Peroxodicarbonate
Encyclopedia
In chemistry
, peroxodicarbonate is a divalent
anion with formula C2O62−. It is one of the oxocarbon anion
s, that consist solely of carbon
and oxygen
. Its molecular structure can be viewed as two carbonate
anions joined so as to form a peroxide
bridge -O-O-.
The anion is formed, together with peroxocarbonate
CO42−, at the negative electrode
during electrolysis
of molten lithium carbonate
. The anion can also be obtained by electrolysis of a saturated solution of rubidium carbonate in water.
Potassium peroxodicarbonate K2C2O6 was obtained by Constam and von Hansen in 1895; its crystal structure was determined only in 2002. It too can be obtained by electrolysis of a saturated potassium carbonate solution at −20°C. It is a light blue crystalline solid that decomposes at 141°C, releasing oxygen
and carbon dioxide, and decomposes slowly at lower temperatures.
Rubidium peroxodicarbonate is a light blue crystalline solid that decomposes at 424 K. Its structure was published in 2003. In both salts, each of the two carbonate units is planar. In the rubidium
salt the whole molecule is planar, whereas in the potassium
salt the two units lie on different and nearly perpendicular planes, both of which contain the O-O bond.
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
, peroxodicarbonate is a divalent
Valence (chemistry)
In chemistry, valence, also known as valency or valence number, is a measure of the number of bonds formed by an atom of a given element. "Valence" can be defined as the number of valence bonds...
anion with formula C2O62−. It is one of the oxocarbon anion
Oxocarbon anion
In chemistry, an oxocarbon anion is a negative ion consisting solely of carbon and oxygen atoms, and therefore having the general formula CxOyn− for some integers x, y, and n....
s, that consist solely of 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...
and 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...
. Its molecular structure can be viewed as two carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
anions joined so as to form a peroxide
Peroxide
A peroxide is a compound containing an oxygen–oxygen single bond or the peroxide anion .The O−O group is called the peroxide group or peroxo group. In contrast to oxide ions, the oxygen atoms in the peroxide ion have an oxidation state of −1.The simplest stable peroxide is hydrogen peroxide...
bridge -O-O-.
The anion is formed, together with peroxocarbonate
Peroxocarbonate
In chemistry, peroxocarbonate is a divalent anion with formula CO42−. It is an oxocarbon anion that consists solely of carbon and oxygen. It would be the anion of an hypothetical peroxocarbonic acid HO–CO–O–OH....
CO42−, at the negative electrode
Electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit...
during electrolysis
Electrolysis
In chemistry and manufacturing, electrolysis is a method of using a direct electric current to drive an otherwise non-spontaneous chemical reaction...
of molten lithium carbonate
Lithium carbonate
Lithium carbonate is a chemical compound of lithium, carbon, and oxygen with the formula Li2CO3. This colorless salt is widely used in the processing of metal oxides and has received attention for its use in psychiatry. It is found in nature as the rare mineral zabuyelite.-Properties:Like almost...
. The anion can also be obtained by electrolysis of a saturated solution of rubidium carbonate in water.
Potassium peroxodicarbonate K2C2O6 was obtained by Constam and von Hansen in 1895; its crystal structure was determined only in 2002. It too can be obtained by electrolysis of a saturated potassium carbonate solution at −20°C. It is a light blue crystalline solid that decomposes at 141°C, releasing 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...
and carbon dioxide, and decomposes slowly at lower temperatures.
Rubidium peroxodicarbonate is a light blue crystalline solid that decomposes at 424 K. Its structure was published in 2003. In both salts, each of the two carbonate units is planar. In the rubidium
Rubidium
Rubidium is a chemical element with the symbol Rb and atomic number 37. Rubidium is a soft, silvery-white metallic element of the alkali metal group. Its atomic mass is 85.4678. Elemental rubidium is highly reactive, with properties similar to those of other elements in group 1, such as very rapid...
salt the whole molecule is planar, whereas in the potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
salt the two units lie on different and nearly perpendicular planes, both of which contain the O-O bond.