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Potassium Tris(3,5-dimethyl-1-pyrazolyl)borate
Potassium tris(3,5-dimethyl-1-pyrazolyl)borate, abbreviated KTp*, is the potassium salt of the anion HB((CH3)2C3N2H)3. Tp*− is a tripodal ligand that binds to a metal in a facial manner, more specifically a Scorpionate ligand. KTp* is a white crystalline solid that is soluble in polar solvents, including water and several alcohols. Synthesis KTp* is synthesized in a manner similar to that of KTp by the reaction of potassium borohydride and 3,5-dimethylpyrazole. Hydrogen gas is evolved as each of the pyrazole reacts at the boron. The rate of B-N bond formation becomes more difficult with each successive 3,5-dimethylpyrazolyl due to the increase in steric hindrance around the boron: :3 Me2C3N2H2 + KBH4 → KHB(Me2C3N2H)3 + 3 H2 The required dimethylpyrazole is obtained by condensation of hydrazine and acetylacetone Acetylacetone is an organic compound with the chemical formula . It is a colorless liquid, classified as a 1,3-diketone. It exists in equilibrium with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tripodal Ligand
Tripodal ligands are tri- and tetradentate ligands. They are popular in research in the areas of coordination chemistry A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ''ligands'' or complexing ... and homogeneous catalysis. Because the ligands are polydentate, they do not readily dissociate from the metal centre. Many tripodal ligands have C3 symmetry group, symmetry. Coordination chemistry In their coordination complexes with an octahedral molecular geometry the tridentate tripod ligands occupy one face, leading to a fixed Coordination complexes#Cis–trans isomerism and facial–meridional isomerism, facial (or ''fac'') geometry. The tetradentate tripodal ligands occupy four contiguous sites, leaving two ''cis'' positions available on the octahedral metal center. When bound to four- and five-coordinate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scorpionate Ligand
In coordination chemistry, the term scorpionate ligand refers to a tridentate (three-donor-site) ligand which would bind to a metal in a ''fac'' manner. The most popular class of scorpionates are the hydrotris(pyrazolyl)borates or Tp ligands. These were also the first to become popular. These ligands first appeared in journals in 1966 from the then little-known DuPont chemist of Ukrainian descent, Swiatoslaw Trofimenko. Trofimenko called this discovery "a new and fertile field of remarkable scope". The term scorpionate comes from the fact that the ligand can bind a metal with two donor sites like the pincers of a scorpion; the third and final donor site reaches over the plane formed by the metal and the other two donor atoms to bind to the metal. The binding can be thought of as being like a scorpion grabbing the metal with two pincers before stinging it. While many scorpionate ligands are of the Tp class, many other scorpionate ligands are known. For example, the Tm and tripo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Scientific
World Scientific Publishing is an academic publisher of scientific, technical, and medical books and journals headquartered in Singapore. The company was founded in 1981. It publishes about 600 books annually, along with 135 journals in various fields. In 1995, World Scientific co-founded the London-based Imperial College Press together with the Imperial College of Science, Technology and Medicine. Company structure The company head office is in Singapore. The Chairman and Editor-in-Chief is Dr Phua Kok Khoo, while the Managing Director is Doreen Liu. The company was co-founded by them in 1981. Imperial College Press In 1995 the company co-founded Imperial College Press, specializing in engineering, medicine and information technology Information technology (IT) is the use of computers to create, process, store, retrieve, and exchange all kinds of data . and information. IT forms part of information and communications technology (ICT). An information technolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Trispyrazolylborate
Potassium trispyrazolylborate, commonly abbreviated KTp, is the potassium salt with the formula :. This salt is the source of the trispyrazolylborate ligand. KTp is a white crystalline solid that is soluble in polar solvents, alcohols, and water. The synthesis of KTp involves potassium borohydride and pyrazole without a solvent. : The tris(pyrazolyl)borate forms octahedral coordination compounds with the formula M psub>2 with first row transition metals. KTp also forms 1:1 complexes, for example it can be converted to K pMo(CO)3 : When K pMo(CO)3is treated with butyl nitrite Butyl nitrite is the organic compound with the formula CH3(CH2)3ONO. It is an alkyl nitrite made from ''n''-butanol. Butyl nitrite is used recreationally as poppers. Synonyms include ''1-butyl nitrite'', n''-butyl nitrite'' and ''nitrous acid ... it yields the neutral orange complex TpMo(CO)2NO. :K pMo(CO)3 BuONO→TpMo(CO)2NO+CO+KOBu References {{boron compounds Potassium compounds Boron compo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Borohydride
Borohydride refers to the anion , which is also called tetrahydroborate, and its salts. Borohydride or hydroborate is also the term used for compounds containing , where ''n'' is an integer from 0 to 3, for example cyanoborohydride or cyanotrihydroborate and triethylborohydride or triethylhydroborate . Borohydrides find wide use as reducing agents in organic synthesis. The most important borohydrides are lithium borohydride and sodium borohydride, but other salts are well known (see Table). Tetrahydroborates are also of academic and industrial interest in inorganic chemistry. History Alkali metal borohydrides were first described in 1940 by Hermann Irving Schlesinger and Herbert C. Brown. They synthesized lithium borohydride from diborane : :, where M = Li, Na, K, Rb, Cs, etc. Current methods involve reduction of trimethyl borate with sodium hydride. Structure In the borohydride anion and most of its modifications, boron has a tetrahedral structure. The reactivity of the B−H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3,5-Dimethylpyrazole
3,5-Dimethylpyrazole is an organic compound with the formula (CH3C)2CHN2H. It is one of several isomeric derivatives of pyrazole that contain two methyl substituents. The compound is unsymmetrical but the corresponding conjugate acid (pyrazolium) and conjugate base (pyrazolide) have C2v symmetry. It is a white solid that dissolves well in polar organic solvents. It is a precursor to a variety of ligands that are widely studied in coordination chemistry including trispyrazolylborate, a trispyrazolylmethane, and a pyrazolyldiphosphine. Condensation of acetylacetone and hydrazine Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazin ... gives 3,5-dimethylpyrazole: :CH3C(O)CH2C(O)CH3 + N2H4 → (CH3C)2CHN2H + 2 H2O It has found use as a bloc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylacetone
Acetylacetone is an organic compound with the chemical formula . It is a colorless liquid, classified as a 1,3- diketone. It exists in equilibrium with a tautomer . These tautomers interconvert so rapidly under most conditions that they are treated as a single compound in most applications. It is a colorless liquid that is a precursor to acetylacetonate anion (commonly abbreviated acac−), a bidentate ligand. It is also a building block for the synthesis of heterocyclic compounds. Properties Tautomerism The keto and enol tautomers of acetylacetone coexist in solution. The enol form has C2v symmetry, meaning the hydrogen atom is shared equally between the two oxygen atoms. In the gas phase, the equilibrium constant, ''K''keto→enol, is 11.7, favoring the enol form. The two tautomeric forms can be distinguished by NMR spectroscopy, IR spectroscopy and other methods. The equilibrium constant tends to be high in nonpolar solvents; when k = >1, the enol form is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organoboron Compounds
Organoborane or organoboron compounds are chemical compounds of boron and carbon that are organic derivatives of BH3, for example trialkyl boranes. Organoboron chemistry or organoborane chemistry is the chemistry of these compounds. Organoboron compounds are important reagents in organic chemistry enabling many chemical transformations, the most important one called hydroboration. Reactions of organoborates and boranes involve the transfer of a nucleophilic group attached to boron to an electrophilic center either inter- or intramolecularly. α,β-Unsaturated borates, as well as borates with a leaving group at the α position, are highly susceptible to intramolecular 1,2-migration of a group from boron to the electrophilic α position. Oxidation or protonolysis of the resulting organoboranes may generate a variety of organic products, including alcohols, carbonyl compounds, alkenes, and halides. Properties of the B-C bond The C-B bond has low polarity (the difference in electro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
