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Tin(IV) Bromide
Tin(IV) bromide is the chemical compound SnBr4. It is a colourless low melting solid. SnBr4 can be prepared by reaction of the elements at normal temperatures: :Sn + 2Br2 → SnBr4 In aqueous solution Sn(H2O)64+ is the principal ionic species amongst a range of 6 coordinate ions with from 0-6 bromide ligands (e.g. Sn(H2O)64+, SnBr(H2O)53+); in basic solution the Sn(OH)62− ion is present. SnBr4 forms 1:1 and 1:2 complexes with ligands, e.g. with trimethylphosphine Trimethylphosphine is a neutral organophosphorus compound with the formula P(CH3)3, commonly abbreviated as PMe3. This colorless liquid has a strongly unpleasant odor, characteristic of alkylphosphines. The compound is a common ligand in coordin ... the following can be produced, SnBr4.P(CH3)3 and SnBr4.2P(CH3)3. SnBr4 crystallises in a monoclinic form with molecular SnBr4 units that have distorted tetrahedral geometry, with mean Sn-Br bond lengths of 242.3 pm. References {{DEFAULTSORT:Tin(Iv) Bromide Bro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tin(IV) Fluoride
Tin(IV) fluoride is a chemical compound of tin and fluorine with the chemical formula SnF4 and is a white solid with a melting point above 700 °C. SnF4 can be prepared by the reaction of tin metal with fluorine gas: :Sn + 2F2 → SnF4 However, a passivating metal fluoride layer will be created and the surface will eventually become unreactive. An alternative synthesis is the reaction of SnCl4 with anhydrous hydrogen fluoride: :SnCl4 + 4HF → SnF4 + 4HCl With alkali metal fluorides (e.g. KF) hexafluorostannates are produced (e.g.K2SnF6), which contain the octahedral SnF62− anion. SnF4 behaves as a Lewis acid and adducts L2·SnF4 and L·SnF4 have been produced. Structure Unlike the other tin tetrahalides, tin(IV) chloride, tin(IV) bromide, and tin(IV) iodide, which contain tetrahedrally coordinated tin, tin(IV) fluoride contains planar layers of octahedrally coordinated tin, where the octahedra share four corners and there are two terminal, unshared, fluorine atoms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aqueous Solution
An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, or sodium chloride (NaCl), in water would be represented as . The word ''aqueous'' (which comes from ''aqua'') means pertaining to, related to, similar to, or dissolved in, water. As water is an excellent solvent and is also naturally abundant, it is a ubiquitous solvent in chemistry. Since water is frequently used as the solvent in experiments, the word solution refers to an aqueous solution, unless the solvent is specified. A ''non-aqueous solution'' is a solution in which the solvent is a liquid, but is not water. (See also Solvent and Inorganic nonaqueous solvent.) Characteristics Substances that are ''hydrophobic'' ('water-fearing') do not dissolve well in water, whereas those that are ''hydrophilic'' ('water-friendly') do. An example of a hydrophilic substance is sodium chlo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromides
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant materials, and cell stains. Although uncommon, chronic toxicity from bromide can result in bromism, a syndrome with multiple neurological symptoms. Bromide toxicity can also cause a type of skin eruption, see potassium bromide. The bromide ion has an ionic radius of 196 pm. Natural occurrence Bromide is present in typical seawater (35 PSU) with a concentration of around 65 mg/L, which is about 0.2% of all dissolved salts. Seafood and deep sea plants generally have higher levels than land-derived foods. Bromargyrite—natural, crystalline silver bromide—is the most common bromide mineral known but is still very rare. In addition to silver, bromine is also in minerals combined with mercury and copper. Formation and react ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeitschrift Für Kristallographie – Crystalline Materials
''Zeitschrift für Kristallographie – Crystalline Materials'' is a monthly peer-reviewed scientific journal published in English. The journal publishes theoretical and experimental studies in crystallography of both organic and inorganic substances. The editor-in-chief of the journal is from the University of Münster. The journal was founded in 1877 under the title ''Zeitschrift für Krystallographie und Mineralogie'' by crystallographer and mineralogist Paul Heinrich von Groth, who served as the editor for 44 years. It has used several titles over its history, with the present title having been adopted in 2010. The journal is indexed in a variety of databases and has a 2020 impact factor of 1.616. History The journal was established in 1877 by Paul von Groth as a German-language publication under the title ''Zeitschrift für Krystallographie und Mineralogie'', and he served as its editor until the end of 1920. Groth was appointed as the inaugural Professor of Mineralogy at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acta Crystallographica
''Acta Crystallographica'' is a series of peer-reviewed scientific journals, with articles centred on crystallography, published by the International Union of Crystallography (IUCr). Originally established in 1948 as a single journal called ''Acta Crystallographica'', there are now six independent ''Acta Crystallographica'' titles: *'' Acta Crystallographica Section A: Foundations and Advances'' *'' Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials'' *'' Acta Crystallographica Section C: Structural Chemistry'' *'' Acta Crystallographica Section D: Structural Biology'' *'' Acta Crystallographica Section E: Crystallographic Communications'' *'' Acta Crystallographica Section F: Structural Biology Communications'' ''Acta Crystallographica'' has been noted for the high quality of the papers that it produces, as well as the large impact that its papers have had on the field of crystallography. The current six journals form part of the journal portf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoclinic Crystal System
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 organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethylphosphine
Trimethylphosphine is a neutral organophosphorus compound with the formula P(CH3)3, commonly abbreviated as PMe3. This colorless liquid has a strongly unpleasant odor, characteristic of alkylphosphines. The compound is a common ligand in coordination chemistry. Structure and bonding It is a pyramidal molecule with approximate ''C''3''v'' symmetry. The C–P–C bond angles are approximately 98.6°. The C–P–C bond angles are consistent with the notion that phosphorus predominantly uses the 3p orbitals for forming bonds and that there is little sp hybridization of the phosphorus atom. The latter is a common feature of the chemistry of phosphorus. As a result, the lone pair of trimethylphosphine has predominantly s-character as is the case for phosphine, PH3. PMe3 can be prepared by the treatment of triphenyl phosphite with methylmagnesium chloride: : 3 CH3MgCl + P(OC6H5)3 → P(CH3)3 + 3 C6H5OMgCl The synthesis is conducted in dibutyl ether, from which the more volatile PMe3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligand
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electron pairs, often through Lewis bases. The nature of metal–ligand bonding can range from covalent to ionic. Furthermore, the metal–ligand bond order can range from one to three. Ligands are viewed as Lewis bases, although rare cases are known to involve Lewis acidic "ligands". Metals and metalloids are bound to ligands in almost all circumstances, although gaseous "naked" metal ions can be generated in a high vacuum. Ligands in a complex dictate the reactivity of the central atom, including ligand substitution rates, the reactivity of the ligands themselves, and redox. Ligand selection requires critical consideration in many practical areas, including bioinorganic and medicinal chemistry, homogeneous catalysis, and environmental chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Melting Point Metal
A fusible alloy is a metal alloy capable of being easily fused, i.e. easily meltable, at relatively low temperatures. Fusible alloys are commonly, but not necessarily, eutectic alloys. Sometimes the term "fusible alloy" is used to describe alloys with a melting point below . Fusible alloys in this sense are used for solder. Introduction From a practical view, low-melting alloys can be divided into the following categories: * Mercury-containing alloys *Only alkali metal-containing alloys *Gallium-containing alloys (but neither alkali metal nor mercury) *Only bismuth, lead, tin, cadmium, zinc, indium, and sometimes thallium-containing alloys *Other alloys (rarely used) Some reasonably well-known fusible alloys are Wood's metal, Field's metal, Rose metal, Galinstan, and NaK. Applications Melted fusible alloys can be used as coolants as they are stable under heating and can give much higher thermal conductivity than most other coolants; particularly with alloys made with a high th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tin(IV) Chloride
Tin(IV) chloride, also known as tin tetrachloride or stannic chloride, is an inorganic compound with the formula Sn Cl4. It is a colorless hygroscopic liquid, which fumes on contact with air. It is used as a precursor to other tin compounds. It was first discovered by Andreas Libavius (1550–1616) and was known as ''spiritus fumans libavii''. Preparation It is prepared from reaction of chlorine gas with tin at . : Sn + 2 Cl2 → SnCl4 Structure Anhydrous tin(IV) chloride solidifies at −33 °C to give monoclinic crystals with the P21/c space group. It is isostructural with SnBr4. The molecules adopt near-perfect tetrahedral symmetry with average Sn–Cl distances of 227.9(3) pm. Reactions Tin(IV) chloride is well known as a Lewis acid. Thus it forms hydrates. The pentahydrate SnCl4·5H2O was formerly known as butter of tin. They all consist of nCl4(H2O)2molecules together with varying amounts of water of crystallization. The additional water molecules link together ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transparency And Translucency
In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable scattering of light. On a macroscopic scale (one in which the dimensions are much larger than the wavelengths of the photons in question), the photons can be said to follow Snell's law. Translucency (also called translucence or translucidity) allows light to pass through, but does not necessarily (again, on the macroscopic scale) follow Snell's law; the photons can be scattered at either of the two interfaces, or internally, where there is a change in index of refraction. In other words, a translucent material is made up of components with different indices of refraction. A transparent material is made up of components with a uniform index of refraction. Transparent materials appear clear, with the overall appearance of one color, or any combination leading up to a brilliant spectrum of every color. The opposit ... [...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] |
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