Chlorine pentafluoride

Chlorine pentafluoride
Identifiers
13637-63-3 Yes
Jmol-3D images Image
PubChem 61654
RTECS number FO2975000
Properties
ClF5
Molar mass 130.445 g mol−1
Appearance colorless gas
Density 4.5 g/cm3
Melting point −103 °C (−153 °F; 170 K)
Boiling point −13.1 °C (8.4 °F; 260.0 K)
hydrolyzes
Structure
Molecular shape Square pyramidal
Thermochemistry
310.73 J K−1 mol−1
Std enthalpy of
formation (ΔfHo298)
−238.49 kJ mol−1
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Chlorine pentafluoride is an interhalogen compound with formula ClF5. This colourless gas is an strong oxidant that was once a candidate oxidizer for rockets. The molecule adopts a square pyramidal structure with C4v symmetry,[1] as confirmed by its high resolution 19F NMR spectrum.[2]

Preparation

Some of the earliest research on the preparation was classified.[3][4] It was first prepared by fluorination of chlorine trifluoride at high temperatures and high pressures:

ClF3 + F2 → ClF5

NiF2 catalyzes this reaction.[5]

Certain metal fluorides, MClF4 (i.e. KClF4, RbClF4, CsClF4) react with F2 to produce ClF5 and the corresponding alkali metal fluoride.[4]

Reactions

In a highly exothermic reaction, water hydrolyses ClF5 to produce chloryl fluoride and hydrogen fluoride:[6]

ClF
5
+ 2 H
2
O
FClO
2
+ 4 HF

It is also a strong fluorinating agent. At room temperature it reacts readily with all elements except noble gases, nitrogen, oxygen and fluorine.[2]

See also

References

  1. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 833. ISBN 0080379419.
  2. 2.0 2.1 Pilipovich, D., Maya, W., Lawton, E.A., Bauer, H.F., Sheehan, D. F., Ogimachi, N. N., Wilson, R. D., Gunderloy, F. C., Bedwell, V. E. (1967). "Chlorine pentafluoride. Preparation and Properties". Inorganic Chemistry 6 (10): 1918. doi:10.1021/ic50056a036.
  3. Clark, John (1972). Ignition! An Informal History of Liquid Rocket Propellants. Rutgers University Press. pp. 87–88. ISBN 0-8135-0725-1.
  4. 4.0 4.1 Smith D. F. (1963). "Chlorine Pentafluoride". Science 141 (3585): 1039–1040. doi:10.1126/science.141.3585.1039. PMID 17739492.
  5. Šmalc, A., Žemva, B., Slivnik, J., and Lutar K. (1981). "On the Synthesis of Chlorine Pentafluoride". Journal of Fluorine Chemistry 17 (4): 381–383. doi:10.1016/S0022-1139(00)81783-2.
  6. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 834. ISBN 0080379419.

External links