Benzoquinonetetracarboxylic dianhydride is an organic compound with formula C
8 (an oxide of carbon) which can be seen as the result of removing two molecules of water H
2O from benzoquinonetetracarboxylic acid.
It is a red solid, stable in dry air up to 140 °C and insoluble in ether, carbon tetrachloride, dichloromethane, and carbon disulfide. It reacts with acetone, ethyl acetate, tetrahydrofuran, ethanol, and water. It dissolves in methylated derivatives of benzene to give solutions ranging from orange to violet. When the molecule is exposed to moist air it quickly turns blue.
The compound was synthesized in 1963 by P. R. Hammond who claimed it was "one of the strongest π-electron acceptors so far described."
|Preferred IUPAC name
3D model (JSmol)
|Molar mass||248.102 g·mol−1|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
In chemistry, 1,4-benzoquinonetetracarboxylic acid is an organic compound with formula C10H4O10, or (C6O2)(-(CO)OH)4, which can be viewed as deriving from para-benzoquinone C6H4O2 through replacement of the four hydrogen atoms by carboxyl functional groups -(CO)OH.
By removal of four protons, the acid is expected to yield the anion C10O4−10, benzoquinonetetracarboxylate, which is one of the oxocarbon anions (consisting solely of oxygen and carbon. By loss of 1 through 3 protons it forms the anions C10H3O−10, C10H2O2−10, and C10HO3−10, called respectively trihydrogen-, dihydrogen-, and hydrogenbenzoquinonetetracarboxylate. The same names are used for the corresponding esters.
Removal of two water molecules gives the compound benzoquinonetetracarboxylic dianhydride, C10O8, one of the oxides of carbon.The acid can be obtained by from durene (1,2,4,5-tetramethylbenzene) via dinitropyromellitic and
diaminopyromellitic acids.Organic acid anhydride
An organic acid anhydride is an acid anhydride that is an organic compound. An acid anhydride is a compound that has two acyl groups bonded to the same oxygen atom. A common type of organic acid anhydride is a carboxylic anhydride, where the parent acid is a carboxylic acid, the formula of the anhydride being (RC(O))2O. Symmetrical acid anhydrides of this type are named by replacing the word acid in the name of the parent carboxylic acid by the word anhydride. Thus, (CH3CO)2O is called acetic anhydride. Mixed (or unsymmetrical) acid anhydrides, such as acetic formic anhydride (see below), are known, whereby reaction occurs between two different carboxylic acids. Nomenclature of unsymmetrical acid anhydrides list the names of both of the reacted carboxylic acids before the word "anhydride" (for example, the dehydration reaction between benzoic acid and propanoic acid would yield "benzoic propanoic anhydride").One or both acyl groups of an acid anhydride may also be derived from another type of organic acid, such as sulfonic acid or a phosphonic acid. One of the acyl groups of an acid anhydride can be derived from an inorganic acid such as phosphoric acid. The mixed anhydride 1,3-bisphosphoglyceric acid, an intermediate in the formation of ATP via glycolysis, is the mixed anhydride of 3-phosphoglyceric acid and phosphoric acid. Acidic oxides are also classified as acid anhydrides.Oxocarbon
An oxocarbon or oxide of carbon is a chemical compound consisting only of carbon and oxygen.The simplest and most common oxocarbons are carbon monoxide (CO) and carbon dioxide (CO2) with IUPAC names carbon(II) oxide and carbon(IV) oxide respectively. Many other stable (practically if not thermodynamically) or metastable oxides of carbon are known, but they are rarely encountered, such as carbon suboxide (C3O2 or O=C=C=C=O) and mellitic anhydride (C12O9).
While textbooks will often list only the first three, and rarely the fourth, a large number of other oxides are known today, most of them synthesized since the 1960s. Some of these new oxides are stable at room temperature. Some are metastable or stable only at very low temperatures, but decompose to simpler oxocarbons when warmed. Many are inherently unstable and can be observed only momentarily as intermediates in chemical reactions or are so reactive that they can exist only in the gas phase or under matrix isolation conditions.
The inventory of oxocarbons appears to be steadily growing. The existence of graphene oxide and of other stable polymeric carbon oxides with unbounded molecular structures suggests that many more remain to be discovered.Polyimide
Polyimide (sometimes abbreviated PI) is a polymer of imide monomers. Polyimides have been in mass production since 1955. With their high heat-resistance, polyimides enjoy diverse applications in roles demanding rugged organic materials, e.g. high temperature fuel cells, displays, and various military roles. A classic polyimide is Kapton, which is produced by condensation of pyromellitic dianhydride and 4,4'-oxydianiline.
|Compounds derived from oxides|