Imidogen
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Names | |||
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IUPAC name
λ1-Azanylidene[1]
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Other names
Aminylene
Azanylene hydridonitrogen | |||
Identifiers | |||
3D model (
JSmol ) |
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ChEBI | |||
ChemSpider | |||
66 | |||
PubChem CID
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CompTox Dashboard (EPA)
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Properties | |||
HN | |||
Molar mass | 15.015 g·mol−1 | ||
Conjugate acid
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Nitrenium ion | ||
Structure | |||
linear | |||
Thermochemistry | |||
Heat capacity (C)
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21.19 J K−1 mol−1 | ||
Std molar
entropy (S⦵298) |
181.22 kJ K−1 mol−1 | ||
Std enthalpy of (ΔfH⦵298)formation |
358.43 kJ mol−1 | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Imidogen is an
Production and properties
Imidogen can be generated by
Imidogen has a large rotational splitting and a weak spin–spin interaction, therefore it will be less likely to undergo collision-induced
The ground state of imidogen is a triplet, with a singlet excited state only slightly higher in energy.[4]
The first excited state (a1Δ) has a long lifetime as its relaxation to ground state (X3Σ−) is spin-forbidden.[5] Imidogen undergoes collision-induced intersystem crossing.[4]
Reactivity
Ignoring hydrogen atoms, imidogen is
- NH + NO → N2 + OH
- NH + NO → N2O + H
The former reaction is more favorable with a ΔH0 of −408±2 kJ/mol compared to a ΔH0 of −147±2 kJ/mol for the latter reaction.[6]
Nomenclature
The
In appropriate contexts, imidogen can be viewed as ammonia with two hydrogen atoms removed, and as such, azylidene may be used as a context-specific systematic name, according to substitutive nomenclature. By default, this name pays no regard to the radicality of the imidogen molecule. Although, in even more specific context, it can also name the non-radical state, whereas the diradical state is named azanediyl.
Astrochemistry
Interstellar NH was identified in the diffuse clouds toward
Reactions relevant to astrochemistry
Chemical reactions[10][11] Reaction Rate constant Rate/[H2]2 N + H− → NH + e− 1×10−9 3.5×10−18 NH2 + O → NH + OH 2.546×10−13 1.4×10−13 NH+
2 + e− → NH + H3.976×10−7 2.19×10−21 NH+
3 + e− → NH + H + H8.49×10−7 2.89×10−19 NH + N → N2 + H 4.98×10−11 4.36×10−16 NH + O → OH + N 1.16×10−11 1.54×10−14 NH + C+ → CN+ + H 7.8×10−10 4.9×10−19 NH + H+
3 → NH+
2 + H21.3×10−9 3.18×10−19 NH + H+ → NH+ + H 2.1×10−9 4.05×10−20
Within diffuse clouds H− + N → NH + e− is a major formation mechanism. Near chemical equilibrium important NH formation mechanisms are recombinations of NH+
2 and NH+
3 ions with electrons. Depending on the radiation field in the diffuse cloud, NH2 can also contribute.
NH is destroyed in diffuse clouds by photodissociation and photoionization. In dense clouds NH is destroyed by reactions with atomic oxygen and nitrogen. O+ and N+ form OH and NH in diffuse clouds. NH is involved in creating N2, OH, H, CN+, CH, N, NH+
2, NH+ for the interstellar medium.
NH has been reported in the diffuse
See also
References
- IUPAC Red Book2005
- ISBN 978-0-08-037941-8.
- ^ S2CID 28355332.
- ^ .
- ^ .
- .
- ^ doi:10.1086/186100.
- .
- doi:10.1086/154775.
- doi:10.1086/190665.
- ^ "The UMIST Database for Astrochemistry 2012/ astrochemistry.net".
- S2CID 36447926.
- doi:10.1063/1.478453.
- ISSN 0004-6361.
- S2CID 119236652.
External links
- Buchowiecki, Marcin (28 January 2021). "Uncertainty of High Temperature Heat Capacities: The Case Study of the NH Radical". The Journal of Physical Chemistry A. 125 (3): 795–800. PMID 33448217.