A new borogermanate, viz. piperazine-1,4-diium difluorononaoxotrigermaniumdiboron, (C4H12N2)[(GeO2)3(BO1.5F)2], was solvo/hydrothermally synthesized. The crystal structure consists of layers composed of three-membered-ring Ge3O9 subunits and nine-membered-ring channels formed by six GeO4 tetrahedra and three BO3F tetrahedral pairs. The diprotonated piperazine cations, which lie about inversion centres, are located between adjacent layers and connect the layers via hydrogen bonds.
Supporting information
CCDC reference: 226107
The title compound (I), was synthesized via a solvo/hydrothermal route using a mixture of pyridine and water. In a typical synthesis, GeO2 (0.25 g), H3BO3 (0.75 g) and piperazine (2.4 g) were dissolved in a mixed solution of pyridine (7.7 ml) and H2 (O1.7 ml). HF (0.17 ml, 40 wt%) was added, and the mixture was stirred continuously for 3 h. The final solution had a molar ratio of GeO2: 40pyridine: 38H2O: 5H3BO3: 12piperazine: 2HF and a pH higher than 13. The solution was sealed in a Teflon-lined autoclave, heated and kept at 438 K for 3 d. The autoclave was left to cool to room temperature. The products were filtered, washed with distilled water and dried at room temperature. Two distinct kinds of large colourless crystals were obtained, viz. (I) and ASU-14 (Li et al., 1999). All reagents (Aldrich) were of analytical grades and were not further purified before use.
All H-atoms were positioned geometrically and allowed to ride on their parent atoms (C—H=0.97 Å and N—H=0.90 Å).
Data collection: EXPOSURE (Stoe & Cie, 1997); cell refinement: CELL (Stoe & Cie, 1997); data reduction: INTEGRATE (Stoe & Cie, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2000); software used to prepare material for publication: SHELXL97.
Crystal data top
B2F2Ge3O9·C4H12N2 | F(000) = 984 |
Mr = 509.54 | Dx = 2.574 Mg m−3 |
Orthorhombic, Pbcn | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2n 2ab | Cell parameters from 5000 reflections |
a = 6.9776 (14) Å | θ = 3.4–25.9° |
b = 11.779 (2) Å | µ = 6.89 mm−1 |
c = 15.997 (3) Å | T = 293 K |
V = 1314.8 (4) Å3 | Plate, colourless |
Z = 4 | 0.15 × 0.10 × 0.08 mm |
Data collection top
Stoe IPDS diffractometer | 1278 independent reflections |
Radiation source: fine-focus sealed tube | 1092 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.034 |
Detector resolution: 6.0 pixels mm-1 | θmax = 25.9°, θmin = 3.4° |
ϕ–oscill., ϕ–incr.=1.4°; 129 exposure scans | h = −8→8 |
Absorption correction: numerical (X-RED; Stoe & Cie, 1997) | k = −14→14 |
Tmin = 0.444, Tmax = 0.558 | l = −19→19 |
8492 measured reflections | |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.019 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.046 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0299P)2] where P = (Fo2 + 2Fc2)/3 |
1278 reflections | (Δ/σ)max = 0.010 |
101 parameters | Δρmax = 0.36 e Å−3 |
0 restraints | Δρmin = −0.40 e Å−3 |
Crystal data top
B2F2Ge3O9·C4H12N2 | V = 1314.8 (4) Å3 |
Mr = 509.54 | Z = 4 |
Orthorhombic, Pbcn | Mo Kα radiation |
a = 6.9776 (14) Å | µ = 6.89 mm−1 |
b = 11.779 (2) Å | T = 293 K |
c = 15.997 (3) Å | 0.15 × 0.10 × 0.08 mm |
Data collection top
Stoe IPDS diffractometer | 1278 independent reflections |
Absorption correction: numerical (X-RED; Stoe & Cie, 1997) | 1092 reflections with I > 2σ(I) |
Tmin = 0.444, Tmax = 0.558 | Rint = 0.034 |
8492 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.019 | 0 restraints |
wR(F2) = 0.046 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.36 e Å−3 |
1278 reflections | Δρmin = −0.40 e Å−3 |
101 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 | x | y | z | Uiso*/Ueq | |
Ge1 | 0.22110 (4) | 0.29873 (2) | 0.234953 (16) | 0.00981 (9) | |
Ge2 | 0.5000 | 0.02738 (3) | 0.2500 | 0.00902 (10) | |
B1 | 0.4634 (4) | 0.2154 (2) | 0.36068 (17) | 0.0120 (6) | |
F1 | 0.4338 (3) | 0.21278 (15) | 0.44838 (9) | 0.0255 (4) | |
O1 | 0.3539 (3) | 0.31078 (15) | 0.32642 (11) | 0.0149 (4) | |
O2 | 0.3879 (3) | 0.10669 (15) | 0.32676 (11) | 0.0147 (4) | |
O3 | 0.6688 (3) | 0.22610 (16) | 0.34489 (11) | 0.0168 (4) | |
O4 | 0.1721 (3) | 0.43889 (15) | 0.20393 (11) | 0.0156 (4) | |
O5 | 0.0000 | 0.2311 (2) | 0.2500 | 0.0176 (6) | |
N1 | 0.1437 (3) | −0.0016 (2) | 0.43606 (14) | 0.0182 (5) | |
H1A | 0.2391 | 0.0328 | 0.4079 | 0.080* | |
H1B | 0.1284 | −0.0715 | 0.4145 | 0.080* | |
C1 | 0.1979 (4) | −0.0113 (3) | 0.52590 (18) | 0.0262 (7) | |
H2A | 0.2267 | 0.0634 | 0.5481 | 0.080* | |
H2B | 0.3119 | −0.0578 | 0.5312 | 0.080* | |
C2 | −0.0358 (4) | 0.0640 (3) | 0.42471 (17) | 0.0234 (6) | |
H3A | −0.0695 | 0.0656 | 0.3659 | 0.080* | |
H3B | −0.0162 | 0.1415 | 0.4431 | 0.080* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Ge1 | 0.00628 (15) | 0.00709 (14) | 0.01606 (14) | 0.00107 (10) | 0.00041 (9) | −0.00130 (9) |
Ge2 | 0.00828 (19) | 0.00549 (19) | 0.01328 (17) | 0.000 | 0.00214 (13) | 0.000 |
B1 | 0.0109 (16) | 0.0098 (13) | 0.0153 (13) | −0.0005 (11) | 0.0028 (10) | −0.0001 (10) |
F1 | 0.0292 (9) | 0.0303 (9) | 0.0170 (8) | 0.0010 (8) | 0.0044 (7) | 0.0001 (7) |
O1 | 0.0140 (10) | 0.0104 (9) | 0.0203 (9) | 0.0040 (8) | −0.0036 (7) | −0.0040 (7) |
O2 | 0.0147 (11) | 0.0082 (9) | 0.0212 (9) | −0.0022 (8) | 0.0076 (7) | −0.0029 (7) |
O3 | 0.0090 (10) | 0.0195 (11) | 0.0220 (10) | −0.0010 (8) | 0.0002 (7) | 0.0086 (7) |
O4 | 0.0176 (10) | 0.0095 (9) | 0.0197 (10) | 0.0026 (8) | 0.0052 (7) | 0.0030 (7) |
O5 | 0.0089 (13) | 0.0097 (13) | 0.0342 (15) | 0.000 | 0.0024 (10) | 0.000 |
N1 | 0.0193 (13) | 0.0188 (11) | 0.0166 (11) | −0.0062 (11) | 0.0065 (9) | −0.0032 (9) |
C1 | 0.0183 (15) | 0.0378 (19) | 0.0225 (14) | −0.0004 (14) | −0.0032 (11) | 0.0086 (13) |
C2 | 0.0207 (17) | 0.0291 (16) | 0.0205 (13) | 0.0014 (13) | 0.0006 (11) | 0.0104 (11) |
Geometric parameters (Å, º) top
Ge1—O1 | 1.7376 (18) | C1—C2iii | 1.513 (4) |
Ge1—O3i | 1.7186 (18) | N1—C1 | 1.490 (4) |
Ge1—O4 | 1.7575 (18) | N1—C2 | 1.482 (4) |
Ge1—O5 | 1.7529 (12) | N1—H1A | 0.9000 |
Ge2—O2 | 1.7299 (17) | N1—H1B | 0.9000 |
Ge2—O4ii | 1.7524 (18) | C1—H2A | 0.9700 |
B1—F1 | 1.419 (3) | C1—H2B | 0.9700 |
B1—O1 | 1.465 (3) | C2—H3A | 0.9700 |
B1—O2 | 1.488 (3) | C2—H3B | 0.9700 |
B1—O3 | 1.460 (3) | | |
| | | |
O3i—Ge1—O1 | 115.35 (9) | Ge1—O5—Ge1v | 125.94 (15) |
O3i—Ge1—O5 | 105.63 (8) | Ge2vi—O4—Ge1 | 124.98 (10) |
O1—Ge1—O5 | 113.00 (7) | C2—N1—C1 | 111.9 (2) |
O3i—Ge1—O4 | 110.16 (9) | C2—N1—H1A | 109.2 |
O1—Ge1—O4 | 105.36 (9) | C1—N1—H1A | 109.2 |
O5—Ge1—O4 | 107.12 (10) | C2—N1—H1B | 109.2 |
O2—Ge2—O2i | 114.63 (12) | C1—N1—H1B | 109.2 |
O2—Ge2—O4iv | 108.06 (9) | H1A—N1—H1B | 107.9 |
O2i—Ge2—O4iv | 109.42 (9) | N1—C1—C2iii | 110.2 (2) |
O2—Ge2—O4ii | 109.42 (9) | N1—C1—H2A | 109.6 |
O2i—Ge2—O4ii | 108.06 (9) | C2iii—C1—H2A | 109.6 |
O4iv—Ge2—O4ii | 107.01 (12) | N1—C1—H2B | 109.6 |
F1—B1—O3 | 108.4 (2) | C2iii—C1—H2B | 109.6 |
F1—B1—O1 | 108.1 (2) | H2A—C1—H2B | 108.1 |
O3—B1—O1 | 112.4 (2) | N1—C2—C1iii | 110.8 (2) |
F1—B1—O2 | 106.9 (2) | N1—C2—H3A | 109.5 |
O3—B1—O2 | 111.0 (2) | C1iii—C2—H3A | 109.5 |
O1—B1—O2 | 109.8 (2) | N1—C2—H3B | 109.5 |
B1—O1—Ge1 | 122.06 (16) | C1iii—C2—H3B | 109.5 |
B1—O2—Ge2 | 124.31 (16) | H3A—C2—H3B | 108.1 |
B1—O3—Ge1i | 127.59 (16) | | |
| | | |
F1—B1—O1—Ge1 | −136.91 (18) | F1—B1—O3—Ge1i | −145.36 (17) |
O3—B1—O1—Ge1 | 103.4 (2) | O1—B1—O3—Ge1i | −25.9 (3) |
O2—B1—O1—Ge1 | −20.7 (3) | O2—B1—O3—Ge1i | 97.6 (2) |
O3i—Ge1—O1—B1 | −42.6 (2) | O3i—Ge1—O4—Ge2vi | 158.85 (12) |
O5—Ge1—O1—B1 | 79.1 (2) | O1—Ge1—O4—Ge2vi | −76.13 (14) |
O4—Ge1—O1—B1 | −164.28 (18) | O5—Ge1—O4—Ge2vi | 44.44 (14) |
F1—B1—O2—Ge2 | −138.57 (18) | O3i—Ge1—O5—Ge1v | −136.30 (7) |
O3—B1—O2—Ge2 | −20.5 (3) | O1—Ge1—O5—Ge1v | 96.72 (7) |
O1—B1—O2—Ge2 | 104.4 (2) | O4—Ge1—O5—Ge1v | −18.87 (6) |
O2i—Ge2—O2—B1 | −36.80 (17) | C2—N1—C1—C2iii | 56.3 (4) |
O4iv—Ge2—O2—B1 | −159.08 (19) | C1—N1—C2—C1iii | −56.6 (4) |
O4ii—Ge2—O2—B1 | 84.7 (2) | | |
Symmetry codes: (i) −x+1, y, −z+1/2; (ii) x+1/2, y−1/2, −z+1/2; (iii) −x, −y, −z+1; (iv) −x+1/2, y−1/2, z; (v) −x, y, −z+1/2; (vi) x−1/2, y+1/2, −z+1/2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O2 | 0.90 | 1.88 | 2.754 (3) | 164.6 |
N1—H1B···O1iv | 0.90 | 1.98 | 2.822 (3) | 155.0 |
Symmetry code: (iv) −x+1/2, y−1/2, z. |
Experimental details
Crystal data |
Chemical formula | B2F2Ge3O9·C4H12N2 |
Mr | 509.54 |
Crystal system, space group | Orthorhombic, Pbcn |
Temperature (K) | 293 |
a, b, c (Å) | 6.9776 (14), 11.779 (2), 15.997 (3) |
V (Å3) | 1314.8 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 6.89 |
Crystal size (mm) | 0.15 × 0.10 × 0.08 |
|
Data collection |
Diffractometer | Stoe IPDS diffractometer |
Absorption correction | Numerical (X-RED; Stoe & Cie, 1997) |
Tmin, Tmax | 0.444, 0.558 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8492, 1278, 1092 |
Rint | 0.034 |
(sin θ/λ)max (Å−1) | 0.615 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.019, 0.046, 1.00 |
No. of reflections | 1278 |
No. of parameters | 101 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.36, −0.40 |
Selected geometric parameters (Å, º) topGe1—O1 | 1.7376 (18) | B1—O1 | 1.465 (3) |
Ge1—O3i | 1.7186 (18) | B1—O2 | 1.488 (3) |
Ge1—O4 | 1.7575 (18) | B1—O3 | 1.460 (3) |
Ge1—O5 | 1.7529 (12) | C1—C2iii | 1.513 (4) |
Ge2—O2 | 1.7299 (17) | N1—C1 | 1.490 (4) |
Ge2—O4ii | 1.7524 (18) | N1—C2 | 1.482 (4) |
B1—F1 | 1.419 (3) | | |
| | | |
B1—O1—Ge1 | 122.06 (16) | Ge1—O5—Ge1iv | 125.94 (15) |
B1—O2—Ge2 | 124.31 (16) | Ge2v—O4—Ge1 | 124.98 (10) |
B1—O3—Ge1i | 127.59 (16) | | |
Symmetry codes: (i) −x+1, y, −z+1/2; (ii) x+1/2, y−1/2, −z+1/2; (iii) −x, −y, −z+1; (iv) −x, y, −z+1/2; (v) x−1/2, y+1/2, −z+1/2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O2 | 0.90 | 1.88 | 2.754 (3) | 164.6 |
N1—H1B···O1vi | 0.90 | 1.98 | 2.822 (3) | 155.0 |
Symmetry code: (vi) −x+1/2, y−1/2, z. |
Porous materials are widely used in industry owing to their sorption, ion-exchange and catalyst properties (Chen et al., 1989; Jansen et al., 1994), and these materials often show great structural diversity (Smith, 1988). During the past decade, the classes of porous materials, built of pure tetrahedra or mixed polyhedra, have expanded in terms of framework-forming elements (Cheetham et al., 1999)?. Recent studies have shown that germanium oxides can be crystallized by solvo/hydrothermal synthetic methods in basic solutions to form open frameworks with tetrahedral or mixed-polyhedral Ge—O coordinations, for example, in ICMM2 (Cascales et al., 1999), ASU-16 (Plevert et al., 2001), ASU-14 (Li et al., 1999) and Ge10O21(OH)·N4C6H21 (Beitone et al., 2002). Although more than 20 elements have been incorporated sucessfully into silicate frameworks, very few elements have been reported to be incorporated into germanates. One of the elements that has been incorporated is boron, although up to now only two borogermanates prepared via molecular templating methods have been reported. The first is (C2H10N2)2[(GeO2)3(BO2.5)2], a layered structure containing nine-ring channels, templated by ethylenediamine (Dadachov et al., 2000). The second is KBGe2O6, a chiral borogermanate with seven-rings channels (Lin et al., 2003). We report here another layered borogermanate containing nine- and three-membered-ring channels and templated by piperazine, viz. the title compound, (I), which is also denoted SU-13 (Stockholm University No. 13).
The asymmetric unit of (I) contains two unique Ge atoms and one unique B atom (Fig. 1). All of the Ge and B atoms are tetrahedrally coordinated, Ge by four O atoms, and B by three O atoms and one F atom (Table 1). The GeO4 and BO3F groups are vertex-connected via the O atoms, as seen in zeolites. Three GeO4 tetrahedra are connected to form a three-unit ring, a configuration that is very common in germanates. Three such rings are connected via three pairs of BO3F tetrahedra, in an alternating manner, to form a layer containing nine-unit rings composed of six GeO4 tetrahedra and three pairs of BO3F tetrahedra (Fig. 2).
The diprotonated piperazine cations are located between the adjacent layers, inside the nine-membered-ring channels (Fig. 2). The cations balance the framework charge and connect the layers, via hydrogen bonds (Table 2), into a three-dimensional structure. The Ge and B tetrahedra have average angles close to that of an ideal tetrahedron (109.5°). The Ge—O—Ge and B—O—Ge angles are all smaller than, but still close to, the T—O—T angles reported for other germanates (130°; O'Keeffe & Yaghi, 1999).
The [(GeO2)3(BO1.5F)2] layer in (I) is the same as that in (C2H10N2)2[(GeO2)3(BO2.5)2] (Dadachov et al., 2000), although the relative positions of the adjacent layers are different, as a result of the shape and size differences of the organic cations in these two compounds. The distances between the layers are also different, viz. 8.0 Å in (I) and 7.2 Å in (C2H10N2)2[(GeO2)3(BO2.5)2]. The [(GeO2)3(BO1.5F)2] layers in both borogermanates are also similar to the [(GeO2)3(GeO1.5F3)2] layer in several pure germanate compounds, for example, K4[(GeO2)3(GeO1.5F3)2] (Bu et al., 1999) and (NH4)[(GeO2)3(GeO1.5F3)2].0.67H2O (Conradsson, et al., 2000). The main structural difference between the borogermanates and the germanates is that the BO3F tetrahedral pair in [(GeO2)3(BO1.5F)2] is replaced by the GeO3F3 octahedral pair in [(GeO2)3(GeO1.5F3)2].