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Names | |||
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IUPAC name
Dichlorine hexoxide
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Other names
Chlorine trioxide; Chloryl perchlorate; Chlorine(V,VII) oxide
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Identifiers | |||
3D model (
JSmol)
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ChemSpider |
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PubChem
CID
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Properties | |||
Cl2O6 | |||
Molar mass | 166.901 g/mol | ||
Appearance | red liquid | ||
Density | 1.65 g/cm3 | ||
Melting point | 3.5 °C (38.3 °F; 276.6 K) | ||
Boiling point | 200 °C (392 °F; 473 K) | ||
Reacts | |||
Hazards | |||
Occupational safety and health (OHS/OSH): | |||
Main hazards
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oxidizer | ||
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Dichlorine hexoxide is the
chemical compound with the
molecular formula Cl
2O
6, which is correct for its gaseous state. However, in liquid or solid form, this
chlorine oxide ionizes into the dark red ionic compound chloryl perchlorate [ClO
2+
[ClO
4−
, which may be thought of as the mixed
anhydride of
chloric and
perchloric acids. This compound is a notable perchlorating agent.
[1]
It is produced by reaction between chlorine dioxide and excess ozone:
It was originally reported to exist as the monomeric chlorine trioxide ClO3 in gas phase, [2] but was later shown to remain an oxygen-bridged dimer after evaporation and until thermal decomposition into chlorine perchlorate, Cl2O4, and oxygen. [3] The compound ClO3 was then rediscovered. [4]
It is a dark red fuming liquid at room temperature that crystallizes as a red ionic compound, chloryl perchlorate, [ClO
2+
[ClO
4−
. The red color shows the presence of
chloryl ions. Thus, chlorine's formal oxidation state in this compound remains a mixture of chlorine (V) and chlorine (VII) both in the gas phase and when condensed; however by breaking one oxygen-chlorine bond some electron density does shifts towards the chlorine (VII).
Cl2O6 is
diamagnetic and is a very strong oxidizing agent. Although stable at room temperature, it explodes violently on contact with organic compounds
[5] and reacts with
gold to produce the
chloryl salt
[ClO
2+
[Au(ClO
4)
4−
.
[6] Many other reactions involving Cl2O6 reflect its ionic structure, [ClO
2+
[ClO
4−
, including the following:
[7]
Nevertheless, it can also react as a source of the ClO3 radical: