Article
Inorganic Chemistry, Vol. 48, No. 23, 2009 11257
conjunction with quantum-chemical calculations and X-ray
diffraction. The WSF CH CN adduct can serve as the
¼ in. thin wall FEP reactor equipped with a Kel-F valve. Approxi-
mately 0.35 mL of dry CH CN was vacuum distilled onto the
3
solid. Slow melting of the solvent at -43.3 °C resulted in a dark
brown solution. After 5 min of agitation, volatiles were removed
under dynamic vacuum while the reaction mixture was allowed
4
3
3
synthetic equivalent to monomeric WSF , with its reactivity
4
currently under investigation in our laboratory.
to slowly warm to -30 °C. Gray-colored WSF
4
3 CH3CN (0.018 g,
Experimental Section
0
.054 mmol) was recovered in 98% yield.
Materials and Apparatus. All volatile materials were handled
a) on a Pyrex vacuum line equipped with glass/Teflon J. Young
4
Vibrational Spectroscopy. The Raman spectra of WSF and
(
WSF4 CH CN were recorded on a Bruker RFS 100 FT Raman
3
3
valves and (b) a vacuum line constructed of nickel, stainless
steel, and FEP. Nonvolatile materials were handled in the dry
nitrogen atmosphere of a drybox (Omni Lab, Vacuum
Atmospheres). Reaction vessels and NMR sample tubes were
fabricated from ¼ in. o.d. thin-wall (3/16 in. i.d.) and 4 mm o.d.,
spectrometer with a quartz beam splitter, a liquid-nitrogen-
cooled Ge detector, and a low-temperature accessory. The
backscattered (180°) radiation was sampled. The actual usable
-
1
Stokes range was 50 to 3500 cm with a spectral resolution of
-1
2 cm . The 1064 nm line of an Nd:YAG laser was used for
excitation of the sample. All Raman spectra were corrected for
effects arising form the optics and the frequency dependence of
the Raman scattering by using the white light spectrum of a
tungsten lamp. The low-temperature spectra of WSF4 and
WSF4 CH CN were recorded on a powdered sample in pow-
2
.8 mm i.d. FEP tubing, respectively, and outfitted with
Kel-F valves. All reaction vessels and sample tubes were rigor-
ously dried under dynamic vacuum prior to passivation with
1
atm of F
Anhydrous HF (Air Products, 99.9%) was dried over
NiF . The solvents, CH CN (Sigma-Aldrich, HPLC grade)
2
gas.
3
3
K
2
6
3
dered samples in melting point capillaries using laser powers of
150 and 100 mW, respectively. The FT-infrared spectra were
recorded on a Nicolet Avatar 360 FTIR spectrometer at ambi-
ent temperature. A KBr sandwich was formed in a Wilks
minipress inside the drybox by sandwiching the sample between
two layers of KBr. The spectra were acquired in 64 scans at a
1
1
was dried according to standard literature methods and
CH Cl was dried using molecular sieves (type 4 A). Tungsten
2
ꢀ
˚
2
hexafluoride (Elf Atochem) was used without further purifica-
tion, whereas Sb (Alfa Aesar, 99.5%) was purified by drying
under dynamic vacuum at 160 °C for about 6 h.
Preparation of WSF . Inside the drybox, dried Sb
.400 mmol) was added to a ¼ in. FEP T-reactor equipped with
a Kel/F valve. After distillation of 1.76 g of aHF, WF (0.326 g,
.09 mmol) was condensed onto the frozen reaction mixture at
2 3
S
-
1
2
S
3
(0.136 g,
resolution of 2 cm .
4
0
Nuclear Magnetic Resonance Spectroscopy. All NMR spectra
were recorded unlocked on a 300 MHz Bruker Avance II NMR
spectrometer equipped with a 5 mm broadband probe. Fluor-
ine-19 (282.404 MHz) NMR spectra were referenced externally
6
1
-
196 °C. The reactor was backfilled with dry N2(g) and allowed
1
9
to warm to room temperature. After warming to room tem-
perature, and with intermittent agitation over the course of 16 h,
the reaction progressed slowly, going from a colorless solution
to neat CFCl at 25 °C. The F NMR spectra were typically
3
acquired in 128 K memory with spectral settings of 56 kHz,
yielding an acquisition time of 1.15 s and a data point resolution
of 0.433 Hz/data point. The number of transients accumulated
was 100 using a pulse width of 10.3 μs.
2 3
above black Sb S to a deep yellow solution. The deep yellow
solution was decanted to the side arm of the FEP T-reactor
where the solution was cooled to about -78 °C causing yellow
WSF to precipitate. More WSF was extracted from the solid
4 4
reaction mixture by condensing HF solvent back onto the solid
and washing the solid again at room temperature, followed by
decanting the yellow solution into the side arm. The washing
procedure was repeated 2 to 3 times. Anhydrous HF was
removed under vacuum at -78 °C over several hours, leaving
some yellow crystalline material that was pumped on for an
additional 10 min at room temperature to ensure total
X-ray Crystal Structure Determination of WSF
4
and
WSF4 CH CN. (a). Crystal Growth and Crystal Mounting.
3
3
Crystals of WSF
slow removal of solvent HF at -78 °C under dynamic vacuum.
Crystals of WSF CH CN were grown in aHF solvent at a
temperature slowly varied from -53 to -59 °C. Crystals of
WSF and WSF CH
4
were grown directly from a HF solution upon
4
3
3
4
4
3
3
CN having the dimensions 0.10 ꢀ 0.06 ꢀ
3
3
0
.03 mm and 0.55 ꢀ 0.33 ꢀ 0.24 mm , respectively, were selected at
-
flow of cold nitrogen and mounted as previously described.
80 °C for low-temperature X-ray structure determination under a
12
4
HF removal. The amount of recovered WSF was 0.258 g
(
0.867 mmol) with a yield of 79.3%.
Preparation of WSF4 CH CN. (a) Inside a glovebox, 0.055 g
(b). Collection and Reduction of X-ray Data. The crystal was
3
3
centered on a Bruker SMART APEX II diffractometer,
equipped with an APEX II 4K CCD area detector and a
triple-axis goniometer, controlled by the APEX2 Graphical
(
2 3
0.16 mmol) of Sb S was transferred into the straight arm of a
T-reactor fabricated out of ¼ in. o.d. FEP tubing. After vacuum
distillation of about 0.27 mL of aHF onto Sb , 0.172 g (0.577
1
3
2 3
S
User Interface (GUI) software, and a sealed source emitting
˚
mmol) of WF was condensed onto the Sb S at -196 °C by
6
2
3
graphite-monochromated Mo KR radiation (λ = 0.71073 A).
vacuum-distillation. The reaction was allowed to proceed at
room temperature overnight, producing a bright yellow solution
above a dark gray precipitate. After decanting the solution into
Diffraction data collection at -120 °C consisted of four ω scans
at various j settings of 366 frames each at a fixed χ = 54.74°
with a width of 0.5°. The data collection was carried out in a
512 ꢀ 512 pixel mode using 2 ꢀ 2 pixel binning. Processing of the
the side arm, 0.044 g (1.07 mmol) of CH CN was then vacuum-
3
1
3
distilled into the side arm at -196 °C. The reaction mixture was
vigorously agitated at -35 °C, resulting in a bright yellow
solution with some undissolved bright yellow solid. The mixture
was then slowly cooled to -61 °C to allow complete precipita-
raw data was completed by using the APEX2 software, which
applied Lorentz and polarization corrections to three-dimen-
sionally integrated diffraction spots. The program SADABS
1
4
was used for the scaling of diffraction data, the application of a
decay correction, and an empirical absorption correction on the
basis of the intensity ratios of redundant reflections.
4 3
tion of WSF CH CN. The remaining HF was decanted back
3
into the main arm, frozen at -196 °C, and the main arm was heat
sealed under dynamic vacuum. Volatiles in the side arm were
removed under dynamic vacuum while the cooling bath
was allowed to slowly warm to 13 °C. Greenish-yellow
WSF4 CH CN (0.1283 g, 0.3853 mmol) was collected inside
(c). Solution and Refinement of the Structure. The XPREP
program was used to confirm the unit cell dimensions and the
3
3
the drybox in 79.3% yield. (b) Inside a dry nitrogen atmosphere
drybox, 0.016 g of WSF (0.055 mmol) was transferred into a
(
12) Gerken, M.; Dixon, D. A.; Schrobilgen, G. J. Inorg. Chem. 2000, 39,
4244–4255.
4
(
(
13) APEX 2, Version 2.2-0; Bruker AXS Inc.: Madison, WI, 2007.
14) Sheldrick, G. M. SADABS, Version, 2007/4; Bruker AXS Inc.:
(
11) Winfield, J. M. J. Fluorine Chem. 1984, 25, 91–98.
Madison, WI, 2007.