inorganic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoSTRUCTURAL
CHEMISTRY
ISSN: 2053-2296

Ammonium scandium tetra­fluoride

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aSchool of Chemistry, University of St Andrews, Fife KY16 9ST, Scotland
*Correspondence e-mail: pl@st-and.ac.uk

(Received 27 September 2006; accepted 24 October 2006; online 22 November 2006)

The title compound, NH4ScF4, is an addition to the AMF4 family of layered perovskite-like structures. The structure consists of a two-dimensional array of corner-sharing ScF6 octa­hedra, which produces anionic sheets of stoichiometry [ScF4] stacked along the c axis. The layers are separated by charge-balancing ammonium cations, which hydrogen bond to the apical F atoms of adjacent layers. This structure may be viewed as a `single-layer' fluoride analogue of the Dion–Jacobson family of oxides.

Comment

The title compound, NH4ScF4, (I), was produced during our exploratory studies in the hydro­thermal chemistry of organically templated scandium fluorides (Stephens et al., 2004[Stephens, N. F., Slawin, A. M. Z. & Lightfoot, P. (2004). Chem. Commun. pp. 614-615.]; Stephens & Lightfoot, 2006[Stephens, N. F. & Lightfoot, P. (2006). Solid State Sci. 8, 197-202.]). This compound arises from an in situ breakdown of the organic template (see Experimental[link]). It is related to several other layered fluorides of stoichiometry AMF4 and may also be regarded as an n = 1 Dion–Jacobson phase (Dion et al., 1981[Dion, M., Ganne, M. & Tournoux, M. (1981). Mater. Res. Bull. 16, 1429-1435.]).

The asymmetric unit (Fig. 1[link]) contains one unique Sc site on a general position, having quite regular octa­hedral symmetry (Table 1[link]). There are five crystallographically independent F sites and two N sites, both on mirror planes.

Fig. 2[link] shows that (I) is built from puckered layers of vertex-sharing octa­hedra, typical of layered perovskites. The layers are eclipsed relative to each other with respect to the a axis, but staggered by b/4 along b. Extensive hydrogen bonding occurs between adjacent layers, mediated by the ammonium cations (Table 2[link]). The only N—H⋯F hydrogen bonds are those between ammonium cations and the `apical' F atoms that project into the inter­layer space. This hydrogen bonding fulfills bond-valence requirements around the apical F atoms F2 and F3, as shown in Table 3[link].

Both the raw diffraction data and the derived model display a significant degree of pseudosymmetry (e.g. the bond lengths involving F1/F4 and F2/F3). An alternative model in space group Amma, with b′ = b/2, was also considered. However, our refinements confirm that the chosen model is correct; refinements in the higher-symmetry model lead to anomalously elongated ellipsoids for the `in-plane' F atoms, transverse to the Sc—F—Sc linkages. In fact, the pseudosymmetry is due to `octa­hedral tilting', and the difference between the two models is clarified in Fig. 3[link]. In addition to the tilting relative to the b axis, shown in Fig. 2[link](b), there is a second tilt mode around the c axis, which is allowed in the correct Pmcn model but forbidden in the approximate Amma model. The two models are analogous to those in KFeF4 (Lapasset et al., 1986[Lapasset, J., Sciau, P., Moret, J. & Gros, N. (1986). Acta Cryst. B42, 258-262.]), which undergoes a structural phase transition from KFeF4(III) to KFeF4(II) at 368 K, corresponding to Pmcn to Amma. We have not explored the possibility of such a phase transition in the present case.

In comparison with other compositionally related AMF4 compounds, (I) is isotypic with KGaF4 (Courbion et al., 1989[Courbion, G., Randrianohavy, J. V. & Rousseau, J. J. (1989). J. Solid State Chem. 81, 285-292.]). Inter­estingly, however, more precisely similar compositions have different structure types; for example, NH4FeF4 (Leblanc et al., 1985[Leblanc, M., Ferey, G., De Pape, R. & Teillet, J. (1985). Acta Cryst. C41, 657-660.]) has the same type of layer as (I), but the [ScF4] sheets are eclipsed along both a and b, whereas KScF4, has a unique `corrugated sheet' structure containing both cis- and trans-vertex-sharing octa­hedra (Champarnaud-Mesjard & Frit, 1992[Champarnaud-Mesjard, J. C. & Frit, B. (1992). Eur. J. Solid State Inorg. Chem. 29, 161-170.]).

[Figure 1]
Figure 1
The asymmetric unit of (I), with displacement ellipsoids drawn at the 50% probability level [symmetry code: (i) −x, y + [{1\over 2}], −z + [{1\over 2}]].
[Figure 2]
Figure 2
(a) A projection along [100], showing staggered octa­hedra. (b) A projection along [010], showing eclipsed octa­hedra.
[Figure 3]
Figure 3
A view of a single layer along [001], showing (a) the Pmcn model with the additional c axis tilt mode and (b) the Amma model, with b′ = b/2.

Experimental

Scandium oxide (0.138 g), water (5 ml) and a 40% aqueous solution of HF (0.5 ml) were heated in a Teflon-lined steel autoclave for 1 h at 463 K. To this, ethyl­ene glycol (5 ml) and 1,3-diamino­propane (0.4 ml) were added, and the resulting mixture was heated at the same temperature for four days. The product was filtered off, washed with water and allowed to dry at room temperature overnight. Powder X-ray diffraction revealed predominantly (I) as the product, together with a small amount of ScF3. Compound (I) was heated to 1073 K at a rate of 5 K min−1 under N2 gas. Thermogravimmetric analysis shows a single-step weight loss of 19.6% from 573 to 698 K (20% calculated). Powder X-ray diffraction of the residue shows that this decomposition product is ScF3.

Crystal data
  • NH4ScF4

  • Mr = 139.00

  • Orthorhombic, P m c n

  • a = 7.862 (2) Å

  • b = 8.088 (2) Å

  • c = 13.503 (4) Å

  • V = 858.6 (4) Å3

  • Z = 8

  • Dx = 2.151 Mg m−3

  • Mo Kα radiation

  • μ = 1.67 mm−1

  • T = 93 (2) K

  • Prism, colourless

  • 0.10 × 0.03 × 0.02 mm

Data collection
  • Rigaku/MSC CCD area-detector diffractometer

  • ω scans

  • Absorption correction: multi-scan (SADABS; Bruker, 1999[Bruker (1999). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.825, Tmax = 0.970

  • 5191 measured reflections

  • 847 independent reflections

  • 587 reflections with I > 2σ(I)

  • Rint = 0.026

  • θmax = 25.3°

Refinement
  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.028

  • wR(F2) = 0.102

  • S = 1.11

  • 847 reflections

  • 75 parameters

  • Only H-atom coordinates refined

  • w = 1/[σ2(Fo2) + (0.0519P)2 + 0.1485P] where P = (Fo2 + 2Fc2)/3

  • (Δ/σ)max = 0.005

  • Δρmax = 0.40 e Å−3

  • Δρmin = −0.40 e Å−3

Table 1
Selected geometric parameters (Å, °)

Sc—F2 1.9904 (12) 
Sc—F3 1.9919 (12)
Sc—F1 2.0272 (7)
Sc—F4 2.0273 (7)
Sc—F5i 2.0320 (19)
Sc—F5 2.0325 (19)
F2—Sc—F3 179.61 (9)
F1—Sc—F4 179.82 (7)
F5i—Sc—F5 179.713 (18)
Scii—F1—Sc 151.46 (10)
Sciii—F4—Sc 151.82 (10)
Sciv—F5—Sc 168.48 (8)
Symmetry codes: (i) [-x, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) [-x-{\script{1\over 2}}, y, z]; (iii) [-x+{\script{1\over 2}}, y, z]; (iv) -x, [y-{\script{1\over 2}}, -z+{\script{1\over 2}}].

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯F2 0.91 (3) 1.97 (3) 2.836 (2) 159 (2)
N1—H2⋯F3v 0.97 (4) 2.11 (3) 2.858 (3) 132.0 (9)
N1—H3⋯F2vi 0.86 (4) 2.21 (3) 2.853 (3) 131.3 (14)
N2—H4⋯F3vii 0.84 (4) 2.24 (3) 2.867 (3) 132.1 (14)
N2—H5⋯F3 0.93 (3) 1.95 (3) 2.837 (2) 158 (2)
N2—H6⋯F2viii 0.99 (4) 2.11 (3) 2.872 (4) 132.1 (9)
Symmetry codes: (v) [-x+{1\over2}, -y+{3\over2}, z-{1\over2}]; (vi) [x+{1\over2}, -y+2, -z]; (vii) [x-{1\over2}], -y+2, -z+1; (viii) [-x-{1\over2}, -y+{3\over2}, z+{1\over2}].

Table 3
Bond valence parameters

Bond sij sij
Sc F2 0.54
Sc F3 0.53
Sc F1 0.49
Sc F4 0.49
Sc F5 0.48
Sc F5 0.48
  3.00
F1 Sc 0.49 × 2 0.97
F2 Sc 0.54 0.54
F3 Sc 0.53 0.53
F4 Sc 0.49 × 2 0.97
F5 Sc 0.48
F5 Sc 0.48 0.96
Note: sij values calculated for B = 0.37; Brese & O'Keeffe (1991[Brese, N. E. & O'Keeffe, M. (1991). Acta Cryst. B47, 192-197.]) extrapolated.

Systematic absences were consistent with space groups Pmcn (62) or P21cn (33). Successful refinement of the structure in centrosymmetric Pmcn, together with the lack of any contradictory physical property measurements, meant that this was preferred over P21cn. Pmcn [a non-standard setting of Pnma (62)] was chosen as this defines the perovskite-like layers to lie perpendicular to c, which is the convention in perovskite chemistry. H atoms were located from a difference Fourier map and were refined freely; the Uiso(H) values were fixed at 0.018 Å2.

Data collection: CrystalClear (Rigaku/MSC, 2005[Rigaku/MSC (2005). CrystalClear. Rigaku/MSC Inc., The Woodlands, Texas, USA.]); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. Release 97-2. University of Göttingen, Germany.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. Release 97-2. University of Göttingen, Germany.]); molecular graphics: DIAMOND (Brandenburg, 2001[Brandenburg, K. (2001). DIAMOND. Version 2.1. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

The title compound, NH4ScF4 (I) was produced during our exploratory studies in the hydrothermal chemistry of organically templated scandium fluorides (Stephens et al., 2004; Stephens & Lightfoot, 2006). This compound arises from an in situ breakdown of the organic template (see Experimental). It is related to several other layered fluorides of stoichiometry AMF4 and may also be regarded as an n = 1 Dion–Jacobson phase (Dion et al., 1981).

The asymmetric unit (Fig. 1) contains of one unique Sc site on a general position, having quite regular octahedral symmetry (Table 1). There are five crytallographically independent F sites and two N sites, both on mirror planes.

Fig. 2 shows that (I) is built from puckered layers of vertex-sharing octahedra, typical of layered perovskites. The layers are eclipsed relative to each other with respect to the a axis, but staggered by b/4 along b. Extensive hydrogen bonding occurs between adjacent layers, mediated by the ammonium cations (Table 2). The only N—H···F hydrogen bonds are those between ammonium cations and the `apical' F atoms that project into the interlayer space. This hydrogen bonding fulfills bond valence requirements around the apical F atoms F2 and F3, as shown in Table 3.

Both the raw diffraction data and the derived model display a significant degree of pseudo-symmetry (e.g. bond lengths involving F1/F4 and F2/F3). An alternative model in space group Amma, with b' = b/2, was also considered. However, our refinements confirm that the chosen model is correct; refinements in the higher-symmetry model lead to anomalously elongated ellipsoids for the `in-plane' F atoms, transverse to the Sc—F—Sc linkages. In fact, the pseudo-symmetry is due to 'octahedral tilting', and the difference between the two models is clarified in Fig. 3. In addition to the tilting relative to the b axis, shown in Fig. 2(b), there is a second tilt mode around the c axis, which is allowed in the correct Pmcn model but forbidden in the approximate Amma model. The two models are analogous to those in KFeF4 (Lapasset et al., 1986), which undergoes a structural phase transition from KFeF4(III) to KFeF4(II) at 368 K, corresponding to Pmcn to Amma. We have not explored the possibility of such a phase transition in the present case.

In comparison with other compositionally related AMF4 compounds, (I) is isotypic with KGaF4 (Courbion et al., 1989). Interestingly, however, more precisely similar compositions have different structure types; for example, NH4FeF4 (Leblanc et al., 1985) has the same type of layer as (I), but the [ScF4] sheets are eclipsed along both a and b, whereas KScF4, has a unique `corrugated sheet' structure containing both cis- and trans-vertex-sharing octahedra (Champarnaud-Mesjard & Frit, 1992).

Experimental top

Scandium oxide (0.138 g), water (5 ml) and 0.5 ml of a 40% aqueous solution of HF were heated in a Teflon-lined steel autoclave for 1 h at 463 K. To this, ethylene glycol (5 ml) and 1,3-diaminopropane (0.4 ml) was added and heated at the same temperature for four days. The product was filtered off, washed in water and allowed to dry at room temperature overnight. Powder X-ray diffraction revealed predominantly (I) as the product, together with a small amount of ScF3. Compound (I) was heated to 1073 K at 5 K min−1 under N2 gas. Thermogravimmetric analysis shows a single-step weight loss of 19.6% from 573 to 698 K (20% calculated). Powder X-ray diffraction of the residue shows that this decomposition product is ScF3.

Refinement top

Systematic absences were consistent with space groups Pmcn (62) or P21cn (33). Successful refinement of the structure in centrosymmetric Pmcn, together with the lack of any contradictory physical property measurements meant that this was preferred over P21cn. Pmcn (a non-standard setting of Pnma (62)) was chosen as this defines the perovskite-like layers to lie perpendicular to c, which is the convention in perovskite chemistry. H atoms were located from a difference Fourier map and their coordinates were refined with the Uiso(H) fixed at 0.018 Å2.

Computing details top

Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2001); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. The asymmetric unit of (I), with displacement ellipsoids drawn at the 50% probability level [symmetry codes: (i) −x, 1/2 + y, 1/2 − z].
[Figure 2] Fig. 2. (a) Projection along [100], showing staggered octahedra. (b) Projection along [010], showing eclipsed octahedra
[Figure 3] Fig. 3. Plan view of a single layer along [001]. (a) Pmcn model showing the additional c axis tilt mode. (b) Amma model, with b' = b/2.
Ammonium scandium tetrafluoride top
Crystal data top
NH4ScF4Dx = 2.151 Mg m3
Mr = 139.00Melting point: not measured K
Orthorhombic, PmcnMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2aCell parameters from 120 reflections
a = 7.862 (2) Åθ = 2.5–25.4°
b = 8.088 (2) ŵ = 1.67 mm1
c = 13.503 (4) ÅT = 93 K
V = 858.6 (4) Å3Prism, colorless
Z = 80.10 × 0.03 × 0.02 mm
F(000) = 544
Data collection top
Rigaku/MSC CCD area-detector
diffractometer
847 independent reflections
Radiation source: rotating anode587 reflections with I > 2σ(I)
Confocal monochromatorRint = 0.026
Detector resolution: 14.6306 pixels mm-1θmax = 25.3°, θmin = 2.9°
ω scansh = 98
Absorption correction: multi-scan
(SADABS; Bruker, 1999)
k = 89
Tmin = 0.825, Tmax = 0.970l = 1616
5191 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.028Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.102Only H-atom coordinates refined
S = 1.11 w = 1/[σ2(Fo2) + (0.0519P)2 + 0.1485P]
where P = (Fo2 + 2Fc2)/3
847 reflections(Δ/σ)max = 0.005
75 parametersΔρmax = 0.40 e Å3
0 restraintsΔρmin = 0.40 e Å3
Crystal data top
NH4ScF4V = 858.6 (4) Å3
Mr = 139.00Z = 8
Orthorhombic, PmcnMo Kα radiation
a = 7.862 (2) ŵ = 1.67 mm1
b = 8.088 (2) ÅT = 93 K
c = 13.503 (4) Å0.10 × 0.03 × 0.02 mm
Data collection top
Rigaku/MSC CCD area-detector
diffractometer
847 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 1999)
587 reflections with I > 2σ(I)
Tmin = 0.825, Tmax = 0.970Rint = 0.026
5191 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0280 restraints
wR(F2) = 0.102Only H-atom coordinates refined
S = 1.11Δρmax = 0.40 e Å3
847 reflectionsΔρmin = 0.40 e Å3
75 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
Sc10.00011 (3)0.87501 (8)0.25037 (2)0.0052 (3)
F10.25000.9003 (2)0.28413 (13)0.0112 (5)
F20.05123 (18)0.87620 (18)0.10600 (8)0.0120 (3)
F30.05074 (18)0.87219 (18)0.39488 (8)0.0120 (3)
F40.25000.8499 (2)0.21704 (13)0.0118 (5)
F50.02582 (19)0.6250 (2)0.25142 (7)0.0134 (4)
N10.25000.8765 (5)0.0095 (2)0.0105 (6)
N20.25000.8760 (5)0.5110 (2)0.0118 (6)
H10.163 (3)0.851 (3)0.0327 (19)0.018*
H20.25000.779 (5)0.051 (3)0.018*
H30.25000.977 (5)0.031 (3)0.018*
H40.25000.974 (5)0.531 (3)0.018*
H50.160 (3)0.847 (3)0.4696 (19)0.018*
H60.25000.775 (5)0.553 (3)0.018*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Sc10.0039 (4)0.0042 (4)0.0074 (4)0.00004 (11)0.00071 (12)0.00001 (11)
F10.0058 (8)0.0155 (11)0.0122 (10)0.0000.0000.0013 (7)
F20.0118 (7)0.0155 (7)0.0088 (7)0.0003 (7)0.0023 (5)0.0033 (7)
F30.0120 (7)0.0161 (7)0.0081 (7)0.0005 (7)0.0022 (5)0.0035 (7)
F40.0047 (8)0.0178 (11)0.0129 (10)0.0000.0000.0006 (8)
F50.0156 (6)0.0043 (8)0.0204 (10)0.0005 (6)0.0004 (4)0.0001 (4)
N10.0131 (13)0.0107 (15)0.0076 (14)0.0000.0000.0025 (17)
N20.0138 (14)0.0090 (14)0.0126 (14)0.0000.0000.0041 (17)
Geometric parameters (Å, º) top
Sc1—F21.9904 (12)F5—Sc1iv2.0320 (19)
Sc1—F31.9919 (12)N1—H10.91 (3)
Sc1—F12.0272 (7)N1—H20.97 (4)
Sc1—F42.0273 (7)N1—H30.86 (4)
Sc1—F5i2.0320 (19)N2—H40.84 (4)
Sc1—F52.0325 (19)N2—H50.93 (3)
F1—Sc1ii2.0272 (7)N2—H60.99 (4)
F4—Sc1iii2.0273 (7)
F2—Sc1—F3179.61 (9)F1—Sc1—F590.14 (7)
F2—Sc1—F191.38 (6)F4—Sc1—F589.92 (7)
F3—Sc1—F188.59 (6)F5i—Sc1—F5179.713 (18)
F2—Sc1—F488.79 (6)Sc1ii—F1—Sc1151.46 (10)
F3—Sc1—F491.24 (6)Sc1iii—F4—Sc1151.82 (10)
F1—Sc1—F4179.82 (7)Sc1iv—F5—Sc1168.48 (8)
F2—Sc1—F5i90.22 (6)H1—N1—H2100 (2)
F3—Sc1—F5i90.17 (6)H1—N1—H3115 (2)
F1—Sc1—F5i89.97 (7)H2—N1—H3125 (3)
F4—Sc1—F5i89.97 (7)H4—N2—H5116 (2)
F2—Sc1—F589.52 (6)H4—N2—H6126 (3)
F3—Sc1—F590.10 (6)H5—N2—H698 (2)
Symmetry codes: (i) x, y+1/2, z+1/2; (ii) x1/2, y, z; (iii) x+1/2, y, z; (iv) x, y1/2, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···F20.91 (3)1.97 (3)2.836 (2)159 (2)
N1—H2···F3v0.97 (4)2.11 (3)2.858 (3)132 (1)
N1—H3···F2vi0.86 (4)2.21 (3)2.853 (3)131 (1)
N2—H4···F3vii0.84 (4)2.24 (3)2.867 (3)132 (1)
N2—H5···F30.93 (3)1.95 (3)2.837 (2)158 (2)
N2—H6···F2viii0.99 (4)2.11 (3)2.872 (4)132 (1)
Symmetry codes: (v) x+1/2, y+3/2, z1/2; (vi) x+1/2, y+2, z; (vii) x1/2, y+2, z+1; (viii) x1/2, y+3/2, z+1/2.

Experimental details

Crystal data
Chemical formulaNH4ScF4
Mr139.00
Crystal system, space groupOrthorhombic, Pmcn
Temperature (K)93
a, b, c (Å)7.862 (2), 8.088 (2), 13.503 (4)
V3)858.6 (4)
Z8
Radiation typeMo Kα
µ (mm1)1.67
Crystal size (mm)0.10 × 0.03 × 0.02
Data collection
DiffractometerRigaku/MSC CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 1999)
Tmin, Tmax0.825, 0.970
No. of measured, independent and
observed [I > 2σ(I)] reflections
5191, 847, 587
Rint0.026
(sin θ/λ)max1)0.602
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.028, 0.102, 1.11
No. of reflections847
No. of parameters75
H-atom treatmentOnly H-atom coordinates refined
Δρmax, Δρmin (e Å3)0.40, 0.40

Computer programs: CrystalClear (Rigaku/MSC, 2005), CrystalClear, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), DIAMOND (Brandenburg, 2001), SHELXL97.

Selected geometric parameters (Å, º) top
Sc1—F21.9904 (12)Sc1—F42.0273 (7)
Sc1—F31.9919 (12)Sc1—F5i2.0320 (19)
Sc1—F12.0272 (7)Sc1—F52.0325 (19)
F2—Sc1—F3179.61 (9)Sc1ii—F1—Sc1151.46 (10)
F1—Sc1—F4179.82 (7)Sc1iii—F4—Sc1151.82 (10)
F5i—Sc1—F5179.713 (18)Sc1iv—F5—Sc1168.48 (8)
Symmetry codes: (i) x, y+1/2, z+1/2; (ii) x1/2, y, z; (iii) x+1/2, y, z; (iv) x, y1/2, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···F20.91 (3)1.97 (3)2.836 (2)159 (2)
N1—H2···F3v0.97 (4)2.11 (3)2.858 (3)132.0 (9)
N1—H3···F2vi0.86 (4)2.21 (3)2.853 (3)131.3 (14)
N2—H4···F3vii0.84 (4)2.24 (3)2.867 (3)132.1 (14)
N2—H5···F30.93 (3)1.95 (3)2.837 (2)158 (2)
N2—H6···F2viii0.99 (4)2.11 (3)2.872 (4)132.1 (9)
Symmetry codes: (v) x+1/2, y+3/2, z1/2; (vi) x+1/2, y+2, z; (vii) x1/2, y+2, z+1; (viii) x1/2, y+3/2, z+1/2.
Bond valence parameters. top
Bonds(ij)Σ s(ij)
Sc F20.54
Sc F30.53
Sc F10.49
Sc F40.49
Sc F50.48
Sc F50.48
3.00
F1 Sc0.49 x 20.97
F2 Sc0.540.54
F3 Sc0.530.53
F4 Sc0.49 x 20.97
F5 Sc0.48
F5 Sc0.480.96
s(ij) values calculated for B = 0.37; Brese & O'Keeffe (1991) extrapolated.
 

Acknowledgements

We thank Professor Alex Slawin for X-ray data collection and the University of St Andrews for funding.

References

First citationBrandenburg, K. (2001). DIAMOND. Version 2.1. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationBrese, N. E. & O'Keeffe, M. (1991). Acta Cryst. B47, 192–197.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationBruker (1999). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationChamparnaud-Mesjard, J. C. & Frit, B. (1992). Eur. J. Solid State Inorg. Chem. 29, 161–170.  CAS Google Scholar
First citationCourbion, G., Randrianohavy, J. V. & Rousseau, J. J. (1989). J. Solid State Chem. 81, 285–292.  CrossRef CAS Web of Science Google Scholar
First citationDion, M., Ganne, M. & Tournoux, M. (1981). Mater. Res. Bull. 16, 1429–1435.  CrossRef CAS Web of Science Google Scholar
First citationLapasset, J., Sciau, P., Moret, J. & Gros, N. (1986). Acta Cryst. B42, 258–262.  CrossRef CAS IUCr Journals Google Scholar
First citationLeblanc, M., Ferey, G., De Pape, R. & Teillet, J. (1985). Acta Cryst. C41, 657–660.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationRigaku/MSC (2005). CrystalClear. Rigaku/MSC Inc., The Woodlands, Texas, USA.  Google Scholar
First citationSheldrick, G. M. (1997). SHELXS97 and SHELXL97. Release 97-2. University of Göttingen, Germany.  Google Scholar
First citationStephens, N. F. & Lightfoot, P. (2006). Solid State Sci. 8, 197–202.  Web of Science CSD CrossRef CAS Google Scholar
First citationStephens, N. F., Slawin, A. M. Z. & Lightfoot, P. (2004). Chem. Commun. pp. 614–615.  CrossRef Google Scholar

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