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Acta Cryst. (2009). E65, m1074    [ doi:10.1107/S1600536809031717 ]

Tetra-[mu]-oxido-tetrakis{dioxido[3-(2-pyridyl)-1H-pyrazole]molybdenum(VI)}

D. Li, Y. Liu, P. Wei, B. Hu and X. Zhang

Abstract top

In the title compound, [Mo4O12(C8H7N3)4], the MoVI ion has a distorted octahedral coordination completed by two terminal O atoms, two [mu]-oxide atoms and two N atoms from one 3-(2-pyridyl)-1H-pyrazole ligand. It is noteworthy that in the tetranuclear unit (\overline4 symmetry), any three MoVI atoms define a plane, and the fourth lies 1.8 (1) Å out of that plane. The degree of linearity of the oxide bridges between two Mo atoms is 175.38 (13)°. Moreover, the N-H group forms an intramolecular hydrogen bond (four per molecule).

Comment top

The design and synthesis of polyoxometalate clusters has attracted continuous research interest not only because of their appealing structural and topological novelty, but also due to their unusual optical, electronic, magnetic, and catalytic properties, as well as their potential medical application (Pope et al.; Khenkin et al.; Zhang et al. (2007); Zhang et al. (2006); Zhang et al. (2009). In the present paper, we describe the synthesis and structural characterization of tetrakis((µ-oxo)-bis(3-(2-pyridyl)pyrazole)molybdenum(vi)).

In the asymmetric unit of complex I, there exhibit one 3-(2-pyridyl)pyrazole ligand and one molybdenum oxide MoVIO3, Fig. 1. The MoVI ion surrounded by one 3-(2-pyridyl)pyrazole ligand is hexa-coordinated by four oxygen atoms and two nitrogen atoms, with distorted octahedral coordination sphere. The bond distances of Mo—O and Mo—N are in the normal range compared to the reported complexes containing the N—Mo—O atoms (Rana et al.). It is worthy noting that the simple basic Mo3HL units are assembled to form one 8-MC-4 complex, which could be described as `folded' with two adjacent Mo3 planes forming a dihedral angle of about 38.65°. Moreover, the N—H group forms a very nice intramolecular hydrogen bond (4 per molecule), shown in Fig. 2.

Related literature top

For the properties and potential medical applications of polyoxometalate clusters, see: Pope et al. (1991); Khenkin et al. (2008); Zhang et al. (2006, 2007, 2009). For Mo—O and Mo—N distances, see: Rana et al. (2003). For related literature, see: Mezei et al. (2007);

Zhang et al. (2006).

Experimental top

A mixture of 3-(2-pyridyl)pyrazole (1 mmoL) and molybdenum trioxide (1 mmoL) in 10 ml distilled water sealed in a 25 ml Teflon-lined stainless steel autoclave was kept at 433 K for three days. Colourless crystals suitable for an X-ray experiment were obtained. Anal. Calc. for C32H28Mo4N12O12: C 33.22, H 1.90, N 14.53%; Found: C 33.13, H 1.79, N 14.32%.

Refinement top

All hydrogen atoms bound to carbon were refined using a riding model with C—H = 0.93 Å and Uiso = 1.2Ueq (C) for aromatic atoms. The H atom on nitrogen was located from difference density maps and was refined with a distance restraint of N–H = 0.97 (1) Å.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. A view of the title compound with the unique atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 2] Fig. 2. The packing diagram of the title compound with the hydrogen bonds of N2—H1A···O2.
Tetra-µ-oxido-tetrakis{dioxido[3-(2-pyridyl)-1H-pyrazole]molybdenum(VI)} top
Crystal data top
[Mo4O12(C8H7N3)4]Dx = 2.025 Mg m−3
Mr = 1156.42Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P42/nCell parameters from 1675 reflections
Hall symbol: -P 4bcθ = 2.0–25.0°
a = 14.4412 (16) ŵ = 1.37 mm−1
c = 9.094 (2) ÅT = 298 K
V = 1896.6 (5) Å3Block, colourless
Z = 20.12 × 0.10 × 0.08 mm
F(000) = 1136
Data collection top
Bruker APEXII CCD area-detector
diffractometer		1675 independent reflections
Radiation source: fine-focus sealed tube1316 reflections with I > 2σ(I)
graphiteRint = 0.036
φ and ω scansθmax = 25.0°, θmin = 2.0°
Absorption correction: multi-scan
(SADABS; Bruker, 2001)		h = −17→16
Tmin = 0.853, Tmax = 0.898k = −12→17
7579 measured reflectionsl = −9→10
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)] = 0.024Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.064H atoms treated by a mixture of independent and constrained refinement
S = 1.00 w = 1/[σ2(Fo2) + (0.0295P)2 + 2.0306P]
where P = (Fo2 + 2Fc2)/3
1675 reflections(Δ/σ)max = 0.001
139 parametersΔρmax = 0.35 e Å−3
1 restraintΔρmin = −0.35 e Å−3
Crystal data top
[Mo4O12(C8H7N3)4]Z = 2
Mr = 1156.42Mo Kα radiation
Tetragonal, P42/nµ = 1.37 mm−1
a = 14.4412 (16) ÅT = 298 K
c = 9.094 (2) Å0.12 × 0.10 × 0.08 mm
V = 1896.6 (5) Å3
Data collection top
Bruker APEXII CCD area-detector
diffractometer		1675 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2001)		1316 reflections with I > 2σ(I)
Tmin = 0.853, Tmax = 0.898Rint = 0.036
7579 measured reflectionsθmax = 25.0°
Refinement top
R[F2 > 2σ(F2)] = 0.024H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.064Δρmax = 0.35 e Å−3
S = 1.00Δρmin = −0.35 e Å−3
1675 reflectionsAbsolute structure: ?
139 parametersFlack parameter: ?
1 restraintRogers parameter: ?
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
Mo10.642839 (18)0.904662 (19)0.19761 (3)0.02233 (12)
N10.61994 (19)0.90081 (18)0.4404 (3)0.0257 (6)
N20.6811 (2)0.8938 (2)0.5516 (3)0.0311 (7)
N30.4862 (2)0.8976 (2)0.2532 (3)0.0314 (7)
O10.76035 (15)0.88536 (16)0.2362 (2)0.0302 (5)
O20.61894 (17)0.86807 (17)0.0193 (3)0.0359 (6)
O30.63381 (18)1.02324 (17)0.1907 (3)0.0370 (6)
C10.6375 (3)0.8821 (3)0.6815 (4)0.0345 (9)
H10.66560.87650.77310.041*
C20.5439 (3)0.8800 (2)0.6536 (4)0.0354 (9)
H2A0.49630.87260.72150.042*
C30.5355 (2)0.8917 (2)0.4995 (4)0.0283 (8)
C40.4595 (2)0.8907 (2)0.3953 (4)0.0321 (8)
C50.3667 (3)0.8828 (2)0.4346 (5)0.0413 (10)
H50.34920.87960.53290.050*
C60.3014 (3)0.8798 (3)0.3248 (5)0.0519 (11)
H60.23910.87240.34770.062*
C70.3291 (3)0.8878 (3)0.1802 (5)0.0504 (11)
H70.28530.88700.10540.060*
C80.4208 (3)0.8969 (3)0.1471 (5)0.0423 (10)
H80.43860.90270.04920.051*
H1A0.746 (3)0.894 (3)0.540 (5)0.080*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Mo10.02453 (18)0.02550 (18)0.01698 (17)0.00112 (12)0.00115 (11)0.00047 (12)
N10.0347 (15)0.0237 (14)0.0187 (14)0.0010 (12)−0.0011 (12)−0.0010 (11)
N20.0367 (17)0.0338 (16)0.0227 (16)0.0002 (14)0.0014 (13)−0.0026 (13)
N30.0298 (16)0.0315 (16)0.0328 (16)0.0037 (13)−0.0038 (13)−0.0050 (13)
O10.0245 (12)0.0387 (14)0.0273 (13)0.0000 (11)0.0026 (10)0.0028 (11)
O20.0466 (15)0.0403 (14)0.0209 (13)−0.0016 (12)−0.0022 (11)0.0006 (11)
O30.0448 (15)0.0294 (13)0.0368 (15)0.0040 (11)0.0047 (12)0.0037 (11)
C10.044 (2)0.039 (2)0.0201 (19)0.0018 (17)0.0019 (16)0.0017 (16)
C20.041 (2)0.034 (2)0.031 (2)0.0022 (17)0.0135 (17)0.0045 (16)
C30.0357 (19)0.0203 (17)0.0289 (19)0.0051 (14)0.0086 (16)−0.0006 (14)
C40.036 (2)0.0216 (17)0.039 (2)0.0017 (15)0.0111 (17)0.0006 (16)
C50.034 (2)0.035 (2)0.055 (3)0.0049 (17)0.0090 (19)0.0055 (19)
C60.033 (2)0.055 (3)0.067 (3)0.0006 (19)0.002 (2)0.003 (2)
C70.033 (2)0.067 (3)0.051 (3)0.005 (2)−0.010 (2)−0.007 (2)
C80.036 (2)0.046 (2)0.044 (2)0.0043 (18)−0.0021 (18)−0.0070 (19)
Geometric parameters (Å, °) top
Mo1—O31.719 (2)C1—C21.375 (5)
Mo1—O21.740 (2)C1—H10.9300
Mo1—O11.755 (2)C2—C31.416 (5)
Mo1—O1i2.207 (2)C2—H2A0.9300
Mo1—N12.233 (3)C3—C41.449 (5)
Mo1—N32.320 (3)C4—C51.392 (5)
N1—C31.340 (4)C5—C61.374 (6)
N1—N21.346 (4)C5—H50.9300
N2—C11.349 (4)C6—C71.379 (6)
N2—H1A0.94 (5)C6—H60.9300
N3—C81.350 (5)C7—C81.364 (6)
N3—C41.353 (5)C7—H70.9300
O1—Mo1ii2.207 (2)C8—H80.9300
O3—Mo1—O2104.69 (12)N2—C1—C2107.4 (3)
O3—Mo1—O1103.82 (11)N2—C1—H1126.3
O2—Mo1—O1109.26 (11)C2—C1—H1126.3
O3—Mo1—O1i159.53 (10)C1—C2—C3105.4 (3)
O2—Mo1—O1i86.03 (10)C1—C2—H2A127.3
O1—Mo1—O1i88.51 (13)C3—C2—H2A127.3
O3—Mo1—N192.85 (10)N1—C3—C2109.3 (3)
O2—Mo1—N1152.17 (11)N1—C3—C4115.3 (3)
O1—Mo1—N186.65 (10)C2—C3—C4135.3 (3)
O1i—Mo1—N171.30 (9)N3—C4—C5121.7 (4)
O3—Mo1—N388.74 (11)N3—C4—C3114.1 (3)
O2—Mo1—N389.78 (11)C5—C4—C3124.2 (3)
O1—Mo1—N3153.15 (10)C6—C5—C4118.4 (4)
O1i—Mo1—N373.68 (9)C6—C5—H5120.8
N1—Mo1—N368.85 (10)C4—C5—H5120.8
C3—N1—N2106.7 (3)C5—C6—C7119.5 (4)
C3—N1—Mo1122.3 (2)C5—C6—H6120.3
N2—N1—Mo1130.4 (2)C7—C6—H6120.3
N1—N2—C1111.2 (3)C8—C7—C6120.0 (4)
N1—N2—H1A124 (3)C8—C7—H7120.0
C1—N2—H1A124 (3)C6—C7—H7120.0
C8—N3—C4118.9 (3)N3—C8—C7121.4 (4)
C8—N3—Mo1121.8 (3)N3—C8—H8119.3
C4—N3—Mo1119.3 (2)C7—C8—H8119.3
Mo1—O1—Mo1ii175.38 (13)
Symmetry codes: (i) −y+3/2, x, −z+1/2; (ii) y, −x+3/2, −z+1/2.
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N2—H1A···O2ii0.94 (5)1.86 (5)2.783 (4)168 (4)
Symmetry codes: (ii) y, −x+3/2, −z+1/2.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N2—H1A···O2i0.94 (5)1.86 (5)2.783 (4)168 (4)
Symmetry codes: (i) y, −x+3/2, −z+1/2.
references
References top

Bruker (2001). SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.

Bruker (2004). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.

Khenkin, A. M. & Neumann, R. (2008). J. Am. Chem. Soc. 130, 14474–14476.

Mezei, G., Zaleski, C. M. & Pecoraro, V. L. (2007). Chem. Rev. 107, 4933–5003.

Pope, M. T. & Müller, A. (1991). Angew. Chem. Int. Ed. Engl. 30, 34–38.

Rana, A., Dinda, R., Ghosh, S. & Blake, A. J. (2003). Polyhedron, 22, 3075–3082.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Zhang, X. T., Dou, J. M., Wang, D. Q., Zhou, Y., Zhang, Y. X., Li, R. J., Yan, S. S., Ni, Z. H. & Jiang, J. Z. (2007). Cryst. Growth Des. 7, 1699–1705.

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. T., Wang, D. Q., Dou, J. M., Yan, S. S., Yao, X. X. & Jang, J. Z. (2006). Inorg. Chem. 45, 10629–10635.