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In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions (cations) and negatively charged ions (anions), which results in a compound with no net electric charge. The constituent ions are held together by electrostatic forces termed ionic bonds.
Perchloric acid is a mineral acid with the formula HClO4. It is an oxoacid of chlorine. Usually found as an aqueous solution, this colorless compound is a stronger acid than sulfuric acid, nitric acid and hydrochloric acid. It is a powerful oxidizer when hot, but aqueous solutions up to approximately 70% by weight at room temperature are generally safe, only showing strong acid features and no oxidizing properties. Perchloric acid is useful for preparing perchlorate salts, especially ammonium perchlorate, an important rocket fuel component. Perchloric acid is dangerously corrosive and readily forms potentially explosive mixtures.
Ionic radius, rion, is the radius of a monatomic ion in an ionic crystal structure. Although neither atoms nor ions have sharp boundaries, they are treated as if they were hard spheres with radii such that the sum of ionic radii of the cation and anion gives the distance between the ions in a crystal lattice. Ionic radii are typically given in units of either picometers (pm) or angstroms (Å), with 1 Å = 100 pm. Typical values range from 31 pm (0.3 Å) to over 200 pm (2 Å).
Bismuth(III) oxide is a compound of bismuth, and a common starting point for bismuth chemistry. It is found naturally as the mineral bismite (monoclinic) and sphaerobismoite, but it is usually obtained as a by-product of the smelting of copper and lead ores. Dibismuth trioxide is commonly used to produce the "Dragon's eggs" effect in fireworks, as a replacement of red lead.
Chromium hexacarbonyl is a chromium(0) organometallic compound with the formula Cr(CO)6. It is a homoleptic complex, which means that all the ligands are identical. It is a colorless crystalline air-stable solid, with a high vapor pressure.
In chemistry, a vanadate is an anionic coordination complex of vanadium. Often vanadate refers to oxoanions of vanadium, most of which exist in its highest oxidation state of +5. The complexes [V(CN)6]3− and [V2Cl9]3− are referred to as hexacyanovanadate(III) and nonachlorodivanadate(III), respectively.
Silver azide is the chemical compound with the formula AgN3. It is a silver(I) salt of hydrazoic acid. It forms a colorless crystals. Like most azides, it is a primary explosive.
Ruthenium(IV) oxide is the inorganic compound with the formula RuO2. This black solid is the most common oxide of ruthenium. It is widely used as an electrocatalyst for producing chlorine, chlorine oxides, and O2. Like many dioxides, RuO2 adopts the rutile structure.
Osmium compounds are compounds containing the element osmium (Os). Osmium forms compounds with oxidation states ranging from −2 to +8. The most common oxidation states are +2, +3, +4, and +8. The +8 oxidation state is notable for being the highest attained by any chemical element aside from iridium's +9 and is encountered only in xenon, ruthenium, hassium, iridium, and plutonium. The oxidation states −1 and −2 represented by the two reactive compounds Na
2[Os
4(CO)
13] and Na
2[Os(CO)
4] are used in the synthesis of osmium cluster compounds.
Niobium pentoxide is the inorganic compound with the formula Nb2O5. A colorless, insoluble, and fairly unreactive solid, it is the most widespread precursor for other compounds and materials containing niobium. It is predominantly used in alloying, with other specialized applications in capacitors, optical glasses, and the production of lithium niobate.
Osmium dioxide is an inorganic compound with the formula OsO2. It exists as brown to black crystalline powder, but single crystals are golden and exhibit metallic conductivity. The compound crystallizes in the rutile structural motif, i.e. the connectivity is very similar to that in the mineral rutile.
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The Nickel oxyacid salts are a class of chemical compounds of nickel with an oxyacid. The compounds include a number of minerals and industrially important nickel compounds.
A selenate selenite is a chemical compound or salt that contains selenite and selenate anions (SeO32- and SeO42-). These are mixed anion compounds. Some have third anions.
A transition metal nitrate complex is a coordination compound containing one or more nitrate ligands. Such complexes are common starting reagents for the preparation of other compounds.
Alexander Frank Wells, or A. F. Wells, was a British chemist and crystallographer. He is known for his work on structural inorganic chemistry, which includes the description and classification of structural motifs, such as the polyhedral coordination environments, in crystals obtained from X-ray crystallography. His work is summarized in a classic reference book, Structural inorganic chemistry, first appeared in 1945 and has since gone through five editions. In addition, his work on crystal structures in terms of nets have been important and inspirational for the field of metal-organic frameworks and related materials.
Nickel(II) perchlorate is a collection of inorganic compounds with the chemical formula of Ni(ClO4)2(H2O)x. Its colors of these solids vary with the degree of hydration. For example, the hydrate forms cyan crystals, the pentahydrate forms green crystals, but the hexahydrate (Ni(ClO4)2·6H2O) forms blue crystals. Nickel(II) perchlorate hexahydrate is highly soluble in water and soluble in some polar organic solvents.
Corundum is the name for a structure prototype in inorganic solids, derived from the namesake polymorph of aluminum oxide (α-Al2O3). Other compounds, especially among the inorganic solids, exist in corundum structure, either in ambient or other conditions. Corundum structures are associated with metal-insulator transition, ferroelectricity, polar magnetism, and magnetoelectric effects.
Charles Thompson Prewitt was an American mineralogist and solid state chemist known for his work on structural chemistry of minerals and high-pressure chemistry.
References
- ↑ Van Noorden, Richard; Maher, Brendan; Nuzzo, Regina (2014). "The top 100 papers". Nature. 514 (7524): 550–553. Bibcode:2014Natur.514..550V. doi: 10.1038/514550a . PMID 25355343. S2CID 4466906.
- ↑ Shannon RD, Calvo C (1973) Refinement of Crystal-Structure of Low-Temperature Li3VO4 and Analysis of Mean Bond Lengths in Phosphates, Arsenates, and Vanadates. Journal of Solid state Chemistry 6, 538–549.
- ↑ Brown ID, Shannon RD (1973) Empirical Bond Strength – Bond-Length Curves for Oxides. Acta Crystallographica Section A, 29. 266–282.
- ↑ Gondrand M, Collomb A, Joubert JC, Shannon RD (1974) Synthesis of new high-pressure columbite phases containing petntavalent vanadium. Journal of Solid State Chemistry 11, 1–9.
- ↑ Medenbach O, Shannon RD (1997) Refractive indices and optical dispersion of 103 synthetic and mineral oxides and silicates measured by a small-prism technique. Journal of the Optical Society of America B – Optical Physics 14, 3299–3318.
- ↑ "Robert D. Shannon". ResearchGate .
- ↑ "Fellows". Mineralogical Society of America.
- ↑ "Robert SHANNON | Research Associate | University of Colorado Boulder, CO | CUB | Cooperative Institute for Research in Environmental Sciences (CIRES)".
- 1 2 van Noorden R, Maher B, Nuzzo R (2014) The top 100 Papers – the most-cited research of all time. Nature 514, 550–553.
- ↑ Shannon RD (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica, Section A: Crystal Physics, Diffraction, Theoretical and General Crystallography, A32, 751–67.
- ↑ "Robert D. Shannon Inventions, Patents and Patent Applications – Justia Patents Search".
- ↑ "Bobshannonite".
- ↑ Sokolova E, Cámara F, Abdu YA, Hawthorne FC, Horváth L, Pfenninger-Horváth E (2018) Bobshannonite, Na2KBa(Mn,Na)8(Nb,Ti)4(Si2O7)4O4(OH)4(O,F)2, a new TS-block mineral from Mont Saint-Hilaire, Québec, Canada: Description and crystal structure. Mineralogical Magazine 79, 1791–1811.