Nitrogen trichloride
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| Nitrogen trichloride | |
|---|---|
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| General | |
| Other names | Trichloramine Agene® Nitrogen(III) chloride Trichloroazane |
| Molecular formula | NCl3 |
| Molar mass | 120.36 g/mol |
| Appearance | yellow oily liquid |
| CAS number | [10025-85-1] |
| Properties | |
| Density and phase | 1.635 g/mL, liquid |
| Solubility in water | Immiscible slowly decomposes |
| Melting point | -40 °C (233 K) |
| Boiling point | 71 °C (344 K) |
| Viscosity | ? mPa·s at ? °C |
| Structure | |
| Molecular shape | trigonal pyramidal |
| Bond length | 175.3 pm (N–Cl) |
| Bond angle | 107.78° (Cl–N–Cl) |
| Dipole moment | 0.6 D |
| Thermodynamic data | |
| Standard enthalpy of formation ΔfH°solid |
+232 kJ/mol |
| Standard molar entropy S°solid |
? J.K−1.mol−1 |
| Safety data | |
| EU classification | not listed |
| NFPA 704 |
3
2
4
OX
|
| Explosive limits | explosive liquid |
| RTECS number | QW974000 |
| Related compounds | |
| Other anions | Nitrogen trifluoride Nitrogen tribromide Nitrogen triiodide |
| Other cations | Phosphorus trichloride Arsenic trichloride |
| Related chloramines | Chloramine Dichloramine |
| Related compounds | Nitrosyl chloride |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Nitrogen trichloride, also known as trichloramine, is the chemical compound with the formula NCl3. This yellow, oily, pungent-smelling liquid, is often encountered as a byproduct of chemical reactions between ammonia-derivatives and chlorine. In pure form, NCl3 is highly unstable, explosively so. Nitrogen trichloride was trademarked as Agene and used to artificially bleach and age flour. Nitrogen trichloride can form in small amounts when public water supplies are disinfected with monochloramine.
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[edit] Preparation and structure
The compound is prepared by treatment of ammonium salts, such as ammonium nitrate with chlorine:
- 4 NH3 + 3 Cl2 → NCl3 + 3 NH4Cl
Intermediates in this coversion include chloramine and dichloramine, NH2Cl and NHCl2, respectively.
NCl3 is a pyramidal molecule, not unlike ammonia. The N-Cl distances are 1.76 Â, and the Cl-N-Cl angles are 107°.[1]
[edit] Safety
Nitrogen trichloride is a dangerous explosive, being sensitive to light, heat, and organic compounds. An explosion from NCl3 blinded Sir Humphry Davy temporarily, inducing him to hire Michael Faraday as a coworker. In 2003, Belgian researchers reported a possible link between NCl3 and rising numbers of childhood asthma cases.[2] It also causes severe brain damage.[citation needed]
[edit] References
- ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
- ^ Bernard A, Carbonnelle S, de Burbure C, Michel O, Nickmilder M (2006). "Chlorinated pool attendance, atopy, and the risk of asthma during childhood". Enviromental Health Perspectives 114 (10).
[edit] Further reading
- Jander, J. (1976). Adv. Inorg. Chem. Radiochem. 19: 2.
- P. Kovacic, M. K. Lowery, K. W. Field (1970). "Chemistry of N-bromamines and N-chloramines". Chemical Reviews 70 (6). DOI:10.1021/cr60268a002.
- Hartl H, Schoner J, Jander J, Schulz H (1975). "Structure of Solide Nitrogen-Trichloride (-125°C)". Zeitschrift für Anorganische und Allgemeine Chemie 413 (1).
- Cazzoli G., Favero P. G., Dalborgo A. (1974). "Molecula-Structure, Nuclear-Quadruple Coupling-Constant and Dipole-Moment of Nitrogen Trichloride from Microwave Spectroscopy". Journal of Molecular Spectroscopy 50 (1-3).
- Bayersdo, L., Engelhar, U., Fischer, J., Hohne, K., Jander, J. (1969). "Nitrogen-chlorine compounds: Infrared spectra and Raman spectra of nitrogen trichloride". Zeitschrift Fur anorgansische und allgemeine chemie 366 (3-4).
