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Chromium(III) Acetate
Chromium(III) acetate, commonly known as basic chromium acetate, describes a family of salts where the cation has the formula r3O(O2CCH3)6(OH2)3sup>+. The trichromium cation is encountered with a variety of anions, such as chloride and nitrate. Data in the table above are for the chloride hexahydrate, r3O(O2CCH3)6(OH2)3l(H2O)6. Salts of basic chromium acetate has long attracted interest because of its distinctive structure, which features octahedral Cr(III) centers, a triply bridging oxo ligand, six acetate ligands, and three aquo ligands. The same structure is shared with basic iron acetate and basic manganese acetate. Little evidence exists for a simple chromium(III) acetate, i.e. lacking the oxo ligand A transition metal oxo complex is a coordination complex containing an oxo ligand. Formally O2-, an oxo ligand can be bound to one or more metal centers, i.e. it can exist as a terminal or (most commonly) as bridging ligands (Fig. 1). Oxo ligan .... Chromium(III) aceta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manganese(III) Acetate
Manganese(III) acetate describes a family of materials with the approximate formula Mn(O2CCH3)3. These materials are brown solids that are soluble in acetic acid and water. They are used in organic synthesis as oxidizing agents. Structure Although manganese(III) triacetate has not been reported, salts of basic manganese(III) acetate are well characterized. Basic manganese acetate adopts the structure reminiscent of those of basic chromium acetate and basic iron acetate. The formula is n3O(O2CCH3)6Ln where L is a ligand and X is an anion. The salt n3O(O2CCH3)62CCH3.HO2CCH3 has been confirmed by X-ray crystallography. Preparation It is usually used as the dihydrate, although the anhydrous form is also used in some situations. The dihydrate is prepared by combining potassium permanganate and manganese(II) acetate in acetic acid. Addition of acetic anhydride to the reaction produces the anhydrous form. It is also synthesized by electrochemical method starting from Mn(OAc)2. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron(III) Acetate
Ferric acetate is the acetate salt of the coordination complex [Fe3O(OAc)6(H2O)3]+ (OAc− is CH3CO2−). Commonly the salt is known as "basic iron acetate". The formation of the red-brown complex was once used as a test for ferric ions. Structure and synthesis Basic iron acetate forms on treating aqueous solutions of iron(III) sources with acetate salts. A typical precursor is freshly precipitated iron oxide/hydroxide, which is halide-free. Early work showed that the cation is trinuclear. The Fe centres are equivalent, each being octahedral molecular geometry, octahedral, being bound to six oxygen ligands, including a triply bridging oxide at the center of the equilateral triangle. The compound was an early example of a molecular complex of iron that features an oxide ligand. The cation has idealized D3h symmetry group, symmetry. Reactions The terminal aqua ligands on the trimetallic framework can be substituted with other ligands, such as pyridine and dimethylformamide. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt (chemistry)
In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively charged sodium ions and negatively charged chloride ions. The component ions in a salt compound can be either inorganic, such as chloride (Cl−), or organic, such as acetate (). Each ion can be either monatomic, such as fluoride (F−), or polyatomic, such as sulfate (). Types of salt Salts can be classified in a variety of ways. Salts that produce hydroxide ions when dissolved in water are called '' alkali salts'' and salts that produce hydrogen ions when dissolved in water are called '' acid salts''. ''Neutral salts'' are those salts that are neither acidic nor basic. Zwitterions contain an anionic and a cationic centre in the same molecule, but are not considered salts. Examples of zwitterions are amino acids, many metabol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxo Ligand
A transition metal oxo complex is a coordination complex containing an oxo ligand. Formally O2-, an oxo ligand can be bound to one or more metal centers, i.e. it can exist as a terminal or (most commonly) as bridging ligands (Fig. 1). Oxo ligands stabilize high oxidation states of a metal.Nugent, W. A., Mayer, J. M. "Metal-Ligand Multiple Bonds." John Wiley & Sons, New York, 1988. They are also found in several metalloproteins, for example in molybdenum cofactors and in many iron-containing enzymes. One of the earliest synthetic compounds to incorporate an oxo ligand is potassium ferrate (K2FeO4), which was likely prepared by Georg E. Stahl in 1702. Reactivity Olation and acid-base reactions A common reaction exhibited by metal-oxo compounds is olation, the condensation process that converts low molecular weight oxides to polymers with M-O-M linkages. Olation often begins with the deprotonation of a metal-hydroxo complex. It is the basis for mineralization and the precipit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetate
An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called an anion) typically found in aqueous solution and written with the chemical formula . The neutral molecules formed by the combination of the acetate ion and a ''positive'' ion (called a cation) are also commonly called "acetates" (hence, ''acetate of lead'', ''acetate of aluminum'', etc.). The simplest of these is hydrogen acetate (called acetic acid) with corresponding salts, esters, and the polyatomic anion , or . Most of the approximately 5 billion kilograms of acetic acid produced annually in industry are used in the production of acetates, which usually take the form of polymers. In nature, acetate is the most common building block for biosynthesis. Nomenclature and common formula When part of a salt, the formula of the acetate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquo Ligand
In chemistry, metal aquo complexes are coordination compounds containing metal ions with only water as a ligand. These complexes are the predominant species in aqueous solutions of many metal salts, such as metal nitrates, sulfates, and perchlorates. They have the general stoichiometry . Their behavior underpins many aspects of environmental, biological, and industrial chemistry. This article focuses on complexes where water is the only ligand ("homoleptic aquo complexes"), but of course many complexes are known to consist of a mix of aquo and other ligands. Stoichiometry and structure Hexa-aquo complexes Most aquo complexes are mono-nuclear, with the general formula , with or 3; they have an octahedral structure. The water molecules function as Lewis bases, donating a pair of electrons to the metal ion and forming a dative covalent bond with it. Typical examples are listed in the following table. : Tutton's salts are crystalline compounds with the generic formula (w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromium Acetate Hydroxide
Chromium acetate hydroxide is the coordination complex with the formula r2(OH)3(OAc)3sub>4. A dark violet solid, it crystallizes as the triacontatetrahydrate (34 molecules of water of crystallization). It is water soluble. Structure The complex is a tetramer of binuclear Cr2(OH)3(OAc)3. The subunits are linked by acetate and hydroxide ligands. The oxidation state of chromium is III, which explains the stability of the complex since octahedral d3 ions give kinetically robust complexes. Overall, the complex's structure is unusual compared to other transition metal carboxylate complexes. See also * Chromium(II) acetate * Chromium(III) acetate Chromium(III) acetate, commonly known as basic chromium acetate, describes a family of salts where the cation has the formula r3O(O2CCH3)6(OH2)3sup>+. The trichromium cation is encountered with a variety of anions, such as chloride and nitrate. ... References External links *http://www.chemicalbook.com/ChemicalProductProperty_EN_CB97 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromium(II) Acetate
Chromium(II) acetate hydrate, also known as chromous acetate, is the coordination compound with the formula Cr2(CH3CO2)4(H2O)2. This formula is commonly abbreviated Cr2(OAc)4(H2O)2. This red-coloured compound features a quadruple bond. The preparation of chromous acetate once was a standard test of the synthetic skills of students due to its sensitivity to air and the dramatic colour changes that accompany its oxidation. It exists as the dihydrate and the anhydrous forms. Cr2(OAc)4(H2O)2 is a reddish diamagnetic powder, although diamond-shaped tabular crystals can be grown. Consistent with the fact that it is non ionic, Cr2(OAc)4(H2O)2 exhibits poor solubility in water and methanol. Structure The Cr2(OAc)4(H2O)2 molecule contains two atoms of chromium, two ligated molecules of water, and four acetate bridging ligands. The coordination environment around each chromium atom consists of four oxygen atoms (one from each acetate ligand) in a square, one water molecule (in an axial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromium(III) Compounds
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hardness. A major development in steel production was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel. Stainless steel and chrome plating (electroplating with chromium) together comprise 85% of the commercial use. Chromium is also greatly valued as a metal that is able to be highly polished while resisting tarnishing. Polished chromium reflects almost 70% of the visible spectrum, and almost 90% of infrared, infrared light. The name of the element is derived from the Ancient Greek, Greek word χρῶμα, ''chrōma'', meaning color, because many chromium compounds are intensely colored. Industrial production of chromium proceeds from chromite ore (mostly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetates
An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called an anion) typically found in aqueous solution and written with the chemical formula . The neutral molecules formed by the combination of the acetate ion and a ''positive'' ion (called a cation) are also commonly called "acetates" (hence, ''acetate of lead'', ''acetate of aluminum'', etc.). The simplest of these is hydrogen acetate (called acetic acid) with corresponding salts, esters, and the polyatomic anion , or . Most of the approximately 5 billion kilograms of acetic acid produced annually in industry are used in the production of acetates, which usually take the form of polymers. In nature, acetate is the most common building block for biosynthesis. Nomenclature and common formula When part of a salt, the formula of the acetate ion is w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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