Nitrosyl perchlorate

{{Chembox

| ImageFile = NOClO4.svg

| ImageSize = 240px

| ImageAlt = Structure of nitrosyl perchlorate

| ImageFile1 = Nitrosyl perchlorate.png

| IUPACNames = Perchloryl nitrite

Nitrosonium perchlorate

| OtherNames = Nitrosyl perchlorate
Perchloric nitrous anhydride

| Section1 = {{Chembox Identifiers

| CASNo = 15605-28-4

| CASNo_Ref =

| PubChem = 177613

| ChemSpiderID = 154629

| StdInChI = 1S/ClNO5/c3-1(4,5)7-2-6

| StdInChIKey = ONKVXKHGDFDPFZ-UHFFFAOYSA-N

| SMILES = N(=O)OCl(=O)(=O)=O

}}

| Section2 = {{Chembox Properties

| Formula = {{chem2|NOClO4}}

| MolarMass = 129.46 g/mol

| Appearance = white solid

| Density = 2.169 g/cm³

| MeltingPtC = 100

| MeltingPt_notes = (decomposes)

| BoilingPt =

| Solubility = Reacts

}}

| Section3 = {{Chembox Structure

| Coordination =

| CrystalStruct = Rhombic

| MolShape =

}}

| Section4 = {{Chembox Thermochemistry

| DeltaGf =

| DeltaHc =

| DeltaHf = −154.0 kJ/mol

| Entropy =

| HeatCapacity =

}}

Nitrosyl perchlorate or nitrosonium perchlorate is the inorganic compound with the formula {{chem2|NO(ClO4)}}. A hygroscopic white solid, it is the salt of the nitrosonium cation with the perchlorate anion. It is an oxidant and strong electrophile, but has fallen out of use with the availability of the closely related salt nitrosonium tetrafluoroborate {{chem2|NO(BF4)}}.

Preparation

Nitrosyl perchlorate was first produced in 1909 by passing dinitrogen trioxide gas into concentrated perchloric acid:{{cite journal |author1=K. A. Hofmann |author2=Graf Armin Zedtwitz |title=Nitrosyl-perchlorat: das Anhydrid der salpetrigen Säure mit der Überchlorsäure |journal=Berichte der deutschen chemischen Gesellschaft |date=1909 |volume=42 |issue=2 |pages=2031-2034 |doi=10.1002/cber.19090420285 |trans-title=Nitrosyl perchlorate: the anhydride of nitrous acid with perchloric acid |language=de}}

:{{chem2|N2O3 + 2 HClO4 → 2 NOClO4 + H2O}}

A standard laboratory preparation involves treating a mixture of nitric oxide and nitrogen dioxide with concentrated perchloric acid:{{cite book|author=M. Schmeisser|chapter=Nitrosyl perchlorate|title=Handbook of Preparative Inorganic Chemistry, 2nd Ed. |editor=G. Brauer|publisher=Academic Press|year=1963|place=NY,NY|volume=2pages=320}}

:{{chem2|NO2 + NO + 2 HClO4 → 2 NOClO4 + H2O}}

It can also be prepared by passing dinitrogen trioxide gas into a mixture of sodium perchlorate and sulfuric acid. A much purer product can be produced by reacting dichlorine heptoxide with anhydrous nitric acid.{{cite journal |title=Perchlorates: A Review of their Thermal Decomposition and Combustion, with an Appendix on Perchloric Acid |journal=R.P.E. Technical Report |date=1968 |volume=68 |issue=11 |url=https://apps.dtic.mil/sti/pdfs/AD0857556.pdf |access-date=28 December 2023}}

Structure

The structure of NOClO₄ has not been elucidated by X-ray crystallography. However, the Raman spectroscopy of NOClO₄ suggests that nitrosyl perchlorate consists of distinct NO⁺ and ClO₄^– ions.{{cite journal |author1=William Rogie Angus |author2=Alan H. Leckie |title=Investigations of raman spectra II—The raman spectra of perchloric acid and nitrosyl perchlorate |journal=Proceedings of the Royal Society of London. Series A - Mathematical and Physical Sciences |date=1935 |volume=150 |issue=871 |pages=615-618 |doi=10.1098/rspa.1935.0125 |language=en}}

Properties

Nitrosyl perchlorate decomposes at 100 °C to nitronium perchlorate, which then subsequently decomposes into chlorine and nitrogen oxides.{{cite journal |last1=Markowitz |first1=Meyer M. |last2=Ricci |first2=John E. |last3=Goldman |first3=Richard J. |last4=Winternitz |first4=Paul F. |title=The Chemical Properties of Nitrosyl Perchlorate: The Neutralization Equivalent |journal=J. Am. Chem. Soc. |date=1 July 1957 |volume=79 |issue=14 |pages=3659–3661 |doi=10.1021/ja01571a013 |url=https://pubs.acs.org/doi/abs/10.1021/ja01571a013 |access-date=31 October 2023}}{{cite journal |last1=Glasner |first1=A. |last2=Pelly |first2=I. |last3=Steinberg |first3=M. |title=Thermal decomposition of nitrosyl perchlorate and nitryl perchlorate—I: Mechanism of decomposition |journal=J. Inorg. Nucl. Chem. |date=4 February 1969 |volume=31 |pages=3395–3404 |doi=10.1016/0022-1902(69)80322-2 |url=https://dx.doi.org/10.1016/0022-1902%2869%2980322-2 |access-date=31 October 2023}}

This compound hydrolyzes in water to form nitrous acid and perchloric acid:

:NOClO₄ + H₂O → HNO₂ + HClO₄

With a strong base, such as sodium hydroxide, it produces perchlorate, nitrite, nitrate, nitric oxide, and water. This reaction was used to calculate the heat of formation of nitrosyl perchlorate. As a strong oxidizer, nitrosyl perchlorate reacts explosively with various organic compounds, such as ethanol, acetone, ether, and aniline.

Uses

Nitrosyl perchlorate is used in the laboratory as a perchlorating agent.{{cite journal |author1=Thomas J. Wierenga |author2=J. Ivan Legg |title=Synthesis and characterization of cobalt(III) nicotinic acid complexes |journal=Inorganic Chemistry |date=1982 |volume=21 |issue=7 |pages=2881–2885 |doi=10.1021/ic00137a071 |language=en}}{{cite journal |author1=M.M. Markowitz |author2=J.E. Ricci |author3=R.J. Goldman |author4=P.F. Winternitz |title=A new method for the conversion of inorganic salts to the corresponding perchlorates |journal=Journal of Inorganic and Nuclear Chemistry |date=1960 |volume=16 |issue=1-2 |pages=159-161 |doi=10.1016/0022-1902(60)80104-2 |language=en}} Although it has been investigated as a potential rocket propellant, it has not been commercialized.

Nitrosyl perchlorate

Preparation

Structure

Properties

Uses

References

Further reading