chemistry Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...

, chloryl refers to a triatomic

cation An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

with

chemical formula 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, such as pare ...

. This species has the same general structure as

chlorite The chlorite ion, or chlorine dioxide anion, is the halite (oxyanion), halite with the chemical formula of . A chlorite (compound) is a compound that contains this group, with chlorine in the oxidation state of +3. Chlorites are also known as s ...

() but it is electronically different, with chlorine having a +5

oxidation state In chemistry, the oxidation state, or oxidation number, is the hypothetical Electrical charge, charge of an atom if all of its Chemical bond, bonds to other atoms are fully Ionic bond, ionic. It describes the degree of oxidation (loss of electrons ...

(rather than the +3 of

). This makes it a rare example of a positively charged oxychloride. Chloryl compounds, such as and lO₂RuF₆], are all highly reactive and react violently with water and most organic compounds.

Structure

The cation is

isoelectronic Isoelectronicity is a phenomenon observed when two or more molecules have the same structure (positions and connectivities among atoms) and the same electronic configurations, but differ by what specific elements are at certain locations in th ...

with , and has a bent structure with a bond angle close to 120°. The Cl–O bond is of

bond order In chemistry, bond order is a formal measure of the multiplicity of a covalent bond between two atoms. As introduced by Gerhard Herzberg, building off of work by R. S. Mulliken and Friedrich Hund, bond order is defined as the difference between t ...

1.5, with its Lewis structure consisting of a

double bond In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...

and a

dative bond In coordination chemistry, a coordinate covalent bond, also known as a dative bond, dipolar bond, or coordinate bond is a kind of two-center, two-electron covalent bond in which the two electrons derive from the same atom. The bonding of metal io ...

which does not utilize d-orbitals. The red color of is caused by electron transitions into an antibonding orbital. The analogous transition in is not in the

visible spectrum The visible spectrum is the spectral band, band of the electromagnetic spectrum that is visual perception, visible to the human eye. Electromagnetic radiation in this range of wavelengths is called ''visible light'' (or simply light). The optica ...

, so is colorless. The strength of interaction with the counterion affects the energy of this antibonding orbital; thus, in colorless chloryl compounds, strong interactions with the counterion, corresponding with the higher covalent character of the bonding, shift the transition energy out of the visible spectrum.

Compounds

Chloryl-hexafluoroantimonate-xtal-2008-Cl-coordination-CM-3D-ellipsoids

There are two categories of chloryl compounds. The first category is colorless, and includes

chloryl fluoride Chloryl fluoride is the chemical compound with the formula . This compound is a gas boiling at −6 °C. It is commonly encountered as side-product in reactions of chlorine fluorides with oxygen sources. It is the acyl fluoride of chloric ac ...

(). These are moderately reactive. Although named as an ionic "chloryl" compound, chloryl fluoride is more a covalent compound than an ionic compound of fluoride and chloryl cation. The second category features red-colored compounds that are highly reactive. These include

chloryl fluorosulfate In chemistry, chloryl refers to a triatomic cation with chemical formula . This species has the same general structure as chlorite () but it is electronically different, with chlorine having a +5 oxidation state (rather than the +3 of chlorite). ...

, , and dichloryl trisulfate, . These chloryl compounds form red solutions in

fluorosulfuric acid Fluorosulfuric acid (IUPAC name: sulfurofluoridic acid) is the inorganic compound with the chemical formula . It is one of the strongest acids commercially available. It is a tetrahedral molecule and is closely related to sulfuric acid, , substitu ...

, and do contain a red-colored cation which dissociates in solution. In the solid state, the Raman and

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

spectra indicate strong interactions with the counterion. Not all chloryl compounds in the solid state are necessarily ionic. The reaction products of with and are assumed to be molecular

adduct In chemistry, an adduct (; alternatively, a contraction of "addition product") is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components. The resultant is ...

s rather than true

salts In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions ( cations) and negatively charged ions (anions), which results in a compound with no net electric charge (electrically neutral). ...

. One notable chloryl compound is

dichlorine hexoxide Dichlorine hexoxide is the chemical compound with the molecular formula or , 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 or dioxochlor ...

, which exists as an ionic compound more accurately described as ''chloryl perchlorate'', . It is a red fuming liquid under standard conditions. Chloryl compounds are best prepared by the reaction of with a strong

Lewis acid A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any ...

. For example: : + → lO₂AsF₆] Other synthesis routes are also possible, including: :5 + 3 → 2 lO₂AsF₆] + + 4 : + 2 → lO₂SbF₆] + + Salt metathesis reaction, Metathesis reactions may be carried out with strong

Lewis base A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any sp ...

s. For example, the reaction of the hexafluoroplatinate salt with

nitryl fluoride Nitryl fluoride, NO2F, is a colourless gas and strong oxidizing agent, which is used as a fluorinating agent and has been proposed as an oxidiser in rocket propellants (though never flown). It is a molecular species, not ionic, consistent with it ...

yields the

nitronium The nitronium ion, , is a cation. It is an onium ion because its nitrogen atom has +1 charge, similar to ammonium ion . It is created by the removal of an electron from the paramagnetic nitrogen dioxide molecule A molecule is a grou ...

salt: : lO₂PtF₆] + → O₂PtF₆] +

References

External links

*{{Commonscatinline, Chloryl cation Chloryl compounds, Cations Oxycations Chlorine oxides