Chlorine tetroxide is an unstable

chlorine oxide Chlorine and oxygen can bond in many ways: * chlorine monoxide, , chlorine (II) oxide * chlorine peroxide, , dimer of chlorine (II) oxide * chlorine dioxide, , chlorine (IV) oxide * chloroperoxyl, *chlorine trioxide, ClO3, chlorine (VI) oxide * ...

with the

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...

History

Gomberg's mistaken 1923 production

In 1923, the famous radical chemist

Moses Gomberg Moses Gomberg (February 8, 1866 – February 12, 1947) was a chemistry professor at the University of Michigan. He was elected to the National Academy of Sciences and served as president of the American Chemical Society. Early life and education ...

proposed a production method of chlorine tetroxide. He claimed that treating

iodine Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a vi ...

and

silver perchlorate Silver perchlorate is the chemical compound with the formula AgClO4. This white solid forms a monohydrate and is mildly deliquescent. It is a useful source of the Ag+ ion, although the presence of perchlorate presents risks. It is used as a cata ...

in anhydrous

diethyl ether Diethyl ether, or simply ether, is an organic compound in the ether class with the formula , sometimes abbreviated as (see Pseudoelement symbols). It is a colourless, highly volatile, sweet-smelling ("ethereal odour"), extremely flammable liq ...

produced it. :I₂ + 2 AgClO₄ → 2 AgI + (ClO₄)₂ However, later researchers claimed that the product was

iodine perchlorate Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a viol ...

. So far, however, there is no certain evidence for the existence of iodine perchlorate either.

Eachus' 1968 production

In 1968, Eachus synthesized it by exposing

potassium chlorate Potassium chlorate is a compound containing potassium, chlorine and oxygen, with the molecular formula KClO3. In its pure form, it is a white crystalline substance. After sodium chlorate, it is the second most common chlorate in industrial use. It ...

to gamma rays at 77 K. It is a

reaction intermediate In chemistry, a reaction intermediate or an intermediate is a molecular entity that is formed from the reactants (or preceding intermediates) but is consumed in further reactions in stepwise chemical reactions that contain multiple elementary st ...

of the decomposition of

dichlorine heptoxide Dichlorine heptoxide is the chemical compound with the formula Cl2O7. This chlorine oxide is the anhydride of perchloric acid. It is produced by the careful distillation of perchloric acid in the presence of the dehydrating agent phosphorus pentox ...

Properties

The electron affinity energy of chlorine tetroxide can be figured out using the

Born–Haber cycle The Born–Haber cycle is an approach to analyze reaction energies. It was named after the two German scientists Max Born and Fritz Haber, who developed it in 1919. It was also independently formulated by Kasimir Fajans and published concurrently ...

and the

lattice energy In chemistry, the lattice energy is the energy change upon formation of one mole of a crystalline ionic compound from its constituent ions, which are assumed to initially be in the gaseous state. It is a measure of the cohesive forces that bind ...

data of

perchlorates A perchlorate is a chemical compound containing the perchlorate ion, . The majority of perchlorates are commercially produced salts. They are mainly used as oxidizers for pyrotechnic devices and to control static electricity in food packaging. Pe ...

. It is about 561 kJ/mol. The structure of chlorine tetroxide is uncertain; the

molecular point group Molecular symmetry in chemistry describes the symmetry present in molecules and the classification of these molecules according to their symmetry. Molecular symmetry is a fundamental concept in chemistry, as it can be used to predict or explain m ...

may be ''C''_s, ''C''_2v, or ''T''_d. In a solid oxygen matrix ClO₄ reacts to form ClO₆Cl, which has three double bonded oxygen atoms, and a chain of three oxygen atoms -O-O-O^• attached to the chlorine.

References

Chlorine oxides {{Inorganic-compound-stub