The sa
lt [F
5SN(H)
Xe][AsF
6] has been synthesized by the reaction of [F
5SNH
3][AsF
6] with XeF
2 in anhydrous HF (aHF) and BrF
5 so
lvents and by so
lvo
lysis of [F
3S
NXeF][AsF
6] in aHF. Both F
5SN(H)Xe
+ and F
5SNH
3+ have been characterized by
129Xe,
19F, and
1H NMR spectroscopy in aHF (−20 °C) and BrF
5 (supercoo
led to −70 °C). The ye
llow [F
5SN(H)Xe][AsF
6] sa
lt was crysta
llized from aHF at −20 °C and characterized by Raman spectroscopy at −45 °C and by sing
le-crysta
l X-ray diffraction at −173 °C. The Xe−N bond
length (2.069(4) Å) of the F
5SN(H)Xe
+ cation is among the shortest Xe−N bonds present
ly known. The cation interacts with the AsF
6− anion by means of a Xe---F−As bridge in which the Xe---F distance (2.634(3) Å) is significant
ly
less than the sum of the Xe and F van der Waa
ls radii (3.63 Å) and the AsF
6− anion is significant
ly distorted from
Oh symmetry. The
19F and
129Xe NMR spectra estab
lished that the [F
5SN(H)Xe][AsF
6] ion pair is dissociated in aHF and BrF
5 so
lvents. The F
5SN(H)Xe
+ cation decomposes by HF so
lvo
lysis to F
5SNH
3+ and XeF
2, fo
llowed by so
lvo
lysis of F
5SNH
3+ to SF
6 and NH
4+. A minor decomposition channe
l leads to sma
ll quantities of F
5SNF
2. The co
lor
less sa
lt, [F
5SNH
3][AsF
6], was synthesized by the HF so
lvo
lysis of F
3S
NAsF
5 and was crysta
llized from aHF at −35 °C. The sa
lt was characterized by Raman spectroscopy at −160 °C, and its unit ce
ll parameters were determined by
low-temperature X-ray diffraction. E
lectronic structure ca
lcu
lations using MP2 and DFT methods were used to ca
lcu
late the gas-phase geometries, charges, bond orders, and va
lencies as we
ll as the vibrationa
l frequencies of F
5SNH
3+ and F
5SN(H)Xe
+ and to aid in the assignment of their experimenta
l vibrationa
l frequencies. In addition to F
5TeN(H)Xe
+, the F
5SN(H)Xe
+ cation provides the on
ly other examp
le of
xenon bonded to an sp
3-hybridized nitrogen center that has been synthesized and structura
lly characterized. These cations represent the strongest Xe−N bonds that are present
ly known.