نيتروسونيوم

نيتروسونيوم
Nitrosonium-2D-dimensions.svg
Nitrosonium-3D-balls.png
الأسماء
اسم أيوپاك النظامي
Oxidonitrogen(1+)[1]
أسماء أخرى
Nitrosonium
Iminooxidanium
المُعرِّفات
رقم CAS
3D model (JSmol)
اختصارات NO(+)
ChEBI
ChemSpider
مرجع Gmelin 456
ما لم يُذكر غير ذلك، البيانات المعطاة للمواد في حالاتهم العيارية (عند 25 °س [77 °ف]، 100 kPa).
مراجع الجدول

The nitrosonium ion is NO+
, in which the nitrogen atom is bonded to an oxygen atom with a bond order of 3, and the overall diatomic species bears a positive charge. It can be viewed as nitric oxide with one electron removed. This ion is usually obtained as the following salts: NOClO
4
, NOSO
4
H
(nitrosylsulfuric acid, more descriptively written ONSO
3
OH
) and NOBF
4
. The ClO
4
and BF
4
salts are slightly soluble in acetonitrile CH
3
CN
. NOBF4 can be purified by sublimation at 200–250 °C and 0.01 mmHg (1.3 Pa).

NO+
is isoelectronic with CO, CN
and N
2
. It arises via protonation of nitrous acid:

HONO + H+ في اتزان مع NO+ + H2O

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chemical properties

Hydrolysis

NO+
reacts readily with water to form nitrous acid:

NO+ + H
2
O → HONO + H+

For this reason, nitrosonium compounds must be protected from water or even moist air. With base, the reaction generates nitrite:

NO+ + 2 NaOH → NaNO
2
+ Na+ + H
2
O

As a diazotizing agent

NO+
reacts with aryl amines, ArNH
2
, to give diazonium salts, ArN+
2
. The resulting diazonium group is easily displaced (unlike the amino group) by a variety of nucleophiles.

Reaction of nitrosonium with aniline to form a diazonium salt

As an oxidizing agent

NO+
, e.g. as NOBF
4
, is a strong oxidizing agent:[2]

  • vs. ferrocene/ferrocenium, [NO]+
    in CH
    2
    Cl
    2
    solution has a redox potential of 1.00 V (or 1.46–1.48 V vs SCE),
  • vs. ferrocene/ferrocenium, [NO]+
    in CH
    3
    CN
    solution has a redox potential of 0.87 V vs. (or 1.27–1.25 V vs SCE).

NOBF
4
is a convenient oxidant because the byproduct NO is a gas, which can be swept from the reaction using a stream of N
2
. Upon contact with air, NO forms NO
2
, which can cause secondary reactions if it is not removed. NO
2
is readily detectable by its characteristic orange color.

Nitrosylation of arenes

Electron-rich arenes are nitrosylated using NOBF4.[3] One example involves anisole:

CH3OC6H5 + NOBF4 → CH3OC6H4NO + HBF4

Nitrosonium, NO+
, is sometimes confused with nitronium, NO+2, the active agent in nitrations. These species are quite different, however. Nitronium is a more potent electrophile than is nitrosonium, as anticipated by the fact that the former is derived from a strong acid (nitric acid) and the latter from a weak acid (nitrous acid).

As a source of nitrosyl complexes

NOBF4 reacts with some metal carbonyl complexes to yield related metal nitrosyl complexes.[4] One must be careful that [NO]+ is transferred vs. electron transfer (see above).

(C6Et6)Cr(CO)3 + NOBF4 → [(C6Et6)Cr(CO)2(NO)]BF4 + CO

انظر أيضاً

المصادر

  1. ^ Nomenclature of Inorganic Chemistry : IUPAC Recommendations 2005 (Red Book). Cambridge: The Royal Society of Chemistry. 2005. p. 315. ISBN 978-0-85404-438-2.
  2. ^ N. G. Connelly, W. E. Geiger (1996). "Chemical Redox Agents for Organometallic Chemistry". Chem. Rev. 96 (2): 877–910. doi:10.1021/cr940053x. PMID 11848774.
  3. ^ E. Bosch and J. K. Kochi. "Direct Nitrosation of Aromatic Hydrocarbons and Ethers with the Electrophilic Nitrosonium Cation". Journal of Organic Chemistry, 1994, volume 59, pp. 5573–5586.
  4. ^ T. W. Hayton, P. Legzdins, W. B. Sharp. "Coordination and Organometallic Chemistry of Metal-NO Complexes". Chemical Reviews 2002, volume 102, pp. 935–991.