Dipotassium hexa­chloro­tantalate(IV), K₂TaCl₆

K₂TaCl₆ was obtained as a by-product during the reaction of VCl₃ and KCl in a sealed tantalum container. The compound is isotypic with K₂PtCl₆ and contains octahedrally coordinated Ta atoms.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](Ta-Cl) = 0.003 Å
• R factor = 0.020
• wR factor = 0.042
• Data-to-parameter ratio = 14.8

checkCIF/PLATON results

No syntax errors found



Alert level B
CHEMS01_ALERT_1_B  The sum formula contains elements in the wrong order.
            Ta precedes Cl
            Sequence must be C, H, then alphabetical.

Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       0.50 Ratio
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          2
              K0.04

Alert level G
ABSTM02_ALERT_3_G  The ratio of expected to reported Tmax/Tmin(RR') is < 0.75
            Tmin and Tmax reported:      0.127     0.240
            Tmin' and Tmax expected:      0.246     0.263
            RR' =      0.564
            Please check that your absorption correction is appropriate.

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

   4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 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 & Cie, 2002); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1996) and XP in SHELXTL-Plus (Sheldrick, 1991).

(I)

Crystal data

K2TaCl6	Melting point: unknown K
Mr = 471.85	Mo Kα radiation, λ = 0.71073 Å
Cubic, Fm3m	Cell parameters from 1314 reflections
Hall symbol: -F 423	θ = 1.9–28.2°
a = 9.9935 (16) Å	µ = 13.37 mm^−1
V = 998.1 (3) Å^3	T = 293 K
Z = 4	Cube, black
F(000) = 852	0.1 × 0.1 × 0.1 mm
Dx = 3.140 Mg m^−3

Data collection

Stoe IPDS-I diffractometer	89 independent reflections
Radiation source: fine-focus sealed tube	89 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.051
Detector resolution: not measured pixels mm^-1	θmax = 27.8°, θmin = 3.5°
φ scans	h = −13→12
Absorption correction: numerical the absorption correction (X-RED; Stoe & Cie, 2002) was performed after optimizing the crystal shape using X-SHAPE (Stoe & Cie, 1999)	k = −13→12
Tmin = 0.127, Tmax = 0.240	l = −13→13
2354 measured reflections

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)] = 0.020	Secondary atom site location: difference Fourier map
wR(F^2) = 0.042	w = 1/[σ^2(Fo^2) + 21.1812P] where P = (Fo^2 + 2Fc^2)/3
S = 1.23	(Δ/σ)max < 0.001
89 reflections	Δρmax = 0.59 e Å^−3
6 parameters	Δρmin = −0.87 e Å^−3

Special details

Experimental. A suitable single-crystal was carefully selected under a polarizing microscope and mounted in a glass capillary. The scattering intensities were collected with an imaging plate diffractometer (IPDS I, Stoe & Cie) equipped with a fine focus sealed tube X-ray source (Mo Kα, λ = 0.71073 Å) operating at 50 kV and 40 mA. Intensity data for K₂TaCl₆ were collected at 293 K by φ-scans in 100 frames (0 < φ < 200°; Δφ = 2°, exposure time of 5 min) in the 2 Θ range 3.80 to 56.30°. Structure solution and refinement were carried out using the program SHELXL97 (Sheldrick, 1997). A numerical absorption correction (X-RED (Stoe & Cie, 2001) was applied after optimization of the crystal shape (X-SHAPE (Stoe & Cie, 1999)). The final difference maps were free of any chemically significant features. The refinement was based on F² for ALL reflections.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor 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
Ta	0.0000	0.0000	0.0000	0.0274 (3)
Cl	0.0000	−0.2399 (3)	0.0000	0.0639 (10)
K	0.2500	−0.2500	0.2500	0.0614 (14)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ta	0.0274 (3)	0.0274 (3)	0.0274 (3)	0.000	0.000	0.000
Cl	0.0832 (15)	0.0252 (13)	0.0832 (15)	0.000	0.000	0.000
K	0.0614 (14)	0.0614 (14)	0.0614 (14)	0.000	0.000	0.000

Geometric parameters (Å, º)

Ta—Cl^i	2.397 (3)	K—Cl^x	3.5347 (6)
Ta—Cl^ii	2.397 (3)	K—Cl^xi	3.5347 (6)
Ta—Cl	2.397 (3)	K—Cl^xii	3.5347 (6)
Ta—Cl^iii	2.397 (3)	K—Cl^xiii	3.5347 (6)
Ta—Cl^iv	2.397 (3)	K—Cl^xiv	3.5347 (6)
Ta—Cl^v	2.397 (3)	K—Cl^viii	3.5347 (6)
Cl—K^vi	3.5347 (6)	K—Cl^xv	3.5347 (6)
Cl—K	3.5347 (6)	K—Cl^v	3.5347 (6)
Cl—K^vii	3.5347 (6)	K—Cl^vii	3.5347 (6)
Cl—K^viii	3.5347 (6)	K—Cl^iii	3.5347 (6)
K—Cl^ix	3.5347 (6)
Cl^i—Ta—Cl^ii	90.0	Cl^ix—K—Cl^viii	119.973 (2)
Cl^i—Ta—Cl	90.0	Cl^x—K—Cl^viii	62.68 (8)
Cl^ii—Ta—Cl	90.0	Cl^xi—K—Cl^viii	90.047 (3)
Cl^i—Ta—Cl^iii	180.0	Cl—K—Cl^viii	90.047 (3)
Cl^ii—Ta—Cl^iii	90.0	Cl^xii—K—Cl^viii	57.31 (8)
Cl—Ta—Cl^iii	90.0	Cl^xiii—K—Cl^viii	119.973 (2)
Cl^i—Ta—Cl^iv	90.0	Cl^xiv—K—Cl^viii	119.973 (2)
Cl^ii—Ta—Cl^iv	90.0	Cl^ix—K—Cl^xv	119.973 (2)
Cl—Ta—Cl^iv	180.0	Cl^x—K—Cl^xv	90.047 (3)
Cl^iii—Ta—Cl^iv	90.0	Cl^xi—K—Cl^xv	62.68 (8)
Cl^i—Ta—Cl^v	90.0	Cl—K—Cl^xv	119.973 (2)
Cl^ii—Ta—Cl^v	180.0	Cl^xii—K—Cl^xv	57.31 (8)
Cl—Ta—Cl^v	90.0	Cl^xiii—K—Cl^xv	90.047 (3)
Cl^iii—Ta—Cl^v	90.0	Cl^xiv—K—Cl^xv	62.68 (8)
Cl^iv—Ta—Cl^v	90.0	Cl^viii—K—Cl^xv	57.31 (8)
Ta—Cl—K^vi	91.64 (5)	Cl^ix—K—Cl^v	62.68 (8)
Ta—Cl—K	91.64 (5)	Cl^x—K—Cl^v	90.047 (3)
K^vi—Cl—K	176.71 (9)	Cl^xi—K—Cl^v	119.973 (2)
Ta—Cl—K^vii	91.64 (5)	Cl—K—Cl^v	57.31 (8)
K^vi—Cl—K^vii	89.953 (3)	Cl^xii—K—Cl^v	119.973 (2)
K—Cl—K^vii	89.953 (3)	Cl^xiii—K—Cl^v	90.047 (3)
Ta—Cl—K^viii	91.64 (5)	Cl^xiv—K—Cl^v	119.973 (2)
K^vi—Cl—K^viii	89.953 (3)	Cl^viii—K—Cl^v	119.973 (2)
K—Cl—K^viii	89.953 (3)	Cl^xv—K—Cl^v	176.71 (9)
K^vii—Cl—K^viii	176.71 (9)	Cl^ix—K—Cl^vii	62.68 (8)
Cl^ix—K—Cl^x	57.31 (8)	Cl^x—K—Cl^vii	119.973 (2)
Cl^ix—K—Cl^xi	57.31 (8)	Cl^xi—K—Cl^vii	90.047 (3)
Cl^x—K—Cl^xi	57.31 (8)	Cl—K—Cl^vii	90.047 (3)
Cl^ix—K—Cl	119.973 (2)	Cl^xii—K—Cl^vii	119.973 (2)
Cl^x—K—Cl	119.973 (2)	Cl^xiii—K—Cl^vii	57.31 (8)
Cl^xi—K—Cl	176.71 (9)	Cl^xiv—K—Cl^vii	57.31 (8)
Cl^ix—K—Cl^xii	176.71 (9)	Cl^viii—K—Cl^vii	176.71 (9)
Cl^x—K—Cl^xii	119.973 (2)	Cl^xv—K—Cl^vii	119.973 (2)
Cl^xi—K—Cl^xii	119.973 (2)	Cl^v—K—Cl^vii	62.68 (8)
Cl—K—Cl^xii	62.68 (8)	Cl^ix—K—Cl^iii	90.047 (3)
Cl^ix—K—Cl^xiii	119.973 (1)	Cl^x—K—Cl^iii	62.68 (8)
Cl^x—K—Cl^xiii	176.71 (9)	Cl^xi—K—Cl^iii	119.973 (2)
Cl^xi—K—Cl^xiii	119.973 (2)	Cl—K—Cl^iii	57.31 (8)
Cl—K—Cl^xiii	62.68 (8)	Cl^xii—K—Cl^iii	90.047 (3)
Cl^xii—K—Cl^xiii	62.68 (8)	Cl^xiii—K—Cl^iii	119.973 (2)
Cl^ix—K—Cl^xiv	90.047 (3)	Cl^xiv—K—Cl^iii	176.71 (9)
Cl^x—K—Cl^xiv	119.973 (2)	Cl^viii—K—Cl^iii	62.68 (8)
Cl^xi—K—Cl^xiv	62.68 (8)	Cl^xv—K—Cl^iii	119.973 (2)
Cl—K—Cl^xiv	119.973 (2)	Cl^v—K—Cl^iii	57.31 (8)
Cl^xii—K—Cl^xiv	90.047 (3)	Cl^vii—K—Cl^iii	119.973 (2)
Cl^xiii—K—Cl^xiv	57.31 (8)

Symmetry codes: (i) z, x, y; (ii) y, −x, −z; (iii) −z, −x, −y; (iv) −x, −y, −z; (v) −y, x, z; (vi) x−1/2, y, z−1/2; (vii) −x+1/2, −y−1/2, −z; (viii) −x, −y−1/2, −z+1/2; (ix) z+1/2, x, y+1/2; (x) y+1/2, −x, −z+1/2; (xi) x+1/2, y, z+1/2; (xii) z, x−1/2, y+1/2; (xiii) y+1/2, −x−1/2, −z; (xiv) −z+1/2, −x−1/2, −y; (xv) −y, x−1/2, z+1/2.