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Gold Halide
Gold halides are compounds of gold with the halogens. Monohalides AuCl, AuBr, and AuI are all crystalline solids with a structure containing alternating linear chains: ..-X-Au-X-Au-X-Au-X-... The X-Au-X angle is less than 180°. The monomeric AuF molecule has been detected in the gas phase. Trihalides Gold triiodide does not exist or is unstable. Gold(III) fluoride, AuF3, has a unique polymeric helical structure, containing corner-sharing {AuF4} squares. Pentahalides Gold(V) fluoride, AuF5, is the only known example of gold in the +5 oxidation state In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. .... It most commonly occurs as the dimer Au2F10. References Metal halides Gold–halogen compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental (native state), as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium ( gold tellurides). Gold is resistant to most acids, though it does dissolve in aqua regia (a mixture of nitric acid and hydrochloric acid), forming a soluble tetrachloroau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halogen
The halogens () are a group in the periodic table consisting of five or six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Ts). In the modern IUPAC nomenclature, this group is known as group 17. The word "halogen" means "salt former" (or "salt maker"). When halogens react with metals, they produce a wide range of salts, including calcium fluoride, sodium chloride (common table salt), silver bromide and potassium iodide. The group of halogens is the only periodic table group that contains elements in three of the main states of matter at standard temperature and pressure. All of the halogens form acids when bonded to hydrogen. Most halogens are typically produced from minerals or salts. The middle halogens—chlorine, bromine, and iodine—are often used as disinfectants. Organobromides are the most important class of flame retardants, while elemental halogens are dangerous and can be toxic. Hist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold(I) Chloride
Gold(I) chloride is a compound of gold and chlorine with the chemical formula AuCl. Preparation Gold(I) chloride is prepared by thermal decomposition of gold(III) chloride. Reactions Although there is a region of stability at higher temperatures at the appropriate chlorine vapor pressures, the compound is metastable at ambient conditions. When heated with water, the compound disporpotionates to metallic gold and gold(III) chloride in an autoredox reaction: : 3 AuCl → 2 Au + AuCl3 At still higher temperatures, around 500 °C, all gold chlorides convert to gold. This conversion is key to the Miller process, which is widely used for the purification of gold. Reaction with potassium bromide yields potassium auric bromide and potassium chloride Potassium chloride (KCl, or potassium salt) is a metal halide salt composed of potassium and chlorine. It is odorless and has a white or colorless vitreous crystal appearance. The solid dissolves readily in water, and its solutio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold(I) Bromide
Gold(I) bromide can be formed by synthesis from the elements or partial decomposition of gold(III) bromide by careful control of temperatures and pressures. Structure It occurs in two modifications. One (I-AuBr) is isostructural with gold(I) chloride and has a body centered tetragonal unit cell with a = 6.734 Å, c = 8.674 Å, and space group I41/amd. The other (P-AuBr) is isostructural with gold(I) iodide and has a primitive tetragonal cell a = 4.296 Å, c = 12.146 Å, and space group P42/ncm. Single crystals of both modifications have been grown by chemical vapor transport. Small amounts of aluminum, gallium, or iron were used as catalysts for the transport process to obtain the I-AuBr modification. The two structures both consist of -Br-Au-Br-Au-Br- polymeric A polymer (; Greek ''poly-'', "many" + '' -mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold(I) Iodide
Gold monoiodide is the inorganic compound of gold and iodine with the formula AuI. It can be synthesized by dissolving gold powder in an aqueous solution of iodine and potassium iodide Potassium iodide is a chemical compound, medication, and dietary supplement. It is a medication used for treating hyperthyroidism, in radiation emergencies, and for protecting the thyroid gland when certain types of radiopharmaceuticals are us .... With Lewis bases, AuI reacts to give numerous complexes. References {{inorganic-compound-stub Gold(I) compounds Iodides Metal halides Gold–halogen compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angewandte Chemie International Edition In English
''Angewandte Chemie'' (, meaning "Applied Chemistry") is a weekly peer-reviewed scientific journal that is published by Wiley-VCH on behalf of the German Chemical Society (Gesellschaft Deutscher Chemiker). Publishing formats include feature-length reviews, short highlights, research communications, minireviews, essays, book reviews, meeting reviews, correspondences, corrections, and obituaries. This journal contains review articles covering all aspects of chemistry. According to the ''Journal Citation Reports'', the journal had a 2021 impact factor of 16.823. Editions The journal appears in two editions with separate volume and page numbering: a German edition, ''Angewandte Chemie'' ( (print), (online)), and a fully English-language edition, ''Angewandte Chemie International Edition'' ( (print), (online)). The editions are identical in content with the exception of occasional reviews of German-language books or German translations of IUPAC recommendations. Business model '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold Triiodide
Gold iodide is the 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 ele ... with the formula . Although is predicted to be stable, gold(III) iodide remains an example of a nonexistent or unstable compound.; also secover picturedescription Attempts to isolate pure samples result in the formation of gold(I) iodide and iodine: : References Gold(III) compounds Iodides Metal halides Gold–halogen compounds Hypothetical chemical compounds {{Hyp-chem-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold(III) Fluoride
Gold(III) fluoride, , is an orange solid that sublimes at 300 °C. It is a powerful fluorinating agent. Preparation AuF3 can be prepared by reacting AuCl3 with F2 or BrF3. Structure The crystal structure In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric patterns t ... of AuF3 consists of spirals of square-planar AuF4 units. References External links * Fluorides Metal halides Gold(III) compounds Fluorinating agents Gold–halogen compounds {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold(V) Fluoride
Gold(V) fluoride is the inorganic compound with the formula Au2F10. This fluoride compound features gold in its highest known oxidation state. This red solid dissolves in hydrogen fluoride but these solutions decompose, liberating fluorine. The structure of gold(V) fluoride in the solid state is centrosymmetric with hexacoordinated gold and an octahedral arrangement of the fluoride centers on each gold center. It is the only known dimeric pentafluoride, although sulfur can form disulfur decafluoride; other pentafluorides are monomeric ( P, As, Sb, Cl, Br, I), tetrameric ( Nb, Ta, Cr, Mo, W, Tc, Re, Ru, Os, Rh, Ir, Pt), or polymeric ( Bi, V, U). In the gas phase, a mixture of dimer and trimer in the ratio 82:18 has been observed. Gold pentafluoride is the strongest known fluoride ion acceptor, exceeding the acceptor tendency of even antimony pentafluoride. Synthesis Gold(V) fluoride can be synthesized by heating gold metal in an atmosphere of oxygen and fluori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidation State
In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. Conceptually, the oxidation state may be positive, negative or zero. While fully ionic bonds are not found in nature, many bonds exhibit strong ionicity, making oxidation state a useful predictor of charge. The oxidation state of an atom does not represent the "real" formal charge on that atom, or any other actual atomic property. This is particularly true of high oxidation states, where the ionization energy required to produce a multiply positive ion is far greater than the energies available in chemical reactions. Additionally, the oxidation states of atoms in a given compound may vary depending on the choice of electronegativity scale used in their calculation. Thus, the oxidation state of an atom in a compound is purely a formalis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal Halides
Metal halides are compounds between metals and halogens. Some, such as sodium chloride are ionic, while others are covalently bonded. A few metal halides are discrete molecules, such as uranium hexafluoride, but most adopt polymeric structures, such as palladium chloride. File:NaCl polyhedra.png, Sodium chloride crystal structure File:Uranium-hexafluoride-unit-cell-3D-balls.png, Discrete UF6 molecules File:Alpha-palladium(II)-chloride-xtal-3D-balls.png, Infinite chains of one form of palladium chloride Preparation The halogens can all react with metals to form metal halides according to the following equation: :2M + nX2 → 2MXn where M is the metal, X is the halogen, and MXn is the metal halide. In practice, this type of reaction may be very exothermic, hence impractical as a preparative technique. Additionally, many transition metals can adopt multiple oxidation states, which complicates matters. As the halogens are strong oxidizers, direct combination of the elements u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
