Chapter 18
Group 18 elements
Occurrence, extraction, and uses
Physical Properties
Compounds of xenon
Compounds of argon, krypton and radon
1
tris(-hydroquinone) xenon clathrate
Relative abundances
Uses of helium
2
Compounds of Xenon
Xe forms colorless fluorides, XeF2, XeF4, XeF6
XeF2
XeF4
XeF6
Excess AsF5
in liq BrF5
XeF4
[XeF3]+[AsF6]XeF4
[XeF5]+[AsF6]-
XeF6 – gas phase
XeF2
-KrF2
Vibrational spectrum
indicates C3v symmetry
XeF6 – solid state
[XeF5]+ square
pyramidal units
(Xe-F = 184 pm)
with fluoride
bridges
(Xe-F = 223 and
260 pm)
3
XeF2 reacts with F- acceptors, e.g. SbF5, AsF5, BrF5, NbF5, and IrF5
Forms one of three types of complex:
•[XeF]+[MF6]•[Xe2F3]+[MF6]•[XeF]+[M2F11]XeF2 reacts with metal tetrafluorides
polymeric
[XeF]+[RuF6]-
[XeF]+[CrF5]-
XeF6 acts as a donor to numerous pentafluorides to give complexes of
types [XeF5]+[MF6]-, [XeF5]+[M2F11]- (M = Sb, V), and [Xe2F11]+[MF6]-.
[Xe2F11]2[NiF6]
Xe
Ni
4
XeF4 may react with F- acceptors, and accept F- from a donor.
Reaction between NO2F and excess XeF6 gives [NO2]+[Xe2F13]-.
MF + XeF6
M[XeF7]
D, -XeF6
M2[XeF8]
M = Rb, Cs, NO
[XeF7]
5
Xenon chlorides
Xenon oxides, oxofluorides, and others.
XeO3
XeO4
6
[Sb(OTeF5)6]
[(2,6-F2C5H3N)Xe(C6F5)]
SO2ClF adduct
[(2,6-F2C6H3)Xe][BF4]
7
[cis-AuXe2][Sb2F11]2
8
[F3AsAuXe][Sb2F11]
[BrOF2][AsF6]•2KrF2
9