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(Cyclopentadienyl)titanium Trichloride
(Cyclopentadienyl)titanium trichloride is an organotitanium compound with the formula (CH)TiCl. It is a moisture sensitive orange solid. The compound adopts a piano stool geometry. Preparation and reactions is prepared by the reaction of titanocene dichloride Titanocene dichloride is the organotitanium compound with the formula (hapticity, ''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 t ... and titanium tetrachloride: : The complex is electrophilic, readily forming alkoxide complexes upon treatment with alcohols. Reduction of (cyclopentadienyl)titanium trichloride with zinc powder gives the polymeric Ti(III) derivative (cyclopentadienyl)titanium dichloride: : A related reduction can be effected with cobaltocene: : Other evidence for the Lewis acidity of the trichloride is the ready formation of adducts with phosphine ligands: : See also * (Cyclopentadi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organotitanium Compound
Organotitanium chemistry is the science of organotitanium compounds describing their physical properties, synthesis, and reactions. Organotitanium compounds in organometallic chemistry contain carbon-titanium chemical bonds. They are reagents in organic chemistry and are involved in major industrial processes. Brief history Although the first attempt to prepare an organotitanium compound dates back to 1861, the first example was not reported until 1954. In that year titanocene dichloride was described by Wilkinson and Birmingham. Independently, titanium-based Ziegler–Natta catalysts were described leading to major commercial applications, for which the 1963 Nobel Prize in Chemistry was awarded. This technology underscored the technical significance of organotitanium chemistry. Properties The titanium electron configuration ( rd24s2) vaguely resembles that of carbon and like carbon, the +4 oxidation state dominates. Titanium is however a much larger element than carbon, reflected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piano Stool Complex
Half sandwich compounds, also known as piano stool complexes, are organometallic complexes that feature a cyclic polyhapto ligand bound to an MLn center, where L is a unidentate ligand. Thousands of such complexes are known. Well-known examples include cyclobutadieneiron tricarbonyl and (C5H5)TiCl3. Commercially useful examples include (C5H5)Co(CO)2, which is used in the synthesis of substituted pyridines, and methylcyclopentadienyl manganese tricarbonyl, an antiknock agent in petrol. MMT-2D-skeletal.png, MMT is a commercially useful antiknock compound. Cpco(CO)2.png, CpCo(CO)2 is a catalyst for the synthesis of pyridines. Cyclobutadiene-iron-tricarbonyl-from-xtal-3D-balls.png, (C4H4)Fe(CO)3. Cp2Fe(CO)2I-2D-skeletal.png, CpFe(CO)2I is an example of a piano stool complex with two different monodentate ligands. RuCymCl2.png, The diruthenium of cymene is readily cleaved by ligands to give monoRu half-sandwich derivatives. CHTMo(CO)3.png, Cycloheptatriene molybdenum tricarbony ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanocene Dichloride
Titanocene dichloride is the organotitanium compound with the formula (hapticity, ''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 Geoffrey Wilkinson, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium Tetrachloride
Titanium tetrachloride is the inorganic compound with the formula . It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. is a volatile liquid. Upon contact with humid air, it forms thick clouds of titanium dioxide () and hydrochloric acid, a reaction that was formerly exploited for use in smoke machines. It is sometimes referred to as "tickle" or "tickle 4", as a phonetic representation of the symbols of its molecular formula (). Properties and structure is a dense, colourless liquid, although crude samples may be yellow or even red-brown. It is one of the rare transition metal halides that is a liquid at room temperature, being another example. This property reflects the fact that molecules of weakly self-associate. Most metal chlorides are polymers, wherein the chloride atoms bridge between the metals. Its melting point is similar to that of . has a "closed" electronic shell, with the same number of electrons as the nobl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkoxide
In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as , where R is the organyl substituent. Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands. Alkoxides, although generally not stable in protic solvents such as water, occur widely as intermediates in various reactions, including the Williamson ether synthesis.excerpt Transition metal alkoxides are widely used for coatings and as catalysts. Enolates are unsaturated alkoxides derived by deprotonation of a bond adjacent to a ketone or aldehyde. The nucleophilic center for simple alkoxides is located on the oxygen, whereas the nucleophilic site on enolates is delocalized onto both carbon and oxygen sites. Ynolates are also unsaturated alkoxides derived from acetylenic alcohols. Phenoxides are close relatives of the alkoxides, in which the alkyl group is replaced by a phe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobaltocene
Cobaltocene, known also as bis(cyclopentadienyl)cobalt(II) or even "bis Cp cobalt", is an organocobalt compound with the formula Co(C5H5)2. It is a dark purple solid that sublimes readily slightly above room temperature. Cobaltocene was discovered shortly after ferrocene, the first metallocene. Due to the ease with which it reacts with oxygen, the compound must be handled and stored using air-free techniques. Synthesis Cobaltocene is prepared by the reaction of sodium cyclopentadienide (NaC5H5) with anhydrous cobalt(II) chloride in THF solution. Sodium chloride is cogenerated, and the organometallic product is usually purified by vacuum sublimation. Structure and bonding In Co(C5H5)2 the Co centre is "sandwiched" between two cyclopentadienyl (Cp) rings. The Co–C bond lengths are about 2.1 Å, slightly longer than the Fe–C bond in ferrocene. Co(C5H5)2 belongs to a group of organometallic compounds called metallocenes or sandwich compounds. Cobaltocene has 19 valen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lewis Acid
A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any species that has a filled orbital containing an electron pair which is not involved in bonding but may form a dative bond with a Lewis acid to form a Lewis adduct. For example, NH3 is a Lewis base, because it can donate its lone pair of electrons. Trimethylborane CH3)3Bis a Lewis acid as it is capable of accepting a lone pair. In a Lewis adduct, the Lewis acid and base share an electron pair furnished by the Lewis base, forming a dative bond. In the context of a specific chemical reaction between NH3 and Me3B, a lone pair from NH3 will form a dative bond with the empty orbital of Me3B to form an adduct NH3•BMe3. The terminology refers to the contributions of Gilbert N. Lewis. From p. 142: "We are inclined to think of substances as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphine Ligand
A metal-phosphine complex is a coordination complex containing one or more phosphine ligands. Almost always, the phosphine is an organophosphine of the type R3P (R = alkyl, aryl). Metal phosphine complexes are useful in homogeneous catalysis. Prominent examples of metal phosphine complexes include Wilkinson's catalyst (Rh(PPh3)3Cl), Grubbs' catalyst, and tetrakis(triphenylphosphine)palladium(0). Preparation Many metal phosphine complexes are prepared by reactions of metal halides with preformed phosphines. For example, treatment of a suspension of palladium chloride in ethanol with triphenylphosphine yields monomeric bis(triphenylphosphine)palladium(II) chloride units. : dCl2sub>n + 2PPh3 → PdCl2(PPh3)2 The first reported phosphine complexes were ''cis''- and ''trans''-PtCl2(PEt3)2 reported by Cahours and Gal in 1870. Often the phosphine serves both as a ligand and as a reductant. This property is illustrated by the synthesis of many platinum-metal complexes of triphenylp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
(Cyclopentadienyl)zirconium Trichloride
(Cyclopentadienyl)zirconium trichloride is an organozirconium compound with the formula (CH)ZrCl. It a moisture-sensitive white solid. The compound adopts a polymeric structure. The compound has been well studied spectroscopically. Synthesis and reactions It is prepared by chlorination of zirconocene dichloride. Being polymeric, complex is insoluble in nonpolar solvents. It dissolves in the presence of basic ligands to give adducts. See also *(Cyclopentadienyl)titanium trichloride (Cyclopentadienyl)titanium trichloride is an organotitanium compound with the formula (CH)TiCl. It is a moisture sensitive orange solid. The compound adopts a piano stool geometry. Preparation and reactions is prepared by the reaction of tita ..., which exists as a monomer. References {{DEFAULTSORT:Cyclopentadienyl)zirconium trichloride Zirconium(IV) compounds Chloro complexes Organozirconium compounds Cyclopentadienyl complexes Coordination polymers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
(Pentamethylcyclopentadienyl)titanium Trichloride
(Pentamethylcyclopentadienyl)titanium trichloride is an organotitanium compound with the formula Cp*TiCl3 (Cp* = C5(CH3)5). It is an orange solid. The compound adopts a piano stool geometry. An early synthesis involve the combination of lithium pentamethylcyclopentadienide and titanium tetrachloride. The compound is an intermediate in the synthesis of decamethyltitanocene dichloride. In the presence of organoaluminium compounds and other additives, it catalyzes the polymerization of alkenes. See also * (Cyclopentadienyl)titanium trichloride (Cyclopentadienyl)titanium trichloride is an organotitanium compound with the formula (CH)TiCl. It is a moisture sensitive orange solid. The compound adopts a piano stool geometry. Preparation and reactions is prepared by the reaction of tita ... References {{DEFAULTSORT:Pentamethyclopentadienyl)titanium trichloride Chloro complexes Titanium compounds Half sandwich compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloro Complexes
Chlorine is a chemical element; it has symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity on the revised Pauling scale, behind only oxygen and fluorine. Chlorine played an important role in the experiments conducted by medieval alchemists, which commonly involved the heating of chloride salts like ammonium chloride ( sal ammoniac) and sodium chloride ( common salt), producing various chemical substances containing chlorine such as hydrogen chloride, mercury(II) chloride (corrosive sublimate), and . However, the nature of free chlorine gas as a separate substance was only recognised around 1630 by Jan Baptist van Helmont. Car ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
