Trifluoroiodomethane

Trifluoroiodomethane, also referred to as trifluoromethyl iodide is a halomethane with the formula CF₃I. It is an experimental alternative to Halon 1301 (CBrF₃) in unoccupied areas [2]. It would be used as a gaseous fire suppression flooding agent for in-flight aircraft and electronic equipment fires.

It has been reviewed as environment-safe and non-toxic.^[1][2]

Additional recommended knowledge

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Chemistry

It is used in the rhodium-catalyzed α-trifluoromethylation of α,β-unsaturated ketones.^[3]

In the presence of sunlight or at temperatures above 100°C it undergoes decomposition with hazardous by-products as hydrogen fluoride (HF), hydrogen iodide (HI) and carbonyl fluoride (COF₂).

Environmental effects

It contains carbon, fluorine, and iodine atoms. Although iodine is several hundred times more efficient at destroying stratospheric ozone than chlorine, experiments have shown that because the weak C-I bond breaks easily under the influence of water (owing to the electron-attracting fluorine atoms), trifluoroiodomethane has an ozone depleting potential less than one-thousandth that of Halon 1301 (0.008-0.01). Its atmospheric lifetime, at less than 1 month, is less than 1 percent that of Halon 1301, and less even than hydrogen chloride formed from volcanoes.

There is, however, still the problem of the C-F bonds absorbing in the atmospheric window. Thus, even after decomposition, trifluoroiodomethane is likely to be a very effective greenhouse gas.

Further reading

For further information, a report from the Board on Environmental Studies and Toxicology of the National Academy of Sciences entitled Iodotrifluoromethane: Toxicity Review (2004) is available for free online reading and research in several formats.

References

• Duan Y. Y., Shi L., Sun L. Q., Zhu M. S., Han L. Z. (March 2000). "Thermodynamic Properties of Trifluoroiodomethane (CF3I)". International Journal of Thermophysics 21 (2): 393-404(12). Retrieved on 2007-06-02.
• Duan Y. Y., Shi L., Zhu M. S., Han L. Z. (January 1999). "Surface tension of trifluoroiodomethane (CF3I)". Fluid Phase Equilibria 154 (1): 71-77(7). doi:10.1016/S0378-3812(98)00439-7. Retrieved on 2007-06-02.
• Duan Y. Y., Shi L., Sun L. Q., Zhu M. S., Han L. Z. (1997). "Thermal Conductivity of Gaseous Trifluoroiodomethane (CF3I)". J. Chem. Eng. Data 42 (5): 890-893 (4). Retrieved on 2007-06-02.
• Duan Y. Y., Shi L., Zhu M. S., Han L. Z. (1999). "Critical Parameters and Saturated Density of Trifluoroiodomethane (CF3I)". J. Chem. Eng. Data 44 (3): 501 -504. Retrieved on 2007-06-02.
• Chamber Studies of Photolysis and Hydroxyl Radical Reactions of Trifluoroiodomethane

1. ^ Acute Toxicity Evaluation of Halon Replacement Trifluoroiodomethane (CF₃I)
2. ^ Reproductive Toxicity Screen of Trifluoroiodomethane (CF31) in Sprague-Dawley Rats
3. ^ [1]

See also

• Haloalkane
• Halomethane
• Tetrahalomethane
• Bromotrifluoromethane
• Tetrafluoromethane