metal-organic compounds Acta Crystallographica Section E
Structure Reports Online ISSN 1600-5368
Bis{tris[3-(2-pyridyl)-1H-pyrazole]iron(II)} tetradecamolybdo(V,VI)silicate Peihai Wei,a Dong Yuan,a Wencai Zhu,a Xiutang Zhanga,b* and Bo Hua a
Advanced Material Institute of Research, Department of Chemistry and Chemical Engineering, ShanDong Institute of Education, Jinan 250013, People’s Republic of China, and bCollege of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, People’s Republic of China Correspondence e-mail:
[email protected] Received 12 January 2010; accepted 19 January 2010 ˚; Key indicators: single-crystal X-ray study; T = 293 K; mean (C–C) = 0.021 A disorder in main residue; R factor = 0.059; wR factor = 0.157; data-to-parameter ratio = 11.0.
Experimental Crystal data
The asymmetric unit of the title compound, [Fe(C8H7N3)3]2[SiMo14O44], consists of a complex [Fe(C8H7N3)3]2+ cation and half of a derivative of an -Keggin-type anion, [SiMo14O44]4. In the mixed-valent MoV/VI anion, the -Keggin type core is capped on two oppositely disposed tetragonal faces by additional (MoO2) units. The [SiMo14O44]4 anion shows disorder. Two O atoms of the central SiO4 group (1 symmetry) are equally disordered about an inversion centre. Moreover, two of the outer bridging O atoms and the O atoms of the capping (MoO2) unit are likewise disordered. The Fe2+ cation is surrounded in a slightly distorted octahedral coordination by six N atoms from three 3-(2-pyridyl)-1H-pyrazole ligands. N—H O hydrogen bonding between the cations and anions leads to a consolidation of the structure.
Data collection
Related literature
Si1—O17A Si1—O18A Si1—O18B Si1—O17B Fe1—N2
For general background to polyoxometalates, see: Pope & Mu¨ller (1991). For polyoxometalates modified with amines, see: Zhang, Dou et al. (2009); Zhang, Wei, Shi et al. (2010a,b); Zhang, Wei, Sun et al. (2009); Zhang, Wei, Zhu et al. (2010); Zhang, Yuan et al. (2010). For another structure containing the -Keggin-type derivative [SiMo14O44]4, see: Dolbecq et al. (1999). For background to the bond-valence method, see: Brese & O’Keeffe (1991). For the role of amines in hydrothermal synthesis, see: Yang et al. (2003).
˚3 V = 4002.6 (14) A Z=2 Mo K radiation = 2.58 mm1 T = 293 K 0.12 0.10 0.08 mm
[Fe(C8H7N3)3]2[SiMo14O44] Mr = 3057.95 Monoclinic, P21 =c ˚ a = 13.055 (3) A ˚ b = 16.931 (3) A ˚ c = 18.562 (4) A = 102.69 (3)
Bruker APEXII CCD diffractometer Absorption correction: multi-scan (SADABS; Bruker, 2001) Tmin = 0.747, Tmax = 0.820
27223 measured reflections 7026 independent reflections 4730 reflections with I > 2(I) Rint = 0.076
Refinement R[F 2 > 2(F 2)] = 0.059 wR(F 2) = 0.157 S = 1.00 7026 reflections 638 parameters
444 restraints H-atom parameters constrained ˚ 3 max = 1.47 e A ˚ 3 min = 1.52 e A
Table 1 ˚ ). Selected bond lengths (A 1.606 1.648 1.670 1.684 2.105
(13) (13) (13) (13) (11)
Fe1—N8 Fe1—N5 Fe1—N3 Fe1—N9 Fe1—N6
2.119 2.153 2.173 2.186 2.206
(11) (11) (11) (12) (11)
Table 2 ˚ , ). Hydrogen-bond geometry (A D—H A i
N4—H4 O13 N1—H1A O21Aii N1—H1A O21ii
D—H
H A
D A
D—H A
0.86 0.86 0.86
2.15 2.17 2.05
2.973 (17) 2.96 (3) 2.844 (19)
159 152 153
Symmetry codes: (i) x; y þ 32; z 12; (ii) x þ 1; y þ 1; z þ 1.
Data collection: APEX2 (Bruker, 2004); cell refinement: SAINTPlus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics:
m190
Wei et al.
doi:10.1107/S1600536810002412
Acta Cryst. (2010). E66, m190–m191
metal-organic compounds SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.
Financial support from the Chinese Academy of Sciences (‘Hundred Talents Program’) and the Ministry of Science and Technology of China (grant No. 2007CB607608), Shandong Provincial Education Department and Shandong Institute of Education are gratefully acknowledged. Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: WM2300).
References Brese, N. E. & O’Keeffe, M. (1991). Acta Cryst. B47, 192–197.
Acta Cryst. (2010). E66, m190–m191
Bruker (2001). SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Bruker (2004). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA. Dolbecq, A., Cadot, E., Eisner, D. & Secheresse, F. (1999). Inorg. Chem. 38, 4127–4134. Pope, M. T. & Mu¨ller, A. (1991). Angew. Chem. Int. Ed. 30, 34–38. Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Yang, W. B., Lu, C. Z., Wu, C. D. & Zhuang, H. H. (2003). Chin. J. Struct. Chem. 22, 137–142. Zhang, X. T., Dou, J. M., Wei, P. H., Li, D. C., Li, B., Shi, C. W. & Hu, B. (2009). Inorg. Chim. Acta, 362, 3325–3332. Zhang, X., Wei, P., Shi, C., Li, B. & Hu, B. (2010a). Acta Cryst. E66, m26–m27. Zhang, X., Wei, P., Shi, C., Li, B. & Hu, B. (2010b). Acta Cryst. E66, m174– m175. Zhang, X. T., Wei, P. H., Sun, D. F., Ni, Z. H., Dou, J. M., Li, B., Shi, C. W. & Hu, B. (2009). Cryst. Growth Des. 9, 4424–4428. Zhang, X., Wei, P., Zhu, W., Li, B. & Hu, B. (2010). Acta Cryst. E66, m127– m128. Zhang, X., Yuan, D., Wei, P., Li, B. & Hu, B. (2010). Acta Cryst. E66, m152– m153.
Wei et al.
[Fe(C8H7N3)3]2[SiMo14O44]
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supplementary materials
supplementary materials Acta Cryst. (2010). E66, m190-m191
[ doi:10.1107/S1600536810002412 ]
Bis{tris[3-(2-pyridyl)-1H-pyrazole]iron(II)} tetradecamolybdo(V,VI)silicate P. Wei, D. Yuan, W. Zhu, X. Zhang and B. Hu Comment The design and synthesis of polyoxometalates has attracted continuous research interest not only because of their appealing structural and topological novelties, but also due to their interesting optical, electronic, magnetic, and catalytic properties, as well as their potential medical applications (Pope & Müller, 1991). In our research group, organic amines, such as 3-(2pyridyl)pyrazole and pyrazine, are used to effectively modify polyoxomolybdates under hydrothermal condictions (Zhang, Dou et al., 2009; Zhang, Wei, Shi et al., 2010a,b; Zhang, Wei, Sun et al., 2009; Zhang, Wei, Zhu et al., 2010; Zhang, Yuan et al., 2010). Here, we describe the synthesis and structural characterization of the title compound. As shown in Figure 1, the title compound consists of two subunits, viz. of a complex caion [Fe(C8H7N3)3]2+ and a derivative of the α-Keggin-type anion with overall composition [SiMo14O44]4-. The iron(II) ion is in a distorted octahedral coordination by six N atoms from two 3-(2-pyridyl)pyrazole ligands. The Fe—N bond lengths are in the range of 2.105 (11)—2.206 (11) Å. The anion [SiMo14O44]4- can be described as a derivative of an α-Keggin-type core capped on two oppositely disposed tetragonal faces by (MoO2) subunits (Dolbecq et al., 1999). The molybdenum atoms of the disordered capping unit have a highly distorted coordination environment with short Mo—Ot bonds [1.70 (15)–1.84 (3) Å] and longer Mo—O bridging bonds [1.998 (16)–2.174 (15) Å]. The formula sum of the title compound reveals that the valence of some metal atoms in the title compound are (partly) reduced (part of Mo6+ to Mo5+; Fe3+ to Fe2+). The employed organic ligand appears to adjust the pH value, and additionally supplies reducing electrons, which is a commonly observed feature of hydrothermal syntheses when organic amines are used to prepare various hybrid materials, zeolites or metal phosphates (Yang et al., 2003). The oxidation states of the metals are confirmed by bond valence sum calculations (Brese & O'Keeffe, 1991). For the Mo and Fe atoms in the title compound the bond valence sums equal to 5.93, 4.95, 5.83, 6.17, 5.81, 6.18, 5.24, and 2.01. N—H···O hydrogen bonding between the cations and anions leads to a consolidation of the structure (Fig. 2; Table 2). Experimental A mixture of 3-(2-pyridyl)pyrazole (1 mmoL 0.14 g), sodium molybdate (2 mmoL, 0.48 g), sodium silicate nonahydrate (0.2 mmoL, 0.05 g) and iron(III) chloride hexahydrate (0.25 mmol, 0.06 g) in 10 ml distilled water was sealed in a 25 ml Teflon-lined stainless steel autoclave and was kept at 433 K for three days. Brown crystals suitable for the X-ray experiment were obtained. Anal. C48H42Fe2Mo14N18O44Si: C, 18.85; H, 1.38; N, 8.25. Found: C, 18.75; H, 1.12; N, 8.15%. The TGA measure,ent shows that the release of organic liangds takes place above ca 623 K. The overall thermal decomposition process can be described by the following equation: C48H42Fe2Mo14N18O44Si + 84O2 = 21H2O + 48CO2 + 9N2O5 + Fe2O3 + SiO2 + 14MoO3 Eq.(1). IR bands appear at the following wavelengths (cm-1): 3303, 3117, 1697, 1604, 1550, 1485, 1355, 1300, 1171, 1088, 1051, 903, 765, 664, 507, 451, 414.
sup-1
supplementary materials Refinement All hydrogen atoms bound to aromatic carbon atoms were refined in calculated positions using a riding model with a C—H distance of 0.93 Å and Uiso = 1.2Ueq(C). Hydrogen atoms attached to aromatic N atoms were refined with a N—H distance of 0.86 Å and Uiso = 1.2Ueq(N). In the SiO4 unit, the two oxygen atoms (O17 and O18) are equally disordered about the inversion centre. Four O atoms (O11, O16, O20, O21) are also disordered and were refined with split positions and an occupancy ratio of 1:1 (O 11, 16) and 3:1 (O20, 21). In the final difference Fourier map the highest peak is 1.25 Å from atom O20A and the deepest hole is 0.67 Å from atom Mo3. The highest peak is located in the voids of the crystal structure and may be associated with an additional water molecule. However, refinement of this position did not result in a reasonable model. Hence this position was also excluded from the final refinement.
Figures Fig. 1. The building blocks of the title compound with the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level; H atoms are given as spheres of arbitrary radius.
Fig. 2. The crystal packing of the title compound, displayed with hydrogen bonds as dashed lines.
Bis{tris[3-(2-pyridyl)-1H-pyrazole]iron(II)} tetradecamolybdo(V,VI)silicate Crystal data [Fe(C8H7N3)3]2[SiMo14O44]
F(000) = 2924
Mr = 3057.95
Dx = 2.537 Mg m−3
Monoclinic, P21/c
Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc a = 13.055 (3) Å
Cell parameters from 7026 reflections θ = 1.7–25.0°
b = 16.931 (3) Å
µ = 2.58 mm−1 T = 293 K Block, brown
c = 18.562 (4) Å β = 102.69 (3)° V = 4002.6 (14) Å3 Z=2
sup-2
0.12 × 0.10 × 0.08 mm
supplementary materials Data collection Bruker APEXII CCD diffractometer Radiation source: fine-focus sealed tube
7026 independent reflections
graphite
4730 reflections with I > 2σ(I) Rint = 0.076
phi and ω scans
θmax = 25.0°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2001) Tmin = 0.747, Tmax = 0.820
h = −15→15 k = −20→20 l = −21→22
27223 measured reflections
Refinement
R[F2 > 2σ(F2)] = 0.059
Primary atom site location: structure-invariant direct methods Secondary atom site location: difference Fourier map Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.157
H-atom parameters constrained
Refinement on F2 Least-squares matrix: full
w = 1/[σ2(Fo2) + (0.058P)2 + 47.4341P]
S = 1.00
where P = (Fo2 + 2Fc2)/3
7026 reflections
(Δ/σ)max = 0.001
638 parameters
Δρmax = 1.47 e Å−3
444 restraints
Δρmin = −1.52 e Å−3
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 Rfactors(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) Si1 Fe1 Mo1 Mo2 Mo3 Mo4
x
y
z
Uiso*/Ueq
0.0000 0.36074 (14) 0.20889 (7) −0.00697 (9) 0.33482 (8) 0.21554 (8)
0.5000 0.58896 (11) 0.55765 (6) 0.46521 (7) 0.44820 (7) 0.59444 (6)
0.5000 0.17093 (11) 0.41647 (5) 0.30342 (6) 0.54989 (6) 0.61448 (6)
0.0193 (8) 0.0497 (5) 0.0364 (3) 0.0431 (3) 0.0464 (3) 0.0408 (3)
Occ. (
