A Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, is a catalyst used in the synthesis of polymers of 1-alkenes (alpha-olefins). Two broad classes of Ziegler–Natta catalysts are employed, distinguished by their solubility:
Titanium tetrachloride is the inorganic compound with the formula TiCl4. It is an important intermediate in the production of titanium metal and the pigment titanium dioxide. TiCl4 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" due to the phonetic resemblance of its molecular formula to the word.
A Kaminsky catalyst is a catalytic system for alkene polymerization. Kaminsky catalysts are based on metallocenes of group 4 transition metals activated with methylaluminoxane (MAO). These and other innovations have inspired development of new classes of catalysts that in turn led to commercialization of novel engineering polyolefins.
Hafnium(IV) chloride is the inorganic compound with the formula HfCl4. This colourless solid is the precursor to most hafnium organometallic compounds. It has a variety of highly specialized applications, mainly in materials science and as a catalyst.
Titanocene dichloride is the organotitanium compound with the formula (η5-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.
Zirconium(IV) chloride, also known as zirconium tetrachloride, is an inorganic compound frequently used as a precursor to other compounds of zirconium. This white high-melting solid hydrolyzes rapidly in humid air.
Organotitanium compounds in organometallic chemistry contain carbon-titanium chemical bonds. Organotitanium chemistry is the science of organotitanium compounds describing their physical properties, synthesis and reactions. They are reagents in organic chemistry and are involved in major industrial processes.
Organoaluminium chemistry is the study of compounds containing bonds between carbon and aluminium. It is one of the major themes within organometallic chemistry. Illustrative organoaluminium compounds are the dimer trimethylaluminium, the monomer triisobutylaluminium, and the titanium-aluminium compound called Tebbe's reagent. The behavior of organoaluminium compounds can be understood in terms of the polarity of the C−Al bond and the high Lewis acidity of the three-coordinated species. Industrially, these compounds are mainly used for the production of polyolefins.
Organozirconium compounds are organometallic compounds containing a carbon to zirconium chemical bond. Organozirconium chemistry is the corresponding science exploring properties, structure, and reactivity of these compounds. Organozirconium compounds have been widely studied, in part because they are useful catalysts in Ziegler-Natta polymerization.
In organometallic chemistry, a metallacycle is a derivative of a carbocyclic compound wherein a metal has replaced at least one carbon center; this is to some extent similar to heterocycles. Metallacycles appear frequently as reactive intermediates in catalysis, e.g. olefin metathesis and alkyne trimerization. In organic synthesis, directed ortho metalation is widely used for the functionalization of arene rings via C-H activation. One main effect that metallic atom substitution on a cyclic carbon compound is distorting the geometry due to the large size of typical metals.
Organochromium chemistry is a branch of organometallic chemistry that deals with organic compounds containing a chromium to carbon bond and their reactions. The field is of some relevance to organic synthesis. The relevant oxidation states for organochromium complexes encompass the entire range of possible oxidation states from –4 (d10) in Na4[Cr–IV(CO)4] to +6 (d0) in oxo-alkyl complexes like Cp*CrVI(=O)2Me.
Organovanadium chemistry is the chemistry of organometallic compounds containing a carbon (C) to vanadium (V) chemical bond. Organovanadium compounds find only minor use as reagents in organic synthesis but are significant for polymer chemistry as catalysts.
Organomolybdenum chemistry is the chemistry of chemical compounds with Mo-C bonds. The heavier group 6 elements molybdenum and tungsten form organometallic compounds similar to those in organochromium chemistry but higher oxidation states tend to be more common.
In organometallic chemistry, bent metallocenes are a subset of metallocenes. In bent metallocenes, the ring systems coordinated to the metal are not parallel, but are tilted at an angle. A common example of a bent metallocene is Cp2TiCl2. Several reagents and much research is based on bent metallocenes.
Titanium ethoxide is a chemical compound with the formula Ti4(OCH2CH3)16. It is a colorless liquid that is soluble in organic solvents but hydrolyzes readily. It is sold commercially as a colorless solution. Alkoxides of titanium(IV) and zirconium(IV) are used in organic synthesis and materials science. They adopt more complex structures than suggested by their empirical formulas.
Brookhart's acid is the salt of the diethyl ether oxonium ion and tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BAr′4). It is a colorless solid, used as a strong acid. The compound was first reported by Volpe, Grant, and Brookhart in 1992.
Transition-metal allyl complexes are coordination complexes with allyl and its derivatives as ligands. Allyl is the radical with the connectivity CH2CHCH2, although as a ligand it is usually viewed as an allyl anion CH2=CH−CH2−, which is usually described as two equivalent resonance structures.
Zirconocene is a hypothetical compound with 14 valence electrons, which has not been observed or isolated. It is an organometallic compound consisting of two cyclopentadienyl rings bound on a central zirconium atom. A crucial question in research is what kind of ligands can be used to stabilize the Cp2ZrII metallocene fragment to make it available for further reactions in organic synthesis.
(Cyclopentadienyl)zirconium trichloride is an organozirconium compound with the formula (C5H5)ZrCl3. It a moisture-sensitive white solid. The compound adopts a polymeric structure. The compound has been well studied spectroscopically.
Transition metal phosphinimide complexes are metal complexes that contain phosphinimide ligands of the general formula NPR3− (R = organic substituent). Several coordination modes have been observed, including terminal and various bridging geometries. In the terminal bonding mode the M-N=P core is usually linear but some are quite bent. The preferred coordination type varies with the oxidation state and coligands on the metal and the steric and electronic properties of the R groups on phosphorus. Many transition metal phosphinimide complexes have been well-developed and, more recently, main group phosphinimide complexes have been synthesized.
