Dichlorine heptoxide is the chemical compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 with the formula

Chemical formula

A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 Cl₂O₇. This chlorine oxide

Chlorine oxide

Chlorine and oxygen can bond in many different ways:* chlorine monoxide * chlorine dioxide * chlorine trioxide * dichlorine monoxide * dichlorine dioxide * dichlorine trioxide...

 is the anhydride of perchloric acid

Perchloric acid

Perchloric acid is the inorganic compound with the formula HClO4. Usually encountered as an aqueous solution, this colourless compound is a strong acid comparable in strength to sulfuric and nitric acids. It is a powerful oxidizer, but its aqueous solutions up to appr. 70% are remarkably inert,...

. It is produced by the careful distillation of perchloric acid in the presence of the dehydrating agent phosphorus pentoxide

Phosphorus pentoxide

Phosphorus pentoxide is a chemical compound with molecular formula P4O10 . This white crystalline solid is the anhydride of phosphoric acid. It is a powerful desiccant.-Structure:...

:

2 HClO₄ + P₄O₁₀ → Cl₂O₇ + H₂P₄O₁₁

The chlorine(VII) oxide can be distilled off from the mixture.

It may also be formed by illumination on mixtures of chlorine and ozone

Ozone

Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope...

. It slowly hydrolyzes back to perchloric acid

Perchloric acid

Perchloric acid is the inorganic compound with the formula HClO4. Usually encountered as an aqueous solution, this colourless compound is a strong acid comparable in strength to sulfuric and nitric acids. It is a powerful oxidizer, but its aqueous solutions up to appr. 70% are remarkably inert,...

, which is also hazardous when anhydrous

Anhydrous

As a general term, a substance is said to be anhydrous if it contains no water. The way of achieving the anhydrous form differs from one substance to another...

.

Structure

Cl₂O₇ is an endothermic molecule, which means that it is intrinsically unstable.

2 Cl₂O₇ → 2 Cl₂ + 7 O₂ (ΔH = -135 kJ/mol)

Cl₂O₇ is bent with Cl-O-Cl angle of 118.6° giving the molecule C₂ symmetry

Symmetry group

The symmetry group of an object is the group of all isometries under which it is invariant with composition as the operation...

. The terminal Cl-O distances are 1.709 Å and the Cl=O distances are 1.405 Å. In this compound, chlorine exists in its highest formal oxidation state

Oxidation state

In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. The formal oxidation state is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic. Oxidation states are typically represented by...

 of +7, although the bonding in this molecule is significantly covalent.

Chemistry

Dichlorine heptoxide reacts with primary and secondary amine

Amine

Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...

s in carbon tetrachloride

Carbon tetrachloride

Carbon tetrachloride, also known by many other names is the organic compound with the formula CCl4. It was formerly widely used in fire extinguishers, as a precursor to refrigerants, and as a cleaning agent...

 solution to yield N-perchloryls:

2 + → 2 +

2 + → 2 +

It also reacts with olefin

Alkene

In organic chemistry, an alkene, olefin, or olefine is an unsaturated chemical compound containing at least one carbon-to-carbon double bond...

s to give alkyl perchlorates. For example, it reacts with propene in carbon tetrachloride solution to yield isopropyl perchlorate and 1-chloro-2-propyl perchlorate.

Safety

Although it is the most stable chlorine oxide, Cl₂O₇ is a strong oxidizer as well as an explosive that can be set off with flame or mechanical shock, or by contact with iodine

Iodine

Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....

. Nevertheless, it is less strongly oxidising than the other chlorine oxides, and does not attack sulfur

Sulfur

Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...

, phosphorus

Phosphorus

Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...

, or paper

Paper

Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....

 when cold. It has the same effects on the human body as elemental chlorine

Chlorine

Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...

, and requires the same precautions.