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Alternating C6H14N22+ and [BeF4]2- units within the ac plane of 1,4-diazo­niabi­cyclo­[2.2.2]­octane tetra­fluoro­beryl­lium hemihydrate, (C6H14N2)[BeF4]·0.5H2O, combine to form double chains via hydrogen bonding. These double chains connect through bifurcated hydrogen bonds to water mol­ecules, which lie on twofold axes, producing a two-dimensional sheet. Very weak hydrogen-bond interactions, along the b axis, join the sheets to produce a three-dimensional network.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102009654/bm1497sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270102009654/bm1497Isup2.hkl
Contains datablock I

CCDC reference: 192952

Comment top

The title compound, (I), has been prepared as a precursor in the formation of beryllium-containing framework materials. The cocrystallization of the templating agent as a beryllium salt aids in the formation of these frameworks.

The beryllium coordination geometry is fairly regular tetrahedral, with the four Be—F bond distances ranging from 1.524 (2) to 1.572 (2) Å, and the F—Be—F angles ranging from 105.8 (1) to 113.7 (1)°. These values are in good agreement with other [BeF4]2- geometries in the literature (Le Fur et al., 1991; Srivastava et al., 1999; Tedenac et al., 1971). In the doubly protonated 1,4-diazabicyclo[2.2.2]octane (dabco), the C—N distances of 1.485 (3) Å and C—C distances of 1.509 (3) Å are typical of the average values found for this group (Fig. 1 and Table 1).

Each [BeF4l2- unit is linked to two dabconium moieties and one water molecule through bifurcated N—H···F and O—H···F interactions, which have D···A distances of 2.5932 (16)–3.0737 (17) Å (Table 2) [weaker interactions, namely C—H···F contacts characterized by C···F distances of 3.091 (2)–3.339 (2) Å, have not been tabulated]. Thus, one-dimensional hydrogen-bonded chains consisting of C6H14N22+ and [BeF4]2- units run parallel to the b axis. These chains are linked in the ab plane by weak hydrogen-bonding interactions involving water molecules, linking pairs of parallel chains (Fig. 2) into hydrogen-bonded double-chain units. These units lie parallel to one another, intersecting the normal to the ac plane. Water molecules lie in between the hydrogen-bonded double-chain units, where each parallel set is rotated through 90° to give an alternating pattern.

Other possible hydrogen bonds have been found using PLATON (Spek, 1990, 1998), which indicates very weak C—H···F interactions between the C—H groups on the dabconium and the F atoms of the [BeF4]2- dianion. For each water link there are two C—H···F crosslinks between the parallel double chains (Fig. 3). Overall, these hydrogen bonds result in the formation of a three-dimensional network.

Experimental top

Beryllium(II) fluoride (0.1 g, 0.002 mol) was dissolved in an acidic aqueous solution of distilled water (2 ml) and 30% hydrofluoric acid (0.085 ml, 0.002 mol). 1,4-Diazabicyclo[2.2.2]octane (dabco) (0.224 g, 0.002 mol) was added to give an overall molar ratio of 1:1:1. The solution was placed in a 23 ml Teflon-lined autoclave and heated at 423 K for 24 h. The resulting solution was placed in a plastic sample vial and left to evaporate slowly. The title compound crystallized as a colourless crystalline solid. Finally, the product was recovered by filtration and air-dried.

Refinement top

Two of the three dabconium ethylene groups show slight disorder. Each group has one C atom with an elongated displacement parameter perpendicular to the C—C and C—N bonds. A static disorder model was investigated as an alternative to the dynamic disorder model but the latter was preferred due to the instability of the former model during refinement. H atoms were initially located in difference maps and their positions idealized. Thereafter they were refined riding on their parent atoms, with C—H distances of 0.99 Å and Uiso(H) values of 1.2Ueq(C) for Csp3 atoms. The H atoms of the N—H and O—H groups were located and freely refined.

Computing details top

Data collection: COLLECT (Hooft, 1998); cell refinement: SCALEPACK (Otwinoski & Minor, 1997) and COLLECT (Hooft, 1998); data reduction: COLLECT, DENZO and maXus (Mackay et al., 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ATOMS (Dowty, 1999); software used to prepare material for publication: WinGX (Farrugia, 1998).

Figures top
[Figure 1] Fig. 1. The three discrete moieties in the title compound. Displacement ellipsoids are shown at the 30% probability level.
[Figure 2] Fig. 2. The hydrogen-bonding arrangement forming the double chain, viewed along the bc plane.
[Figure 3] Fig. 3. The three-dimensional hydrogen-bonded network, viewed down the b axis.
(I) top
Crystal data top
(C6H14N2)[BeF4]·0.5H2ODx = 1.537 Mg m3
Mr = 208.21Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, PbcnCell parameters from 14284 reflections
a = 19.523 (4) Åθ = 2.9–27.5°
b = 9.2726 (19) ŵ = 0.15 mm1
c = 9.939 (2) ÅT = 293 K
V = 1799.3 (6) Å3Block, colourless
Z = 80.12 × 0.10 × 0.10 mm
F(000) = 872
Data collection top
Nonius KappaCCD area-detector
diffractometer
1814 reflections with I > 2σ(I)
Radiation source: Nonius FR591 rotating anodeRint = 0.051
Graphite monochromatorθmax = 27.5°, θmin = 3.2°
Detector resolution: 9.091 pixels mm1 pixels mm-1h = 2425
ϕ and ω scans to fill the Ewald spherek = 1211
14284 measured reflectionsl = 1212
2041 independent 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)] = 0.043Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.117H atoms treated by a mixture of independent and constrained refinement
S = 1.07 w = 1/[σ2(Fo2) + (0.051P)2 + 1.245P]
where P = (Fo2 + 2Fc2)/3
2040 reflections(Δ/σ)max = 0.001
135 parametersΔρmax = 0.39 e Å3
0 restraintsΔρmin = 0.40 e Å3
Crystal data top
(C6H14N2)[BeF4]·0.5H2OV = 1799.3 (6) Å3
Mr = 208.21Z = 8
Orthorhombic, PbcnMo Kα radiation
a = 19.523 (4) ŵ = 0.15 mm1
b = 9.2726 (19) ÅT = 293 K
c = 9.939 (2) Å0.12 × 0.10 × 0.10 mm
Data collection top
Nonius KappaCCD area-detector
diffractometer
1814 reflections with I > 2σ(I)
14284 measured reflectionsRint = 0.051
2041 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0430 restraints
wR(F2) = 0.117H atoms treated by a mixture of independent and constrained refinement
S = 1.07Δρmax = 0.39 e Å3
2040 reflectionsΔρmin = 0.40 e Å3
135 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
Be10.12801 (9)0.2660 (2)0.97524 (19)0.0226 (4)
F10.16538 (5)0.16332 (9)0.87368 (10)0.0277 (2)
F20.07625 (5)0.36227 (10)0.89402 (10)0.0315 (3)
F30.09067 (5)0.17170 (10)1.07715 (10)0.0293 (2)
F40.17983 (5)0.37152 (9)1.03947 (9)0.0274 (2)
N10.36198 (6)0.39678 (13)0.93155 (13)0.0224 (3)
H10.3573 (10)0.493 (3)0.922 (2)0.040 (5)*
N20.37643 (8)0.13232 (15)0.95264 (16)0.0341 (4)
H20.3807 (13)0.037 (3)0.957 (3)0.063 (8)*
C10.31404 (8)0.32307 (16)0.83630 (15)0.0243 (3)
H1A0.32410.35300.74270.029*
H1B0.26620.35010.85730.029*
C20.32331 (8)0.16037 (16)0.85081 (17)0.0280 (3)
H2A0.27960.11540.87870.034*
H2B0.33720.11810.76350.034*
C30.34629 (9)0.35374 (19)1.07268 (16)0.0301 (4)
H3A0.29870.38091.09580.036*
H3B0.37770.40351.13570.036*
C40.35522 (19)0.1922 (2)1.0840 (2)0.0738 (10)
H4A0.39040.17001.15270.089*
H4B0.31150.14751.11260.089*
C50.43452 (8)0.35848 (18)0.89909 (18)0.0291 (4)
H5A0.46600.40650.96300.035*
H5B0.44610.39100.80700.035*
C60.44201 (10)0.1979 (2)0.9093 (3)0.0688 (9)
H6A0.45550.15810.82080.083*
H6B0.47840.17400.97500.083*
O10.00000.16025 (18)0.75000.0318 (4)
H70.0216 (13)0.218 (2)0.796 (3)0.053 (7)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Be10.0232 (9)0.0193 (8)0.0254 (9)0.0002 (7)0.0010 (7)0.0002 (7)
F10.0308 (5)0.0212 (4)0.0311 (5)0.0013 (4)0.0059 (4)0.0019 (4)
F20.0317 (5)0.0235 (5)0.0391 (6)0.0022 (4)0.0093 (4)0.0015 (4)
F30.0280 (5)0.0293 (5)0.0306 (5)0.0041 (4)0.0032 (4)0.0032 (4)
F40.0286 (5)0.0241 (5)0.0295 (5)0.0035 (3)0.0024 (4)0.0017 (4)
N10.0219 (6)0.0186 (6)0.0266 (6)0.0004 (5)0.0007 (5)0.0003 (5)
N20.0431 (9)0.0180 (6)0.0411 (8)0.0017 (6)0.0199 (7)0.0009 (6)
C10.0231 (7)0.0238 (7)0.0260 (7)0.0009 (5)0.0030 (6)0.0006 (6)
C20.0289 (8)0.0237 (7)0.0313 (8)0.0006 (6)0.0088 (6)0.0020 (6)
C30.0317 (8)0.0359 (8)0.0227 (7)0.0010 (7)0.0019 (6)0.0028 (6)
C40.165 (3)0.0324 (10)0.0237 (9)0.0399 (15)0.0110 (13)0.0032 (8)
C50.0192 (7)0.0322 (8)0.0360 (9)0.0012 (6)0.0019 (6)0.0018 (6)
C60.0215 (9)0.0307 (10)0.154 (3)0.0044 (7)0.0109 (12)0.0290 (13)
O10.0302 (8)0.0282 (8)0.0369 (9)0.0000.0060 (7)0.000
Geometric parameters (Å, º) top
Be1—F11.567 (2)C1—H1B0.9900
Be1—F21.572 (2)C2—H2A0.9900
Be1—F31.524 (2)C2—H2B0.9900
Be1—F41.546 (2)C3—C41.512 (3)
N1—C31.490 (2)C3—H3A0.9900
N1—C51.4953 (19)C3—H3B0.9900
N1—C11.4964 (19)C4—H4A0.9900
N1—H10.90 (2)C4—H4B0.9900
N2—C21.472 (2)C5—C61.500 (3)
N2—C41.478 (3)C5—H5A0.9900
N2—C61.481 (3)C5—H5B0.9900
N2—H20.89 (3)C6—H6A0.9900
C1—C21.526 (2)C6—H6B0.9900
C1—H1A0.9900O1—H70.82 (2)
F1—Be1—F2108.27 (13)N2—C2—H2B109.9
F1—Be1—F3107.60 (12)C1—C2—H2B109.9
F1—Be1—F4110.24 (12)H2A—C2—H2B108.3
F2—Be1—F3111.08 (12)N1—C3—C4108.16 (14)
F2—Be1—F4105.86 (12)N1—C3—H3A110.1
F3—Be1—F4113.69 (13)C4—C3—H3A110.1
C3—N1—C5109.52 (12)N1—C3—H3B110.1
C3—N1—C1110.16 (12)C4—C3—H3B110.1
C5—N1—C1110.33 (12)H3A—C3—H3B108.4
C3—N1—H1110.4 (14)N2—C4—C3109.80 (15)
C5—N1—H1107.9 (13)N2—C4—H4A109.7
C1—N1—H1108.5 (14)C3—C4—H4A109.7
C2—N2—C4110.09 (18)N2—C4—H4B109.7
C2—N2—C6109.65 (17)C3—C4—H4B109.7
C4—N2—C6110.18 (18)H4A—C4—H4B108.2
C2—N2—H2106.0 (17)N1—C5—C6108.28 (14)
C4—N2—H2110.8 (18)N1—C5—H5A110.0
C6—N2—H2110.0 (17)C6—C5—H5A110.0
N1—C1—C2108.51 (12)N1—C5—H5B110.0
N1—C1—H1A110.0C6—C5—H5B110.0
C2—C1—H1A110.0H5A—C5—H5B108.4
N1—C1—H1B110.0N2—C6—C5110.05 (15)
C2—C1—H1B110.0N2—C6—H6A109.7
H1A—C1—H1B108.4C5—C6—H6A109.7
N2—C2—C1108.85 (12)N2—C6—H6B109.7
N2—C2—H2A109.9C5—C6—H6B109.7
C1—C2—H2A109.9H6A—C6—H6B108.2
C3—N1—C1—C260.47 (16)C6—N2—C4—C359.7 (3)
C5—N1—C1—C260.56 (16)N1—C3—C4—N20.1 (3)
C4—N2—C2—C160.91 (18)C3—N1—C5—C662.4 (2)
C6—N2—C2—C160.47 (18)C1—N1—C5—C659.0 (2)
N1—C1—C2—N20.38 (18)C2—N2—C6—C562.7 (2)
C5—N1—C3—C461.1 (2)C4—N2—C6—C558.6 (3)
C1—N1—C3—C460.4 (2)N1—C5—C6—N22.1 (3)
C2—N2—C4—C361.3 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···F1i0.90 (2)1.71 (2)2.5932 (16)166 (2)
N1—H1···F3i0.90 (2)2.48 (2)3.0737 (17)123 (2)
N2—H2···F2ii0.89 (3)1.93 (3)2.7320 (18)149 (2)
N2—H2···F4ii0.89 (3)2.10 (3)2.7927 (18)134 (2)
O1—H7···F20.82 (2)1.97 (2)2.7881 (15)176 (3)
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) x+1/2, y1/2, z.

Experimental details

Crystal data
Chemical formula(C6H14N2)[BeF4]·0.5H2O
Mr208.21
Crystal system, space groupOrthorhombic, Pbcn
Temperature (K)293
a, b, c (Å)19.523 (4), 9.2726 (19), 9.939 (2)
V3)1799.3 (6)
Z8
Radiation typeMo Kα
µ (mm1)0.15
Crystal size (mm)0.12 × 0.10 × 0.10
Data collection
DiffractometerNonius KappaCCD area-detector
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
14284, 2041, 1814
Rint0.051
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.043, 0.117, 1.07
No. of reflections2040
No. of parameters135
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.39, 0.40

Computer programs: , SCALEPACK (Otwinoski & Minor, 1997) and COLLECT (Hooft, 1998), COLLECT, DENZO and maXus (Mackay et al., 1998), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ATOMS (Dowty, 1999), WinGX (Farrugia, 1998).

Selected geometric parameters (Å, º) top
Be1—F11.567 (2)Be1—F31.524 (2)
Be1—F21.572 (2)Be1—F41.546 (2)
F1—Be1—F2108.27 (13)F2—Be1—F3111.08 (12)
F1—Be1—F3107.60 (12)F2—Be1—F4105.86 (12)
F1—Be1—F4110.24 (12)F3—Be1—F4113.69 (13)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···F1i0.90 (2)1.71 (2)2.5932 (16)166 (2)
N1—H1···F3i0.90 (2)2.48 (2)3.0737 (17)123 (2)
N2—H2···F2ii0.89 (3)1.93 (3)2.7320 (18)149 (2)
N2—H2···F4ii0.89 (3)2.10 (3)2.7927 (18)134 (2)
O1—H7···F20.82 (2)1.97 (2)2.7881 (15)176 (3)
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) x+1/2, y1/2, z.
 

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