|
Germanium Dibromide
Germanium dibromide is a bromide of germanium with the chemical formula GeBr2. Preparation Germanium dibromide can be obtained by reducing germanium tetrabromide with germanium or zinc.Georg Brauer (Hrsg.), unter Mitarbeit von Marianne Baudler u. a.: ''Handbuch der Präparativen Anorganischen Chemie.'' 3., umgearbeitete Auflage. Band I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6, S. 724. : Properties Germanium dibromide is a yellow-white solid that is soluble in ethanol and acetone. It disproportionates into germanium tetrabromide and germanium. It hydrolyzes to germanium dihydroxide. Germanium dibromide is monoclinic, space group P21/c (No. 14), lattice parameters a = 11.68 Å, b = 9.12 Å, c = 7.02 Å, and β = 101.9°. It can react with cyclopentadienylsodium or cyclopentadienylthallium in ether In organic chemistry, ethers are a class of compounds that contain an ether group, a single oxygen atom bonded to two separate carbon atoms, each part of an o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germanium Difluoride
Germanium difluoride (GeF2) is a chemical compound of germanium and fluorine. It is a white solid with a melting point of 110 °C, and can be produced by reacting germanium tetrafluoride with germanium powder at 150–300 °C. Structure Germanium difluoride forms orthorhombic crystals with a space group P212121 (No. 19), Pearson symbol oP12, and lattice constants a = 0.4682 nm, b = 0.5178 nm, c = 0.8312 nm, Z = 4 (four structure units per unit cell). Its crystal structure is characterized by strong polymeric chains composed by GeF3 pyramids. One of the fluorine atom in the pyramid is shared by two neighboring chains, providing a weak link between them. Another, less common crystal form of GeF2 has tetragonal symmetry with a space group P41212 (No. 92), Pearson symbol tP12, and lattice constants a = 0.487 nm, b = 0.6963 nm, c = 0.858 nm. References {{Fluorides Fluorides Metal halides Germanium(II) compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetone
Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a characteristic pungent odor. Acetone is miscibility, miscible with properties of water, water and serves as an important organic solvent in industry, home, and laboratory. About 6.7 million tonnes were produced worldwide in 2010, mainly for use as a solvent and for production of methyl methacrylate and bisphenol A, which are precursors to widely used plastics.Acetone World Petrochemicals report, January 2010Stylianos Sifniades, Alan B. Levy, "Acetone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. It is a common building block in organic chemistry. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ether
In organic chemistry, ethers are a class of compounds that contain an ether group, a single oxygen atom bonded to two separate carbon atoms, each part of an organyl group (e.g., alkyl or aryl). They have the general formula , where R and R′ represent the organyl groups. Ethers can again be classified into two varieties: if the organyl groups are the same on both sides of the oxygen atom, then it is a simple or symmetrical ether, whereas if they are different, the ethers are called mixed or unsymmetrical ethers. A typical example of the first group is the solvent and anaesthetic diethyl ether, commonly referred to simply as "ether" (). Ethers are common in organic chemistry and even more prevalent in biochemistry, as they are common linkages in carbohydrates and lignin. Structure and bonding Ethers feature bent linkages. In dimethyl ether, the bond angle is 111° and C–O distances are 141 pm. The barrier to rotation about the C–O bonds is low. The bonding of ox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopentadienylthallium
Cyclopentadienylthallium, also known as thallium cyclopentadienide, is an organothallium compound with formula C5H5Tl. This light yellow solid is insoluble in most organic solvents, but sublimes readily. It is used as a precursor to transition metal and main group cyclopentadienyl complexes, as well as organic cyclopentadiene derivatives. Preparation and structure Cyclopentadienylthallium is prepared by the reaction of thallium(I) sulfate, sodium hydroxide, and cyclopentadiene: : Tl2SO4 + 2 NaOH → 2 TlOH + Na2SO4 : TlOH + C5H6 → TlC5H5 + H2O The compound adopts a polymer A polymer () is a chemical substance, substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeat unit, repeating subunits derived from one or more species of monomers. Due to their br ...ic structure, consisting of infinite chains of bent metallocenes. The Tl---Tl---Tl angles are 130°.Falk Olbrich, Ulrich Behrens "Crystal structure of caten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopentadienylsodium
Sodium cyclopentadienide is an organosodium compound with the formula C5H5Na. The compound is often abbreviated as NaCp, where Cp− is the cyclopentadienide anion. Sodium cyclopentadienide is a colorless solid, although samples often are pink owing to traces of oxidized impurities. Preparation The first salt of cyclopentadienide to be reported was potassium cyclopentadienide, prepared by Johannes Thiele. In 1901 there was not much interest in the topic. Sodium cyclopentadienyl is prepared by treating cyclopentadiene with sodium: : The conversion can be conducted by heating a suspension of molten sodium in dicyclopentadiene.Tarun K. Panda, Michael T. Gamer, Peter W. Roesky "An Improved Synthesis of Sodium and Potassium Cyclopentadienide" Organometallics, 2003, 22, 877–878. In former times, the sodium was provided in the form of "sodium wire" or "sodium sand", a fine dispersion of sodium prepared by melting sodium in refluxing xylene and rapidly stirring. Sodium hydride is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lattice Parameter
A lattice constant or lattice parameter is one of the physical dimensions and angles that determine the geometry of the unit cells in a crystal lattice, and is proportional to the distance between atoms in the crystal. A simple cubic crystal has only one lattice constant, the distance between atoms, but, in general, lattices in three dimensions have six lattice constants: the lengths ''a'', ''b'', and ''c'' of the three cell edges meeting at a vertex, and the angles ''α'', ''β'', and ''γ'' between those edges. The crystal lattice parameters ''a'', ''b'', and ''c'' have the dimension of length. The three numbers represent the size of the unit cell, that is, the distance from a given atom to an identical atom in the same position and orientation in a neighboring cell (except for very simple crystal structures, this will not necessarily be distance to the nearest neighbor). Their SI unit is the meter, and they are traditionally specified in angstroms (Å); an angstrom being 0.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Group
In mathematics, physics and chemistry, a space group is the symmetry group of a repeating pattern in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of the pattern that leave it unchanged. In three dimensions, space groups are classified into 219 distinct types, or 230 types if chiral copies are considered distinct. Space groups are discrete cocompact groups of isometries of an oriented Euclidean space in any number of dimensions. In dimensions other than 3, they are sometimes called Bieberbach groups. In crystallography, space groups are also called the crystallographic or Fedorov groups, and represent a description of the symmetry of the crystal. A definitive source regarding 3-dimensional space groups is the ''International Tables for Crystallography'' . History Space groups in 2 dimensions are the 17 wallpaper groups which have been known for several centuries, though the proof that the list ... [...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 Vector (geometric), vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic system. They form a parallelogram prism (geometry), 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. The length a of the primitive cell below equals \frac \sqrt of the conventional cell above. Crystal class ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germanium Dihydroxide
Germanium(II) hydroxide, normally written as Ge(OH)2, is a poorly characterised compound, sometimes called hydrous germanium(II) oxide or germanous hydroxide. It was first reported by Winkler in 1886. Properties and preparation Germanium(II) hydroxide is formed as a white or yellow precipitate when base is added to solutions containing GeII, produced for example by the reduction of an acid solution of germanium dioxide, GeO2, with hypophosphorous acid, H3PO2, or alternatively by hydrolysis of GeCl2. The initial precipitate, which has no definite stoichiometry, can be represented by GeO·''x''H2O, Ge(OH)2·''x''H2O, or loosely Ge(OH)2. It is only slightly soluble in water or alkali and not appreciably soluble in perchloric acid, HClO4, but is soluble in hydrochloric acid, HCl. On digestion with sodium hydroxide, NaOH, it yields a brown insoluble compound, which after drying ''in vacuo'' forms a brown pyrophoric substance with the approximate stoichiometry of (HGe)2O3. On the basis of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethanol
Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the pseudoelement symbol for ethyl group, ethyl. Ethanol is a Volatility (chemistry), volatile, flammable, colorless liquid with a characteristic wine-like odor and pungent taste. As a psychoactive depressant, it is the active ingredient in alcoholic beverages, and the second most consumed drug globally behind caffeine. Ethanol is naturally produced by the fermentation process of sugars by yeasts or via petrochemical processes such as ethylene hydration. Historically it was used as a general anesthetic, and has modern medical applications as an antiseptic, disinfectant, solvent for some medications, and antidote for methanol poisoning and ethylene glycol poisoning. It is used as a chemical solvent and in the Chemical synthesis, synthesis of orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germanium Dichloride
Germanium dichloride is a chemical compound of germanium and chlorine with the formula . It is a yellow solid. Germanium dichloride is an example of a compound featuring germanium in the +2 oxidation state. Preparation Solid germanium dichloride can be produced by comproportionation by passing germanium tetrachloride, , over germanium metal at 300 °C and reduced pressure (0.1 mmHg). : Germanium dichloride is also formed from the decomposition of trichlorogermane, , at 70 °C. Trichlorogermane is generated when germanium reacts with hydrogen chloride. This reaction involves dehydrohalogenation. : Another route to germanium dichloride is the reduction of germanium tetrachloride with hydrogen at 800 °C. : Reactions is hydrolysed to give yellow germanium(II) hydroxide, which on warming gives brown germanium monoxide: : : Alkalizing a solution containing germanium(II) ions: : Germanium oxides and hydroxides are amphoteric. Solutions of in HCl are strongly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
