Article
Inorganic Chemistry, Vol. 48, No. 16, 2009 7727
˚
at -196 ꢀC to give a total of ca. 0.18 g (1.7 mmol) of NtSF
3
. The
radiation (λ = 0.71073 A). The diffraction data collection (at
reaction vessel was initially warmed to -78 ꢀC, followed by
warming to -20 ꢀC for ca. 6 h with occasional mixing. The white
solid corresponding to [F StNXeF][AsF ] slowly dissolved in
-173 ꢀC) consisted of a full j rotation at a fixed χ=54.74ꢀ with
0.36ꢀ (1010) frames, followed by a series of short (250 frames) ω
scans at various j settings to fill the gaps. The crystal-to-
detector distance was 4.953 cm, and the data collection was
carried out in a 512 ꢂ 512 pixel mode using 2 ꢂ 2 pixel binning.
Processing of the raw data was completed by using the APEX2
GUI software, which applied Lorentz and polarization correc-
tions to three-dimensionally integrated diffraction spots. The
program SADABS was used for the scaling of diffraction data,
the application of a decay correction, and an empirical absorp-
tion correction based on redundant reflections.
3
6
3
excess liquid NtSF to form a yellow solution from which a
deep yellow microcrystalline solid deposited. With gradual
warming to 0 ꢀC over an additional 15 h period, the solid
redissolved, and two liquid phases separated, a colorless upper
5
6
3
layer and a deep yellow lower layer. Excess NtSF was removed
5
7
under dynamic vacuum at -50 ꢀC over a period of ca. 30 min,
yielding a bright yellow powder, [F SdN-Xe---NtSF ][AsF ]
4
3
6
(
eq 1), which was stored at -78 ꢀC until it was characterized by
Raman spectroscopy.
Synthesis of [F S(NtSF
SdN-Xe---NtSF ][AsF
(b) Solution and Refinement of the Structure. The XPREP
program was used to confirm the unit cell dimensions and the
crystal lattice. The final refinement was obtained by introducing
anisotropic parameters for all of the atoms, an extinction
parameter, and the recommended weight factor. The maximum
electron densities in the final difference Fourier maps were
located around the heavy atoms. All calculations were per-
formed with the SHELXTL package for structure determina-
tion, refinement, and molecular graphics. Solutions were
obtained by direct methods which located the Xe and As atoms.
Successive difference Fourier syntheses revealed the positions of
the fluorine, nitrogen, and sulfur atoms.
3
3
)
2
][AsF
6
]. In a typical synthesis,
[
F
4
3
6
] (0.1456 g, 0.2669 mmol) was
prepared in a ¼-in. o.d. FEP reaction tube fitted with a
Kel-F valve following the procedure described above up to the
point of solvent removal. At that point, the solution was
maintained in liquid NtSF
which time the solution slowly changed from yellow to colorless.
Excess NtSF was then removed under dynamic vacuum at
50 ꢀC over a period of ca. 5 min, yielding a friable white solid
that was a mixture of [F S(NtSF ) ][AsF ] and cis-N F (eq 2),
3
at 0 ꢀC for an additional 6 h, over
5
8
3
-
3
3 2
6
2 2
which was stored at -78 ꢀC until it was characterized by Raman
spectroscopy. Further pumping at -45 ꢀC for ca. 15 min,
resulted in removal of cis-N F and coordinated NtSF , yield-
2 2 3
Raman Spectroscopy. The low-temperature (-160 ꢀC) Raman
spectra of [F SdN-Xe---NtSF ][AsF ], [F S(NtSF ) ]-
[AsF ], and [SE ][AsF ] were recorded on a Bruker RFS
6 3 6
4
3
6
3
3 2
ing [SF ][AsF ].
3
6
Crystal Growth of [F SdN-Xe---NtSF ][AsF ] and
100 FT Raman spectrometer using 1064-nm excitation and a
4
3
6
-
1
59
[
condensed onto [F
-
F S(NtSF ) ][AsF ]. Thiazyl trifluoride (NtSF , ca. 1 mL) was
StNXeF][AsF
resolution of 1 cm , as previously described. The spectra were
recorded using a laser power of 300 mW and a total of 1600,
1500, and 1500 scans, respectively.
3
3 2
6
3
3
6
] (0.1186 g, 0.2681 mmol) at
196 ꢀC that had been synthesized in situ in one arm of a ¼-in.
o.d. FEP T-shaped reactor fitted with a Kel-F valve. The reactor
was warmed to -78 ꢀC and pressurized to 1 atm with dry
nitrogen before warming to -20 ꢀC, and then to 0 ꢀC, as
described under the syntheses of these compounds (vide supra).
While maintaining the solution temperature at 0 ꢀC, the reaction
vessel was attached to a vacuum line, and the arm containing the
solution was inclined at ca. 5ꢀ from horizontal inside the glass
Dewar of a crystal growing apparatus that had been pre-
viously adjusted to 0 ꢀC. The temperature was lowered over a
period of 1 h to -10 ꢀC, where it was held for a further 30 min to
allow for more complete crystallization. The resulting crystal-
line material was isolated by decanting the solvent under dry
nitrogen into the side arm of the FEP vessel, which was
immersed in liquid nitrogen. This was followed by lowering
the sample temperature to -40 ꢀC and evacuation to remove
residual NtSF3 followed by heat sealing off the side arm
containing the supernatant at -196 ꢀC. The crystalline sample
was further dried under a dynamic vacuum at -80 ꢀC before the
crystallization vessel was backfilled with dry nitrogen and stored
at -78 ꢀC until suitable crystals could be mounted for X-ray
structure determinations. A pale yellow, block-shaped crystal of
Nuclear Magnetic Resonance Spectroscopy. (a) NMR Sam-
ple Preparation. Samples containing [F S(NtSF ) ][AsF ] and
cis-N F were prepared in 4-mm o.d. FEP tubes fused to lengths
3
3 2
6
2
2
of ¼-in. o.d. FEP tubing fitted with Kel-F valves which con-
tained [F StNXeF][AsF ] (ca. 0.048 g) that had been prepared
3
6
1
in situ as previously described. The samples were warmed to,
9
and maintained at, 0 ꢀC for ca. 20 h in NtSF solvent to allow
3
5
4
þ
the reaction of F SdNXe with NtSF (eq 2) to take place. The
4
3
NMR sample tubes were heat-sealed under dynamic vacuum
and stored at -196 ꢀC until NMR spectra could be obtained.
Samples were redissolved at -5 ꢀC and warmed to 0 ꢀC just prior
to data acquisition and remained at this temperature while their
spectra were recorded. Low-temperature spectra were obtained
from sealed 4-mm o.d. FEP sample tubes that had been inserted
into 5-mm o.d. thin-wall precision glass NMR tubes (Wilmad).
(b) NMR Instrumentation and Spectral Acquisitions. Fluor-
ine-19 NMR spectra were recorded unlocked (field drift <0.1 Hz
-1
h
) on a Bruker DRX-500 spectrometer equipped with an
1.744-T cryomagnet. The NMR probe was cooled using a
1
nitrogen flow and variable-temperature controller (BV-T 3000).
Fluorine-19 NMR spectra were acquired using a 5-mm
1
19
[
0
[
0
F
4
SdN-Xe---NtSF
3
][AsF
.20 ꢂ 0.16 mm , and a colorless, blade-shaped crystal of
S(NtSF ][AsF
], having the dimensions 0.28 ꢂ 0.12 ꢂ
.06 mm , were selected at -104 (2 ꢀC and mounted in a cold
6
], having the dimensions 0.22 ꢂ
combination H/ F probe operating at 470.592 MHz. The
spectra were recorded in 32K memories, with spectral width
settings of 24 kHz and acquisition times of 1.39 s, and were zero-
filled to 64K, yielding data point resolutions of 0.36 Hz/data
point. Relaxation delays of 0.10 s were applied, and 1600
transients were accumulated.
3
F
3
3
)
2
6
3
stream (-173 ꢀC) on the goniometer head of the X-ray diffract-
ometer, as previously described.
5
5
X-ray Crystallography. (a) Collection and Reduction of the
X-ray Data. The crystals were centered on a Bruker SMART
APEX II diffractometer, equipped with an APEX II 4K CCD
area detector and a three-axis goniometer, controlled by the
APEX2 Graphical User Interface (GUI) software, and
a sealed source emitting graphite-monochromated Mo KR
The pulse width, corresponding to a bulk magnetization
tip angle of approximately 90ꢀ, was 8.5 μs. A line broadening
of 0.10 Hz was used in the exponential multiplication of
the free induction decay prior to Fourier transformation.
5
6
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(
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