K₃Sn₅Cl₃F₁₀ with a corrugated layered structure

Single crystals of K₃Sn₅Cl₃F₁₀, tri­potassium trichloro­deca­fluoro­penta­stannate(II), were isolated from a batch of needle-shaped crystals containing several potassium tin(II) fluorides, chlorides and chloride fluorides. The title compound crystallizes in the centrosymmetric space group Cmcm and the unit cell contains three crystallographically distinct tin units, with one SnF₃Cl₂E, in the unusual SnX₅E pseudo-octa­hedral coordination, while the other two are in an SnX₄E pseudo-trigonal bipyramid (E is a stereoactive lone pair). The SnF₃Cl₂ units form [SnF₂Cl₂]_n^2n- rows parallel to the a axis of the unit cell, sandwiched between rows of [Sn₂F₄]_n units also parallel to the a axis, with adjacent [Sn₂F₄]_n rows being held together by rows of Cl^- ions, also parallel to a. This ensemble forms [(Sn₂F₄)(SnF₂Cl₂)(Sn₂F₄)Cl]_n^3n- anionic planes parallel to ac. Two adjacent anionic planes, their terminal F atoms pointing towards each other, are held together by K⁺ ions and form bilayers. Each pair of adjacent bilayers is separated by a sheet of Sn lone pairs, making the structure highly layered.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](n-Cl) = 0.002 Å
• R factor = 0.025
• wR factor = 0.058
• Data-to-parameter ratio = 13.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        Sn1
PLAT804_ALERT_4_C ARU-Pack Problem in PLATON Analysis ............          !

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: X-AREA (Stoe, 2005); cell refinement: X-AREA; data reduction: X-RED32 (Stoe, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003) and CAMERON (Watkin et al., 1993); software used to prepare material for publication: WinGX (Farrugia, 1999).

pentapotassium trichlorodecafluoropentastannate(II)

Crystal data

K3Sn5Cl3F10	F(000) = 1792
Mr = 1007.10	Dx = 3.938 Mg m^−3
Orthorhombic, Cmcm	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2c 2	Cell parameters from 13477 reflections
a = 4.3051 (3) Å	θ = 2.0–29.7°
b = 19.0324 (15) Å	µ = 8.54 mm^−1
c = 20.7335 (19) Å	T = 173 K
V = 1698.8 (2) Å^3	Rod, colourless
Z = 4	0.50 × 0.14 × 0.12 mm

Data collection

Stoe IPDS-II diffractometer	927 independent reflections
Radiation source: fine-focus sealed tube	919 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.046
ω scans	θmax = 25.5°, θmin = 2.0°
Absorption correction: multi-scan (MULABS in PLATON; Spek, 2003)	h = −5→5
Tmin = 0.106, Tmax = 0.359	k = −22→22
6270 measured reflections	l = −25→25

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F^2 > 2σ(F^2)] = 0.025	Secondary atom site location: difference Fourier map
wR(F^2) = 0.058	w = 1/[σ^2(Fo^2) + (0.0678P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.21	(Δ/σ)max = 0.001
927 reflections	Δρmax = 1.31 e Å^−3
69 parameters	Δρmin = −1.07 e Å^−3

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement of F² against ALL reflections. The weighted R-fa-tor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Sn2	0.50000	0.17178 (2)	0.50135 (2)	0.0205 (2)
Sn3	1.00000	0.12898 (2)	0.64825 (2)	0.0226 (2)
F3	0.50000	0.1230 (2)	0.60082 (17)	0.0176 (11)
F4	1.00000	0.14144 (19)	0.53827 (18)	0.0161 (10)
F5	1.00000	0.02572 (19)	0.62785 (18)	0.0171 (11)
F6	0.50000	0.07285 (19)	0.46732 (17)	0.0150 (10)
Sn1	0.50000	0.29533 (3)	0.75000	0.0164 (2)
Cl1	0.50000	0.31708 (10)	0.61499 (8)	0.0286 (5)
F1	1.00000	0.3259 (5)	0.75000	0.063 (3)
F2	0.50000	0.4022 (3)	0.75000	0.0333 (19)
Cl2	1.00000	0.57658 (13)	0.75000	0.0269 (7)
K1	1.00000	0.44224 (8)	0.83925 (7)	0.0198 (4)
K2	1.00000	0.00000	0.50000	0.0137 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn2	0.0263 (3)	0.0099 (2)	0.0254 (3)	0.0000	0.0000	−0.0015 (2)
Sn3	0.0334 (3)	0.0137 (2)	0.0208 (3)	0.0000	0.0000	−0.0051 (2)
F3	0.0138 (18)	0.026 (2)	0.0130 (17)	0.0000	0.0000	0.0023 (15)
F4	0.0153 (18)	0.0163 (18)	0.0167 (18)	0.0000	0.0000	0.0028 (14)
F5	0.0212 (19)	0.0148 (18)	0.0154 (18)	0.0000	0.0000	−0.0003 (15)
F6	0.0147 (18)	0.0127 (17)	0.0177 (18)	0.0000	0.0000	−0.0006 (14)
Sn1	0.0143 (3)	0.0152 (3)	0.0197 (3)	0.0000	0.0000	0.0000
Cl1	0.0350 (10)	0.0310 (9)	0.0199 (8)	0.0000	0.0000	−0.0032 (7)
F1	0.062 (6)	0.080 (7)	0.046 (5)	0.0000	0.0000	0.0000
F2	0.053 (4)	0.022 (3)	0.025 (3)	0.0000	0.0000	0.0000
Cl2	0.0449 (15)	0.0184 (11)	0.0175 (11)	0.0000	0.0000	0.0000
K1	0.0219 (7)	0.0204 (7)	0.0171 (7)	0.0000	0.0000	0.0019 (5)
K2	0.0130 (9)	0.0121 (9)	0.0161 (9)	0.0000	0.0000	−0.0010 (7)

Geometric parameters (Å, º)

Sn1—F1	2.230 (3)	Sn2—F4^i	2.3565 (15)
Sn1—F2	2.034 (6)	Sn3—F3	2.3693 (15)
Sn1—F1^i	2.230 (3)	Sn3—F4	2.293 (4)
Sn1—Cl1^ii	2.8297 (17)	Sn3—F5	2.010 (4)
Sn2—F3	2.262 (4)	Sn3—F3^iii	2.3693 (15)
Sn2—F4	2.3565 (15)	Sn1—Cl1	2.8297 (17)
Sn2—F6	2.011 (4)
Cl1^ii—Sn1—F1^i	87.81 (4)	F4^i—Sn2—F6	83.37 (10)
Cl1—Sn1—F1^i	87.81 (4)	F3—Sn3—F4	65.93 (8)
Cl1—Sn1—Cl1^ii	163.18 (6)	F3—Sn3—F5	82.28 (10)
F1—Sn1—F2	74.9 (2)	F3—Sn3—F3^iii	130.61 (11)
F1—Sn1—F1^i	149.8 (3)	F4—Sn3—F5	83.79 (14)
Cl1^ii—Sn1—F1	87.81 (4)	F3^iii—Sn3—F4	65.93 (8)
Cl1—Sn1—F1	87.81 (4)	F3^iii—Sn3—F5	82.28 (10)
Cl1—Sn1—F2	81.59 (4)	Sn1—F1—Sn1^iii	149.8 (5)
Cl1^ii—Sn1—F2	81.59 (4)	Sn2—F4—Sn2^iii	131.98 (16)
F1^i—Sn1—F2	74.9 (2)	Sn2^iii—F4—Sn3	110.39 (9)
F3—Sn2—F4	66.62 (8)	Sn2—F3—Sn3^i	111.02 (9)
F3—Sn2—F6	86.31 (14)	Sn2—F3—Sn3	111.02 (9)
F3—Sn2—F4^i	66.62 (8)	Sn2—F4—Sn3	110.39 (9)
F4—Sn2—F6	83.37 (10)	Sn3—F3—Sn3^i	130.61 (16)
F4—Sn2—F4^i	131.98 (12)
F4—Sn2—F3—Sn3	18.90 (13)	F5—Sn3—F3—Sn2	−106.17 (17)
F6—Sn2—F3—Sn3	103.27 (13)	F4—Sn3—F3—Sn2	−19.55 (14)
F6—Sn2—F4—Sn3	−108.30 (16)	F3—Sn3—F4—Sn2	18.66 (13)
F3—Sn2—F4—Sn3	−19.47 (14)	F5—Sn3—F4—Sn2	102.96 (12)

Symmetry codes: (i) x−1, y, z; (ii) −x+1, y, −z+3/2; (iii) x+1, y, z.