Tetra­potassium dianti­mony(III) tin(IV) tetra­deca­fluoride

A V Gerasimenko; E B Merkulov; T I Usol’tseva

doi:10.1107/S1600536808012865

. 2008 May 7;64(Pt 6):i32. doi: 10.1107/S1600536808012865

Tetrapotassium diantimony(III) tin(IV) tetradecafluoride

A V Gerasimenko ^a,^*, E B Merkulov ^a, T I Usol’tseva ^a

PMCID: PMC2961491 PMID: 21202434

Abstract

The title compound, K₄Sb₂SnF₁₄, is built from anionic layers, with an overall composition of [Sb₂SnF₁₄]⁴⁻ extending parallel to the ac plane, and K⁺ cations. The layers are made up from vertex-sharing centrosymmetric SnF₆ octahedra and Sb₂F₁₂ dimers. The Sn—F distances are in the range 1.9581 (14)–1.9611 (17) Å. The Sb polyhedra contain three short terminal Sb—F bonds [1.9380 (14)–2.0696 (15) Å], one short bridging bond [2.0609 (17) Å], one bridging bond of medium length [2.7516 (15) Å], and two longer bridging bonds [3.0471 (18) and 3.117 (2) Å]. The K⁺ ions are coordinated by F atoms with coordination numbers 10 and 8, and K—F bond lengths are in the range 2.6235 (16)–3.122 (2) Å.

Related literature

For related literature, see: Blatov (2004 ▶); Davidovich & Zemnukhova (1975 ▶); Gillespie (1970 ▶); Kriegsmann & Kessler (1962 ▶); Serezhkin et al. (1997 ▶).

Experimental

Crystal data

K₄Sb₂SnF₁₄
M _r = 784.59
Triclinic,
a = 6.7356 (2) Å
b = 7.4704 (2) Å
c = 7.6370 (2) Å
α = 92.691 (1)°
β = 91.461 (1)°
γ = 115.323 (1)°
V = 346.53 (2) Å³
Z = 1
Mo Kα radiation
μ = 7.00 mm⁻¹
T = 298 (2) K
0.4 × 0.35 × 0.28 mm

Data collection

Bruker SMART 1000 CCD area-detector diffractometer
Absorption correction: Gaussian (XPREP and SADABS; Bruker, 2003 ▶) T _min = 0.136, T _max = 0.291
7147 measured reflections
4635 independent reflections
4250 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.090
S = 1.30
4635 reflections
98 parameters
Δρ_max = 1.91 e Å⁻³
Δρ_min = −3.69 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 2003 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: XP in SHELXTL; software used to prepare material for publication: publCIF (Westrip, 2008 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808012865/fi2062sup1.cif

e-64-00i32-sup1.cif^{(36.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808012865/fi2062Isup2.hkl

e-64-00i32-Isup2.hkl^{(227KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected bond lengths (Å).

Sb—F1	1.9380 (14)
Sb—F3	1.9539 (13)
Sb—F4	2.0609 (17)
Sb—F2	2.0696 (15)
Sb—F4ⁱ	2.7516 (15)
Sb—F5ⁱⁱ	3.0471 (18)
Sb—F6	3.117 (2)
Sn—F5	1.9581 (14)
Sn—F7	1.9611 (17)
Sn—F6	1.9611 (16)
K1—F4^iv	2.6235 (16)
K1—F2	2.7086 (14)
K1—F1^v	2.7268 (16)
K1—F6^vi	2.811 (2)
K1—F3^iv	2.8390 (18)
K1—F5^iv	2.8578 (16)
K1—F1	2.9262 (15)
K1—F3	2.9485 (18)
K1—F4^vi	2.982 (2)
K1—F7^vi	3.122 (2)
K2—F2^vii	2.6662 (15)
K2—F2^v	2.6777 (18)
K2—F3^iv	2.7136 (15)
K2—F1	2.7216 (15)
K2—F7^viii	2.7620 (19)
K2—F7^ix	2.8795 (17)
K2—F6ⁱ	2.8943 (16)
K2—F5^iv	2.9912 (18)

Open in a new tab

Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) ; (viii) ; (ix) .

Acknowledgments

The authors thank the Russian Foundation for Basic Research (project No. 08-03-00355) for financial support.

supplementary crystallographic information

Comment

The asymmetric unit of the title compound, K₄Sb₂SnF₁₄, (I), contains one crystallographically independent Sb atom, one Sn atom on a special position (Wyckoff position 1a), seven fluorine atoms and two potassium cations. The Sn atoms are coordinated by six F atoms in a centrosymmetric, slightly distorted octahedral environment (Fig. 1a), with Sn—F distances ranging from 1.9581 (14) to 1.9611 (17) Å (Table 1). The nearest environment of the Sb atom is formed by four fluorine atoms with Sb—F bond distances ranging from 1.9380 (14) to 2.0696 (15) Å. Taking into account a lone electron pair (E), the coordination polyhedron of Sb(III) can be described as a trigonal bipyramid (Gillespie, 1970). Three fluorine atoms, F4ⁱ, F5ⁱⁱ and F6, are involved in the second coordination sphere of Sb with Sb—F bond distances of 2.7516 (15), 3.0471 (18) and 3.117 (2) Å, respectively. Two Sb polyhedra are linked by double fluorine bridges (F4 and F4ⁱ) to form a centrosymmetric dimer (Fig. 1 b), with an Sb···Sbⁱ distance of 3.9925 (2) Å.

The Sn(IV) and Sb(III) complexes are bound via fluorine bridges yielding the anionic layers [Sb₂SnF₁₄]^4- parallel to the ac plane (Fig. 2), with Sn···Sb distances of 4.21660 (15) and 4.33908 (16) Å. Such layers alternate with layers of potassium cations (Fig.3).

The coordination numbers (CN) of the potassium cations were calculated by the method of intersecting spheres (Serezhkin et al., 1997) with use of the program package TOPOS (Blatov, 2004). For the K1 (Fig. 4a), the CN is 10 [K1—F, 2.6235 (16) – 3.122 (2) Å] and for the K2 (Fig. 4 b), the CN is 8 [K2—F, 2.6662 (15) – 2.9912 (18) Å].

Experimental

KSbF₄ (5.94 g, 0.025 mol) was reacted with K₂SnF₆.H₂O (8.21 g, 0.025 mol) in a solution of hydrofluoric acid (10%, 200 ml; Reachem(Russia), 99.99% purity). The solution obtained was evaporated in air at room temperature down to 1/3 of the initial volume. Then the precipitate was separated from solution and dried to constant weight (1.98 g). The complexes KSbF₄ and K₂SnF₆.H₂O were prepared according to (Davidovich & Zemnukhova, 1975; Kriegsmann & Kessler, 1962).