| IUPAC name
| Other names
|Molar mass||182.901 g/mol|
|Density||1.811 g/cm3 (20 °C)|
|Melting point||−91.57 °C (−132.83 °F; 181.58 K)|
|Boiling point||82 °C (180 °F; 355 K)|
|Hydrolyzes to form perchloric acid|
|Solubility|| Reacts with organic solvents|
Miscible with carbon tetrachloride
Soluble in benzene, phosphoryl chloride
|Vapor pressure||72 mmHg (20 °C)|
Std enthalpy of
|Safety data sheet||None|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Dichlorine heptoxide is a chemical compound, a clear, oily liquid. It is a strong oxidizing agent. The compound has the chemical formula Cl2O7.
Dichlorine heptoxide reacts exothermically with water to yield perchloric acid.
- 2 RNH2 + Cl2O7 → 2 RNHClO3 + H2O
- 2 R2NH + Cl2O7 → 2 R2NClO3 + H2O
Unlike other chlorine oxides, dichlorine heptoxide does not attack sulfur, phosphorus, or paper at standard conditions.
Dichlorine heptoxide is a clear, oily, very volatile liquid. It reacts with water and organic compounds, but dissolves in halocarbons.
Dichlorine heptoxide is not available due to its hazards, but can be made in situ.
This preparation is extremely dangerous because of the explosive and very oxidizing nature of Cl2O7.
- 12 HClO4 + P4O10 → 4 H3PO4 + 6 Cl2O7
The reaction has to be performed under 0 °C, optimally between -70 °C to -10 °C. The resulting product has to be distilled very carefully under vacuum to safely obtain pure dichlorine heptoxide.
- Make pure perchloric acid
Dichlorine heptoxide is explosive and a strong oxidizer, that can be set off in contact with flame or mechanical shock, or in presence of iodine. It is very corrosive and toxic in contact with skin, mouth or eyes.
Best to use it as quickly as possible.
Dichlorine heptoxide can be safely neutralized by slowly adding it in cold water or ice, followed by neutralization with a base.
- Rosolovskii, V. Ya.; Zinov'ev, A. A.; Prokhorov, V. A.; Zhurnal Neorganicheskoi Khimii; vol. 5; (1960); p. 334 - 335; Zhurnal Neorganicheskoi Khimii; vol. 5; (1960); p. 692 - 694