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Hydrosulfide Ion
Bisulfide (or bisulphide in British English) is an inorganic anion with the chemical formula HS− (also written as SH−). It contributes no color to bisulfide salts, and its salts may have a distinctive putrid smell. It is a strong base. Bisulfide solutions are corrosive and attack the skin. It is an important chemical reagent and an industrial chemical, mainly used in paper pulp industry (Kraft process), textiles, synthetic flavors, coloring brasses, and iron control. Properties A variety of salts are known, including sodium hydrosulfide and potassium hydrosulfide. Ammonium hydrosulfide, a component of "stink bombs" has not been isolated as a pure solid. Some compounds described as salts of the sulfide dianion contain primarily hydrosulfide. For example, the hydrated form of sodium sulfide, nominally with the formula , is better described as . Aqueous bisulfide absorbs light at around 230 nm in the UV–visible spectrum. Using this approach, bisulfide has been det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Sulfide
Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The underground mine gas term for foul-smelling hydrogen sulfide-rich gas mixtures is ''stinkdamp''. Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777. The British English spelling of this compound is hydrogen sulphide, a spelling no longer recommended by the Royal Society of Chemistry or the International Union of Pure and Applied Chemistry. Hydrogen sulfide is toxic to humans and most other animals by inhibiting cellular respiration in a manner similar to hydrogen cyanide. When it is inhaled or it or its salts are ingested in high amounts, damage to organs occurs rapidly with symptoms ranging from breathing difficulties to convulsions and death. Despite this, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjugate Acid
A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a hydrogen ion. On the other hand, a conjugate base is what is left over after an acid has donated a proton during a chemical reaction. Hence, a conjugate base is a species formed by the removal of a proton from an acid, as in the reverse reaction it is able to gain a hydrogen ion. Because some acids are capable of releasing multiple protons, the conjugate base of an acid may itself be acidic. In summary, this can be represented as the following chemical reaction: :acid + base conjugate\ base + conjugate\ acid Johannes Nicolaus Brønsted and Martin Lowry introduced the Brønsted–Lowry theory, which proposed that any compound that can transfer a proton to any other compound is an acid, and the compound that accepts the proton is a b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur Ions
Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula S8. Elemental sulfur is a bright yellow, crystalline solid at room temperature. Sulfur is the tenth most abundant element by mass in the universe and the fifth most on Earth. Though sometimes found in pure, native form, sulfur on Earth usually occurs as sulfide and sulfate minerals. Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses in ancient India, ancient Greece, China, and ancient Egypt. Historically and in literature sulfur is also called brimstone, which means "burning stone". Today, almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas and petroleum.. Downloahere The greatest commercial use of the element is the production of su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anions
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiol
In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl group, or a sulfanyl group. Thiols are the sulfur analogue of alcohols (that is, sulfur takes the place of oxygen in the hydroxyl () group of an alcohol), and the word is a blend of "''thio-''" with "alcohol". Many thiols have strong odors resembling that of garlic or rotten eggs. Thiols are used as odorants to assist in the detection of natural gas (which in pure form is odorless), and the "smell of natural gas" is due to the smell of the thiol used as the odorant. Thiols are sometimes referred to as mercaptans () or mercapto compounds, a term introduced in 1832 by William Christopher Zeise and is derived from the Latin ('capturing mercury')''Oxford American Dictionaries'' (Mac OS X Leopard). because the thiolate group () bonds very strong ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfanyl
Sulfanyl (•), also known as the mercapto radical, hydrosulfide radical, or hydridosulfur, is a simple radical molecule consisting of one hydrogen and one sulfur atom. The radical appears in metabolism in organisms as H2S is detoxified. Sulfanyl is one of the top three sulfur-containing gasses in gas giants such as Jupiter and is very likely to be found in brown dwarfs and cool stars. It was originally discovered by Margaret N. Lewis and John U. White at the University of California in 1939. They observed molecular absorption bands around 325 nm belonging to the system designated by 2Σ+ ← 2Πi. They generated the radical by means of a radio frequency discharge in hydrogen sulfide. HS• is formed during the degradation of hydrogen sulfide in the atmosphere of the Earth. This may be a deliberate action to destroy odours or a natural phenomenon. The organic analogue of sulfanyl is thiyl radical with the formula RS., where R = alkyl or aryl. Natural occurrence Absorptio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disulfide
In biochemistry, a disulfide (or disulphide in British English) refers to a functional group with the structure . The linkage is also called an SS-bond or sometimes a disulfide bridge and is usually derived by the coupling of two thiol groups. In biology, disulfide bridges formed between thiol groups in two cysteine residues are an important component of the secondary and tertiary structure of proteins. ''Persulfide'' usually refers to compounds. In inorganic chemistry disulfide usually refers to the corresponding anion (−S−S−). Organic disulfides Symmetrical disulfides are compounds of the formula . Most disulfides encountered in organo sulfur chemistry are symmetrical disulfides. Unsymmetrical disulfides (also called heterodisulfides) are compounds of the formula . They are less common in organic chemistry, but most disulfides in nature are unsymmetrical. Properties The disulfide bonds are strong, with a typical bond dissociation energy of 60 kcal/mol (251&nbs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corrosive
A corrosive substance is one that will damage or destroy other substances with which it comes into contact by means of a chemical reaction. Etymology The word ''corrosive'' is derived from the Latin verb ''corrodere'', which means ''to gnaw'', indicating how these substances seem to "gnaw" their way through flesh or other materials. Chemical terms The word ''corrosive'' refers to any chemical that will dissolve the structure of an object. They can be acids, oxidizers, or bases. When they come in contact with a surface, the surface deteriorates. The deterioration can happen in minutes, e.g. concentrated hydrochloric acid spilled on skin; or slowly over days or years, e.g. the rusting of iron in a bridge. Sometimes the word ''caustic'' is used as a synonym for ''corrosive'' when referring to the effect on living tissues. At low concentrations, a corrosive substance is called an ''irritant'', and its effect on living tissue is called irritation. At high concentrations, a corro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanocene Dichloride
Titanocene dichloride is the organotitanium compound with the formula ( ''η''5-C5H5)2TiCl2, commonly abbreviated as Cp2TiCl2. This metallocene is a common reagent in organometallic and organic synthesis. It exists as a bright red solid that slowly hydrolyzes in air. It shows antitumour activity and was the first non-platinum complex to undergo clinical trials as a chemotherapy drug. Preparation and structure The standard preparations of Cp2TiCl2 start with titanium tetrachloride. The original synthesis by Wilkinson and Birmingham, using sodium cyclopentadienide, is still commonly used: :2 NaC5H5 + TiCl4 → (C5H5)2TiCl2 + 2 NaCl It can also be prepared by using freshly distilled cyclopentadiene rather than its sodium derivative: :2 C5H6 + TiCl4 → (C5H5)2TiCl2 + 2 HCl Focusing on the geometry of the Ti center, Cp2TiCl2 adopts a distorted tetrahedral geometry (counting Cp as a monodentate ligand). The Ti-Cl distance is 2.37 Å and the Cl-Ti-Cl angle is 9 ... [...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 solutions ... [...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] |
HSAB Theory
HSAB concept is a jargon for "hard and soft Lewis acids and bases, (Lewis) acids and bases". HSAB is widely used in chemistry for explaining stability of chemical compound, compounds, reaction mechanisms and pathways. It assigns the terms 'hard' or 'soft', and 'acid' or 'base' to chemical species. 'Hard' applies to species which are small, have high charge states (the charge criterion applies mainly to acids, to a lesser extent to bases), and are weakly Polarizability, polarizable. 'Soft' applies to species which are big, have low charge states and are strongly polarizable. The theory is used in contexts where a qualitative, rather than quantitative, description would help in understanding the predominant factors which drive chemical properties and reactions. This is especially so in transition metal chemistry, where numerous experiments have been done to determine the relative ordering of ligands and transition metal ions in terms of their hardness and softness. HSAB theory is al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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