Download or read book Elucidating the Structures of Ionic Clusters from Ion water Complexes to Ion biomolecule water Complexes written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Influences of Noncovalent Interactions in the Gas Phase written by Terrence Chang and published by . This book was released on 2014 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The physical properties of molecules in solution, such as basicity and structure, depend on the cooperation and competition of noncovalent intra- and intermolecular interactions. Studying these interactions in the condensed phase is made difficult by the presence of competing influences from counterions and impurities. In the gas phase, however, specific ions, ion complexes and hydration states can be isolated and studied by Fourier transform mass spectrometry coupled with infrared (IR) laser spectroscopy. Using these two techniques, it is possible to isolate specific ions before inducing dissociation via absorption of IR photons. The extent of absorption at a given wavelength correlates to the relative abundance of product ions produced via dissociation, which can be measured using mass spectrometry. The absorption of IR photons only occurs at specific wavelengths depending on which functional groups are present and how their vibrational modes are influenced by interactions such as hydrogen bonding. Structural information is obtained from these spectra by interpreting the presence of certain bands and their frequencies. In addition, information can also be obtained by comparing the spectra from ions of interest to the spectra of reference ions, with known structures, or the simulated spectra of computed geometries. These types of studies provide valuable insight into how noncovalent interactions govern the structure of biomolecules and hydrogen-bonded networks. This dissertation reports experiments utilizing IR spectroscopy to study how water-ion interactions can affect both the structure of an ion solvated by an aqueous nanodrop as well as the hydrogen-bonding network of the nanodrop itself. In addition, the structural effects of ion-peptide interactions, which are relevant to understanding how ions influence biological processes, are also investigated. In order to study the ability of water to stabilize protonation sites on larger molecules, I investigated the influence of sequential hydration on the structure of protonated p-aminobenzoic acid (PABAH+), which has different preferred aqueous solution and gas-phase protonation sites. The preferred protonation site of PABA is the amine in aqueous solution, but the preferred protonation site is the carbonyl O atom of the carboxylic acid in the gas phase. The spectrum of PABAH+*(H2O)1 contains an absorption band at a particular photon energy indicating that protonation occurs at the carboxylic acid, i.e. there is a spectroscopic signature for the O-protonated structure. This absorption band persists for PABAH+*(H2O)2-6, indicating that these ions have a population of O-protonated isomers as well. Spectra for PABAH+*(H2O)6 are also consistent with presence of a second isomer, in which the amine is protonated. These results indicate that PABAH+ exists in the preferred gas-phase structure for PABAH+*(H2O)1-6, but there is a transition to the preferred solution-phase structure when the ion is solvated by six or more water molecules. In isolation, the excess charge associated with protonation at the carbonyl O atom of the carboxylic acid can be resonantly stabilized and delocalized into the phenyl ring and amine. When six or more water molecules are attached, however, a more favorable hydrogen-bonding network can be formed at the protonated amine than at the carboxylic acid. In contrast to PABAH+, protonation for m-aminobenzoic acid (MABA) occurs at the amine site even when solvated by only one water molecule due to orientation of the amine and carboxylic acid group. This orientation prevents the positive charge from being delocalized into the amine. Thus, MABAH+ serves as an ideal model for the solvation of the N- and C-termini of a protonated amino acid, for which the N- and C-termini typically interact with each other. The measured spectra for MABAH+*(H2O)1,2 are consistent with the attachment of water to a H atom of the protonated amine. For MABAH+*(H2O)3, the measured spectrum indicates that the dominant isomer has a hydrogen-bonded water bridge between the amine and carbonyl O atom of the carboxylic acid. This result indicates that the formation of this water bridge is more energetically favorable than the formation of a third ionic hydrogen bond to the amine group. The spectra for MABAH+*(H2O)n also indicate that water molecules attach to the carboxylic acid H atom, i.e. the ion is fully hydrogen-bonded when there are ≥6 water molecules attached. Ion spectroscopy can also be used to study how ion-water interactions influence hydration structures. Certain positive ions are known to induce cage-like clathrate structures when hydrated by 20 water molecules. The hydration of NH4+ as well as selected, protonated primary, secondary and tertiary amines solvated by 19 - 21 water molecules was investigated in order to elucidate details about how amines can stabilize clathrate structures. The spectra of NH4+ as well as monomethyl-, n-heptyl-, and tert-butylammonium+ with 20 water molecules attached are consistent with the nearly exclusive presence of clathrate structures, whereas nonclathrate structures are present for the more highly substituted amines. By comparison, nonclathrate structures are observed for all ions when 19 or 21 water molecules are attached. Spectroscopic evidence for clathrate structures for NH4+*(H2O)20 has been previously reported, but the location of the ion, whether at the surface or the interior, was difficult to determine based on the IR spectrum of this ion alone. Thus, the spectra of NH4+, monomethyl- and n-heptylammonium+ solvated by 20 water molecules were compared to those for Rb+ and tert-butylammonium+, which serve as references for clathrate structures with the ion located in the interior or at the surface, respectively. These comparisons indicate that NH4+ goes to the interior, whereas protonated primary amines are located at the surface, irrespective of the size of the alkyl group. In addition to ion-water interactions, ion-biomolecule interactions can also be probed by ion spectroscopy. Although there are several studies that have used ion spectroscopy to investigate cations coordinated to amino acids and peptides, there are fewer studies focused on these same biomolecules complexed with anion adducts. The ions Gly3*X-, Ala3*X- and Leu3*X- (X = Cl, Br and I) were studied in order to investigate how the size of anion adducts and alkyl side chains influence the coordination of halide anions to aliphatic peptides. The spectra of Gly3*Cl-, Ala3*Cl- and Leu3*Cl- suggest that all three complexes adopt similar structures, where Cl- coordinates to the peptides by accepting three or four hydrogen bonds from the amides as well as the N- and C-termini. These results indicate that the size of the alkyl chain does not have a significant influence on the coordination geometry of these complexes. These structures are "inverted" in comparison to previously reported structures for Gly3*Na+ and Ala3*Na+, where the Na+ coordinates to lone pair electrons of the N atom of the N-terminus, or the carbonyl O atoms of the amides and C-terminus. The spectra of Gly3*X-, Ala3*X- and Leu3*X- each appear similar to each other within each peptide, indicating that the size of the anion does not significantly affect the coordination geometry.

Download or read book Biomolecules and Their Noncovalent Complexes in the Gas Phase written by Rebecca Ann Jockusch and published by . This book was released on 2001 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2006 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biological Water written by Gertz I. Likhtenshtein and published by Springer Nature. This book was released on 2021-10-21 with total page 523 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book embraces all physiochemical aspects of the structure and molecular dynamics of water, focusing on its role in biological objects, e.g. living cells and tissue, and in the formation of functionally active structures of biological molecules and their ensembles. Water is the single most abundant chemical found in all living things. It offers a detailed look into the latest modern physical methods for studying the molecular structure and dynamics of the water and provides a critical analysis of the existing literature data on the properties of water in biological objects. Water as a chemical reagent and as a medium for the formation of conditions for enzymatic catalysis is a core focus of this book. Although well suited for active researchers, the book as a whole, as well as each chapter on its own, can be used as fundamental reference material for graduate and undergraduate students throughout chemistry, physics, biophysics and biomedicine.

Download or read book Water in Biological and Chemical Processes written by Biman Bagchi and published by Cambridge University Press. This book was released on 2013-11-14 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unified overview of the dynamical properties of water and its unique and diverse role in biological and chemical processes.

Download or read book Structures and Interactions of Ionic Liquids written by Suojiang Zhang and published by Springer. This book was released on 2013-12-20 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structures, Bonding and Hydrogen Bonds, by Kun Dong, Qian Wang, Xingmei Lu, Suojiang Zhang Aggregation in System of Ionic Liquids, by Jianji Wang, Huiyong Wang Dissolution of Biomass Using Ionic Liquids, by Hui Wang, Gabriela Gurau, Robin D. Rogers Effect of the Structures of Ionic Liquids on Their Physical-Chemical Properties, by Yu-Feng Hu, Xiao-Ming Peng Microstructure study of Ionic liquids by spectroscopy, by Haoran Li Structures and Thermodynamic Properties of Ionic Liquids, by Tiancheng Mu, Buxing Han

Download or read book Cisplatin written by Bernhard Lippert and published by John Wiley & Sons. This book was released on 1999 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: 30 years after its discovery as an antitumor agent, cisplatin represents today one of the most successful drugs in chemotherapy. This book is intended to reminisce this event, to take inventory, and to point out new lines of development in this field. Divided in 6 sections and 22 chapters, the book provides an up-to-date account on topics such as - the chemistry and biochemistry of cisplatin, - the clinical status of Pt anticancer drugs, - the impact of cisplatin on inorganic and coordination chemistry, - new developments in drug design, testing and delivery. It also includes a chapter describing the historical development of the discovery of cisplatin. The ultimate question - How does cisplatin kill a cell? - is yet to be answered, but there are now new links suggesting how Pt binding to DNA may trigger a cascade of cellular reactions that eventually result in apoptosis. p53 and a series of damage recognition proteins of the HMG-domain family appear to be involved. The book addresses the problem of mutagenicity of Pt drugs and raises the question of the possible relevance of the minor DNA adducts, e.g. of interstrand cross-links, and the possible use of trans-(NH3)2Pt(II)-modified oligonucleotides in antisense and antigene strategies. Our present understanding of reactions of cisplatin with DNA is based upon numerous model studies (from isolated model nucleobases to short DNA fragments) and application of a large body of spectroscopic and other physico-chemical techniques. Thanks to these efforts there is presently no other metal ion whose reactions with nucleic acids are better understood than Pt. In a series of chapters, basic studies on the interactions of Pt electrophiles with nucleobases, oligonucleotides, DNA, amino acids, peptides and proteins are reported, which use, among others, sophisticated NMR techniques or X-ray crystallography, to get remarkable understanding of details on such reactions. Reactivity of cisplatin, once bound to DNA and formerly believed to be inert enough to stay, is an emerging phenomenon. It has (not yet) widely been studied but is potentially extremely important. Medicinal bioinorganic chemistry - the role of metal compounds in medicine - has received an enormous boost from cisplatin, and so has bioinorganic chemistry as a whole. There is hardly a better example than cisplatin to demonstrate what bioinorganic chemistry is all about: The marriage between classic inorganic (coordination) chemistry and the other life sciences - medicine, pharmacy, biology, biochemistry. Cisplatin has left its mark also on areas that are generally considered largely inorganic. The subject of mixed-valance Pt compounds is an example: From the sleeping beauty it made its way to the headlines of scientific journals, thanks to a class of novel Pt antitumor agents, the so-called "platinum pyrimidine blues". In the aftermath diplatinum (III) compounds were recognized and studies in large numbers, and now an organometalic chemistry of these diplatinum (III) species is beginning to emerge. The final section of the book is concerned with new developments such as novel di- and trinuclear Pt(II) drugs with DNA binding properties different from those of cisplatin, with orally active Pt(IV) drugs which are presently in clinical studies, and with attempts to modify combinatorial chemistry in such a way that it may become applicable to fast screening of Pt antitumor drugs. The potential of including computational methods in solving questions of Pt-DNA interactions is critically dealt with in the concluding chapter.

Download or read book Anion Receptor Chemistry written by Jonathan L Sessler and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anion recognition plays a critical role in a range of biological processes, and a variety of receptors and carriers can be found throughout the natural world. Chemists working in the area of supramolecular chemistry have created a range of anion receptors, drawing inspiration from nature as well as their own inventive processes. This book traces the origins of anion recognition chemistry as a unique sub-field in supramolecular chemistry while illustrating the basic approaches currently being used to effect receptor design. The combination of biological overview and summary of current synthetic approaches provides a coverage that is both comprehensive and comprehensible. First, the authors detail the key design motifs that have been used to generate synthetic receptors and which are likely to provide the basis for further developments. They also highlight briefly some of the features that are present in naturally occurring anion recognition and transport systems and summarise the applications of anion recognition chemistry. Providing as it does a detailed review for practitioners in the field and a concise introduction to the topic for newcomers, Anion Receptor Chemistry reflects the current state of the art. Fully referenced and illustrated in colour, it is a welcome addition to the literature.

Download or read book Modern Mass Spectrometry written by Peter B. Armentrout and published by Springer Science & Business Media. This book was released on 2003-06-23 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: I Reactivity: E. Uggerud: Physical Organic Chemistry of the Gas Phase. Reactivity Trends for Organic Cations.- S. Petrie, D.K. Bohme: Mass Spectrometric Approaches to Interstellar Chemistry.- F. Turecek: Transient Intermediates of Chemical Reactions by Neutralization-Reionization Mass Spectrometry.- II Metalorganic Chemistry: D. Schröder, H. Schwarz: Diastereoselective Effects in Gas-Phase Ion Chemistry.- D.A. Plattner: Metalorganic Chemistry in the Gas Phase: Insight into Catalysis.- III Mass Spectrometric Methodology: T. Wyttenbach, M.T. Bowers: Gas-Phase Conformations: The Ion Mobility/Ion Chromatography Method.- P.B. Armentrout: Threshold Collision-Induced Dissociations for the Determination of Accurate Gas-Phase Binding Energies and Reaction Barriers.- IV Medicinal Chemistry: S.A. Trauger, T. Junker, G. Siuzdak: Investigating Viral Proteins and Intact Viruses with Mass Spectrometry M. Brönstrup: High-Throughput Mass Spectrometry for Compound Characterization in Drug Discovery.

Download or read book The Structure of Ionic Liquids written by Ruggero Caminiti and published by Springer Science & Business Media. This book was released on 2013-11-09 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume describes the most recent findings on the structure of ILs interpreted through cutting-edge experimental and theoretical methods. Research in the field of ionic liquids (ILs) keeps a fast and steady pace. Since these new-generation molten salts first appeared in the chemistry and physics landscape, a large number of new compounds has been synthesized. Most of them display unexpected behaviour and possess stunning properties. The coverage in this book ranges from the mesoscopic structure of ILs to their interaction with proteins. The reader will learn how diffraction techniques (small and large angle X-Ray and neutron scattering, powder methods), X-Ray absorption spectroscopies (EXAFS/XANES), optical methods (IR, RAMAN), NMR and calorimetric methods can help the study of ILs, both as neat liquids and in mixtures with other compounds. It will enable the reader to choose the best method to suit their experimental needs. A detailed survey of theoretical methods, both quantum-chemical and classical, and of their predictive power will accompany the exposition of experimental ones. This book is a must read for postgraduate students, for post-docs, and for researchers who are interested in understanding the structural properties of ILs.

Download or read book Specific Ion Effects written by Werner Kunz and published by World Scientific. This book was released on 2010 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: Specific ion effects are important in numerous fields of science and technology. This book summarizes the main ideas that came up over the years. It presents the efforts of theoreticians and supports it by the experimental results stemming from various techniques.

Download or read book Neutron Protein Crystallography written by Nobuo Niimura and published by Oxford University Press. This book was released on 2011-02-17 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the first books dedicated to the emerging field of neutron protein crystallography (NPC). It covers all of the practical aspects of NPC and demonstrates how NPC can explore protein features such as hydrogen bonds, protonation and deprotonation of amino acid residues, and hydration structures.

Download or read book Laser Photodissociation and Spectroscopy of Mass separated Biomolecular Ions written by Nicolas C. Polfer and published by Springer. This book was released on 2013-09-13 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This lecture notes book presents how enhanced structural information of biomolecular ions can be obtained from interaction with photons of specific frequency - laser light. The methods described in the book "Laser photodissociation and spectroscopy of mass-separated biomolecular ions" make use of the fact that the discrete energy and fast time scale of photoexcitation can provide more control in ion activation. This activation is the crucial process producing structure-informative product ions that cannot be generated with more conventional heating methods, such as collisional activation. The book describes how the powerful separation capabilities and sensitivity of mass spectrometry (MS) can be combined with the structural insights from spectroscopy by measuring vibrational and electronic spectra of trapped analytes. The implementation of laser-based photodissociation techniques in MS requires basic knowledge of tunable light sources and ion trapping devices. This book introduces the reader to key concepts and approaches in molecular spectroscopy, and the light sources and ion traps employed in such experiments. The power of the methods is demonstrated by spectroscopic interrogation of a range of important biomolecular systems, including peptides, proteins, and saccharides, with laser light in the ultraviolet-visible, and infrared range. The book "Laser photodissociation and spectroscopy of mass-separated biomolecular ions" is an indispensable resource for students and researchers engaged or interested in this emerging field. It provides the solid background of key concepts and technologies for the measurements, discusses state-of-the-art experiments, and provides an outlook on future developments and applications.

Download or read book Introduction to Reticular Chemistry written by Omar M. Yaghi and published by John Wiley & Sons. This book was released on 2019-03-22 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt: A concise introduction to the chemistry and design principles behind important metal-organic frameworks and related porous materials Reticular chemistry has been applied to synthesize new classes of porous materials that are successfully used for myraid applications in areas such as gas separation, catalysis, energy, and electronics. Introduction to Reticular Chemistry gives an unique overview of the principles of the chemistry behind metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and zeolitic imidazolate frameworks (ZIFs). Written by one of the pioneers in the field, this book covers all important aspects of reticular chemistry, including design and synthesis, properties and characterization, as well as current and future applications Designed to be an accessible resource, the book is written in an easy-to-understand style. It includes an extensive bibliography, and offers figures and videos of crystal structures that are available as an electronic supplement. Introduction to Reticular Chemistry: -Describes the underlying principles and design elements for the synthesis of important metal-organic frameworks (MOFs) and related materials -Discusses both real-life and future applications in various fields, such as clean energy and water adsorption -Offers all graphic material on a companion website -Provides first-hand knowledge by Omar Yaghi, one of the pioneers in the field, and his team. Aimed at graduate students in chemistry, structural chemists, inorganic chemists, organic chemists, catalytic chemists, and others, Introduction to Reticular Chemistry is a groundbreaking book that explores the chemistry principles and applications of MOFs, COFs, and ZIFs.

Download or read book Metal Transporters written by Jose M. Arguello and published by Academic Press. This book was released on 2012-10-25 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume of Current Topics in Membranes focuses on metal transmembrane transporters and pumps, a recently discovered family of membrane proteins with many important roles in the physiology of living organisms. The book summarizes the most recent advances in the field of metal ion transport and provides a broad overview of the major classes of transporters involved in homeostasis of heavy metals. Various families of the transporters and metal specificities are discussed with the focus on the structural and mechanistic aspects of their function and regulation. The reader will access information obtained through a variety of approaches ranging from X-ray crystallography to cell biology and bioinformatics, which have been applied to transporters identified in diverse biological systems, such as pathogenic bacteria, plants, humans and others. Field is cutting-edge and a lot of the information is new to research community Wide breadth of topic coverage Contributors of high renown and expertise

Download or read book Water in Confining Geometries written by V. Buch and published by Springer Science & Business Media. This book was released on 2003-04-29 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by leading experts in the field, this book gives a wide-ranging and coherent treatment of water in confining geometries. It compiles and relates interdisciplinary work on this hot topic of research important in many areas of science and technology.