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Zirconium(IV) Iodide
Zirconium(IV) iodide is the chemical compound with the formula Zr I4. It is the most readily available iodide of zirconium. It is an orange-coloured solid that degrades in the presence of water. The compound was once prominent as an intermediate in the purification of zirconium metal. Structure Like most binary metal halides, zirconium(IV) iodide adopts a polymeric structure. As characterized by X-ray crystallography, the compound consists of octahedral Zr(IV) centers interconnected by four doubly bridging iodide ligands. The Zr-I distances of 2.692 (terminal) and 3.030 Å Synthesis and reactions This compound is volatile, subliming as intact tetrahedral ZrI4 molecules. It is prepared by the direct reaction of powdered zirconium metal and iodine.. Pyrolysis of zirconium(IV) iodide gas by contact of hot wire was the first industrial process for the commercial production of pure ductile metallic zirconium. This crystal bar process was developed by Anton Eduard van Arkel and Ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoclinic
In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic system. They form a parallelogram prism. Hence two pairs of vectors are perpendicular (meet at right angles), while the third pair makes an angle other than 90°. Bravais lattices Two monoclinic Bravais lattices exist: the primitive monoclinic and the base-centered monoclinic. For the base-centered monoclinic lattice, the primitive cell has the shape of an oblique rhombic prism;See , row mC, column Primitive, where the cell parameters are given as a1 = a2, α = β it can be constructed because the two-dimensional centered rectangular base layer can also be described with primitive rhombic axes. Note that the length a of the primitive cell below equals \frac \sqrt of the conventional cell above. Crystal classes The table below org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Crystallography
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their crystallographic disorder, and various other information. Since many materials can form crystals—such as salts, metals, minerals, semiconductors, as well as various inorganic, organic, and biological molecules—X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences among various mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodides
An iodide ion is the ion I−. Compounds with iodine in formal oxidation state −1 are called iodides. In everyday life, iodide is most commonly encountered as a component of iodized salt, which many governments mandate. Worldwide, iodine deficiency affects two billion people and is the leading preventable cause of intellectual disability. Structure and characteristics of inorganic iodides Iodide is one of the largest monatomic anions. It is assigned a radius of around 206 picometers. For comparison, the lighter halides are considerably smaller: bromide (196 pm), chloride (181 pm), and fluoride (133 pm). In part because of its size, iodide forms relatively weak bonds with most elements. Most iodide salts are soluble in water, but often less so than the related chlorides and bromides. Iodide, being large, is less hydrophilic compared to the smaller anions. One consequence of this is that sodium iodide is highly soluble in acetone, whereas sodium chloride is not. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeitschrift Für Anorganische Und Allgemeine Chemie
The ''Zeitschrift für anorganische und allgemeine Chemie'' (''Journal of Inorganic and General Chemistry'') is a semimonthly peer-reviewed scientific journal covering inorganic chemistry, published by Wiley-VCH. The editors-in-chief are Thomas F. Fässler, Christian Limberg, Guodong Qian, and David Scheschkewitz. Originally the journal was published in German, but nowadays it is completely in English. Abstracting and indexing The journal is abstracted and indexed in the following databases: According to the ''Journal Citation Reports'', the journal has a 2021 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 1.414, ranking it 40th out of 46 journals in the category "Chemistry, Inorganic & Nuclear". References External links * Chemistry journals Wiley-VCH aca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jan Hendrik De Boer
Jan Hendrik de Boer (19 March 1899 – 25 April 1971) was a Dutch physicist and chemist. De Boer was born in Ruinen, De Wolden, and died in The Hague. He studied at the University of Groningen and was later employed in industry. Together with Anton Eduard van Arkel, de Boer developed a chemical transport reaction for titanium, zirconium, and hafnium known as the crystal bar process. In a closed vessel the metal reacts with iodine at elevated temperature forming the iodide. At a tungsten filament of 1700 °C the reverse reaction occurs, and the iodine and the metal are set free. The metal forms a solid coating at the tungsten filament and the iodine can react with additional metal, resulting in a steady turnover. ::M + 2I2 (>400 °C) → MI4 ::MI4 (1700 °C) → M + 2I2 De Boer became a member of the Royal Netherlands Academy of Arts and Sciences in 1940, and foreign member in 1947. See also *Metal–insulator transition *Van Arkel–de Boer process The va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anton Eduard Van Arkel
Anton Eduard van Arkel, (19 November 1893 – 14 March 1976) was a Dutch chemist. Van Arkel suggested the names "pnictogen" and "pnictide" to refer to chemical elements in group 15 (the nitrogen group or nitrogen family) of the periodic table. Van Arkel, together with Jan Hendrik de Boer, developed a method for the preparation of very pure tungsten: the dissociation of the vapor of tungsten chloride on an incandescent core wire known as the Van Arkel–de Boer process. This method was later used by himself and others for many other metals and non-metals. Van Arkel and de Boer thus provided the first method to fabricate pure titanium. Van Arkel became member of the Royal Netherlands Academy of Arts and Sciences in 1962. See also *Crystal bar process *Hafnium *Jan Hendrik de Boer *Titanium *Van Arkel–Ketelaar triangle Bond triangles or Van Arkel–Ketelaar triangles (named after Anton Eduard van Arkel and J. A. A. Ketelaar) are triangles used for showing different compo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Bar Process
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations. The scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification. The word ''crystal'' derives from the Ancient Greek word (), meaning both "ice" and "rock crystal", from (), "icy cold, frost". Examples of large crystals include snowflakes, diamonds, and table salt. Most inorganic solids are not crystals but polycrystals, i.e. many microscopic crystals fused together into a single solid. Polycrystals include most metals, rocks, ceramics, and ice. A third category of sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrolysis
The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements ''pyro'' "fire", "heat", "fever" and '' lysis'' "separating". Pyrolysis is most commonly used in the treatment of organic materials. It is one of the processes involved in charring wood.''Burning of wood'' , InnoFireWood's website. Accessed on 2010-02-06. In general, pyrolysis of organic substances produces volatile products and leaves , a carbon-rich solid residue. Extreme pyrolysis, which leaves mostly |
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a violet gas at . The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek 'violet-coloured'. Iodine occurs in many oxidation states, including iodide (I−), iodate (), and the various periodate anions. It is the least abundant of the stable halogens, being the sixty-first most abundant element. As the heaviest essential mineral nutrient, iodine is required for the synthesis of thyroid hormones. Iodine deficiency affects about two billion people and is the leading preventable cause of intellectual disabilities. The dominant producers of iodine today are Chile and Japan. Due to its high atomic number and ease of attachment to organic compound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pearson Symbol
The Pearson symbol, or Pearson notation, is used in crystallography as a means of describing a crystal structure, and was originated by W. B. Pearson. The symbol is made up of two letters followed by a number. For example: * Diamond structure, ''cF''8 * Rutile structure, ''tP''6 The two (italicised) letters specify the Bravais lattice. The lower-case letter specifies the crystal family, and the upper-case letter the centering type. The number at the end of the Pearson symbol gives the number of the atoms in the conventional unit cell.Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005 IR-3.4.4, pp. 49–51; IR-11.5, pp. 241–242. |
Zirconium
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name ''zirconium'' is taken from the name of the mineral zircon, the most important source of zirconium. The word is related to Persian '' zargun'' (zircon; ''zar-gun'', "gold-like" or "as gold"). It is a lustrous, grey-white, strong transition metal that closely resembles hafnium and, to a lesser extent, titanium. Zirconium is mainly used as a refractory and opacifier, although small amounts are used as an alloying agent for its strong resistance to corrosion. Zirconium forms a variety of inorganic and organometallic compounds such as zirconium dioxide and zirconocene dichloride, respectively. Five isotopes occur naturally, four of which are stable. Zirconium compounds have no known biological role. Characteristics Zirconium is a lustrous, greyish-white, soft, ductile, malleable metal that is solid at room temperature, though it is hard and brittle at lesser purities. In powder form, zirconium is highl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken and/or new bonds formed. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, using the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
