDF, EPUB and Kindle. Book excerpt: Active Nitrogen focuses on the experimental and theoretical investigations on active nitrogen. Divided into five chapters, the book starts by giving an introduction to the discovery of active nitrogen, the energy content, and the methods by which this may be produced. The succeeding part deals with light emissions from active nitrogen system. This discussion includes molecular spectrum of nitrogen, emission from atomic energy and condensed active nitrogen, emission from molecular species with electronic energy levels below and above 9.76 eV, and light-emitting systems of active nitrogen. The next part focuses on theories on active nitrogen. The theories discussed are long-lived Lewis-Rayleigh afterglow and short-lived, energetic afterglows. Numerical representations are provided to test the validity of the theories. Lastly, the discussions end with chemical reactions of active nitrogen. Topics contained in this part are text on recombination of N(4S) atoms; rate constants for reactions presumably induced by direct N(4S) attack; reactions caused by excited nitrogen molecular attack; and mechanism for reactions of active nitrogen that seem to influence direct N(4S) attack. The book is a valuable source of information for readers interested in the research on active nitrogen.
Download or read book Synthesis of Astrochemically Relevant Small Molecules for Rotational Spectroscopy written by Samuel Kougias (Ph.D.) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over 250 molecular species have been detected in the interstellar medium (ISM) via radioastronomy through the observation and assignment of rotational spectra. While relevant to the understanding of the chemical processes of the ISM, the presence of organic molecules in this environment has relevance to astrobiology regarding the origins of organic components critical for life on Earth. The McMahon/Woods group seeks to further develop the library of known celestial molecules by the synthesis and analysis of species theorized to be part of astrochemical systems. Our group has synthesized seven isomeric organic nitriles hypothesized to be present in the ISM and the atmosphere of Saturn's largest moon, Titan. Additionally, these nitriles are isomers of the aromatic heterocycle, pyridine, which has yet to be identified in the ISM. Synthetic methodology for the production and isolation of samples is presented. The isolation of pure samples of these reactive nitriles enables measurement of their laboratory rotational spectra, which are the critical data needed to search for these species in the cosmos via radioastronomy. Impact and importance of the highlighted species to the field of molecular spectroscopy and radioastronomy will be discussed
Download or read book Nitrogen Containing Molecules written by Dimitris Matiadis and published by . This book was released on 2021-11 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: - A total of 16 original research articles. - Contributions from 10 countries from 3 continents. - Organic synthesis towards novel heterocyclic compounds. - Fully characterized inorganic and organic molecules including X-ray crystallographic analysis. - Cyclization reactions, reactivity of aromatic compounds and improved synthetic methodologies of important intermediate compounds.
Download or read book N Nitrogen written by Walter Hack and published by Springer. This book was released on 1993 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Nitrogen" Suppt. Vol. B 1 describes the compounds of nitrogen with noble gases and, in the major part, binary compounds composed of one nitrogen atom and hydrogen. Nitrogen hydrogen compounds with two and more nitrogen atoms are covered in "Nitrogen" Suppt. Vol. 82. There is some information on various nitrogen-noble gas species, to a large extent because of the interest in their bonding behavior. Experimental data have been obtained chiefly for some singly charged cations, particularly those formed by argon Like ArN + and ArNi. The existence of others has only been established by mass spectrometry. The binary compounds of nitrogen and hydrogen comprise NH, NH , NH , NH , the corre 2 4 5 sponding ions, and some adducts. NH and NH1 are not treated. The predominant part 3 of the volume covers the description of the molecules NH and NH . 8oth species are present 2 in photolytic processes in the atmosphere. They play an essential role in combustion systems regardless of whether the nitrogen stems from the nitrogen-containing fuel or from the air. Thus, much work has been devoted to the understanding of the nitrogen chemistry in combustion and in the atmosphere. The production and detection methods as weiL as the reactions have been comprehensively described. ln addition detailed information is given on the spectral behavior, the knowledge of which is important for detecting the mole cules and for studying their kinetics.
Download or read book Synthesis of Astrochemically Relevant Small Molecules for Rotational Spectroscopy written by Samuel Kougias (Ph.D.) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over 250 molecular species have been detected in the interstellar medium (ISM) via radioastronomy through the observation and assignment of rotational spectra. While relevant to the understanding of the chemical processes of the ISM, the presence of organic molecules in this environment has relevance to astrobiology regarding the origins of organic components critical for life on Earth. The McMahon/Woods group seeks to further develop the library of known celestial molecules by the synthesis and analysis of species theorized to be part of astrochemical systems. Our group has synthesized seven isomeric organic nitriles hypothesized to be present in the ISM and the atmosphere of Saturn's largest moon, Titan. Additionally, these nitriles are isomers of the aromatic heterocycle, pyridine, which has yet to be identified in the ISM. Synthetic methodology for the production and isolation of samples is presented. The isolation of pure samples of these reactive nitriles enables measurement of their laboratory rotational spectra, which are the critical data needed to search for these species in the cosmos via radioastronomy. Impact and importance of the highlighted species to the field of molecular spectroscopy and radioastronomy will be discussed
Download or read book An Experimental and Computational Study of Nitrogen Containing Molecules in the Poly oligoazine and the Poly oligonaphthylamine Systems written by Brian Keith Schmitz and published by . This book was released on 1993 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conformationaly Analysis of Some Nitrogen Containing Molecules by Spectroscopic and Theoretical Methods written by Jennifer Leigh Ives and published by . This book was released on 1992 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rotational and Structural Analyses of Astrochemically Relevant Molecules written by Houston Hartwell Smith Ph.D. and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rotational spectroscopy is an extremely powerful technique that allows for identification of molecules in different gaseous environments given their rotational spectrum has been measured, assigned, and least-squares fit to a proper Hamiltonian. Rotational spectroscopy is unique in that structural isomers, conformers, isotopologues, and vibrational states of a molecule all have a different rotational spectrum enabling their positive identification in a gas sample. Given the specificity of the technique and ubiquity of radio frequencies in the interstellar medium (ISM), the majority of the near 300 molecules detected in the ISM have come from radioastronomy. This thesis comprises the spectral assignment of five molecules with a unifying theme of providing new or updated spectroscopic constants for the search of these molecules in the ISM. Additionally, several molecules (1-cyanocyclobutene, 2-cyanopyrimidine, and cyanopyrazine) have their two lowest-energy vibrationally excited states Coriolis coupled to each other. This thesis uses a two-state, Coriolis coupled Hamiltonian to adequately address the measured rotational spectra, which are greatly affected by this coupling, and this results in an extremely precise determination of the energy separation between the vibrationally excited states. Two other molecules (ketene and methacrylonitrile) utilized the spectroscopic constants of different isotopologues along with high-level theoretical corrections to achieve highly precise and accurate semi-experimental equilibrium structures (reSE) with general precision to the ten-thousandth of an Angstrom and hundredths of a degree for bond distances and angles, respectively.
Download or read book Vibrational spectra and structure written by James R. Durig and published by . This book was released on 1975 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Science and Its Applications ICCSA 2020 written by Osvaldo Gervasi and published by Springer Nature. This book was released on 2020-10-02 with total page 813 pages. Available in PDF, EPUB and Kindle. Book excerpt: The seven volumes LNCS 12249-12255 constitute the refereed proceedings of the 20th International Conference on Computational Science and Its Applications, ICCSA 2020, held in Cagliari, Italy, in July 2020. Due to COVID-19 pandemic the conference was organized in an online event. Computational Science is the main pillar of most of the present research, industrial and commercial applications, and plays a unique role in exploiting ICT innovative technologies. The 466 full papers and 32 short papers presented were carefully reviewed and selected from 1450 submissions. Apart from the general track, ICCSA 2020 also include 52 workshops, in various areas of computational sciences, ranging from computational science technologies, to specific areas of computational sciences, such as software engineering, security, machine learning and artificial intelligence, blockchain technologies, and of applications in many fields.
Download or read book Encyclopedia of Interfacial Chemistry written by and published by Elsevier. This book was released on 2018-03-29 with total page 5276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry, Seven Volume Set summarizes current, fundamental knowledge of interfacial chemistry, bringing readers the latest developments in the field. As the chemical and physical properties and processes at solid and liquid interfaces are the scientific basis of so many technologies which enhance our lives and create new opportunities, its important to highlight how these technologies enable the design and optimization of functional materials for heterogeneous and electro-catalysts in food production, pollution control, energy conversion and storage, medical applications requiring biocompatibility, drug delivery, and more. This book provides an interdisciplinary view that lies at the intersection of these fields. Presents fundamental knowledge of interfacial chemistry, surface science and electrochemistry and provides cutting-edge research from academics and practitioners across various fields and global regions
Download or read book Spectroscopy and Modeling of Biomolecular Building Blocks written by Jean-Pierre Schermann and published by Elsevier. This book was released on 2007-10-16 with total page 499 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spectroscopy and Modeling of Biomolecular Building Blocks presents an overview of recent advances in the intertwining of the following research fields: photon and electron spectroscopy, quantum chemistry, modelling and mass-spectrometry. The coupling of these disciplines offers a new point of view to the understanding of isolated elementary building blocks of biomolecules and their assemblies. It allows the unambiguous separation between intrinsic properties of biomolecular systems and those induced by the presence of their environment. The first chapters provide background in modelling (I), frequency-resolved spectroscopy using microwave, infrared and UV photons, time-resolved spectroscopy in the femtosecond domain and energy-resolved electron spectroscopy (II) and production of gas-phase neutral and ionic biomolecular species, mass-spectrometry, ion mobility and BIRD techniques (III). Chapter IV is devoted to case studies of gas-phase experimental investigations coupled to quantum or classical calculations. The topics are structural studies of nucleobases and oligonucleotides, peptides and proteins, sugars; neuromolecules; non-covalent complexes; chiral systems, interactions of low-energy electrons with biomolecules in the radiation chemistry context and very large gas-phase biomolecular systems. The fifth chapter concerns the link between gas-phase and liquid-phase. Different treatments of solvation are illustrated through examples pointing out the influence of progressive addition of water molecules upon properties of nucleobases, peptides, sugars and neuromolecules. Offer a new perspective to the understanding of isolated elementary building blocks of bio molecules Includes case studies of experimental investigations coupled to quantum or classical calculations
Download or read book Gas Phase Combustion Chemistry written by W.C., Jr. Gardiner and published by Springer Science & Business Media. This book was released on 1999-12-10 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superseding Gardiner's "Combustion Chemistry", this is an updated, comprehensive coverage of those aspects of combustion chemistry relevant to gas-phase combustion of hydrocarbons. The book includes an extended discussion of air pollutant chemistry and aspects of combustion, and reviews elementary reactions of nitrogen, sulfur and chlorine compounds that are relevant to combustion. Methods of combustion modeling and rate coefficient estimation are presented, as well as access to databases for combustion thermochemistry and modeling.
Download or read book Astrochemistry and Astrobiology written by Ian W. M. Smith and published by Springer Science & Business Media. This book was released on 2012-10-28 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astrochemistry and Astrobiology is the debut volume in the new series Physical Chemistry in Action. Aimed at both the novice and experienced researcher, this volume outlines the physico-chemical principles which underpin our attempts to understand astrochemistry and predict astrobiology. An introductory chapter includes fundamental aspects of physical chemistry required for understanding the field. Eight further chapters address specific topics, encompassing basic theory and models, up-to-date research and an outlook on future work. The last chapter examines each of the topics again but addressed from a different angle. Written and edited by international experts, this text is accessible for those entering the field of astrochemistry and astrobiology, while it still remains interesting for more experienced researchers.
Download or read book Handbook of High resolution Spectroscopy written by Martin Quack and published by John Wiley & Sons. This book was released on 2011-09-26 with total page 2236 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of High-Resolution Spectroscopy has been considerably extended and even redefined in some areas. Combining the knowledge of spectroscopy, laser technology, chemical computation, and experiments, Handbook of High-Resolution Spectroscopy provides a comprehensive survey of the whole field as it presents itself today, with emphasis on the recent developments. This essential handbook for advanced research students, graduate students, and researchers takes a systematic approach through the range of wavelengths and includes the latest advances in experiment and theory that will help and guide future applications. The first comprehensive survey in high-resolution molecular spectroscopy for over 15 years Brings together the knowledge of spectroscopy, laser technology, chemical computation and experiments Brings the reader up-to-date with the many advances that have been made in recent times Takes the reader through the range of wavelengths, covering all possible techniques such as Microwave Spectroscopy, Infrared Spectroscopy, Raman Spectroscopy, VIS, UV and VUV Combines theoretical, computational and experimental aspects Has numerous applications in a wide range of scientific domains Edited by two leaders in this field Provides an overview of rotational, vibration, electronic and photoelectron spectroscopy Volume 1 - Introduction: Fundamentals of Molecular Spectroscopy Volume 2 - High-Resolution Molecular Spectroscopy: Methods and Results Volume 3 - Special Methods & Applications
