Download or read book The Reactivity and Dynamics of Gaseous Clusters written by and published by . This book was released on 1996 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to design new strategic materials with specific properties, we need to understand the binding forces that exist in mixed atoms or molecules not present in conventional material. Thus our aim is to understand the adhesive and cohesive forces holding atoms or molecules together in unconventional nanoparticles that do not usually bind together in conventional macroscopic materials. In the broad sense, we like to understand the forces involved in adhesion and cohesion on an atomic level by studying the structure, stability, and the rapid electronic motion in nanoparticles. Due to the large surface to volume ratio, these particles tend to have different properties not present in the bulk nor of the individual atoms or molecules making these nanoparticles. Thus they offer us an opportunity to unravel new properties with new potential applications. The aim of our present research is to synthesize and study the forces between atoms or molecules within nanoclusters. These forces determine the dynamic properties and thus the potential uses of the nanoparticles. In the past several years, we have confined our studies to gaseous clusters and studied the dynamics of their dissociation and their chemical reactivities. During the past year, we have expanded our activity to include the synthesis and study of the dynamics of excitation relaxation in colloidal nano-particles, both semiconductor and metallic. p7.
Download or read book The Reactivity and Dynamics of Gaseous Clusters written by El-Sayed, M.A. and published by . This book was released on with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Reactivity and Dynamics of Gaseous Clusters written by El-Sayed, M.A. and published by . This book was released on with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to design new strategic materials with specific properties, we need to understand the binding forces that exist in mixed atoms or molecules not present in conventional material. Thus our aim is to understand the adhesive and cohesive forces holding atoms or molecules together in unconventional nanoparticles that do not usually bind together in conventional macroscopic materials. In the broad sense, we like to understand these forces by studying the structure, stability, and the dynamic process of the rapid electronic motion in nanoparticles. Due to the large surface to volume ratio, these particles tend to have different properties not present in the bulk nor of the individual atoms or molecules making these nanoparticles. Thus they offer us an opportunity to unravel new properties with new potential applications. The aim of our present research is to synthesize and study the forces between atoms or molecules within metallic and semiconductor nanoclusters. These forces determine the dynamic properties and thus the potential uses of the nanoparticles. In the past several years, we have confined our studies to gaseous clusters and studied the dynamics of their dissociation and their chemical reactivities. During the past couple of years (since we have moved to Georgia Tech), we have expanded our activity to include the synthesis and study of the dynamics of excitation relaxation in colloidal nano-particles, both semiconductor and metallic. The forces that control the shapes of nanoclusters by capping agents are to be examined. The synthetic method we use involves a competition between nucleation of the atoms in the metallic nanoparticles or the semiconductor molecules in the semiconductor nanoparticle and the capping process of the surface with polymeric molecules. The faster the capping process, the smaller would be the average size of the clusters formed.
Download or read book The Synergy Between Dynamics and Reactivity at Clusters and Surfaces written by L.J. Farrugia and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: The analogy between the chemistry of molecular transition metal clusters and the processes of chemisorption and catalysis at metal surfaces (the Cluster Surface analogy) has for a number of years provided an interplay between experimental and theoretical inorganic and physical chemists. This collaborative approach has born fruit in the use of well defined modes of metal-ligand bonding in discrete molecular clusters, models for metal-ligand binding on surfaces. Some of the key topics discussed in The Synergy between Dynamics and Reactivity at Clusters and Surfaces are: (1) Mechanisms of the fluxional behaviour in clusters in the liquid phase and the connections with diffusion processes on extended surfaces. The role of metal-metal bond breaking in diffusion. (2) Analogies in the structure of chemisorbed species and related ligands on metallic clusters. (3) Analogies between benzene surface chemistry on extended metal surfaces and on metal surfaces in molecular cluster compounds with particular reference to structural distortions. (4) The role of mobile precursors for dissociation of chemisorption on extended metals and on clusters. Are there analogies in the ligand attachment during cluster compound synthesis? (5) The role of defect sites on metal surfaces in catalyzing chemical reactions and the connection to the special bonding properties of sites on metal clusters having lowest metal-metal coordination. (6) The size of metal clusters needed to mimic surface phenomena on bulk metal surfaces. Different sites needed for different phenomena.
Download or read book Metal Clusters and Their Reactivity written by Zhixun Luo and published by Springer Nature. This book was released on 2020-10-31 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses current techniques and instrumentation for cluster chemistry. It addresses both the experimental and theoretical aspects of gas-phase metal cluster reactivities, especially those pertaining to pollution removal, energetic reactions and corrosion and anticorrosion. These metal cluster systems have attracted enormous interest as they display a completely new class of physical, chemical, electronic, magnetic and catalytic properties. As these properties change with size and composition, it can thus be understood how their nature evolves from atoms to bulk solids. The book offers readers a basic understanding of the structural chemistry and reactivity of metal clusters in both gas-phase and wet chemistry. Further, the lessons they learn here regarding metal cluster chemistry will prepare researchers for the study of condensed phase dynamics that pertain to wet chemical synthesis, soft-landing deposition and cluster assembly.
Download or read book Size Dependence of Gaseous Cluster Reactivity and Evaporation Dynamics as a Mechanistic Probe written by M. A. El-Sayed and published by . This book was released on 1991 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two different types of cluster studies were carried out in our laboratory. In one, gaseous niobium metal clusters are synthesized by laser ablation and supersonic expansion in helium and detected by using excimer one-photon ionization-mass spectrometry methods. The dependence of their chemical reactivity (towards some carbon compounds) on size examined and used as a new mechanistic probe. In the other type of cluster studies, the mechanisms of the evaporation of one and two CsI molecules from individual mass selected (Cs(CsI)n)+ clusters (made by sputtering techniques) are determined from a study of the kinetic energy released and its distribution during evaporation process.
Download or read book Atomic Clusters with Unusual Structure Bonding and Reactivity written by Pratim Kumar Chattaraj and published by Elsevier. This book was released on 2022-10-06 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomic Clusters with Unusual Structure, Bonding and Reactivity: Theoretical Approaches, Computational Assessment and Applications reviews the latest computational tools and approaches available for accurately assessing the properties of a cluster, while also highlighting how such clusters can be adapted and utilized for the development of novel materials and applications. Sections provide an introduction to the computational methods used to obtain global minima for clusters and effectively analyze bonds, outline experimental approaches to produce clusters, discuss specific applications, and explore cluster reactivity and usage across a number of fields.Drawing on the knowledge of its expert editors and contributors, this book provides a detailed guide to ascertaining the stability, bonding and properties of atomic clusters. Atomic clusters, which exhibit unusual properties, offer huge potential as building blocks for new materials and novel applications, but understanding their properties, stability and bonding is essential in order to accurately understand, characterize and manipulate them for further use. Searching for the most stable geometry of a given cluster is difficult and becomes even more so for clusters of medium and large sizes, where the number of possible isomers sharply increase, hence this book provides a unique and comprehensive approach to the topic and available techniques and applications. Introduces readers to the vast structural and bonding diversity that clusters show and reflects on their potential for novel application and material development Highlights the latest computational methods and theoretical tools available for identification of the most stable isomers and accurate analysis of bonding in the clusters Focuses on clusters which violate the rules established in traditional chemistry and exhibit unusual structure, bonding and reactivity
Download or read book Chemical Reactions in Clusters written by Elliot R. Bernstein and published by Oxford University Press. This book was released on 1996-06-06 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers important new developments of the last five years in the area of cluster chemistry, presenting an excellent view of the successes and shortcomings of both current state-of-the-art theory and experiment. Each chapter, contributed by a leading expert, places heavy emphasis on theory without which the detailed analysis of the spectroscopic and kinetic results would be compromised. The cluster reactions reviewed in this work include electron and proton transfer reactions, hot atom reactions, vibrational predissociation, radical reactions, and ionic reactions. Some of the theories applied throughout the text are product state distribution determinations, state-to-state dynamical information, and access to the transition stage of the reaction. The discussions serve as a benchmark of how far the field has come since the mid 1980's and will be a good update for students and researchers interested in this area of physical chemistry.
Download or read book Dynamics of Electronically Excited States in Gaseous Cluster and Condensed Media written by J. C. Whitehead and published by Royal Society of Chemistry. This book was released on 1998 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploration of the similarities and differences between the dynamics of electronically-excited states in gaseous, cluster and condensed media, focussing on the effect of the medium. The processes involved in studying the dynamics of electronically-excited states include energy transfer, chemical reaction, decomposition to neutral and ionic fragments, proton and electron transfer.
Download or read book Gas Phase Reaction Dynamics and Design of Molecular Clusters and Bioconjugates written by Heather Ann Sumner and published by . This book was released on 2005 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Synergy Between Dynamics and Reactivity at Clusters and Surfaces written by L. J. Farrugia and published by . This book was released on 2014-01-15 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cluster Dynamics written by and published by Royal Society of Chemistry. This book was released on 2001 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamical processes in a cluster environment are presented. The experimental and theoretical papers include work on: reactions of clusters, photodynamics, caging effects, tunneling, global potential energy surfaces, transition state spectroscopy and reactions induced by clustering. Faraday Discussions documents a long-established series of Faraday Discussion meetings which provide a unique international forum for the exchange of views and newly acquired results in developing areas of physical chemistry, biophysical chemistry and chemical physics. The papers presented are published in the Faraday Discussion volume together with a record of the discussion contributions made at the meeting. Faraday Discussions therefore provide an important record of current international knowledge and views in the field concerned.
Download or read book Introduction to Reactive Gas Dynamics written by Raymond Brun and published by Oxford University Press. This book was released on 2009-02-26 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many actual technological problems require the knowledge of the physical and chemical phenomena and processes taking place in high energy gas flows. This book presents an introductory analysis, theoretical and experimental, of these media, highlighting both their fundamental characteristics and applied aspects.
Download or read book Clusters and Small Particles written by Boris Mikhaĭlovich Smirnov and published by Springer Science & Business Media. This book was released on 2000-06-08 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Not merely a discussion of small particles or clusters of atoms, molecules, but also the systems they constitute. The goal is to analyse the properties of such finite aggregates and their behaviour in gases and plasmas, and to investigate processes that involve such clusters, based on lectures and seminar problems for graduates. The main part of the book includes more than 200 problems, covering collisions, charge transfer, chemical reactions, condensed systems and their structures, kinetics of cluster growth, excited clusters, the transition from clusters to bulk particles, and small particles, dust, and aerosols in plasmas. Reference data for corresponding parameters of systems under consideration is given in the appendices. Of interest to physicists, astrophysicists, and chemists.
Download or read book Physics and Chemistry of Small Clusters written by P. Jena and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 932 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in experimental techniques now enable researchers to produce in a laboratory clusters of atoms of desired composition from any of the elements of the periodic table. This has created a new area of research into novel materials since clusters cannot be regarded either as a "large" molecule or as a fragment of the bulk. Both experimental and theoretical studies are revealing unusual properties that are not ob served in solid state environments. The structures of micro-clusters are found to be significantly distorted from the most symmetric arrangement, some even exhibiting pentagonal symmetry commonly found in icosahedric structures. The unusual stability of certain clusters, now described as "magic number species", shows striking similarities with the nuclear shell structure. The relative stabilities of clusters depend not only on the composition of the clusters but also on their charged states. The studies on spontaneous fragmentation of mUltiply charged clusters, commonly referred to as Coulomb explosion, illustrate the role of electronic bonding mechanisms on stability of clusters. The effect of foreign atoms on geometry and stability of clusters and the interaction of gas atoms with clusters are showing promise for an indepth understanding of chemisorption and catalysis. The magnetic and optical properties are dependent not only on cluster size but also on its geometry. These findings have the potential for aiding industry in the area of micro-electronics and catalysis.
Download or read book Chaotic Dynamics of Small Inert Gas Clusters written by Robert J. Hinde and published by . This book was released on 1992 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Free Atoms Clusters and Nanoscale Particles written by Kenneth J. Klabunde and published by Elsevier. This book was released on 2012-12-02 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents coherent and systematic coverage of the broad and dynamic field of free atom and cluster atom chemistry. The text provides a comprehensive overview of the current literature and describes the mostimportant experimental techniques developed since 1980 including bimetallic clusters/catalysts, carbon clusters (fullerenes) and trapped single atoms. Metal atoms, clusters, and particles are covered in sequence with the Periodic Table.
