Chlorine tetroxide is an unstable chlorine 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 proposed a production method of chlorine tetroxide. He claimed that treating

iodine Iodine is a chemical element with the Symbol (chemistry), 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 silver perchlorate 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 vio ...

. 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 ...

of the decomposition of dichlorine heptoxide.

Properties

The electron affinity energy of chlorine tetroxide can be figured out using the Born–Haber cycle 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 b ...

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. ...

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