Propane-1,2-diammonium tetrafluoroberyllate

Cocrystallization of the inorganic [BeF₄]^2- unit with the organic moiety [NH₃CH₂CH(NH₃)CH₃]²⁺ results in the three-dimensional network of the title compound, (C₃H₁₂N₂)[BeF₄] or C₃H₁₂N₂²⁺·BeF₄^2-, created by hydrogen bonds between the protonated ammonium groups and the highly electronegative F atoms of the anion. The structure is described in terms of layers related to each other by crystallographic centres of symmetry.

S1. Comment

Three-dimensional tetrahedral Be frameworks are very rare (Le Fur et al., 1991). Using various organic templating units, Be salts have been synthesized to provide precursors for the production of fluoro-frameworks (Le Fur et al., 1991; Vilminot et al., 1973). Aqueous/HF solutions, under either hydrothermal or ambient conditions, have proved to be satisfactory for the synthesis of such salts and the title compound, (I), is an example. \sch

The coordination of Be in (I) is in the form of a slightly distorted tetrahedron (Fig. 1 and Table 1). The Be—F bond lengths [1.5352 (17)–1.5752 (17) Å] and the F—Be—F angles [106.86 (11)–111.12 (11)°] show little variation and are in good agreement with other similar geometries (Srivastava et al., 1999; Tedenac et al., 1971; Collins et al., 1983; Hahn & Chung, 1972). In the doubly protonated 1,2-diaminopropane group, average C—N [1.492 (1) Å] and C—C [1.521 (2) Å] distances (Table 1) are in good agreement with normal values (Orpen et al., 1992).

Each BeF₄ tetrahedron in (I) is linked to six doubly protonated 1,2-diaminopropane units through N—H···F hydrogen bonds, characterized by H···F distances of 1.78 (2)–1.91 (2) Å (Table 2, Figs. 1–3). Four of these interactions, namely those involving atoms H1, H3, H8 and H9, connect the ions to form sheets perpendicular to (001) (Fig. 2), in which R₄³(10) and R₄⁴(18) connectivity is evident (Motherwell et al., 1999). These sheets, related to each other by crystallographic centres of symmetry and stacked in the direction of c, are connected by two further hydrogen bonds (Fig. 3) involving atoms H2 and H7 to create, as the smallest and simplest examples, centrosymmetric R₄⁴(12) and non-centrosymmetric R₆⁵(19) connectivities.

S2. Experimental

BeF₂ (0.100 g, 0.0022 mol) was dissolved in an acidic aqueous mixture of distilled water (2 ml) and 30% hydrofluoric acid (0.085 ml, 0.002 mol). 1,2-Diaminopropane (0.17 ml, 0.002 mol) was added to give an overall molar ratio of 1:1:1. The resulting solution was placed in a plastic sample vial and left to concentrate slowly by evaporation, yielding colourless crystals of (I) which were recovered by filtration and air dried.

S3. Refinement

All H atoms, with one exception, were located in difference maps and refined isotropically. The exception, atom H6 attached to tertiary C2, which could not be refined satisfactorily in this manner, was fixed in a position with C—H = 1.00 Å and refined with a riding model with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997); data reduction: HKL DENZO (Otwinowski & Minor, 1997) and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 1990, 1998).

Figures

	Fig. 1. The structure of (I), showing the role of the [BeF4]^2- anion in hydrogen-bond formation (dashed lines). Displacement ellipsoids are drawn at the 50% probability level. H atoms connected to C atoms of symmetry-related cations have been omitted for clarity, while the remaining H atoms are shown as open circles. The labelling scheme encompasses all non-H atoms of the asymmetric unit and selected other atoms [symmetry codes: (i) 3/2 - x, y - 1/2, 1/2 - z; (ii) 1/2 + x, 1/2 - y, z - 1/2; (iii) 1/2 - x, y - 1/2, 1/2 - z; (iv) 1/2 + x, 1/2 - y, 1/2 + z; (v) 1 + x, y, z].
	Fig. 2. A portion of a hydrogen-bonded layer in (I) viewed parallel to (001), c/2 thick and centred on z = 1/4.
	Fig. 3. The cell of (I) viewed along a.

(I)

Crystal data

[C3H12N2][BeF4]	F(000) = 336
Mr = 161.16	Dx = 1.55 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 5.5355 (11) Å	Cell parameters from 1114 reflections
b = 13.560 (3) Å	θ = 2.9–27.5°
c = 9.6048 (19) Å	µ = 0.17 mm^−1
β = 106.73 (3)°	T = 120 K
V = 690.4 (3) Å^3	Block, colourless
Z = 4	0.14 × 0.08 × 0.04 mm

Data collection

Nonius KappaCCD area-detector diffractometer	1294 reflections with I > 2σ(I)
Detector resolution: 9.091 pixels mm^-1	Rint = 0.045
ϕ and ω scans to fill the Ewald sphere	θmax = 27.5°, θmin = 3.7°
Absorption correction: multi-scan (SORTAV; Blessing, 1995)	h = −6→7
Tmin = 0.745, Tmax = 0.993	k = −14→17
3623 measured reflections	l = −12→9
1530 independent reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.030	w = 1/[σ^2(Fo^2) + (0.033P)^2 + 0.118P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.077	(Δ/σ)max = 0.001
S = 1.04	Δρmax = 0.25 e Å^−3
1530 reflections	Δρmin = −0.25 e Å^−3
135 parameters

Special details

Refinement. Anisotropic displacement parameters were refined for all non-H atoms.

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

	x	y	z	Uiso*/Ueq
Be1	0.8249 (3)	0.11896 (11)	0.20714 (16)	0.0101 (4)
F1	0.83401 (13)	0.03151 (5)	0.31004 (7)	0.0157 (2)
F2	0.78697 (13)	0.21905 (5)	0.28142 (7)	0.0123 (2)
F3	1.06996 (13)	0.12440 (5)	0.15815 (8)	0.0148 (2)
F4	0.59600 (12)	0.10718 (5)	0.07028 (7)	0.0123 (2)
N1	0.1427 (2)	0.45684 (7)	0.31922 (11)	0.0098 (3)
N2	0.3330 (2)	0.27513 (7)	0.07421 (12)	0.0097 (3)
C1	0.2447 (2)	0.36643 (9)	0.26951 (12)	0.0105 (3)
C2	0.2130 (2)	0.36790 (8)	0.10672 (12)	0.0093 (3)
C3	−0.0605 (2)	0.36782 (9)	0.01410 (13)	0.0122 (3)
H1	0.240 (3)	0.5093 (11)	0.3166 (15)	0.012 (3)*
H2	0.132 (3)	0.4460 (11)	0.4077 (17)	0.016 (4)*
H3	−0.015 (3)	0.4711 (12)	0.2652 (18)	0.022 (4)*
H4	0.159 (3)	0.3119 (11)	0.2922 (15)	0.009 (3)*
H5	0.423 (3)	0.3626 (10)	0.3195 (14)	0.011 (3)*
H6	0.30220	0.42650	0.08170	0.0110*
H7	0.326 (3)	0.2754 (11)	−0.0187 (18)	0.016 (4)*
H8	0.250 (3)	0.2227 (12)	0.0944 (16)	0.017 (4)*
H9	0.497 (3)	0.2673 (12)	0.1365 (18)	0.022 (4)*
H10	−0.143 (3)	0.3091 (12)	0.0356 (17)	0.022 (4)*
H11	−0.068 (3)	0.3681 (11)	−0.0865 (17)	0.017 (4)*
H12	−0.151 (3)	0.4261 (12)	0.0359 (16)	0.018 (3)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Be1	0.0127 (7)	0.0105 (7)	0.0084 (7)	0.0000 (6)	0.0051 (6)	0.0004 (5)
F1	0.0155 (4)	0.0157 (4)	0.0152 (4)	−0.0010 (3)	0.0035 (3)	0.0070 (3)
F2	0.0152 (3)	0.0131 (4)	0.0096 (3)	0.0001 (3)	0.0050 (3)	−0.0022 (3)
F3	0.0144 (4)	0.0135 (4)	0.0202 (4)	0.0015 (3)	0.0109 (3)	0.0024 (3)
F4	0.0149 (4)	0.0134 (4)	0.0083 (3)	0.0007 (3)	0.0027 (3)	−0.0014 (3)
N1	0.0129 (5)	0.0099 (5)	0.0076 (5)	0.0003 (4)	0.0044 (4)	−0.0008 (4)
N2	0.0125 (5)	0.0098 (5)	0.0081 (5)	0.0009 (4)	0.0049 (4)	−0.0002 (4)
C1	0.0129 (6)	0.0104 (6)	0.0085 (6)	0.0006 (5)	0.0035 (5)	−0.0011 (4)
C2	0.0119 (6)	0.0081 (5)	0.0083 (5)	0.0014 (4)	0.0035 (5)	0.0000 (4)
C3	0.0130 (6)	0.0147 (6)	0.0088 (6)	0.0023 (5)	0.0028 (5)	0.0002 (5)

Geometric parameters (Å, º)

Be1—F1	1.5352 (17)	N2—H7	0.882 (17)
Be1—F2	1.5752 (17)	N2—H8	0.897 (16)
Be1—F3	1.5603 (19)	C1—C2	1.5225 (16)
Be1—F4	1.5492 (17)	C2—C3	1.5192 (17)
N1—C1	1.4849 (16)	C1—H4	0.937 (16)
N2—C2	1.4969 (15)	C1—H5	0.967 (16)
N1—H2	0.881 (16)	C2—H6	1.00
N1—H3	0.899 (17)	C3—H10	0.969 (17)
N1—H1	0.897 (16)	C3—H11	0.955 (16)
N2—H9	0.938 (17)	C3—H12	0.990 (17)
H2—N1—H3	105.6 (16)	N1—C1—H4	108.2 (10)
C1—N1—H2	108.0 (10)	H4—C1—H5	110.8 (13)
C1—N1—H3	112.8 (10)	C2—C1—H5	108.1 (8)
C1—N1—H1	111.0 (10)	N2—C2—H6	109.75
H1—N1—H3	107.7 (14)	C3—C2—H6	109.72
H1—N1—H2	111.5 (14)	C1—C2—H6	109.76
C2—N2—H8	109.6 (11)	C2—C3—H12	110.8 (9)
C2—N2—H7	108.3 (10)	H10—C3—H11	109.4 (13)
H7—N2—H8	110.2 (14)	H11—C3—H12	109.5 (13)
H7—N2—H9	113.5 (15)	C2—C3—H10	109.1 (10)
C2—N2—H9	111.6 (10)	H10—C3—H12	108.2 (14)
H8—N2—H9	103.5 (14)	C2—C3—H11	109.8 (10)
N1—C1—C2	112.17 (10)	F1—Be1—F2	110.97 (10)
C1—C2—C3	113.71 (10)	F1—Be1—F3	111.12 (11)
N2—C2—C3	107.73 (10)	F1—Be1—F4	109.50 (11)
N2—C2—C1	106.04 (10)	F2—Be1—F3	109.67 (11)
N1—C1—H5	108.2 (8)	F2—Be1—F4	106.86 (11)
C2—C1—H4	109.4 (9)	F3—Be1—F4	108.59 (10)
N1—C1—C2—N2	177.69 (9)	N1—C1—C2—C3	−64.12 (13)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···F3^i	0.90 (2)	1.86 (2)	2.7461 (13)	169.8 (13)
N1—H2···F4^ii	0.88 (2)	1.78 (2)	2.6446 (13)	165.4 (15)
N1—H3···F1^iii	0.90 (2)	1.89 (2)	2.7646 (15)	163.5 (15)
N2—H7···F2^iv	0.88 (2)	1.87 (2)	2.7507 (14)	175.5 (14)
N2—H8···F3^v	0.90 (2)	1.87 (2)	2.7611 (13)	171.8 (13)
N2—H9···F2	0.94 (2)	1.91 (2)	2.8240 (16)	163.3 (14)

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