bluuebunny/crossref_metadata_2025_split huggingface dataset:
Noble Gases: Inorganic ChemistryBased in part on the article Noble Gases: Inorganic Chemistry by Boris Žemva which appeared in the
Encyclopedia of Inorganic Chemistry, First Edition
.
Authors: Atwood David A. 
Published: December 2011

Abstract
The noble gas (Ng) elements have a rich reaction chemistry despite having a filled valence shell that would indicate otherwise. Halide compounds, usually with fluorine, and various oxides are common. There is also a growing class of carbon and nitrogen derivatives. A wide range of neutral and cationic noble gas compounds can be formed as long as the added elements, or combinations of elements, possess sufficient electron affinity. The range of compounds, along with characterization data and brief bonding descriptions will be presented for each element. Many of the compounds serve as starting materials for other derivatives, including the rapidly growing field of noble gas containing transition metal complexes. For example, there is now a broad range of salts containing transition metals. The article will conclude with a brief overview of the many unusual and disparate applications being found for these elements.
Noncrystalline Solids
Authors: Adam Jean‐Luc , Lucas Jacques 
Published: December 2011

Abstract
This review deals with the formation and physical properties of noncrystalline materials in oxide and nonoxide systems. Structural aspects are also developed. Oxide materials are silica‐based glasses, borate, and phosphate glasses, while nonoxide systems include halide and chalcogenide glasses. They are described in terms of chemical compositions and thermal and optical properties. Special attention is paid to the unique properties of nonoxide glasses for infrared‐light transmission and rare earth emissions. Some applications in the fields of infrared optics, infrared fiber sensors, fiber lasers, and amplifiers are shown. In a special section, the formation and properties of metallic glasses are presented, with special focus on chemical, magnetic, and mechanical properties.
Nutritional Aspects of Metals & Trace ElementsBased in part on the article Nutritional Aspects of Metals & Trace Elements by Paul Saltman which appeared in theEncyclopedia of Inorganic Chemistry, First Edition.
Authors: Yokoi Katsuhiko 
Published: December 2011

AbstractThe essential inorganic nutrients are dietary components that exert nutritional function when they are consumed as inorganic substances. Some essential inorganic nutrients such as selenium and iodine act as organic active constituents after metabolic conversionin vivowhen they are consumed as organic as well as inorganic substances. Inadequate intake of essential inorganic nutrients results in deficiency diseases and/or interruption of life cycles. The essential inorganic nutrients consist of the major elements (sodium, potassium, calcium, magnesium, chlorine, phosphorus, and sulfur) and the trace elements (iron, copper, zinc, manganese, cobalt, chromium, molybdenum, vanadium, nickel, arsenic, selenium, iodine, fluorine, silicon, boron, tin, cadmium, lead, rubidium, and lithium). Evidence of essentiality is limited for arsenic, boron, cadmium, fluorine, lead, lithium, nickel, rubidium, silicon, tin, and vanadium. If the requirement is less than 1 mg day−1for humans or 1 mg kg−1diet for animals, the inorganic nutrients are called ultratrace elements. Further investigation may increase the number of essential inorganic nutrients. Deficiencies of inorganic nutrients such as iodine, iron, and zinc occur worldwide. To prevent deficiencies and toxicosis, the US and other nations have established the Dietary Reference Intakes (DRIs) or the equivalents that are composed of reference values including Estimated Average Requirements (EARs), Recommended Dietary Allowances (RDAs), Adequate Intakes (AIs) and Tolerable Upper Intake Levels (ULs). Essential inorganic nutrients function in vivo through various modalities such as catalytic centers of enzymes, metabolic regulation, modulation of ion channels and receptors. The regulation and control of inorganic nutrients are a function of eight parameters: availability, solubility, permeability, ligand exchange, transport, assimilation, storage, and excretion. Excessive intakes, genetic abnormalities, and other etiologies cause pathologies of metal overload. Functions of selenium and nickel were reviewed. Selenium manifests antioxidant activity as an active site of glutathione peroxidase. Other important selenium‐containing proteins include thioredoxin reductase, iodothyronine deiodinases, selenoprotein P. Nickel occupies the metal centers of urease, carbon monoxide dehydrogenase, and other enzymes. Nickel deprivation results in impaired reproduction (rats and goats) and decreased spermatozoa motility and density (rats). It is our challenge to determine optimal intakes of inorganic nutrients for ensuring optimal health for all.
Organic Synthesis Using Transition Metal Complexes Containing π‐Bonded LigandsBased in part on the article Organic Synthesis using Transition Metal Complexes Containing π‐Bonded Ligands by Martin F. Semmelhack which appeared in the
Encyclopedia of Inorganic Chemistry, First Edition
.
Authors: Morris W. H. , Sullivan Lisa M. , Wellons Matthew S. , Lukehart C. M. 
Published: December 2011

Abstract
A selective overview of reactions of transition metal π‐complexes pertaining to organic synthesis applications is provided. While reactions involving nucleophilic addition to pi‐coordinated ligands are emphasized, alkene insertion/elimination reactions and allyl coupling reactions are also discussed.
Oxide Catalysts in Solid‐State ChemistryBased in part on the article Oxide Catalysts in Solid State Chemistry by Toshio Okuhara & Makoto Misono which appeared in theEncyclopedia of Inorganic Chemistry, First Edition.
Authors: Okuhara Toshio , Kamiya Yuichi 
Published: December 2011

AbstractThis chapter deals with catalysis of metal oxides containing single elements and more than two metallic elements. The metal oxides catalyze typically selective oxidation and acid‐base reactions. The first section outlines factors controlling catalyst performance (activity, selectivity, and durability), which are categorized into geometric (crystal plane and surface defects) and material‐intrinsic factors. Catalysis of the metal oxides is illustrated in detail by examples such as BiMoO, MoVTeNbO, VPO, Perovskite‐type oxide, and heteropoly compounds. Catalyst performances of these metal oxides are discussed from the viewpoint of geometric aspects. For the heteropoly compounds, their synthetic methods, chemical properties, and porosities are also described. Solid acid and base catalysts are finally summarized.
Peptide–Metal InteractionsBased in part on the article Peptide–Metal Interactions by Justin K. Moran & Claude F. Meares which appeared in the
Encyclopedia of Inorganic Chemistry, First Edition
.
Authors: Meares Claude F. 
Published: December 2011

Abstract
Copper–peptide complexes have been the most extensively studied of all the metal–peptide complexes. Copper(II) is the most important oxidation state in copper–peptide complexes, although copper(III) can be stabilized by coordination to peptides. The deprotonated peptide nitrogens help stabilize the higher oxidation state of copper; therefore the more deprotonated peptide nitrogens, the more stable the copper(III) complex. The copper(II) complexes of GlyGlyProGly and (GlyGlyProGly)2 are very similar. At low pH, both peptides bond through the amino nitrogen and carbonyl oxygen of the first peptide linkage. The peptides GlyGlyProLys and (GlyGlyProLys)2 initially form 1N complexes with copper(II). With luteinizing hormone‐releasing hormone the copper(II) is coordinated via the imidazole nitrogen and two deprotonated peptide nitrogens. With angiotensin II, the copper(II) is bonded via the imidazole nitrogen of the histidine residue and two deprotonated peptide nitrogens. The dipeptide TyrPro bonded copper(II) through the amino nitrogen and the peptide carbonyl. Since there was no ionizable hydrogen on the peptide nitrogen, there was no bonding by the peptide nitrogen. The copper(II)AVP (vasopressin analog) complex is one of the most stable 4N copper–peptide complexes known. Owing to their similarities, nickel(II)–peptide complexes are usually studied along with copper(II) complexes. In neutral to acidic solutions, the nickel is coordinated through the amino nitrogen and the carbonyl oxygen (1N). When the pH is raised to 9.0, nickel(II) substitutes for a peptide hydrogen, and the coordination changes. In NiH1L complexes of cysteine‐containing dipeptides, the nickel is coordinated via the amino and deprotonated peptide nitrogens and the thiol group. Zinc‐peptide complexes are less stable. With the dipeptides Ala–His and Gly–His at high pH, zinc(II) was shown to form complexes coordinated through the amino nitrogen, deprotonated peptide nitrogen, and the imidazole nitrogen. Unlike copper(II), both palladium(II) and platinum(II) are soft acceptors and as such are expected to coordinate to soft donors like sulfur and aromatic nitrogen donors in residues such as Met and His, and deprotonated peptide nitrogens. Early investigations of metals showed that divalent metals such as copper(II), cobalt(II), and nickel(II) could catalyze the hydrolysis of amino acid esters. Mechanisms of cobalt(III)‐mediated peptide‐bond cleavage have been investigated; because cobalt(III) complexes bind to the N‐terminal amino acid residue of peptides, only the N‐terminal peptide bond is hydrolyzed. Complexes containing iron can cleave peptide bonds, as can complexes of palladium or platinum.
Periodic Table: Trends in the Properties of the Elements
Authors: Wulfsberg G. P. 
Published: December 2011

Abstract

The article gives examples of trends in properties of the elements, their ions, and their compounds, which can usefully be examined from the perspective of the periodic table as a whole, rather than by looking at one group of elements (or even individual elements) at a time. The properties discussed are those of great interest not only to inorganic chemists but also to research workers in allied fields, such as the other branches of chemistry, medicinal chemistry, environmental science, agricultural and geochemistry, industrial chemistry and safety, metallurgy, materials science, and surface chemistry. These trends can be organized, explained, and predicted on the basis of a small set of parameters of the elements and their ions, most notably the sizes of the ions, their charges (or oxidation numbers), and the Pauling electronegativities of the elements. Trends are emphasized in acid–base reactivity, precipitation and solubility trends, coordination chemistry, oxidation–reduction chemistry, and physical properties of the elements and their compounds. Much acid–base and precipitation chemistry can be predicted after calculating the p
K
a
values of cations and the p
K
b
values of anions, or simply predicting to which of the six acidity and basicity categories an ion belongs. Generally very useful in coordination chemistry are the chelate and macrocyclic effects and the Hard–Soft Acid–Base (HSAB) Principle. Oxidation–reduction chemistry of the elements can be summarized graphically in the form of Pourbaix diagrams or by redox predominance diagrams where the pH is set at the standard pH value of zero. Among physical properties, perhaps the most important for applications in materials science is whether a compound that might be synthesized is a solid with an extended structure; methods are given for predicting this on the basis of the radius ratios of the cations and anions (at least formally) contained in the compound. One physical property, metallic conduction, is discussed in further detail. As an example of chemical properties, trends in the acidity and basicity of oxides of the elements are discussed.
Phosphates: Solid‐State Chemistry
Authors: Attfield J. Paul 
Published: December 2011

Abstract

Phosphates contain oxyanions of phosphorus(V). The most common anion is the orthophosphate group PO
4
3−
, which is found in many solid phosphates including hydrated and acid phosphate salts. Oligomeric polyphosphate chains P

n

O

3
n
+1

(
n
+2)−

up to
n
= 6 and cyclophosphate rings P

n

O

3
n

n
−

up to
n
= 12 are also observed, and a unique cage ultraphosphate anion P
8
O
23
6−
is found in the Na
3
FeP
8
O
23
structure. Polymeric phosphate anions include the infinite chain catenaphosphate anion (PO
3
−
)
∞
and the ultraphosphate networks found in CaP
4
O
11
and the lanthanide MP
5
O
14
structures. Many compound anions and neutral frameworks such as silicophosphates, aluminophosphates, and molybdenum phosphates also exist. Phosphate species are characterized through PO stretching and bending vibrations in infrared and Raman spectroscopies, and by
31
P NMR. Phosphate structures are generally rigid, resistant to chemical attack, and (when anhydrous) insoluble and thermally stable. Some phosphate crystals have important physical properties such as ferrolectricity in KH
2
PO
4
(potassium dihydrogenphosphate, KDP). Diffusion of extra‐framework ions leads to potential uses of solid phosphates as ion exchangers and conductors, for example, NASICON based on NaZr
2
(PO
4
)
3
, and as cathode materials for lithium batteries. Vanadium phosphates are important selective oxidation catalysts. Large pore phosphates in which molecules can be adsorbed and undergo acid‐catalyzed reactions have been intensively studied. These materials are crystalline microporous solids such as aluminophosphates, or lamellar structures, typically based on α‐Zr(HPO
4
)
2
·H
2
O that can be pillared. This area of interest has led to the synthesis of many new organically templated metal phosphates in recent years, usually through hydrothermal reactions. Hydrated and acid orthophosphates can also be prepared in solution, and anhydrous phosphates are synthesized by direct high‐temperature reactions and from phosphate‐rich melts or fluxes. Slow cooling of melts is used to grow crystals, and quenching can result in many stable phosphate glasses. Phosphate anions do not absorb significantly in the UV‐visible region and so solid phosphates can also find use as optical materials such as phosphors, nonlinear crystals, for example, KTiOPO
4
, and lasers. Solid phosphates constitute many minerals, notably Apatites which are also found in living organisms as rigid components such as bones and teeth. Synthetic calcium phosphate biomaterials are used for bone implants.
Phosphides: Solid‐State Chemistry
Authors: Pöttgen Rainer , Hönle Wolfgang , von Schnering Hans Georg 
Published: December 2011

AbstractThe solid‐state chemistry of phosphides, phosphide oxides, and phosphide halides is reviewed. Phosphorus is outstanding, since no other element approaches phosphorus in the variety of homoatomic connected polyanions formed, as a result of its relatively low electronegativity and stereochemical features. The article covers the various synthesis techniques for solid‐state phosphides, the crystal chemistry, and chemical bonding. Besides the metal‐rich phosphides with pronounced metal–metal bonding, the large family of polyphosphides, which exhibits an unexpected wealth of chemical composition, is discussed. Furthermore, the largely varying magnetic, electronic, and catalytic properties are reviewed.
Photochemistry of Transition Metal ComplexesBased in part on the article Photochemistry of Transition Metal Complexes by Lisa McElwee‐White which appeared in theEncyclopedia of Inorganic Chemistry, First Edition.
Authors: Bitterwolf Tom 
Published: December 2011

AbstractPhotochemistry has evolved into a powerful tool for the highly selective generation of reactive intermediates in inorganic and organometallic chemistry. This review examines the state of the art in the examination of mechanisms of photochemical reactions utilizing techniques such as frozen matrices and fast time‐resolved methods. The application of photochemistry to the preparation of dihydrogen, alkane, and noble gas intermediates is reviewed along with the significance of these intermediates in the understanding of the mechanism of oxidative addition processes. Experiment and theory of charge transfer phenomena are extensively discussed along with the application of these processes to semiconductor and biochemical studies. Applications of photocrystallography to the examination of linkage isomers and very short‐lived excited state species are reviewed. Finally, a number of examples of the application of photochemical reactions, such as the photolysis of Fisher carbene species to generate ketenelike intermediates, to synthesis are discussed. The literature is reviewed to the end of 2003.
Photoelectron Spectroscopy of Transition Metal Systems
Authors: Green Jennifer C. 
Published: December 2011

Abstract
Photoelectron spectroscopy measures the binding energies of electrons in molecules and solids. The article briefly considers experimental methods. A photoelectron spectrum is related to the molecular orbital structure of a system. Variation of the band intensities with photon energy gives information on the atomic orbital content of the originating molecular orbital. Band splitting may have a number of origins such as vibrational states, Jahn–Teller distortions, exchange splittings, and spin–orbit coupling. All of these provide additional information on electronic structure. Density functional calculations of ionization energies give good agreement with experiment. All these points are exemplified throughout and the article concludes with a number of case studies.
Polonium: Inorganic Chemistry
Authors: Zingaro Ralph A. 
Published: December 2011

AbstractThe chemistry of polonium is quite limited. Because all of the isotopes of this element are radioactive, and because it is available in such limited quantities, research with polonium is difficult. The metal has been isolated and characterized. Although a number of polonium compounds, such as PoO2 have been well characterized, the evidence for many is insubstantial. Among the halide derivatives, PoCl4 has been studied in greatest detail. A number of other halides, and their complex ions such as PoBr6‐2, have been studied with considerable success. A simple binary nitride has never been prepared, and only indirect evidence for the existence of H2Po has been reported.
Polonium: Organometallic Chemistry
Authors: Zingaro Ralph A. 
Published: December 2011

Abstract
The organometallic chemistry of polonium has received limited research effort. The element is very rare, and all of its isotopes are radioactive. Radioactivity causes rupture of the bonds between carbon and polonium. Also, because polonium is a heavy metal, chemical bonding to carbon is thermodynamically very weak. It is rare for an organometallic compound of polonium to be isolated in weighable quantities and characterized using the conventional techniques of organic chemistry. The identification of organopolonium compounds relies largely on chromatographic behavior and on the use of tellurium compounds having analogous chemical structures as reference compounds.
Polyhedra
Authors: King R. Bruce 
Published: December 2011

Abstract

The concept of a polyhedron is a useful way of describing diverse chemical structures, including those of coordination compounds and metal clusters. In this context, a polyhedron may be regarded as a set consisting of vertices, edges, and faces. Familiar examples of polyhedra are the five regular (Platonic) polyhedra, that is, the tetrahedron, cube, octahedron, dodecahedron, and icosahedron. The relationship between the numbers of vertices (
v
), edges (
e
), and faces (
f
) in a polyhedron can be described by Euler's theorem, that is,
v
−
e
+
f
= 2. A given polyhedron can be converted to larger polyhedra by capping one or more of its faces. Interchanging the vertices and faces of a polyhedron leads to its dual, which has the same symmetry as the original polyhedron. A projection of a polyhedron onto a plane, known as a Schlegel diagram, is often a useful way of visualizing polyhedra, which supplements the usual perspective drawings. There are no formulas, direct or recursive, for which the number of distinct polyhedra having a given number of vertices, edges, or faces can be calculated.
Polysiloxanes & PolysilanesBased in part on the article Polysiloxanes & Polysilanes by Robert West which appeared in theEncyclopedia of Inorganic Chemistry, First Edition.
Authors: Mitra Amitabha , Atwood David A. 
Published: December 2011

AbstractSilicon‐containing polymers, of which polysiloxanes and polysilanes are the most important ones, are becoming more and more important industrially because of their unique properties. Polysiloxanes that contain SiOSi linkage in their structure are most commonly prepared by ring‐opening polymerization of cyclic siloxanes. The monomer for this process is prepared by the ‘Direct Process’. The polysiloxanes are hydrophobic despite having polar SiO bonds in their structures. They possess highly flexible structures with large SiOSi bond angles. They are chemically inert and have good thermal stability, low viscosity, and good gas permeability. These polymers and related copolymers find use in a variety of fields as silicone fluids, elastomers, and resins. Polysilanes consisting of chains exclusively made up of silicon atoms are most commonly prepared by Wurtz coupling reaction. through sodium condensation of dichlorosilanes. The most interesting aspect of their properties is σ‐electron delocalization, which gives rise to many interesting photochemical and photophysical effects like thermochromism, solvatochromism, and ionochromism. These polymers find use in preparation of silicon carbide and as photoresists, photoinitiators, and hole conductors in electrophotography. In this article, the history, synthesis, properties, and application of polysiloxane and polysilane polymers have been reviewed.