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.
Nickel(II) chloride (or just nickel chloride) is the chemical compound NiCl2. The anhydrous salt is yellow, but the more familiar hydrate NiCl2·6H2O is green. Nickel(II) chloride, in various forms, is the most important source of nickel for chemical synthesis. The nickel chlorides are deliquescent, absorbing moisture from the air to form a solution. Nickel salts have been shown to be carcinogenic to the lungs and nasal passages in cases of long-term inhalation exposure.
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.
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.
Titanium(III) chloride is the inorganic compound with the formula TiCl3. At least four distinct species have this formula; additionally hydrated derivatives are known. TiCl3 is one of the most common halides of titanium and is an important catalyst for the manufacture of polyolefins.
Zirconium(IV) bromide is the inorganic compound with the formula ZrBr4. This colourless solid is the principal precursor to other Zr–Br compounds.
Zirconium(IV) iodide is the chemical compound with the formula ZrI4. It is the most readily available iodide of zirconium. It is an orange-coloured solid that degrades in the presence of water. The compound was once prominent as an intermediate in the purification of zirconium metal.
Borohydride refers to the anion [BH4]−, which is also called tetrahydroborate, and its salts. Borohydride or hydroborate is also the term used for compounds containing [BH4−nXn]−, where n is an integer from 0 to 3, for example cyanoborohydride or cyanotrihydroborate [BH3(CN)]− and triethylborohydride or triethylhydroborate [BH(CH2CH3)3]−. 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. Tetrahydroborates are also of academic and industrial interest in inorganic chemistry.
Chromium(III) acetylacetonate is the coordination compound with the formula Cr(C5H7O2)3, sometimes designated as Cr(acac)3. This purplish coordination complex is used in NMR spectroscopy as a relaxation agent because of its solubility in nonpolar organic solvents and its paramagnetism.
Organozirconium chemistry is the science of exploring the properties, structure, and reactivity of organozirconium compounds, which are organometallic compounds containing chemical bonds between carbon and zirconium. Organozirconium compounds have been widely studied, in part because they are useful catalysts in Ziegler-Natta polymerization.
Nickel(II) bis(acetylacetonate) is a coordination complex with the formula [Ni(acac)2]3, where acac is the anion C5H7O2− derived from deprotonation of acetylacetone. It is a dark green paramagnetic solid that is soluble in organic solvents such as toluene. It reacts with water to give the blue-green diaquo complex Ni(acac)2(H2O)2.
Metal acetylacetonates are coordination complexes derived from the acetylacetonate anion (CH
3COCHCOCH−
3) and metal ions, usually transition metals. The bidentate ligand acetylacetonate is often abbreviated acac. Typically both oxygen atoms bind to the metal to form a six-membered chelate ring. The simplest complexes have the formula M(acac)3 and M(acac)2. Mixed-ligand complexes, e.g. VO(acac)2, are also numerous. Variations of acetylacetonate have also been developed with myriad substituents in place of methyl (RCOCHCOR′−). Many such complexes are soluble in organic solvents, in contrast to the related metal halides. Because of these properties, acac complexes are sometimes used as catalyst precursors and reagents. Applications include their use as NMR "shift reagents" and as catalysts for organic synthesis, and precursors to industrial hydroformylation catalysts. C
5H
7O−
2 in some cases also binds to metals through the central carbon atom; this bonding mode is more common for the third-row transition metals such as platinum(II) and iridium(III).
Vanadyl acetylacetonate is the chemical compound with the formula VO(acac)2, where acac– is the conjugate base of acetylacetone. It is a blue-green solid that dissolves in polar organic solvents. The coordination complex consists of the vanadyl group, VO2+, bound to two acac– ligands via the two oxygen atoms on each. Like other charge-neutral acetylacetonate complexes, it is not soluble in water.
Hafnium acetylacetonate, also known as Hf(acac)4, is a coordination compound with formula Hf(C5H7O2)4. This white solid is the main hafnium complex of acetylacetonate. The complex has a square antiprismatic geometry with eight nearly equivalent Hf-O bonds. The molecular symmetry is D2, i.e., the complex is chiral. It is prepared from hafnium tetrachloride and acetylacetone, and base. Zr(acac)4 is very similar in structure and properties.
Iridium acetylacetonate is the iridium coordination complex with the formula Ir(O2C5H7)3, which is sometimes known as Ir(acac)3. The molecule has D3-symmetry. It is a yellow-orange solid that is soluble in organic solvents.
1,1,1-Trifluoroacetylacetone is the organofluorine compound with the formula CF3C(O)CH2C(O)CH3. It is a colorless liquid. Like other 1,3-diketones, it is used as a precursor to heterocycles, e.g. pyrazoles, and metal chelates. It is prepared by condensation of esters of trifluoroacetic acid with acetone.
Platinum(II) bis(acetylacetonate) is the coordination compound with the formula Pt(O2C5H7)2, abbreviated Pt(acac)2. The homoleptic acetylacetonate complex of platinum(II), it is a yellow, benzene-soluble solid. According to X-ray crystallography, the Pt center is square planar. The compound is a widely used precursor to platinum-based catalysts.
Tris(acetylacetonato)cobalt(III) is the coordination complex with the formula Co(C5H7O2)3. Often abbreviated Co(acac)3, it is a green, diamagnetic solid that is soluble in organic solvents, but not in water. Owing to its solubility in organic solvents, tris(acetylacetonato)cobalt(III) is used to produce homogeneous catalysts by reduction.
Holmium acetylacetonate is a coordination complex, with the chemical formula of Ho(C5H7O2)3 or Ho(acac)3. It can be obtained via the reaction between metallic holmium or holmium(III) hydride with acetylacetone, or via the reaction between holmium(III) chloride and ammonium acetylacetonate. Its anhydrous form is stable in a dry atmosphere but forms a hydrate in humid air.
Bis(acetylacetonato)iron(II) is a coordination complex of iron with the formula Fe(C5H7O2)2. It can be prepared by reacting iron(II) chloride with 2,4-pentanedione in presence of piperidine.
