Inorganic Chemistry
Article
a
Table 1. Crystallographic Details
fw (g mol−1)
a (Å)
b (Å)
c (Å)
V (Å3)
ρc (g cm−3) μ (mm−1
)
R(F)
b
R (F )
w o
2
c
q
c
Cs Pt USe
6
1562.88
1281.48
1296.81
1015.41
1468.00
1186.60
1201.93
920.53
10.0904(5)
9.7924(8)
10.1034(5)
9.7874(4)
10.0467(1)
9.755(1)
15.3859(7)
14.8937(8)
15.5046(8)
15.0077(4)
14.7961(1)
14.229(1)
17.5882(8)
17.016(2)
17.5503(8)
16.9773(7)
17.4663(2)
16.897(2)
17.4127(5)
16.8572(3)
16.7541(8)
2730.6(2)
2481.8(3)
2749.2(2)
2493.7(2)
2594.64(4)
2345.5(4)
2598.2(1)
2354.43(7)
2260.4(2)
7.603
6.859
6.266
5.409
7.516
6.721
6.145
5.194
4.865
63.670
53.463
36.665
23.910
68.930
58.698
40.718
27.445
20.765
0.0198
0.0259
0.0194
0.0247
0.0194
0.0155
0.0214
0.0236
0.0391
0.0664
0.0545
0.0629
0.0386
0.0434
0.0656
0.059
0.0123
0.0226
0.0241
0.0293
0.0137
0.0107
0.0224
0.0234
2
3
d
Cs Pt US
6
2
3
Cs Pd USe
2
3
6
d
Cs Pd US
6
2
3
Rb Pt USe
6
2
3
Rb Pt US
6
2
3
Rb Pd USe
10.0525(3)
9.7462(2)
9.7265(5)
14.8432(5)
14.3306(2)
13.8721(6)
2
3
6
Rb Pd US
6
2
3
d
K Pd US
6
827.79
0.0501
0.1327
0.100
2
3
a
23
b
2
2
o
c
2
o
For all structures, T = 100(2) K; λ = 0.71073 Å; Z = 8; space group D − Fmmm. R(F) = ∑||F | − |F ||/∑|F | for F > 2σ(F ). R (F ) =
2
h
o
c
o
o
w
∑w(Fo − F ) /∑wF } . For Fo2 < 0, w = σ (F ); for F ≥ 0, w = σ (F ) + (qF ) . Refined as twilled structures.
2
2
2
4
1/2
−1
2
2
2
−1
2
2
2 2
d
{
c
o
o
o
o
o
1
4
the appropriate following elements in liquid ammonia at 194 K: Cs
Aldrich, 99.5%), Rb (Strem, 99%), K (Cerac, 98%), S (Mallinckrodt,
9.6%), and Se (Cerac, 99.999%). All other reagents were used as
Rb Pd US . A mixture of Rb S (0.252 mmol), U (0.126 mmol),
2 3 6 2 3
(
9
Pd (0.378 mmol), and S (1.512 mmol) was heated according to the
profile used for Cs Pd US to afford several large black hexagonal
2
3
6
obtained: Pd (Johnson Matthey, 99.94%), Pt wire (Omega Engineer-
ing, 0.01 in. diameter, 99.95%), KCl (Aldrich, 99%+), and CsCl
prisms and plates and many smaller truncated hexagonal pyramids in
60 wt % yield. A small crystal was selected for X-ray diffraction
experiments, whereas larger crystals were selected for single-crystal
anisotropic magnetic susceptibility measurements.
(
Aldrich, 99.9%).
All reactants were loaded into 6 mm outer-diameter carbon-coated
fused-silica tubes in an argon-filled glovebox, moved to a high-vacuum
Rb Pt USe . A mixture of Rb Se (0.126 mmol), U (0.126 mmol),
2
3
6
2
3
−3
line, then flame-sealed under 10 Torr vacuum. They were then
placed in a computer-controlled furnace and heated according to the
heating profiles detailed below. All compounds are black and air stable.
They were cleaned with water. The crystals grow as hexagonal thin
plates and thicker prisms. The plates are sturdy and cleave evenly
along the three hexagonal edges. The prisms break evenly normal to
the hexagonal faces, but cutting across the hexagonal faces of a crystal
causes it to fray into plates, which are ductile and may be peeled off.
These prisms are polysynthetically twilled, that is, comprise three
Pt (0.126 mmol), and Se (0.504 mmol) was heated to 1223 K in 96 h,
held there for 192 h, cooled to 773 K in 96 h, and then cooled to
298 K in 24 h, yielding hexagonal prisms in 20 wt % yield. A few
1
17
9
tapered black needles of Rb Pt U Se
were found in the same tube,
2
4
6
along with large amounts of PtSe , also growing in a large rod-like
2
cluster.
Rb Pt US . A mixture of Rb S (0.126 mmol), U (0.126 mmol), Pt
2
3
6
2 3
(0.126 mmol), and S (0.504 mmol) was heated according to the
profile used for Rb Pt USe , yielding hexagonal prisms in 20 wt %
2
3
6
“twin” domains. EDS analysis on single crystals using a Hitachi S-3400
yield, along with large amounts of black hexagonal prisms of PtS in
2
SEM indicated the presence of only the four elements appropriate
for each compound. In all reactions, the primary side product was
the same clusters.
K Pd US . A mixture of K S (0.126 mmol), U (0.126 mmol),
2
3
6
2
1
5,16
β-UQ2.
Cs Pd USe . Small black plates of Cs UPd Se were initially
Pd (0.189 mmol), S (0.504 mmol), and KCl (1.386 mmol) was
heated according to the profile used for Rb Pt USe to afford
2
3
6
2
3
6
2
3
6
11
synthesized as previously reported, using CsCl as a flux. A mixture of
Cs Se (0.126 mmol), U (0.126 mmol), Pd (0.378 mmol), and excess
hexagonal prisms in 40 wt % yield and tiny black hexagonal K Pd S
2 3 4
17
crystals.
Structure Determinations. Data for Rb Pd US , Rb Pt US , and
2
3
Se (0.756 mmol) was heated to 1273 K in 96 h, left for 6 h, cooled to
2
3
6
2
3
6
1
5
223 K in 12 h, left for 24 h, cooled to 873 K in 96 h, then to
23 K in 96 h, and finally to 298 K in 24 h. Small hexagonal prisms in
Rb Pd USe were collected on a Bruker APEXII KAPPA diffrac-
2 3 6
tometer. Data collection strategies composed of ω and ϕ scans were
2
0
approximately 50 wt % yield by U resulted, along with large amounts
of black-turquoise hexagons, identified as Cs Pd Se .
devised using COSMO in APEX2. For Rb Pt USe , data were
2 3 6
17
collected on a Bruker APEXII platform diffractometer. A strategy was
devised using COSMO in APEX2. For all other compounds, full
spheres of data were collected on a Bruker APEXII platform
diffractometer. The data consisted of ω scans at ϕ = 0°, 90°, 180°,
and 270°. Each scan consisted of 606 frames. For all collections, frames
were 0.3° in width, and the initial 50 frames were recollected at the
end to check for crystal degradationnone was noted. All collections
were taken with a detector distance of 60 mm. Counting times were 10
s/frame for Cs Pt USe , Cs Pd USe , Cs Pd US , Rb Pt US ,
2
3
4
Cs Pd US . A mixture of Cs S (0.252 mmol), U (0.126 mmol), Pd
2
3
6
2 3
(
0.378 mmol), and S (1.512 mmol) was heated to 1273 K in 120 h,
left for 6 h, cooled to 1223 K in 12 h, left for 24 h, and then cooled to
298 K in 280 h, yielding hexagonal prisms in about 40 wt % yield.
Cs Pt USe . A mixture of Cs Se (0.126 mmol), U (0.126 mmol),
2
3
6
2
3
Pt (0.378 mmol), and Se (0.630 mmol) was heated to 1273 K in 96 h,
held there for 6 h, cooled to 1223 K in 12 h, held there for 24 h, and
then cooled to 298 K in 288 h, yielding hexagonal plates in 20 wt %
2
3
6
2
3
6
2
3
6
2
3
6
yield. Side products included clusters of black hexagonal PtSe
Rb Pd US , and K Pd US and 20 s/frame for Cs Pt US , Rb Pt USe ,
2
2 3 6 2 3 6 2 3 6 2 3 6
18
crystals.
Cs Pt US . A mixture of Cs S (0.126 mmol), U (0.126 mmol), Pt
and Rb Pd USe . Cell refinement and data reduction for single crystals
2 3 6
20
were carried out with SAINT in APEX2. Numerical face-indexed
2
3
6
2 3
21
(
0.126 mmol), and S (0.504 mmol) was heated according to the
absorption corrections were applied using SADABS. Structure
determinations were carried out by direct methods with XS and
profile used for Cs Pt USe , yielding triangular and hexagonal plates in
2
3
6
2
2
2
0 wt % yield, along with large clusters of black hexagonal PtS
refinements with XL of the SHELX package. Displacement
parameters were refined anisotropically. Secondary corrections for
extinction were applied for all structures except Cs Pd US and
2
18
crystals.
Rb Pd USe . A mixture of Rb Se (0.252 mmol), U (0.126 mmol),
2
3
6
2
3
2
3
6
Pd (0.378 mmol), and Se (1.512 mmol) was heated to 1173 K in 96 h,
left for 192 h, cooled to 873 K in 96 h, and then to 298 K in 96 h, to
afford intergrown hexagonal plates and prisms in about 50 wt % yield.
Crystals were washed with a mixture of water and DMF. Some prisms
were fragile and especially prone to splitting into thinner
plates. A sturdy hexagonal prism was selected for X-ray diffraction
experiments.
Cs Pt US . The atom positions were standardized using STRUC-
2 3 6
23 24
TURE TIDY in PLATON. Twilled crystals were treated identically
except that data reductions were carried out with additional domains
in SAINT and absorption corrections were carried out numerically
2
5
with TWINABS. Crystallographic details are given in Table 1, and
selected metrical details in Table 2. Additional information is in the
Supporting Information.
4
225
dx.doi.org/10.1021/ic2027048 | Inorg. Chem. 2012, 51, 4224−4230