Synthesis and structure of tin(II) hexafluorozirconate

Article abstract of DOI:10.1023/A:1021678111246

The crystal structure of SnZrF₆ is determined. The compound is synthesized by slow crystallization from a melted mixture of SnF₂ and ZrF₄ (2:1). The crystals are monoclinic: a = 6.6119(5), b = 5.2503(5), c = 6.9929(6) A, β

Full text of DOI:10.1023/A:1021678111246

Russian Journal of Coordination Chemistry, Vol. 28, No. 12, 2002, pp. 839–842. Translated from Koordinatsionnaya Khimiya, Vol. 28, No. 12, 2002, pp. 896–899.
Original Russian Text Copyright © 2002 by Gerasimenko, Merkulov, Tkachenko, Kavun, Goncharuk, Sergienko.
Synthesis and Structure of Tin(II) Hexafluorozirconate
A. V. Gerasimenko, E. B. Merkulov, I. A. Tkachenko, V. Ya. Kavun,
V. K. Goncharuk, and V. I. Sergienko
Institute of Chemistry, Far East Division, Russian Academy of Sciences,
pr. Stoletiya Vladivostoka 159, Vladivostok, 690022 Russia
Received December 25, 2001
Abstract—The crystal structure of SnZrF is determined. The compound is synthesized by slow crystallization
6
from a melted mixture of SnF and ZrF (2 : 1). The crystals are monoclinic: a = 6.6119(5), b = 5.2503(5), c =
2
4
6
.9929(6) Å, β = 114.239(4)°, space group P2/n, Z = 2. The structure is layered. The layers are formed from
2
+
the chains of edge-sharing, eight-vertex zirconium polyhedra and Sn cations. The Zr–F and Sn–F bond
lengths in the layer vary from 2.309(1) to 2.269(1) Å and from 2.186(1) to 2.361(1) Å, respectively. The layers
are linked by intermolecular Sn–F bonds with lengths of 2.868(1) and 2.871(1) Å.
INTRODUCTION
been poorly studied. As far as we know, data on the
2
+
structures with Sn are lacking. We studied the crystal
Structural studies of zirconium fluoride complexes structure of SnZrF (I) in order to obtain new data on
6
2
+
+
mainly cover compounds containing Pb , Tl , and structures of complex zirconium fluorides with cations
3
+
Bi [1], while compounds containing p cations have of p elements.
0
c
b
F(2)h
F(3)
F(2)c
Sn
F(1)
F(1)c
F(3)c
Zr
F(2)
a
F(3)a
F(2)i
Fig. 1. Fragment of the (SnZrF6)∞∞ layer in structure I.
1
070-3284/02/2812-0839$27.00 © 2002 åÄIä “Nauka /Interperiodica”

8
40
GERASIMENKO et al.
Table 1. Crystallographic data and details of the experiment
EXPERIMENTAL
and refinement of the SnZrF structure
6
Synthesis of I. Zirconium tetrafluoride and tin di-
fluoride were used as initial reagents. Zirconium tet-
rafluoride was prepared by the decomposition of
ammonium fluorozirconate at 650°C followed by
removal of oxygen-containing admixtures by sublima-
tion in a closed platinum apparatus at 950°C. High-
purity tin difluoride was obtained following a described
procedure [2]. The crystals were synthesized by slow
crystallization from a melted mixture of SnF and ZrF
Parameter
Value
323.91
M
Temperature of recording
295(2) K
P2/n
Space group
a, Å
6.6119(5)
5.2503(5)
6.9929(6)
114.239(4)
221.35(3)
2
2
4
b, Å
taken at a molar ratio of 2 : 1. For this purpose, 25 g of
a mixture of the corresponding salts was heated in a
closed glassy-carbon crucible to 450°C for 15 min until
the components were completely dissolved and then
cooled for 3 h to room temperature. All procedures
were carried out in a box dried with P O . Compound I
c, Å
β, deg
V, Å
2
5
Z
is formed as a porous layer of colorless transparent
needlelike crystals in the middle part of the ingot.
ρ(calcd), g/cm3
4.860
µ, mm–1
X-ray diffraction analysis. A set of reflection
8.031
intensities was obtained on a SMART-1000 CCD dif-
F(000)
288
fractometer at room temperature (MoK radiation,
α
graphite monochromator). Data were collected for two
Shape (size, mm) of crystal
Prism
0.02 × 0.08 × 0.35)
positions of the detector (33° and 80° in sets of 906,
(
6
60, and 345 frames at ϕ = 0°, 90°, and 180°, respec-
Region of data collection by
θ, deg
3.57–51.23
tively; ω scan mode at a step of 0.2° and exposure time
of 10 s per frame). The crystal–detector distance was
45 mm. X-ray absorption in the sample was corrected
for using the SADABS program [3].
Intervals of reflection indices –14 ≤ h ≤ 14, –11 ≤ k ≤ 6,
–
14 ≤ l ≤ 15
The structure was solved by the direct method and
refined in the anisotropic approximation.
The main crystallographic data and details of the
experiment and refinement of structure I are presented
in Table 1. The coordinates of atoms and their isotropic
equivalent thermal parameters are presented in Table 2.
Measured reflections
Independent reflections
Reflections with I > 2σ(I)
Refinement method
4591
2097(Rint = 0.0457)
1648
Full-matrix least-squares
2
method for F
The data were collected and edited and the unit cell
parameters were refined using the SMART and SAINT
Plus program packages [3]. All calculations for deter-
mination and refinement of the structure were per-
formed using the SHTLXTL/PC program packages [4].
Refinement parameters
39
GOOF
0.953
2
R factors for F > 2σ(F )
R = 0.0379, wR = 0.0945
2
1
2
R factors for all reflections
R = 0.0462, wR = 0.0979
1
2
Molar absorption coefficient
0.053(2)
RESULTS AND DISCUSSION
Residual electron density
–2.835/2.829
(near Sn atom)
The crystal structure I is formed from the
3
(min/max), e/Å
(
SnZrF6)∞∞ layers parallel to the (010) plane (Fig. 1).
The layers are formed from slightly bent chains which
extend along the [101] direction and are formed from
Table 2. Coordinates of atoms and their isotropic thermal
2
+
parameters for SnZrF6
the edge-sharing eight-vertex Zr polyhedra and Sn
cations.
2
Atom
Sn
x
y
z
U , Å
eq
The Zr and Sn atoms lie in the two fold axes. The
coordination zirconium polyhedron is a distorted two-
0.75
0.75
0.03100(3) 0.25
0.48265(3) 0.75
0.01165(2) capped trigonal prism [5]. The Zr–F(1) and Zr–F(3)
distances to the terminal fluorine atoms are 2.039(1)
Zr
0.00613(3)
and 2.081(1) Å, respectively (Table 3). The bridging
h
F(2) and F(2) atoms linking the polyhedra into the
chain are remoted from the Zr atom at 2.116(1) and
2.269(1) Å, respectively. The average Zr–F bond length
in structure I is equal to 2.126 Å, and the FZrF angles
vary from 64.94° to 119.78°. The angle directed to the
F(1)
F(2)
F(3)
0.6795(1) 0.2050(2)
0.9184(1) 0.6849(2)
0.5101(1) 0.6842(2)
0.9173(1) 0.0141(2)
1.0332(1) 0.0131(2)
0.8082(1) 0.0172(2)
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 28 No. 12 2002

SYNTHESIS AND STRUCTURE OF TIN(II) HEXAFLUOROZIRCONATE
841
Table 3. Bond lengths and angles in the SnZrF structure
6
Bond
d, Å
Bond
d, Å
Bond
ω, deg
Sn polyhedron
c
f
c
g
e
a
b
d
c
g
Sn–F(1)
Sn–F(1)
Sn–F(2)
Sn–F(3)
2.361(1)
2.871(1)
2.868(1)
2.168(1)
F(1) ···F(1)
3.723(2)
3.092(1)
2.752(1)
2.772(1)
2.593(1)
4.148(1)
2.935(1)
4.438(1)
3.753(1)
3.063(1)
F(1) SnF(1)
90.20(3)
71.74(3)
74.35(3)
74.97(3)
53.71(3)
92.57(3)
69.42(3)
101.37(4)
94.89(3)
93.75(6)
c
c
e
a
b
d
F(1) ···F(2)
F(1) SnF F(2)
d
a
c
c
F(1) ···F(3)
F(1) SnF F(3)
c
c
F(1) ···F(3)
F(1) SnF F(3)
g
g
F(1) ···F(2)
F(1) SnF F(2)
g
e
a
e
a
g
e
a
e
a
F(1) ···F(2)
F(1) SnF F(2)
g
g
F(1) ···F(3)
F(1) SnF F(3)
d
d
F(2) ···F(2)
F(2) SnF F(2)
d
d
F(2) ···F(3)
F(2) SnF F(3)
a
b
a
b
F(3) ···F(3)
F(3) SnF F(3)
Zr polyhedron
Zr–F(1)
Zr–F(2)
Zr–F(2)
Zr–F(3)
2.039(1)
2.116(1)
2.269(1)
2.081(1)
F(1)···F(1)c
F(1)···F(2)
2.852(1)
2.906(1)
2.602(1)
2.593(1)
2.732(1)
3.660(1)
2.357(1)
2.505(1)
2.616(1)
2.619(1)
–x + 1, –y, –z + 1;
F(1)ZrF(1)c
F(1)ZrF(2)
F(1)ZrF(2)
F(1)ZrF(2)i
F(1)ZrF(3)
88.74(6)
88.74(4)
73.78(3)
74.06(3)
83.07(4)
119.78(5)
64.94(4)
73.29(3)
77.14(4)
73.91(4)
h
h
h
F(1)···F(2)
F(1)···F(2)i
F(1)···F(3)
c
c
F(2)···F(2)
F(2)···F(2)i
F(2)···F(3)
F(2)···F(3)c
F(2)ZrF(2)
F(2)ZrF(2)i
F(2)ZrF(3)
F(2)ZrF(3)c
h
h
F(3)···F(3)
F(3)ZrF(3)
a
b
c
d
e
f
Symmetry transformations:
x + 1/2, –y + 1, z – 1/2;
g
h
i
–
–
x + 1, –y + 1, –z + 1;
x + 3/2, y, –z + 3/2;
x + 1/2, –y, z – 1/2;
x – 1/2, –y + 1, z – 1/2;
–x + 2, –y + 1, –z + 2;
x, y – 1, z – 1;
x + 3/2, y – 1, –z + 3/2;
–
i
common F(2)···F(2) edge, whose midpoint coincides isolated chains of the Zr polyhedra are linked into a
with the symmetry center of the structure, is the small- layer by the Sn atoms.
est. The Zr···Zr distance in the chain is 3.701 Å. The
The nearest environment of the Sn atoms includes
four F atoms (Sn–F 2.186 and 2.361 Å). The quaternary
F(3)b
“one-sided” coordination of Sn is thus realized. Taking
into account the unshared electron pair E, we can
describe this coordination as a distorted square pyramid
F(3)a
F(1)c
F(1)
or a derivative of the trigonal SnF E bipyramid. The
4
environment of the Sn atom additionally contains four
F atoms lying at longer Sn–F distances of 2.868(1) and
2.871(1) Å. These bonds are shown in Fig. 2 by dotted
lines. The (SnZrF6)∞∞ layers are united by these fluorine
atoms along the crystallographic b axis. The coordina-
tional polyhedron of the Sn atoms can be described as
a distorted antiprism. The eight-vertex Sn polyhedra are
Sn
F(1) f
F(1)g
c
f
combined into chains by the bridging F(1) and F(1)
atoms remoted from the Sn atom at 2.361(1) and
.871(1) Å, respectively, and are directed along the
101] direction. Through channels containing no atoms
F(2)e
2
[
F(2)d
are formed in the three-dimensional framework parallel
to the [101] direction (Fig. 3).
Fig. 2. Coordination environment of the Sn atom in struc-
ture I.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 28 No. 12 2002

8
42
GERASIMENKO et al.
a
c
0
b
Zr
Sn
F
Fig. 3. Packing of structural units in the SnZrF crystal.
6
ACKNOWLEDGMENTS
This work was supported by the Russian Foundation
2. Murin, I.V., Chernov, S.V., and Vlasov, M.Yu., Zh. Prikl.
Khim. (Leningrad), 1985, no. 10, p. 2340.
3. SMART and SAINT-Plus. Versions 5.0. Data Collection
and Processing Software for the SMART System, Madi-
son: Bruker AXS Inc., 1998.
for Basic Research, project no. 99-03-32672.
4
. SHELXTL/PC. Versions 5.0.: An Integrated System for
Solving, Refining and Displaying Crystal Structures
from Diffraction Data, Madison: BrukerAXS Inc., 1998.
REFERENCES
1
. Davidovich, R.L., Koord. Khim., 1998, vol. 24, no. 11,
p. 803.
5. Porai-Koshits, M.A. and Aslanov, L.A., Zh. Strukt.
Khim., 1972, vol. 13, no. 2, p. 266.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 28 No. 12 2002