Crystal structure and phase transition in (NH₄)₃WO₂F₅: from dynamic to static orientational disorder

Single crystals of tungsten double salt (NH₄)₃WO₂F₅ = (NH₄)₃[WO₂F₄]F have been synthesized by solid-state reaction or from fluoride solution and its crystal structures at 296 and 193 K were determined by X-ray diffraction. At room temperature, the crystal structure of the compound is dynamically disordered with the ligand atoms statistically distributed on two positions (6e and 24m) of the Pm3m unit cell [a = 6.0298 (1) Å], and the tungsten atom dynamically disordered on 12 orientations forming a spatial cuboctahedron [W₁₂] that enables the real geometry of cis-WO₂F₄ octahedron to be determined with two short W—O distances. On cooling, the compound undergoes a first-order phase transition with the symmetry change Pm3m → Pa3 and a doubling of the unit-cell parameter [a = 11.9635 (7) Å]. The ligand F(O) atoms statistically occupy two general 24d sites and form W1X₆ and W2X₆ octahedra, in which the O and F atoms are not crystallographically different that means a static orientational disorder of (NH₄)₃WO₂F₅.

Computing details

For both compounds, data collection: Bruker APEX2; cell refinement: Bruker SAINT; data reduction: Bruker SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Bruker SHELXTL; software used to prepare material for publication: Bruker SHELXTL.

Figures

(296K)

Crystal data

F4WO2·2(H4N)·F(NH4)	Dx = 2.810 Mg m^−3
Mr = 370.98	Mo Kα radiation, λ = 0.71073 Å
Cubic, Pm3m	Cell parameters from 860 reflections
Hall symbol: -P 4 2 3	θ = 3.4–30.0°
a = 6.0298 (1) Å	µ = 13.24 mm^−1
V = 219.23 (1) Å^3	T = 296 K
Z = 1	Sphere, colorless
F(000) = 170	0.18 × 0.18 × 0.18 mm

Data collection

Bruker APEXII CCD diffractometer	93 independent reflections
Radiation source: fine-focus sealed tube	93 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
Detector resolution: 8.33 pixels mm^-1	θmax = 30.0°, θmin = 3.4°
ω scans	h = −8→8
Absorption correction: multi-scan SADABS 2008/1	k = −8→8
Tmin = 0.199, Tmax = 0.199	l = −8→8
2864 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	H-atom parameters not defined
R[F^2 > 2σ(F^2)] = 0.016	w = 1/[σ^2(Fo^2) + (0.0291P)^2 + 0.0078P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.035	(Δ/σ)max = 0.024
S = 1.21	Δρmax = 0.49 e Å^−3
93 reflections	Δρmin = −0.63 e Å^−3
19 parameters	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0478 (14)
Primary atom site location: structure-invariant direct methods

Special details

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	Occ. (<1)
W1	0.02378 (2)	0.0000	0.02378 (2)	0.04325 (4)	0.08
F3	0.5000	0.5000	0.5000	0.0986 (12)
N1	0.5000	0.5000	0.0000	0.129 (2)
F1	0.3108 (10)	0.0000	0.0000	0.113 (3)	0.249 (4)
F2	0.2033 (4)	0.2033 (4)	0.0997 (9)	0.1345 (17)	0.1877 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
W1	0.04631 (5)	0.03712 (7)	0.04631 (5)	0.000	0.00513 (13)	0.000
F3	0.0986 (12)	0.0986 (12)	0.0986 (12)	0.000	0.000	0.000
N1	0.1118 (19)	0.1118 (19)	0.164 (5)	0.000	0.000	0.000
F1	0.048 (2)	0.145 (4)	0.145 (4)	0.000	0.000	0.000
F2	0.1123 (12)	0.1123 (12)	0.179 (4)	−0.0585 (15)	−0.0233 (11)	−0.0233 (11)

Geometric parameters (Å, º)

W1—W1^i	0.2028 (2)	F1—F1^vii	2.650 (9)
W1—W1^ii	0.2028 (2)	F1—F1^iii	2.650 (9)
W1—W1^iii	0.2028 (2)	F1—F1^iv	2.650 (9)
W1—W1^iv	0.2028 (2)	F2—F2^xiii	2.584 (9)
W1—W1^v	0.2868 (3)	F2—F2^xiv	2.584 (9)
W1—W1^vi	0.2868 (3)	F2—F2^xv	2.606 (7)
W1—W1^vii	0.3512 (4)	F2—F2^xvi	2.606 (7)
W1—W1^viii	0.3512 (4)	N1—F2^vi	2.600 (4)
W1—W1^ix	0.3512 (4)	N1—F2^xvii	2.600 (4)
W1—W1^x	0.3512 (4)	N1—F2^xviii	2.600 (4)
W1—W1^xi	0.4055 (4)	N1—F2^xix	2.600 (4)
W1—F1^iii	1.736 (6)	N1—F2^xx	2.600 (4)
W1—F1	1.736 (6)	N1—F2^xxi	2.600 (4)
W1—F1^vii	1.885 (6)	N1—F2^xxii	2.600 (4)
W1—F1^ix	1.885 (6)	N1—F2	2.600 (4)
W1—F1^xi	2.022 (6)	N1—F3^xxiii	3.0149
W1—F1^viii	2.022 (6)	N1—F1	3.223 (2)
W1—F2	1.698 (4)	N1—F1^xviii	3.223 (2)
W1—F2^iv	1.698 (4)	N1—F1^iv	3.223 (2)
W1—F2^xii	1.846 (4)	N1—F1^xxiv	3.223 (2)
W1—F2^xiii	1.846 (4)	N1—F1^xxv	3.223 (2)
W1—F2^viii	1.983 (4)	N1—F1^xxvi	3.223 (2)
W1—F2^xi	1.983 (4)	N1—F1^xxvii	3.223 (2)
F1—F1^viii	2.650 (9)	N1—F1^xxviii	3.223 (2)
F1^viii—W1—F1^vii	85.339 (17)	F2—W1—F2^xv	100.3 (3)
F1^iv—W1—F1^vii	85.339 (17)	F2^xxix—W1—F2^viii	88.8 (2)
F1^viii—W1—F1^xi	85.339 (17)	F2^xv—W1—F2^xi	88.8 (2)
F1^iv—W1—F1^xi	85.339 (17)	F2^ii—W1—F2^ix	82.3 (2)
F1^iii—W1—F1^viii	93.986 (12)	F2^iv—W1—F2^xii	93.5 (3)
F1—W1—F1^viii	93.986 (12)	F2^xxix—W1—F2^xii	94.6 (3)
F1^iii—W1—F1^iv	93.986 (12)	F2^xv—W1—F2^xiii	94.6 (3)
F1—W1—F1^iv	93.986 (12)	F2^xii—W1—F2^viii	85.7 (2)
F1^iii—W1—F1	99.47 (3)	F2^xiii—W1—F2^xi	85.7 (2)
F1^iii—W1—F1^xi	89.329 (5)	F2^xxx—W1—F2^viii	84.8 (2)
F1—W1—F1^vii	89.329 (5)	F2^xvi—W1—F2^xi	84.8 (2)
F1^xi—W1—F1^vii	81.87 (3)	F2^xv—W1—F2^xvi	93.5 (3)
F1^viii—W1—F1^iv	167.65 (4)	F2^xii—W1—F2^xxx	167.39 (3)
F1—W1—F1^xi	171.20 (3)	F2^iv—W1—F2^viii	170.97 (3)
F1^iii—W1—F1^vii	171.20 (3)	F2—W1—F2^xi	170.97 (3)
F2^iv—W1—F2^xxix	100.3 (3)

Symmetry codes: (i) y, −z, x; (ii) z, −x, −y; (iii) y, z, x; (iv) z, x, y; (v) −x, −y, z; (vi) x, y, −z; (vii) −y, −z, −x; (viii) −z, −x, −y; (ix) −y, z, −x; (x) −z, x, y; (xi) −x, −y, −z; (xii) −y, −z, x; (xiii) y, −z, −x; (xiv) −z, x, −y; (xv) z, −x, y; (xvi) −y, z, x; (xvii) −x+1, −y+1, z; (xviii) −x+1, −y+1, −z; (xix) −x+1, y, z; (xx) x, −y+1, −z; (xxi) x, −y+1, z; (xxii) −x+1, y, −z; (xxiii) x, y, z−1; (xxiv) −z+1, −x+1, −y; (xxv) x, y+1, z; (xxvi) −z, −x+1, −y; (xxvii) z+1, x, y; (xxviii) −x+1, −y, −z; (xxix) x, −y, z; (xxx) y, z, −x.

(193K)

Crystal data

F4WO2·F·3(H4N)	Dx = 2.878 Mg m^−3
Mr = 370.98	Mo Kα radiation, λ = 0.71073 Å
Cubic, Pa3	Cell parameters from 868 reflections
Hall symbol: -P 2ac 2ab	θ = 1.7–33.0°
a = 11.9635 (7) Å	µ = 13.56 mm^−1
V = 1712.28 (17) Å^3	T = 193 K
Z = 8	Sphere, colorless
F(000) = 1360	0.18 × 0.18 × 0.18 mm

Data collection

Bruker APEXII CCD diffractometer	1134 independent reflections
Radiation source: fine-focus sealed tube	696 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.033
Detector resolution: 8.33 pixels mm^-1	θmax = 33.0°, θmin = 1.7°
φ and ω scans	h = −18→18
Absorption correction: multi-scan SADABS 2008/1	k = −16→18
Tmin = 0.194, Tmax = 0.194	l = −18→18
27085 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	H-atom parameters not defined
R[F^2 > 2σ(F^2)] = 0.037	w = 1/[σ^2(Fo^2) + (0.031P)^2 + 14.1528P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.101	(Δ/σ)max < 0.001
S = 0.98	Δρmax = 1.90 e Å^−3
1079 reflections	Δρmin = −1.32 e Å^−3
38 parameters	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.00054 (7)
Primary atom site location: structure-invariant direct methods

Special details

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
W1	0.5000	0.0000	0.5000	0.02738 (16)
W2	0.5000	0.5000	0.5000	0.04546 (18)
N1	0.5152 (6)	0.2579 (5)	0.2331 (7)	0.059 (2)
F3	0.2445 (4)	0.2445 (4)	0.2445 (4)	0.0514 (19)
F1	0.4455 (3)	0.1082 (3)	0.3996 (3)	0.0398 (8)
F2	0.4786 (5)	0.3465 (3)	0.5179 (5)	0.0697 (15)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
W1	0.02738 (16)	0.02738 (16)	0.02738 (16)	−0.00399 (10)	0.00399 (10)	0.00399 (10)
W2	0.04546 (18)	0.04546 (18)	0.04546 (18)	0.00152 (16)	0.00152 (16)	0.00152 (16)
N1	0.078 (5)	0.037 (4)	0.063 (5)	−0.019 (4)	−0.009 (4)	0.022 (3)
F3	0.0514 (19)	0.0514 (19)	0.0514 (19)	−0.002 (2)	−0.002 (2)	−0.002 (2)
F1	0.0450 (19)	0.0366 (18)	0.0379 (19)	0.0029 (16)	−0.0047 (16)	0.0123 (15)
F2	0.099 (5)	0.0236 (16)	0.086 (4)	−0.015 (2)	−0.010 (3)	0.009 (2)

Geometric parameters (Å, º)

W1—F1	1.882 (3)	N1—F1	2.806 (7)
W1—F1^i	1.882 (3)	N1—F2^xii	2.894 (11)
W1—F1^ii	1.882 (3)	N1—F1^xiii	2.946 (8)
W1—F1^iii	1.882 (3)	N1—F2^viii	2.969 (10)
W1—F1^iv	1.882 (3)	F1—F1^iii	2.634 (6)
W1—F1^v	1.882 (3)	F1—F1^i	2.634 (6)
W2—F2	1.867 (4)	F1—F1^ii	2.688 (6)
W2—F2^vi	1.867 (4)	F1—F1^iv	2.688 (6)
W2—F2^vii	1.867 (4)	F2—F2^viii	2.632 (8)
W2—F2^viii	1.867 (4)	F2—F2^x	2.632 (8)
W2—F2^ix	1.867 (4)	F2—F2^vii	2.648 (8)
W2—F2^x	1.867 (4)	F2—F2^ix	2.648 (8)
N1—F3^xi	2.760 (8)
F1—W1—F1^i	88.83 (16)	F2^vi—W2—F2^vii	89.6 (3)
F1—W1—F1^iii	88.83 (16)	F2—W2—F2^viii	89.6 (3)
F1^i—W1—F1^iv	88.83 (16)	F2^vi—W2—F2^ix	89.6 (3)
F1^iv—W1—F1^v	88.83 (16)	F2^vii—W2—F2^ix	89.6 (3)
F1^ii—W1—F1^v	88.83 (16)	F2—W2—F2^x	89.6 (3)
F1^ii—W1—F1^iii	88.83 (16)	F2^viii—W2—F2^x	89.6 (3)
F1—W1—F1^ii	91.17 (16)	F2—W2—F2^vii	90.4 (3)
F1^i—W1—F1^iii	91.17 (16)	F2^vi—W2—F2^viii	90.4 (3)
F1—W1—F1^iv	91.17 (16)	F2^vii—W2—F2^viii	90.4 (3)
F1^ii—W1—F1^iv	91.17 (16)	F2—W2—F2^ix	90.4 (3)
F1^i—W1—F1^v	91.17 (16)	F2^vi—W2—F2^x	90.4 (3)
F1^iii—W1—F1^v	91.17 (16)	F2^ix—W2—F2^x	90.4 (3)
F1^i—W1—F1^ii	180.00 (17)	F2—W2—F2^vi	179.999 (1)
F1^iii—W1—F1^iv	180.00 (17)	F2^viii—W2—F2^ix	180.000 (1)
F1—W1—F1^v	179.999 (1)	F2^vii—W2—F2^x	180.0

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