Download or read book Electronic Structure Calculations of Monolayer protected Gold Nanoclusters to Aid Spectroscopic Analysis written by Neranjan Vikum Perera and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronic Structure Calculations of Monolayer protected Gold Nanoclusters to Aid Spectroscopic Analysis written by and published by . This book was released on 2015 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies on the Structural and Electronic Properties of Thiolate protected Gold Nanoclusters by X ray Spectroscopy written by Daniel M. Chevrier and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thiolate-protected gold nanoclusters (Au(SR) NCs) exhibit molecule-like properties that are both remarkable and unusual for metal-based nanoparticles. The ultra-small particle size and high stability enables Au(SR) NCs to be synthesized with atomic precision, where distinct particles have an exact composition of Au atoms and thiolate ligands. Recently, crystal structures of atomically-precise Au(SR) NCs (e.g., Au25(SR)18 and Au102(SR)44) have been elucidated. This structural information enables their fascinating structure and properties to be examined in great detail, allowing for the effect of structural components, such as core, surface and metal-ligand interface, on the molecule-like properties to be addressed. Working towards this remaining challenge, experimental X-ray spectroscopy (mainly X-ray absorption spectroscopy) and supporting techniques were utilized as a suitable means to study the structure and electronic properties of Au(SR) NCs and other NC systems from an element- and site-specific perspective. Herein, studies were devoted to understanding the effect of core structure and protecting ligands on the structure and properties of Au(SR) NCs. The influence of core size and geometry is first examined for icosahedral-based and face-centred cubic (FCC)-based Au(SR) NCs. It is shown that a difference of only a few Au atoms in the core can modulate the valence electronic structure and restructure the surface of icosahedral-based Au(SR) NCs. Au(SR) NCs with a FCC core geometry are found to have a common Au4 core structural component that directs the molecule-like electronic properties and temperature-dependent bonding properties that are unique to FCC-based Au(SR) NCs. Examining the effect of ligand head group, structurally analogous selenolate-protected Au NCs reveal the predominate effect of Se on the electronic and bonding properties of Au NCs through more covalent Au-ligand interactions. The role of water-soluble glutathione ligands on the structure and photoluminescence of Au(SR) NCs were then investigated along with a comparison to organo-soluble Au(SR) NCs of the same composition. Finally, experimental and investigative techniques developed throughout this work were extended to study the structure and properties of protein-protected Au NCs and thiolate-protected Ag NCs.
Download or read book Surface Chemical Control Over the Valence Electronic Structure of Gold Nanoparticles written by Anthony Cirri and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Control over the electronic properties of metallic and semiconducting nanoparticles is critical for the development of new technologies in photocatalysis, solar energy conversion, quantum computing, and nanosensing. Size, shape, crystal structure, and dielectric environment are common parameters that are used to tune the electronic structure of nanomaterials. However, a less explored but equally promising parameter is modification of surface chemistry. The chemisorption of small molecules onto the surface of nanoparticles introduces a wide array of chemical functionality that allows for discrete modification of electronic structure at the metal/molecule interface. Specifically in monolayer-protected gold nanoparticles (AuNPs), previous work suggests that a stark change in surface chemistry (i.e., alkylthiol vs. alkylamine) is required to observe a modification of the electrical, optical, thermal, and magnetic properties of the metal core -- each of which is dependent upon the interfacial electronic structure. Conduction electron spin resonance (CESR) spectroscopy is a valuable technique which has gone unexplored for observing how surface chemistry influences electronic structure. The utility of CESR lies in its selectivity and sensitivity to electronic structure at the Fermi level of the metal. Herein, I show how para-substituted aromatic thiolate and alkanethiolate ligands are capable of modifying the electronic structure through analysis of the measured g-factor -- a parametrization of spin-orbit coupling that comes from the electron spin resonance energy. In conjunction with quantum chemical calculations, we demonstrate that the sigma-bonding strength of the ligand is capable of controlling the degree of interfacial mixing between the metal and adsorbent, and correlate this with changes in the AuNPs' surface potential.
Download or read book Surface Chemistry Characterization and Control of the Electronic Structure of Gold Nanosystems written by Zachary Rhoden and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal nanoparticles (NPs) are valued in fields including biomedical imaging, chemical sensing, catalysis, and fundamental physics. Their utility often stems from their unique optical and electronic properties, but their broad applicability is due to their robust surface chemistry that allows a wide variety of ligands to be bound to them to tune stability, solubility, and reactivity. However, there has been little work focusing on linking these two aspects of nanoparticles, despite their importance. The lack of work, in part, stems from the significant challenges arising from the inherent dispersity within nanoparticle populations and complicated characterization techniques in which sample measurement can be difficult or provide limited information. The focus of this thesis is to refine the understanding of the structure-property relationship in gold nanosystems by improving the characterization of gold surfaces and by controlling gold nanoparticle properties through surface chemistry. This thesis reports the characterization of the gold-thiol surface, where thermal treatment of gold nanoparticles (AuNPs) volatilized gold and sulfur, which was collected and subsequently quantified by inductively coupled plasma mass spectrometry and atomic emission spectroscopy. It was found that the mass loss in these samples ranged from 0-30\% gold by mass, rather than purely from the thiol ligands, and that the level of gold desorption is related to the Au--S bond strength.This study calls into question the usefulness of thermogravimetric analysis as a characterization technique of gold nanosytems. Additionally, the influence of surface chemistry on the electronic structure of gold nanosystems has been probed using magnetic spectroscopies. First, electron spin resonance has been used to examine the perturbation to the superatomic structure of Au$_{25}$(SR)$_#x18;$ nanoclusters (NCs) by a series of alkanethiolate ligands in hexane and tetrahydrofuran solvents. It has been found that the nanocluster electronic is sensitive to surface chemistry, with the $g_x$ component of the electronic \textit{g}-factor shifting linearly towards the free electron \textit{g}-value, $g_e$, and the perturbation is large, given the minute changes in ligand identity. The changes are dissimilar to those seen in gold nanoparticles with similar surface chemistry, indicating that use of AuNCs as model systems for larger, metallic AuNPs should be reevaluated. Finally, Evans Method nuclear magnetic resonance spectroscopy has been used to probe the density of states (DOS) of gold nanoparticles protected by aromatic thiolate ligands. Aromatic ligands are a common tool for tuning the electronic structure of inorganic complexes, and this thesis reports their capability to alter the electronic structure of gold nanoparticles. The DOS of these nanoparticles increases with increasing electron withdrawing character of the aromatic ligands, and it has been found that trends in controlling the gold nanoparticle's DOS found with aromatic thiols cannot necessarily be compared to those found with aliphatic thiols. This work examines not only how surface chemistry influences the properties of nanosystems, but also the usefulness of model systems and naive assumptions about characterization techniques.
Download or read book Atomically Precise Nanochemistry written by Rongchao Jin and published by John Wiley & Sons. This book was released on 2023-06-12 with total page 533 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explore recent progress and developments in atomically precise nanochemistry Chemists have long been motivated to create atomically precise nanoclusters, not only for addressing some fundamental issues that were not possible to tackle with imprecise nanoparticles, but also to provide new opportunities for applications such as catalysis, optics, and biomedicine. In Atomically Precise Nanochemistry, a team of distinguished researchers delivers a state-of-the-art reference for researchers and industry professionals working in the fields of nanoscience and cluster science, in disciplines ranging from chemistry to physics, biology, materials science, and engineering. A variety of different nanoclusters are covered, including metal nanoclusters, semiconductor nanoclusters, metal-oxo systems, large-sized organometallic nano-architectures, carbon clusters, and supramolecular architectures. The book contains not only experimental contributions, but also theoretical insights into the atomic and electronic structures, as well as the catalytic mechanisms. The authors explore synthesis, structure, geometry, bonding, and applications of each type of nanocluster. Perfect for researchers working in nanoscience, nanotechnology, and materials chemistry, Atomically Precise Nanochemistry will also benefit industry professionals in these sectors seeking a practical and up-to-date resource.
Download or read book UNDERSTANDING STRUCTURAL INFLUENCES IN GOLD MONOLAYERED PROTECTED CLUSTERS USING MAGNETO OPTICAL SPECTROSCOPY AND TWO DIMENSIONAL ELECTRONIC SPECTROSCOPY written by Utsab Mitra and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Variable Temperature-Variable Field Magnetic Circular Photoluminescence (VTVH-MCPL) has been developed to characterize the unique structure-dependent optical properties of monolayer-protected gold nanoclusters. VTVH-MCPL compliments the absorption-based Magnetic Circular Dichroism (MCD) technique and is capable of analyzing the electronic Land g-factors, zero-field energy splitting and the relative A, B and C-term contribution to the photoluminescence response of the system. Au25(SC8H9)18 MPC has been taken as a model system to provide a state-resolved characterization of the electronic structure and relaxation dynamics by the application of such a technique. VTVH-MCPL has been able to characterize at least three relaxation channels contributing to the global photoluminescence, a low energy intraband transition (1.67 eV) translating to the relaxation between superatomic-D to superatomic-P orbitals localized in the core of the MPC, another two higher energy interband transitions (1.72 eV and 1.96 eV) corresponding to relaxation between superatomic-D to lower energy states localized in the semiring of the cluster. Such a study helped in extracting information such as at lower temperature (60K), the preferential pathway of relaxation is via core-based states, while at higher temperature (60K) a ligand-based emission pathway is preferred. Explanation of such observation has been done in terms of relative vibrational coupling strengths of the electronic states involved. Quantification of spectroscopic term-symbols relating to the total angular momentum and the Land g-factors of each electronic states reveals the structure-dependent electronic properties of Au MPCs. 2D Electronic Spectroscopic studies on Au25(SC8H9)19 MPC introduces a second dimensional and enables to extract further information about the system. Evidence of a potential energy cross-curve in the LUMO + n levels has been observed through the analysis of the time domain measurements, which displayed a sigmoidal feature when the amplitude of the 2D cross-peaks were plotted against excitation energies. Evidence of a fast-oscillatory mode of frequency 12 THz has also been observed using 2D Electronic Spectroscopy.
Download or read book Atomically Precise Metal Nanoclusters written by Zhikun Wu and published by Morgan & Claypool Publishers. This book was released on 2020-11-06 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomically precise metal nanocluster research has emerged as a new frontier. This book serves as an introduction to metal nanoclusters protected by ligands. The authors have summarized the synthesis principles and methods, the characterization methods and new physicochemical properties, and some potential applications. By pursuing atomic precision, such nanocluster materials provide unprecedented opportunities for establishing precise relationships between the atomic-level structures and the properties. The book should be accessible to senior undergraduate and graduate students, researchers in various fields (e.g., chemistry, physics, materials, biomedicine, and engineering), R&D scientists, and science policy makers.
Download or read book Metal Nanoclusters in Catalysis and Materials Science The Issue of Size Control written by Benedetto Corain and published by Elsevier. This book was released on 2011-08-11 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Nanoclusters in Catalysis and Materials Science: The Issue of Size Control deals with the synthesis of metal nanoclusters along all known methodologies. Physical and chemical properties of metal nanoclusters relevant to their applications in chemical processing and materials science are covered thoroughly. Special attention is given to the role of metal nanoclusters size and shape in catalytic processes and catalytic applications relevant to industrial chemical processing.An excellent text for expanding the knowledge on the chemistry and physics of metal nanoclusters. Divided in two parts; Part I deals with general aspects of the matter and Part II has to be considered a useful handbook dealing with the production of metal nanoclusters, especially from their size-control point of view. * Divided into two parts for ease of reference: general and operational * Separation of synthetic aspects, physical properties and applications* Specific attention is given to the task of metal nanoclusters size-control
Download or read book Protected Metal Clusters From Fundamentals to Applications written by and published by Elsevier. This book was released on 2015-09-06 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: Protected Metal Clusters: From Fundamentals to Applications surveys the fundamental concepts and potential applications of atomically precise metal clusters protected by organic ligands. As this class of materials is now emerging as a result of breakthroughs in synthesis and characterization that have taken place over the last few years, the book provides the first reference with a focus on these exciting novel nanomaterials, explaining their formation, and how, and why, they play an important role in the future of molecular electronics, catalysis, sensing, biological imaging, and medical diagnosis and therapy. Surveys the fundamental concepts and potential applications of atomically precise metal clusters protected by organic ligands. Provides well-organized, tutorial style chapters that are ideal for teaching and self-study In-depth descriptions by top scientists in the field Presents the state-of-the art of protected metal clusters and their future prospects
Download or read book Modern Electroplating written by Mordechay Schlesinger and published by John Wiley & Sons. This book was released on 2011-02-14 with total page 755 pages. Available in PDF, EPUB and Kindle. Book excerpt: The definitive resource for electroplating, now completely up to date With advances in information-age technologies, the field of electroplating has seen dramatic growth in the decade since the previous edition of Modern Electroplating was published. This expanded new edition addresses these developments, providing a comprehensive, one-stop reference to the latest methods and applications of electroplating of metals, alloys, semiconductors, and conductive polymers. With special emphasis on electroplating and electrochemical plating in nanotechnologies, data storage, and medical applications, the Fifth Edition boasts vast amounts of new and revised material, unmatched in breadth and depth by any other book on the subject. It includes: Easily accessible, self-contained contributions by over thirty experts Five completely new chapters and hundreds of additional pages A cutting-edge look at applications in nanoelectronics Coverage of the formation of nanoclusters and quantum dots using scanning tunneling microscopy (STM) An important discussion of the physical properties of metal thin films Chapters devoted to methods, tools, control, and environmental issues And much more A must-have for anyone in electroplating, including technicians, platers, plating researchers, and metal finishers, Modern Electroplating, Fifth Edition is also an excellent reference for electrical engineers and researchers in the automotive, data storage, and medical industries.
Download or read book Luminescent Metal Nanoclusters written by Sabu Thomas and published by Woodhead Publishing. This book was released on 2022-06-28 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: Luminescent Metal Nanoclusters: Synthesis, Characterization, and Applications provides a comprehensive accounting of various protocols used for the synthesis of metal nanoclusters, their characterization techniques, toxicity evaluation and various applications and future prospects. The book provides detailed experimental routes, along with mechanisms on the formation of benign metallic clusters using biomaterials and a comprehensive review regarding the preparation, properties and prospective applications of these nano clusters in various fields, including therapeutic applications. Various methods to protect nanocluster materials to increase their stability are emphasized, including the incorporation of ligands (protein, small molecule, DNA, thiols). This book addresses a gap in the current literature by bringing together the preparation, characterization and applications of all the possible types of reported metal nanoclusters and their hybrids. It is suitable for materials scientists and engineers in academia and those working in research and development in industry. It may also be of interest to those working in the interdisciplinary nanotechnology community, such as physical chemists. Covers the most relevant material categories of luminescent nanoclusters such as metal nanoclusters, nano composites and alloy nanoclusters Provides a comprehensive overview of the various available methods used for the protection of nanoclusters Discusses the latest advances and future opportunities in addressing challenges in producing benign nanomaterials such as toxicity and stability
Download or read book Atomically Precise Metal Nanoclusters written by Thalappil Pradeep and published by Elsevier. This book was released on 2022-10-08 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomically Precise Metal Nanoclusters discusses the host of exciting properties that can be better harnessed with a solid understanding of their different structures and subsequent properties at the molecular level. The book delves into the foundational chemistry of numerous key atomically precise clusters and provides guidance on key approaches employed to examine them. Beginning with an introduction to the properties and fundamental nano-chemistry of atomically precise metal nanoclusters, the book then explores key approaches for their synthesis, examination and modification, including chromatography, mass spectrometry, single crystal diffraction, electron microscopy and computational approaches. A final section covers specific nanoclusters and cluster systems. User will find the important knowledge of an experienced team of contributors who provide a detailed guide to understanding, investigating and utilizing these useful structures that is ideal for anyone working in related fields. Presents a comprehensive guide that combines key knowledge, approaches and other types of metal nanocluster Supports an understanding of important interactions and approaches using clear figures Highlights future needs and prospects in the field
Download or read book Classical And Quantum Dynamics In Condensed Phase Simulations Proceedings Of The International School Of Physics written by Bruce J Berne and published by World Scientific. This book was released on 1998-06-17 with total page 881 pages. Available in PDF, EPUB and Kindle. Book excerpt: The school held at Villa Marigola, Lerici, Italy, in July 1997 was very much an educational experiment aimed not just at teaching a new generation of students the latest developments in computer simulation methods and theory, but also at bringing together researchers from the condensed matter computer simulation community, the biophysical chemistry community and the quantum dynamics community to confront the shared problem: the development of methods to treat the dynamics of quantum condensed phase systems.This volume collects the lectures delivered there. Due to the focus of the school, the contributions divide along natural lines into two broad groups: (1) the most sophisticated forms of the art of computer simulation, including biased phase space sampling schemes, methods which address the multiplicity of time scales in condensed phase problems, and static equilibrium methods for treating quantum systems; (2) the contributions on quantum dynamics, including methods for mixing quantum and classical dynamics in condensed phase simulations and methods capable of treating all degrees of freedom quantum-mechanically.
Download or read book Nanocatalysis written by Ulrich Heiz and published by Springer Science & Business Media. This book was released on 2007-01-10 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanocatalysis, a subdiscipline of nanoscience, seeks to control chemical reactions by changing the size, dimensionality, chemical composition, and morphology of the reaction center and by changing the kinetics using nanopatterning of the reaction center. This book offers a detailed pedagogical and methodological overview of the field. Readers discover many examples of current research, helping them explore new and emerging applications.
Download or read book Advances in Quantum Chemistry Ratner Volume written by and published by Academic Press. This book was released on 2017-05-25 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Quantum Chemistry, Volume 75 presents work and reviews of current progress in computational quantum mechanics as presented by some of the world’s leading experts. This latest release includes chapters on Mean-Field Methods for Time-Dependent Quantum Dynamics of Many-Atom Systems, Electron–Ion Impact Energy Transfer in Nanoplasmas of Coulomb Exploding Clusters, Molecular Properties of Sandwiched Molecules Between Electrodes and Nanoparticles, Criterion for the Validity of D'Alembert's Equations of Motion, and A Time-Dependent Density Functional Theory Study of the Impact of Ligand Passivation on the Plasmonic Behavior of Ag Nanoclusters. Presents reports on current work in molecular and atomic quantum mechanics Contains work reported by many of the best scientists in the field Dedicated to one of the great practitioners in the field, Mark A. Ratner
Download or read book Gold Nanostars written by Giuseppe Chirico and published by Springer. This book was released on 2015-08-03 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Brief focuses on the synthesis, functionalization techniques, optical properties and biomedical application of gold nanostars (GNS). Various facilities of gold nanostars synthesis as well as functionalization of GNS with PEG, organic dyes, bioactive compounds are discussed. The authors discuss physical origin of the Localized Surface Plasmon Resonances and the way the nano-environment affects them. The implication of the LSPR of gold nanostars surface enhanced Raman scattering is also discussed. The emphasis has been done on the application of GNS for current and emerge needs of medicine, biology and pharmacy. Moreover, properties of gold nanostars as contrast agents for in vivo imaging and interaction of GNS with cells are also discussed in this Brief.
