Download or read book The Study of State Selected Ion Molecule Reactions Using the Vacuum Ultraviolet Pulsed Field Ionization Photoion Technique written by and published by . This book was released on 2006 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents the methodology to generate beams of ions in single quantum states for bimolecular ion-molecule reaction dynamics studies using pulsed field ionization (PFI) of atoms or molecules in high-n Rydberg states produced by vacuum ultraviolet (VUV) synchrotron or laser photoexcitation. Employing the pseudocontinuum high-resolution VUV synchrotron radiation at the Advanced Light Source as the photoionization source, PFI photoions (PFI-PIs) in selected rovibrational states have been generated for ion-molecule reaction studies using a fast-ion gate to pass the PFI-PIs at a fixed delay with respect to the detection of the PFI photoelectrons (PFI-PEs). The fast ion gate provided by a novel interleaved comb wire gate lens is the key for achieving the optimal signal-to-noise ratio in state-selected ion-molecule collision studies using the VUV synchrotron based PFI-PE secondary ion coincidence (PFI-PESICO) method. The most recent development of the VUV laser PFI-PI scheme for state-selected ion-molecule collision studies is also described. Absolute integral cross sections for state-selected H+2 ions ranging from v+=0 to 17 in collisions with Ar, Ne, and He at controlled translational energies have been obtained by employing the VUV synchrotron based PFI-PESICO scheme.
Download or read book Rovibrationally Selected Ion molecule Reaction Studies Using the Vacuum Ultraviolet Laser Pulsed Field Ionization photoion and Guided Ion Beam Methods written by Yuntao Xu and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have successfully performed rovibrationally selected ion-molecule studies with translational energy in the center-of-mass (E(cm)) from thermal to 10 eV by implementing the Vacuum ultraviolet (VUV) laser-based pulsed field ionization-photoion (PFI-PI) experimental technique with the newly developed double quadrupole-double octopole (DQDO) apparatus in our laboratory. A novel electric pulsing sequence has been developed to prepare ions of interests in single rovibrational states with not only with high intensity but also high translational energy resolution. An unprecedented translational energy resolution as low as 0.05 eV in the laboratory frame ([Delta]E(lab)) is achieved that allows us to investigate the effect rotational, vibrational and translational energy on the chemical reactivity of ion-molecule reactions. Using VUV-PFI-PI technique we show that N2+ ions can be selected in v+ vibrational states from v+ = 0-2 and in a particular N+ rotational levels from N+ = 0-9 at ground electronic state. Similarly, the triatomic H2O+ ions can be prepared in the v1+v2+v3+ = 000, 100 and 020 states and the N+(Ka+Kc+) = 000, 111, and 211 states, respectively, for rovibrationally selected ion-molecule reaction studies. Absolute integral cross sections ([delta]), as well as branching ratios, as a function of both internal ro-vibrational and translational energies of ions, are obtained for the ion-molecule reactions of N2+(X2[Sigma](g)+ ; v+ = 0-2; N+ = 0-9) + Ar/CH4 and H2O+(X2B1 ; v1+v2+v3+= 000; N+(Ka+Kc+)) + D2/CO. Many fascinating phenomena about chemical reaction dynamics are observed for the first time. These include vibrational enhancements in the charge-transfer cross sections of N2+(X2[Sigma]g+; v+; N+) + Ar [arrow right] Ar+ + N2, rotational enhancements in the chemical reactivity of H2O+(X2B1; v1+v2+v3+; N+(Ka+Kc+)) + D2 [arrow right]H2DO+ + D, and distinct activation thresholds in the reaction of H2O+(X2B1; v1+v2+v3+; N+(Ka+Kc+)) + CO [arrow right] CO+ + H2O. This kind of data is unique and it provides a database that serves as benchmarks for theoretical calculations and the modeling of related reaction systems.
Download or read book Quantum State Selected Ion Molecule Reaction Dynamics Studies by Vacuum Ultraviolet Laser and Pulsed Field Ionization photoion Method written by Bo Xiong and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum state resolved pulsed field ionization-photoion (PFI-PI) spectra of several small molecules have been obtained, and a few state-selected and kinetic energy selected ion molecule reactions have been studied in detail in this dissertation. Tunable vacuum ultraviolet (VUV) laser is employed, along with a PFI-PI double-quadrupole double-octupole (DQDO) mass spectrometer to conduct these spectroscopic and chemical dynamics studies. Electronic, vibrational, and rotational selected ions are produced by direct photoexcitation with intense, high-resolution VUV laser to high-n Rydberg states, then field ionized by external pulsed electric fields. Pulsed electric field sequences, including their intensity and duration, are adjusted for each unique molecular ion studied to achieve ion beam kinetic energy resolution of as good as 0.05 eV in the lab frame (E[subscript lab]). Kinetic energy dependent integral cross section measurements are measured in the center-of-mass kinetic energy (E[subscript CM]) range of 0.05 – 10.0 eV. Octupole ion guides are used to transmit reactant and product ions from the source to the mass spectrometer with high transmission efficiency. Quadrupole mass spectrometer is used to selectively transmit ions with specific mass to charge ratio. It is demonstrated a wide range of molecular species can be studied in the present VUV-PFI-PI-DQDO apparatus. In this dissertation, N2+, CH4+, O2+, H2+, H2O+, as well as a transition metal ion V+ are investigated spectroscopically and kinetically. Some quantum state resolved photoions are produced for the first time (e.g. rotational selected H2+, electronically and vibrational selected O2+, and spin-orbit state selected V+). Ion-molecule reactions involving these molecular ions are studied and quantum state effects on their reactivity are noticed and discussed. These include the vibrational state and kinetic energy dependence of the product channels and cross sections of reaction N2+(X2[sigma][subscript g], v+=0-2) + C2H2, the rotational enhancement and more complicated vibrational effects of reaction H2O+(X2B1, v1+v2+v3+, N+[subscript Ka+Kc+]) +HD, the distinctive charge transfer cross sections of O2+(a4[pi][subscript u], X2[pi][subscript g], v+)+Ar with reactant ions in two different electronic states while close in total internal energy, and the vibrational and rotational enhancement of proton transfer reaction of H2+(X2[sigma][subscript g]+, v+=1-3, N+=0-3)+Ne. For the CH4/CH4+ system, it is also shown that through studying the unimolecular dissociation dynamics by the PFI-PI method, thermochemistry data, e.g. appearance energy (AE) and bond dissociation energy (D0), can be obtained with unprecedented accuracy.
Download or read book VUV Laser Pulsed Field Ionization Studies of Photoelectron Spectroscopy and Photoion Technique for State selected Ion molecule Reaction Dynamics written by Yu Hou and published by . This book was released on 2007 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Resolution State Selected Ion Molecule Reaction Studies Using Pulsed Field Ionization Photoelectron Secondary Ion Coincidence Method written by and published by . This book was released on 2003 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have developed an octopole-quadrupole photoionization apparatus at the Advanced Light Source for absolute integral cross-section measurements of rovibrational-state-selected ion-molecule reactions. This apparatus consists of a high-resolution photoionization ion source, a wired ion gate lens, a dual radio-frequency (rf) octopole ion guide reaction gas cell, and a quadrupole mass spectrometer for reactant and product ion detection. The unique feature of this apparatus is the implementation of the high-resolution pulsed field ionization- photoelectron (PFI-PE)-photoion coincidence (PFI-PEPICO) technique, which has allowed the rotational-state selection of diatomic ions for ion-molecule reaction studies. The novel application of the wired ion gate lens for the rejection of false coincidence background ions is described. This application, along with the differential-ion-gate scheme, has made possible the measurements of rovibrational-state- selected absolute integral reaction cross sections for ion-molecule collisions using the PFI-PE-secondary ion coincidence (PFI-PESICO) method.
Download or read book Mass Analyzed Threshold Ionization photoion with VUV Laser Pulsed Field Ionization and Guided Ion Beam Method Applied to the Study of State selected Ion molecule Reaction Dynamics written by Hong Xu and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation covers four major chapters. In Chapter 1, a general introduction is given on the research methods of state-selected ion-molecule reaction dynamics including VUV generation, pulse field ionization, guided ion beam method, as well as mass analyzed threshold ionization (MATI). Chapter 2 presents the development of instruments construction for the study of state-selected ion-molecule reaction dynamics. Chapter 3 represents a VUV pulsed field ionization-photoelectron spectroscopic study of pyrazine (C6H4N2). The ionization energy was determined to be 74,906.6 ± 2.0 cm−1 (9.28728 ± 0.00025 eV). The PFI-PE spectrum of pyrazine exhibits well-resolved vibrational bands, which have been well characterized. In Chapter 4 the first rotationally resolved mass-analyzed-threshold (MATI) photoion spectra of N2(X2 [sigma][subscript g], v=0, 1) bands of nitrogen is reported with high resolution using the pulsed field ionization method. The rovibrational spectrum of N2+(X2 [sigma]+[subscript g], v+=0, 1) is analyzed. Absolute rovibrationally selected total cross sections for the charge transfer reaction N2+(X2 [sigma]+[subscript g], v+=0, 1) + Ar are measured.
Download or read book Advances in Chemical Physics Volume 70 Part 1 written by Ilya Prigogine and published by Wiley-Interscience. This book was released on 1988-01-18 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Advances in Chemical Physics series provides the chemical physics and physical chemistry fields with a forum for critical, authoritative evaluations of advances in every area of the discipline. Filled with cutting-edge research reported in a cohesive manner not found elsewhere in the literature, each volume of the Advances in Chemical Physics series serves as the perfect supplement to any advanced graduate class devoted to the study of chemical physics.
Download or read book State selected Study of Ion molecule Reaction Dynamics Photodissociation Dynamics and Free Radical Studies Using Synchrotron Radiation written by Tao Zhang and published by . This book was released on 2003 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vacuum Ultraviolet Photoionization and Photodissociation of Molecules and Clusters written by Cheuk-Yiu Ng and published by World Scientific. This book was released on 1991 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph reviews the recent progress in vacuum ultraviolet (VUV) photoionization and photodissociation processes. Photoionization, photoelectron, and fluorescence spectroscopic techniques have played an important role in revealing the photoionization and photodissociation dynamics of molecules in the vacuum ultraviolet region and in providing accurate energetic and spectroscopic information of ions as well as neutral molecules. The book represents the first detailed review of major experimental developments in the studies of single vacuum ultraviolet photon ionization and dissociation processes of gaseous molecules and clusters.
Download or read book State Selected and State to State Ion Molecule Reaction Dynamics Volume 82 Part 1 written by Cheuk-Yiu Ng and published by Wiley-Interscience. This book was released on 1992-04-16 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: State-Selected and State-to-State Ion-Molecules Reaction Dynamics details the recent experimental and theoretical accomplishments in the field to date by some of its foremost researchers and theorists. Divided into two parts, each of which separately describe the experimental and theoretical aspects of the field, State-Selected and State-to-State Ion-Molecule Reaction Dynamics is an accessible, well organized look at a highly useful and emerging chemical specialty. Part 1, "Experiment," contains eight in-depth studies, which illustrate the key experimental work being done in the field today: Chapter 1 provide a comprehensive review of the theory and application of inhomogeneous rf fields for the study of the dynamics of low-energy ion-molecules processes Chapter 2 describes the application of multiphoton ionization (MPI) for the preparation of reactant ion states Chapter 3 reviews the application of MPI schemes for state specific cross-section measurements involving transition metal cations Chapter 4 describes the development of the threshold photoelectron secondary ion coincidence (TESICO) method Chapter 5 presents the conceptual and practical aspects of a multicoincidence technique Chapter 6 details the experimental results obtained using the photoionization and differential reactivity methods Chapter 7 reviews the several recent crossed beam studies of charge transfer and collision-induced dissociation systems involving atomic and molecular ions Chapter 8 is a survey of 15 years of high resolution crossed beam scattering of protons with atoms, diatoms, and poly-atomic molecules State-Selected and State-to-State Ion-Molecule Reaction Dynamics, Part 1: Experiment offers professionals a true state-of-the-science look at this fascinating and increasingly influential subject.
Download or read book Study of State selected Ion Molecule Reactions Using Pulsed Field Techniques written by Denis Rolland and published by . This book was released on 1999 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Chemical Physics State Selected and State to State Ion Molecule Reaction Dynamics written by Michael Baer and published by Wiley-Interscience. This book was released on 2009-09-08 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoionization and Photo Induced Processes in Mass Spectrometry written by Ralf Zimmermann and published by John Wiley & Sons. This book was released on 2021-07-06 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides comprehensive coverage of laser-induced ionization processes for mass spectrometry analysis Drawing on the expertise of the leading academic and industrial research groups involved in the development of photoionization methods for mass spectrometry, this reference for analytical scientists covers both the theory and current applications of photo-induced ionization processes. It places widely used techniques such as MALDI side by side with more specialist approaches such as REMPI and RIMS, and discusses leading edge developments in ultrashort laser pulse desorption, to give readers a complete picture of the state of the technology. Photoionization and Photo-Induced Processes in Mass Spectrometry: Fundamentals and Applications starts with a complete overview of the fundamentals of the technique, covering the basics of the gas phase ionization as well as those of laser desorption and ablation, pulse photoionization, and single particle ionization. Numerous application examples from different analytical fields are described that showcase the power and the wide scope of photo ionization in mass spectrometry. -The first general reference book on photoionization techniques for mass spectrometry -Examines technologies and applications of gas phase resonance-enhanced multiphoton ionization mass spectrometry (REMPI-MS) and gas phase resonance ionization mass spectrometry (RIMS) -Provides complete coverage of popular techniques like MALDI -Discusses the current and potential applications of each technology, focusing on process and environmental analysis Photoionization and Photo-Induced Processes in Mass Spectrometry: Fundamentals and Applications is an excellent book for spectroscopists, analytical chemists, photochemists, physical chemists, and laser specialists.
Download or read book Pulse field Ionization Studies of Ion molecule Reaction Dynamics and Photodissociation Dynamics Using the Third Generation Synchrotron Radiation written by Xiaonan Tang and published by . This book was released on 2007 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reaction Dynamics Involving Ions Radicals Neutral and Excited Species written by Stefano Falcinelli and published by Frontiers Media SA. This book was released on 2020-01-22 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book State Selected Ion Molecule Reaction Dynamics written by R. J. S. Morrison and published by . This book was released on 1984 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: By analyzing the photoelectron energies in several systems, it has been demonstrated that multiphoton ionization (MPI) can selectively produce molecular ions predominantly in a single vibrational level by the proper choice of the laser wavelength employed. Thus MPI provides a powerful new technique for producing high densities of internally state-selected reagent ion for chemical reaction dynamics studies. This approach is being taken for studying the ion-molecule reactions of NH3(+) (v) which has been prepared with v = 0-9 vibrational quanta in the nu sub 2 umbrella-bending mode.
