Chlorine tetroxide


Chlorine tetroxide is a chlorine oxide with the chemical formula ClO


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 and silver perchlorate in anhydrous diethyl ether produced it.[1]

I2 + 2 AgClO4 → 2 AgI + (ClO4)2

However, later researchers claimed that the product was iodine perchlorate.[2] 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 to gamma rays at 77 K. It is a reaction intermediate of the decomposition of dichlorine heptoxide.


The electron affinity energy of chlorine tetroxide can be figured out using the Born-Haber cycle and the lattice energy data of perchlorates. It is about 561 kJ/mol.[3]

The structure of chlorine tetroxide is uncertain, and the symmetry point group may be Cs, C2v, or Td.[4]


  1. ^ Gomberg, M. (1 February 1923). "The Reaction Between Silver Perchlorate and Iodine. Chlorine Tetra-Oxide". Journal of the American Chemical Society. 45 (2): 398–421. doi:10.1021/ja01655a017.
  2. ^ Alcock, N. W.; Waddington, T. C. (1 January 1962). "478. The reaction between iodine and silver perchlorate". Journal of the Chemical Society (Resumed): 2510. doi:10.1039/JR9620002510.
  3. ^ (in Chinese)张青莲. 《无机化学丛书》第六卷:卤素、铜分族、锌分族. 北京: 科学出版社. p. 272. ISBN 7-03-002238-6.
  4. ^ Kopitzky, Rodion; Grothe, Hinrich; Willner, Helge (16 December 2002). "Chlorine Oxide Radicals ClOx (x=1-4) Studied by Matrix Isolation Spectroscopy". Chemistry: A European Journal. 8 (24): 5601–5621. doi:10.1002/1521-3765(20021216)8:24<5601::AID-CHEM5601>3.0.CO;2-Z.