Ethylenetetracarboxylic dianhydride
Encyclopedia
Ethylenetetracarboxylic dianhydride is a chemical compound
with formula , that can be seen as the twofold anhydride of ethylenetetracarboxylic acid
. Its molecular
backbone consists of two five-atom maleic anhydride
rings, each containing one oxygen
atom and four carbon
atoms, sharing a pair of carbons. It is one of the oxides of carbon
. It is a pale yellow oily liquid, soluble in dichloromethane
and trichloromethane.
The compound and its reactions were studied in 1967 by Sauer, Schröder and others. Synthesis of the compound by pyrolysis
of ethylenetetracarboxilic acid was reported in 1981 by Patterson and others.
The compound was also obtained in 2009 by Taherpour, by microwave
pyrolysis
of solid Meldrum's acid
. Two molecules of the acid are believed to dimerize via an alkene linkage. The meldrum's-acid rings open via hydrolysis to form ethylenetetracarboxylic acid, and then the carboxylic acid units recyclize with different partners to form the dianhydride.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
with formula , that can be seen as the twofold anhydride of ethylenetetracarboxylic acid
Ethylenetetracarboxylic acid
Ethylenetetracarboxylic acid is an organic compound with formula , or 2C=C2.By removal of four protons, the acid yields the anion , ethylenetetracarboxylate, which is one of the oxocarbon anions Ethylenetetracarboxylic acid is an organic compound with formula , or (HO(OC)-)2C=C(-(CO)OH)2.By removal...
. Its molecular
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
backbone consists of two five-atom maleic anhydride
Maleic anhydride
Maleic anhydride is an organic compound with the formula C2H22O. It is the acid anhydride of maleic acid and in its pure state it is a colourless or white solid with an acrid odour....
rings, each containing one oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
atom and four carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
atoms, sharing a pair of carbons. It is one of the oxides of carbon
Oxocarbon
An oxocarbon or oxide of carbon is an inorganic compound consisting only of carbon and oxygen.The simplest and most common oxocarbons are carbon monoxide and carbon dioxide...
. It is a pale yellow oily liquid, soluble in dichloromethane
Dichloromethane
Dichloromethane is an organic compound with the formula CH2Cl2. This colorless, volatile liquid with a moderately sweet aroma is widely used as a solvent. Although it is not miscible with water, it is miscible with many organic solvents...
and trichloromethane.
The compound and its reactions were studied in 1967 by Sauer, Schröder and others. Synthesis of the compound by pyrolysis
Pyrolysis
Pyrolysis is a thermochemical decomposition of organic material at elevated temperatures without the participation of oxygen. It involves the simultaneous change of chemical composition and physical phase, and is irreversible...
of ethylenetetracarboxilic acid was reported in 1981 by Patterson and others.
The compound was also obtained in 2009 by Taherpour, by microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
pyrolysis
Pyrolysis
Pyrolysis is a thermochemical decomposition of organic material at elevated temperatures without the participation of oxygen. It involves the simultaneous change of chemical composition and physical phase, and is irreversible...
of solid Meldrum's acid
Meldrum's acid
Meldrum's acid or 2,2-dimethyl-1,3-dioxane-4,6-dione is an organic compound. The compound was first made in 1908 by Andrew Norman Meldrum by a condensation reaction of malonic acid with acetone in acetic anhydride and sulfuric acid. Meldrum misidentified the structure as a β-lactone of...
. Two molecules of the acid are believed to dimerize via an alkene linkage. The meldrum's-acid rings open via hydrolysis to form ethylenetetracarboxylic acid, and then the carboxylic acid units recyclize with different partners to form the dianhydride.