bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nomenclature of Organometallic Compounds of the Transition Elements (IUPAC Recommendations 1999)
Authors: Salzer A. 
Published: October 2007

Organometallic compounds are defined as containing at least one metal-carbon bond between an organic molecule, ion, or radical and a metal. Organometallic nomenclature therefore usually combines the nomenclature of organic chemisty and that of coordination chemistry. Provisional rules outlining nomenclature for such compounds are found both in Nomenclature of Organic Chemistry, 1979 and in Nomenclature of Inorganic Chemistry, 1990This document describes the nomenclature for organometallic compounds of the transition elements, that is compounds with metal-carbon single bonds, metal-carbon multiple bonds as well as complexes with unsaturated molecules (metal-p-complexes).Organometallic compounds are considered to be produced by addition reactions and so they are named on an addition principle. The name therefore is built around the central metal atom name. Organic ligand names are derived according to the rules of organic chemistry with appropriate endings to indicate the different bonding modes. To designate the points of attachment of ligands in more complicated structures, the h, k, and m-notations are used. The final section deals with the abbreviated nomenclature for metallocenes and their derivatives.ContentsIntroduction Systems of Nomenclature2.1 Binary type nomenclature 2.2 Substitutive nomenlcature 2.3 Coordination nomenclature Coordination Nomenclature3.1 General definitions of coordination chemistry 3.2 Oxidation numbers and net charges 3.3 Formulae and names for coordination compounds Nomenclature for Organometallic Compounds of Transition Metals 4.1 Valence-electron-numbers and the 18-valence-electron-rule 4.2 Ligand names 4.2.1 Ligands coordinating by one metal-carbon single bond 4.2.2 Ligands coordinating by several metal-carbon single bonds 4.2.3 Ligands coordinating by metal-carbon multiple bonds 4.2.4 Complexes with unsaturated molecules or groups 4.3 Metallocene nomenclature
Novel strategies for the discovery of plant-derived anticancer agents
Authors: Kinghorn A. D. , Farnsworth Norman R. , Soejarto D. D. , Cordell G. A. , Pezzuto J. M. , Udeani G. O. , Wani M. C. , Wall M. E. , Navarro H. A. , Kramer R. A. , Menendez A. T. , Fairchild Craig R. , Lane K. E. , Forenza Salvatore , Vyas D. M. , Lam K. S. , Shu Y.-Z. 
Published: October 2007

Abstract
Glossary of terms used in theoretical organic chemistry
Authors: Minkin V. I. 
Published: October 2007

Abstract
The glossary contains definitions and explanatory notes for more than 450 terms used in the context of multidisciplinary research and publications related to applications of modern theoretical concepts, computational and graph-theoretical methods to investigation into structure, reactivity, spectroscopic and other physical and physicochemical properties of organic, organometallic and metal coordination compounds. The aim of the glossary is to provide guidance on terminology used in theoretical organic chemistry and to contribute to the elimination of inconsistencies and ambiguities in the meanings of terms in the area.
Studies on Biodegradable Poly(Hexano-6-Lactone) Fibers. Part 2: Environmental Degradation
Authors: Mochizuki M. , Hayashi T. , Nakayama K. , Masuda T. 
Published: October 2007

Abstract
Poly(hexano-6-lactone) (PCL*) fibers were degraded under environmental conditions, including soil burial, sea water exposure, and activated sludge exposure. The extent of degradation was examined by weight loss, mechanical properties loss such as tensile strength and ultimate elongation decreases, and visual observations by scanning electron microscopy. The rate of degradation was found to depend on draw ratio and crystallinity of the PCL fibers with surface erosion of amorphous regions more readily than crystalline regions. The life time of highly-drawn PCL fibers when exposed to soil burial and seawater was evaluated from the view point of environmental applications. In terms of degradation mechanism of PCL fiber breakdown biodegradation seems to be the dominant reaction, that is hydrolysis reaction catalyzed by enzyme secreted by microorganisms.
Nomenclature, Symbols, Units, and Their Usage in Spectrochemical Analysis - Part XVII; Laser-Based Molecular Spectrometry For Chemical Analysis: Absorption
Authors: Gauglitz G. , Moore D. S. 
Published: October 2007

Abstract
This report is the 17th in a series on spectrochemical methods of analysis issued by IUPAC commission V.4. It is concerned with the principles of laser absorption spectroscopy and its application in the optical wavelength region. The present report has four main sections: fundamentals of laser absorption spectroscopy, Doppler-limited spectroscopy; sub-Doppler laser spectroscopy, and time-resolved laser spectroscopy.
Temperature Dependence of the Westcott g-factor for Neutron Reactions in Activation Analysis
Authors: Holden N. E. 
Published: October 2007

Abstract
The Westcott g-factors, which allow the user to determine reaction rates for nuclear reactions taking place at various temperatures, have been calculated using data from the Evaluated Neutron Nuclear Data Library, ENDF/B-VI. Nuclides chosen have g-factors which are significantly different from unity and result in different reaction rates compared to nuclides whose neutron capture cross section varies as the reciprocal of the neutron velocity. Values are presented as a function of temperature up to 673.16 K (400 °C).
The Influence of Reprocessing on the Structure-Property Characteristics of a Plasticised Poly(vinyl chloride) (PVC-p) Compound
Authors: Dehennau C. , Moore D. R. 
Published: October 2007

Abstract

Synopsis: We have conducted a detailed investigation of the change in deformational, structural, molecular and rheological characteristics that are attendant on a PVC-p compound experiencing higher processing temperatures. Our study reflects an experience that occurs in the PVC industry and for which a loss of processing performance accompanies the excursions to higher temperatures. It is apparent that as this process continues the material will eventually become unprocessable, unless changes are made.
The change that accompanies the material as it passes from an experience of low processing temperatures to high processing temperatures has been thoroughly mapped. However, it has been difficult to make precise observation of the molecular and structural changes occurring. This has not been without application of a number of likely candidate methodologies, including DSC, TGA, WAXS, GPC and fluorescence spectroscopy. It would seem that some additional crystallization is accompanying the increase in gelation that occurs at higher processing temperatures. At the same time, the observations on the influence of annealing hint that this is not the only consideration and that diffusion of the plasticiser into the PVC particles might also be playing a role or even residual stresses in the materials might be important.
This study has not only been concerned with an in depth materials characterisation; it has also explored ways of alleviating the loss of processability. Two particular lines of study involving pre-shear history and blending with higher plasticised compounds have provided interest albeit inconclusive results. On the other hand, there are strong implications from the DSC study that reversibility of the "process aging" is not likely.
In conclusion, it is interesting to observe that by conducting this study through an IUPAC Working Party it has been helpful to pool the resources and experience of an international community of scientists which has likely given us an opportunity of conducting this study at much lower costs than might have otherwise been the case.
Electrochemical Biosensors: Recommended Definitions and Classification
Authors: Thevenot D. R. , Tóth K. , Durst R. A. , Wilson G. S. 
Published: October 2007

Abstract
Two Divisions of the International Union of Pure and Applied Chemistry (IUPAC), namely Physical Chemistry (Commission I.7 on Biophysical Chemistry formerly Steering Committee on Biophysical Chemistry) and Analytical Chemistry (Commission V.5 on Electroanalytical Chemistry) have prepared recommendations on the definition, classification and nomenclature related to electrochemical biosensors; these recommendations could, in the future, be extended to other types of biosensors.
An electrochemical biosensor is a self-contained integrated device, which is capable of providing specific quantitative or semi-quantitative analytical information using a biological recognition element (biochemical receptor) which is retained in direct spatial contact with an electrochemical transduction element. Because of their ability to be repeatedly calibrated, we recommend that a biosensor should be clearly distinguished from a bioanalytical system, which requires additional processing steps, such as reagent addition. A device which is both disposable after one measurement, i.e., single use, and unable to monitor the analyte concentration continuously or after rapid and reproducible regeneration should be designated a single use biosensor.
Biosensors may be classified according to the biological specificity-conferring mechanism or, alternatively, to the mode of physico-chemical signal transduction. The biological recognition element may be based on a chemical reaction catalysed by, or on an equilibrium reaction with macromolecules that have been isolated, engineered or present in their original biological environment. In the latter cases, equilibrium is generally reached and there is no further, if any, net consumption of analyte(s) by the immobilized biocomplexing agent incorporated into the sensor. Biosensors may be further classified according to the analytes or reactions that they monitor: direct monitoring of analyte concentration or of reactions producing or consuming such analytes; alternatively, an indirect monitoring of inhibitor or activator of the biological recognition element (biochemical receptor) may be achieved.
A rapid proliferation of biosensors and their diversity has led to a lack of rigour in defining their performance criteria. Although each biosensor can only truly be evaluated for a particular application, it is still useful to examine how standard protocols for performance criteria may be defined in accordance with standard IUPAC protocols or definitions. These criteria are recommended for authors, referees and educators and include calibration characteristics (sensitivity, operational and linear concentration range, detection and quantitative determination limits), selectivity, steady-state and transient response times, sample throughput, reproducibility, stability and lifetime.
Glossary of Terms Used in Combinatorial Chemistry
Authors: Maclean D. , Baldwin J. J. , Ivanov V. T. , Kato Y. , Shaw A. , Schneider P. , Gordon E. M. 
Published: October 2007

Abstract

Introduction: The development of combinatorial chemistry has generated a wide variety of new concepts and much associated terminology. In addition, the nature of research in this area has brought together scientists from diverse backgrounds: statisticians may discuss their work with biologists and heterocyclic chemists; medicinal chemists are talking to engineers, analytical chemists, and polymer scientists. In recognition of the potential for confusion and lack of communication in this field, the International Union of Pure and Applied Chemistry (IUPAC) convened a working party (within the Division of Human Health, Medicinal Chemistry Section) to attempt to capture and define the terminology at the interface of these endeavours. The following Glossary is the result of their efforts. It is hoped that it will provide a resource for those new to the area encountering terms for the first time, and, perhaps, to increase the clarity of communication between more experienced workers in the field.
The Glossary is not intended as a comprehensive review or encyclopaedia of combinatorial chemistry, although occasional attempts have been made to broaden the scope beyond a strict dictionary-type definition of terms by providing illustrative examples of some terms, and directing readers to literature sources where appropriate. These references have not necessarily been chosen to attribute credit for the discovery or invention of a term; rather they should provide the most pertinent information for the topic. Ideally this will be an article or review with the Glossary term as its central theme, in which proper accreditation for the seminal contributions to that area may be found.
Because of the intrinsic interdisciplinary nature of this area of research, it has not been possible to provide a comprehensive coverage of each of the sub-fields, neither has this been the intent. Rather it has been attempted to identify those elements which are particularly pertinent to combinatorial chemistry. Thus, in the analytical sciences "magic angle spinning" gains an entry whereas "mass spectrometry" does not. The interested reader will readily be able to find more detailed treatments of these specialized areas.
Trademarks have been included where, in the judgement of the authors, their use has become sufficiently widespread that they often do not receive appropriate citation; the implicit assumption being that the reader will understand what is meant. This criterion has been adopted over one of inclusiveness, which would rapidly become extreme in many areas. In a field which is developing as rapidly as combinatorial chemistry a document such as this Glossary may soon require revision. The authors welcome suggestions for new terms, clarifications, references, and other comments which will aid in the development of this resource.
Colloidal quantum dots. From scaling laws to biological applications
Authors: Alivisatos Paul 
Published: October 2007

Abstract
Over a twenty-year period, condensed matter physicists and physical chemists have elucidated a series of scaling laws which successfully describe the size dependence of solid state properties [1,2]. Often the experiments were performed under somewhat exotic conditions, for instance on mass-selected clusters isolated in molecular beams or on quantum dots grown by molecular beam epitaxy and interrogated at low temperatures and in high magnetic fields. As a result, we now have an understanding of how thermodynamic, optical, electrical, and magnetic properties evolve from the atomic to the solid state limit. This area of research is presently undergoing a remarkable transformation. The scaling laws, previously the direct subject of research, now provide a tool for the design of advanced new materials. In the case of colloidal quantum dots, or semiconductor nanocrystals, these new insights are poised to have impact in disciplines remote from solid state physics [3].
Wires, switches, and wiring. A route toward a chemically assembled electronic nanocomputer
Authors: Heath James R. 
Published: October 2007

Abstract
A Boolean logic, nonreversible computing machine should, in principle, be capable of 10 18 bit operations per second at a power consumption of 1 W. In order to build such a machine that can even approach this benchmark for efficiency, the development of a robust quantum-state switch capable of ambient operation, as well as a bottom–up manufacturing technology, will be necessary. My group, in collaboration with Hewlett Packard, has developed much of the architecture for such a machine, which we call a chemically assembled electronic nanocomputer (CAEN). More recently, in a collaborative effort with Fraser Stoddart's group at UCLA, we have begun to build it. The fundamental unit of the machine is a field-programmable molecular switch, and the fundamental architecture is a hierarchical organization of wire/switch lattices called crossbars. Electronically, singly configurable molecular-based switch devices based on rotaxane molecular compounds have been fabricated in high yield. These switches were used to construct simple molecular-based logic structures and read-only memory elements.
Purpose-built metal oxide nanomaterials. The emergence of a new generation of smart materials
Authors: Vayssieres Lionel , Hagfeldt Anders , Lindquist Sten Eric 
Published: October 2007

Abstract
A new concept has been developed in order to achieve a new generation of smart materials, namely purpose-built materials, modeled and designed to match the physical and structural requirements of their applications. A model based on the thermodynamic monitoring of the nucleation, growth, and aging process of metal oxide by minimization of the interfacial tension, yielding to the thermodynamic stabilization of the system, results in well-designed and well-ordered nanostructured materials with the required porosity, morphology, size, and orientation on various substrates.
Binary cooperative complementary nanoscale interfacial materials. Reduction of silver nanoparticles in DMF. Formation of monolayers and stable colloids
Authors: Pastoriza-Santos Isabel , Liz-Marzán Luis M. 
Published: October 2007

Abstract
We explore in this article the reduction of Ag + ions by N,N-dimethylformamide (DMF), both in the presence and in the absence of a stabilizing agent. The reduction can lead to the formation of either thin films of silver nanoparticles electrostatically attached onto glass surfaces, or stable dispersions of silver nanoparticles if the silane coupling agent 3-aminopropyltrimethoxysilane (APS) is present. The different parameters affecting the reduction process are discussed, and the reducing ability of DMF is compared with that of ethanol, which is often used for the production of catalytically active metal colloids.
Photophysics and spectroscopy of metal particles
Authors: Hodak José H. , Henglein Arnim , Hartland Gregory V. 
Published: October 2007

Abstract
This paper describes our recent work using ultrafast laser spectroscopy to examine the fundamental properties of metal particles. Two studies are presented. First, the characteristic time scale for electron-phonon coupling in Au particles with sizes between 2 and 120 nm has been examined by bleach recovery measurements. These experiments show that the coupling between the electrons and phonons is independent of particle size, to within the signal-to-noise of our experiments. We have also used transient absorption spectroscopy to examine the low-frequency "breathing" modes of the Au particles. These modes are impulsively excited by the rapid lattice heating that accompanies electron-phonon coupling. The breathing motion contributes to the transient absorption signal because the position of the plasmon band depends on the free electron density and, thus, the particle volume. The measured frequencies are inversely proportional to the radius, and almost exactly match the predictions of classical mechanics calculations for Au.
Nanomeasurements of individual carbon nanotubes by in situ TEM
Authors: Wang Z. L. , Poncharal P. , de Heer W. A. 
Published: October 2007

Abstract
Property characterization of nanomaterials is challenged by the small size of the structure because of the difficulties in manipulation. Here we demonstrate a novel approach that allows a direct measurement of the mechanical and electrical properties of individual nanotube-like structures by in situ transmission electron microscopy (TEM). The technique is powerful in a way that it can be directly correlated to the atomic-scale microstructure of the carbon nanotube with its physical properties, thus providing a complete characterization of the nanotube. Applications of the technique will be demonstrated in measurements of the mechanical properties, the electron field emission, and the ballistic quantum conductance of individual carbon nanotubes. A nanobalance technique is demonstrated that can be applied to measure the mass of a single tiny particle as light as 22 fg (1 f = 10-15 ).
Optical absorption property of oxidized free-standing porous silicon films
Authors: Xu Dongsheng , Guo Guolin , Gui Linlin , Tang Youqi , Qin G. G. 
Published: October 2007

Abstract
We have systematically studied the evolution of the optical absorption of free-standing PS films during thermal oxidation at 200°C in air. Our experiment results show the evolution of transmission curve is quite complicated, which red-shifts first and then blue-shifts during thermal oxidation. At the same time, the transmission at the low energy decreases first and then increases. We propose an explanation as follows: (1) the energy gap associated with each crystallite should increase during thermal oxidation process, due to the quantum confinement effect; (2) the energy gap should decrease with an increase in oxygen termination atoms. Both the increasing of the gap due to the quantum confinement effect and the decreasing of the gap due to the Si-O bond formation cause a complicated evolution of optical absorption.
Effect of atmospheric oxidation on the electronic and photoluminescence properties of silicon nanocrystal
Authors: Germanenko I. N. , Dongol M. , Pithawalla Y. B. , El-Shall M. Samy , Carlisle J. A. 
Published: October 2007

Abstract
Web-like aggregates of coalesced Si nanocrystals produced by a laser vaporization-controlled condensation technique show luminescence properties that are similar to those of porous Si. The results are consistent with a quantum confinement mechanism as the source of the red photoluminescence (PL) in this system. The oxidized Si nanoparticles do not exhibit the red PL that is characteristic of the surface-oxidized Si nanocrystals. The nanoparticles are allowed to oxidize slowly, and the PL is measured as a function of the exposure time in air. A significant blue shift in the red PL peak is observed as a result of the slow oxidation process. The dependence of quantum size effects on the bonding structure is established by correlating the PL data with the photon-yield electronic structure measurements made at the Advanced Light Source. The results indicate that as the nanoparticles oxidize, the radius of the crystalline core decreases in size, which gives rise to a larger bandgap and consequently to the observed blue-shift in the PL band. The correlation between the PL, SXF, and NEXAFS results provides further support for the quantum confinement mechanism as the origin of the visible PL in Si nanocrystals.
Silica-coated metals and semiconductors. Stabilization and nanostructuring
Authors: Alejandro-Arellano Marta , Ung Thearith , Blanco Álvaro , Mulvaney Paul , Liz-Marzán Luis M. 
Published: October 2007

Abstract
We present in this paper the use of silica-coating for nanostructuring metal and semiconductor nanoparticles. The basic concept is the strict tailoring of the interparticle spacing through the thickness of the silica shell. Three different experiments are presented that exemplify this concept. The first example consists of the preparation of thin films using the layer-by-layer self-assembly of gold nanoparticles, either uncoated or coated with thin silica shells. The observed optical effects are interpreted using effective medium theory. The second and third experiments are related to the preparation of three-dimensional nanostructures, either as concentrated dispersions of thickly coated Au or CdS nanoparticles, or as opals prepared from such core-shell nanoparticles. Within these crystalline solids, intercore distance is again dictated by the thickness of the silica shells.