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Sodium Silox
Sodium silox is the name for an organosilicon compound that serves as a source of the siloxide anion CH3)3Csub>3SiO−. Complexes of this bulky anionic ligand often adopt with low coordination numbers. Examples include Ti(silox)3, Nb(silox)3(PMe3), and r(silox)3sup>−. Properties of silox and related complexes The sodium derivative, which has salt-like properties, is a cubane-type cluster. Related bulky anionic ligands include C5Me5−, (Me3Si)2N−, and NacNac−. Silox has a larger cone angle than C5Me5− and is a poorer donor. It is also larger than silylamides. For these reasons, silox anion forms highly unsaturated complexes. Complexes with high coordinative unsaturation display high reactivity so long as they do not undergo intramolecular reactions. Silox offers this possibility. Examples of high reactivity exhibited by metal-silox compounds include the C-O bond in carbon monoxide and the C-N bond in pyridine. Preparation Na(silox) is usually prepared by deprot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organosilicon Compound
Organosilicon compounds are organometallic compounds containing carbon–silicon chemical bond, bonds. Organosilicon chemistry is the corresponding science of their preparation and properties. Most organosilicon compounds are similar to the ordinary organic compounds, being colourless, flammable, hydrophobic, and stable to air. Silicon carbide is an ''inorganic chemistry, inorganic'' compound. History In 1846 Von Ebelman's had synthesized Tetraethyl orthosilicate (Si(OC2H5)4). In 1863 Friedel and Crafts managed to make the first organosilieon compound with C-Si bonds which gone byound the syntheses of orthosilicic acid esters. The same year they also described a «polysilicic acid ether» in the preparation of Ethanol, ethyl- and methyl-o-silicic acid. The early extensive research in the field of organosilicon compounds was pioneerd in the beginning of 20th century by Frederic Kipping. He also had coined the term «silicone» (akin to ketones) in relation to these materials ... [...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] |
Cubane-type Cluster
A cubane-type cluster is an arrangement of atoms in a molecular structure that forms a cube. In the idealized case, the eight vertices are symmetry equivalent and the species has Oh symmetry. Such a structure is illustrated by the hydrocarbon cubane. With chemical formula , cubane has carbon atoms at the corners of a cube and covalent bonds forming the edges. Most cubanes have more complicated structures, usually with nonequivalent vertices. They may be simple covalent compounds or macromolecular or supramolecular cluster compounds. Examples Other compounds having different elements in the corners, various atoms or groups bonded to the corners are all part of this class of structures. Inorganic cubane-type clusters include selenium tetrachloride, tellurium tetrachloride, and sodium silox. Cubane clusters are common throughout bioinorganic chemistry. Ferredoxins containing e4S4iron–sulfur clusters are pervasive in nature. The four iron atoms and four sulfur atoms form an alter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentamethylcyclopentadiene
1,2,3,4,5-Pentamethylcyclopentadiene is a cyclic diene with the formula C5Me5H (Me = CH3). 1,2,3,4,5-Pentamethylcyclopentadiene is the precursor to the ligand ''1,2,3,4,5-pentamethylcyclopentadienyl'', which is often denoted Cp* (C5Me5) and read as "C P star", the "star" signifying the five methyl groups radiating from the core of the ligand. In contrast to less-substituted cyclopentadiene derivatives, Cp*H is not prone to dimerization. Synthesis Pentamethylcyclopentadiene is commercially available. It was first prepared from tiglaldehyde via 2,3,4,5-tetramethylcyclopent-2-enone. Alternatively, 2-butenyllithium adds to ethyl acetate followed by acid-catalyzed dehydrocyclization: Organometallic derivatives Cp*H is a precursor to organometallic compounds containing the ligand, commonly called Cp*−. Some representative reactions leading to such Cp*–metal complexes follow: :Cp*H + C4H9Li → Cp*Li + C4H10 :Cp*Li + TiCl4 → Cp*TiCl3 + LiCl Some Cp* co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diketimine
Diimines are organic compounds containing two imine (RCH=NR') groups. Common derivatives are 1,2-diketones and 1,3-diimines. These compounds are used as ligands and as precursors to heterocycles. Diimines are prepared by condensation reactions where a dialdehyde or diketone is treated with amine and water is eliminated. Similar methods are used to prepare Schiff bases and oximes. 1,2-Diimines The 1,2-diketimine ligands also called α-diimines and 1,4-diazabutadienes. They are derived from the condensation of 1,2-diketones and glyoxal with amines, often anilines. An example is glyoxal-bis(mesitylimine), a yellow solid that is synthesized by condensation of 2,4,6-trimethylaniline and glyoxal. 2,2'-Bipyridine is a 1,2-diimine. 1,2-Diketimines are “non-innocent ligands”, akin to the dithiolenes. : 1,3-Diimines For example, acetylacetone (2,4-pentanedione) and a primary alkyl- or arylamine will react, typically in acidified ethanol, to form a diketimine. 1,3-Diketimi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cone Angle
In coordination chemistry, the ligand cone angle (a common example being the Tolman cone angle or ''θ'') is a measure of the steric bulk of a ligand in a transition metal coordination complex. It is defined as the solid angle formed with the metal at the vertex and the outermost edge of the van der Waals spheres of the ligand atoms at the perimeter of the cone (see figure). Tertiary phosphine ligands are commonly classified using this parameter, but the method can be applied to any ligand. The term ''cone angle'' was first introduced by Chadwick A. Tolman, a research chemist at DuPont. Tolman originally developed the method for phosphine ligands in nickel complexes, determining them from measurements of accurate physical models. Asymmetric cases The concept of cone angle is most easily visualized with symmetrical ligands, e.g. PR3. But the approach has been refined to include less symmetrical ligands of the type PRR′R″ as well as diphosphines. In such asymmetric cases, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coordinative Unsaturation
In chemistry, a saturated compound is a chemical compound (or ion) that resists the addition reactions, such as hydrogenation, oxidative addition, and binding of a Lewis base. The term is used in many contexts and for many classes of chemical compounds. Overall, saturated compounds are less reactive than unsaturated compounds. Saturation is derived from the Latin word ''saturare'', meaning 'to fill'. Organic chemistry Unsaturated compounds generally carry out typical addition reactions that are not possible with saturated compounds such as alkanes. A saturated organic compound has only single bonds between carbon atoms. An important class of saturated compounds are the alkanes. Many saturated compounds have functional groups, e.g., alcohols. Unsaturated organic compounds The concept of saturation can be described using various naming systems, formulas, and analytical tests. For instance, IUPAC nomenclature is a system of naming conventions used to describe the type and loc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrous Oxide
Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or nos, is a chemical compound, an oxide of nitrogen with the formula . At room temperature, it is a colourless non-flammable gas, and has a slightly sweet scent and taste. At elevated temperatures, nitrous oxide is a powerful oxidiser similar to molecular oxygen. Nitrous oxide has significant medical uses, especially in surgery and dentistry, for its anaesthetic and pain-reducing effects. Its colloquial name, "laughing gas", coined by Humphry Davy, is due to the euphoric effects upon inhaling it, a property that has led to its recreational use as a dissociative anaesthetic. It is on the World Health Organization's List of Essential Medicines. It is also used as an oxidiser in rocket propellants, and in motor racing to increase the power output of engines. Nitrous oxide's atmospheric concentration reached 333 parts per billion (ppb) in 2020, increasing at a rate of abo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Trimethylsiloxide
Sodium trimethylsiloxide is an organosilicon compound with the formula NaOSi(CH3)3. It is the sodium salt of the conjugate base derived from trimethylsilanol. A white solid, its molecular structure consists of a cluster with Na-O-Na linkages on the basis of closely related compounds. The salt is used to prepare trimethylsiloxide complexes by salt metathesis. Trimethylsiloxide is a lipophilic pseudohalide. It is a source of oxide dianion. Related compounds *Sodium silox, NaOSi(CMe3)3 (Me = CH3) *Potassium trimethylsilanolate{{cite journal , doi=10.15227/orgsyn.097.0245, title=Anhydrous, Homogeneous, Suzuki-Miyaura Cross-Coupling of Boronic Esters using Potassium Trimethylsilanolate, year=2020, last1= Delaney, first1=Connor P., last2=Heyboer, first2=E. M., last3=Denmark, first3=S. E., journal=Organic Syntheses, volume=97, pages=245–261, pmid=33456091, pmc=7808858 References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organosilicon Compounds
Organosilicon compounds are organometallic compounds containing carbon–silicon bonds. Organosilicon chemistry is the corresponding science of their preparation and properties. Most organosilicon compounds are similar to the ordinary organic compounds, being colourless, flammable, hydrophobic, and stable to air. Silicon carbide is an ''inorganic'' compound. History In 1846 Von Ebelman's had synthesized Tetraethyl orthosilicate (Si(OC2H5)4). In 1863 Friedel and Crafts managed to make the first organosilieon compound with C-Si bonds which gone byound the syntheses of orthosilicic acid esters. The same year they also described a «polysilicic acid ether» in the preparation of ethyl- and methyl-o-silicic acid. The early extensive research in the field of organosilicon compounds was pioneerd in the beginning of 20th century by Frederic Kipping. He also had coined the term «silicone» (akin to ketones) in relation to these materials in 1904. In recognition of Kipping's achiev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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