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The title compound, [Mo2O6(pz)]n (pz is pyrazine, C4H4N2), was synthisized by hydro­thermal reaction of MoO3, pyrazine-2-carboxyl­ic acid and water at 443 K. The compound is a three-dimensional inorganic–organic hybrid polymer, in which pz acts as a bridging ligand. Each Mo atom is coordinated by five O atoms and one N atom in a distorted octahedral geometry, with the Mo—N distance being 2.449 (8) Å and the Mo—O distances ranging from 1.682 (7) to 2.086 (8) Å.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S160053680100441X/bt6019sup1.cif
Contains datablocks I, moo

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S160053680100441X/bt6019Isup2.hkl
Contains datablock I

CCDC reference: 162802

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.012 Å
  • R factor = 0.034
  • wR factor = 0.086
  • Data-to-parameter ratio = 10.9

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


Yellow Alert Alert Level C:
PLAT_214 Alert C Atom O1 (Anion/Solvent) ADP max/min Ratio 4.60 PLAT_214 Alert C Atom O2 (Anion/Solvent) ADP max/min Ratio 4.10 General Notes
ABSTM_02 When printed, the submitted absorption T values will be replaced by the scaled T values. Since the ratio of scaled T's is identical to the ratio of reported T values, the scaling does not imply a change to the absorption corrections used in the study. Ratio of Tmax expected/reported 0.825 Tmax scaled 0.825 Tmin scaled 0.673
0 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
2 Alert Level C = Please check

Comment top

Owing to the important role in the development of catalysis, electric conductivity, magnetism, non-linear optical properties and medicine, metal oxide chemistry has attracted much interest in recent years (Hill, 1998). In order to study the reaction behavior of metal oxides, organoamine ligands were often selected for the construction of inorganic–organic hybrid materials. Organoamines act in three different roles in these inorganic–organic hybrid materials: (i) as charge-compensating cations, (ii) directly bonded to the metal site of the metal oxide skeleton backbone and (iii) bonded to the heterometal atom. Recently, Zubieta and co-workers choose organoamines as a ligand and reported several molybdenum oxide hybrid materials compounds (Zubieta et al., 1999), such as MoO3(2,2'-bpy), Mo2O6(2,2'-bpy), Mo3O9(2,2'-bpy)2, Mo4O13(Hbpa), (H2en)Mo3O10 and [H3N(CH2)6NH3][Mo4O13] with a one-dimensional chain structure (Zubieta et al., 1993, 1997; Zapf et al., 1998; Xu et al., 1996); two-dimensional structure compounds [4,4'-H2bpy][Mo7O22]·H2O (Zapf et al., 1997a,b) and MO3(py) (M = Mo,W) (Johnson et al., 1981) and a three-dimensional network structure HMo2O6(4,4'-bpy). Herein we report the crystal structure of a molybdenum trioxide–pyrazine complex possessing a three-dimensional framework structure prepared via hydrothermal reaction, i.e. Mo3(pz)0.5.

The title compound, (I), consists of Mo2O6 and pyrazine. Mo2O6 forms a two-dimensional layer structure by sharing O atoms. The two-dimensional layer is linked further into three-dimensional framework through pyrazine bridging ligands. In the title compound, pyrazine came from the heat decarboxylated reaction of the pyrazine-2-carboxylic acid. Every MoVI atom was coordinated by five O atoms and one pyrazine N atom to form an [MoO5N] octahedral geometry. The Mo—O bond lengths range from 1.682 (7) to 2.086 (8) Å and the Mo—N distance is 2.449 (8) Å. The O—Mo—O angles range from 78.4 (4) to 160.1 (2)° and the O—Mo—N angles range from 77.4 (2) to 171.0 (3)°.

Experimental top

A mixture of MoO3 (144 mg), pyrazine-2-carboxylic acid (124 mg) and water (16 ml) was sealed in a 25 ml Teflon-lined stainless-steel reactor, heated to 443 K for 72 h, then naturally cooled to room temperature. Block-shaped black crystals suitable for X-ray analysis were obtained in 70% yield.

Computing details top

Data collection: SMART (Siemens, 1994); cell refinement: SMART; data reduction: SMART; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures top
[Figure 1] Fig. 1. A view of (I) with the atomic numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 2] Fig. 2. Packing diagram of compound (I).
(I) top
Crystal data top
[Mo2)6(C4H4N2)]Dx = 3.113 Mg m3
Mr = 367.98Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, PbcaCell parameters from 2590 reflections
a = 7.566 (16) Åθ = 2.9–25.1°
b = 7.39 (2) ŵ = 3.20 mm1
c = 14.04 (3) ÅT = 293 K
V = 785 (3) Å3Block, black
Z = 40.10 × 0.10 × 0.06 mm
F(000) = 348
Data collection top
Siemens Smart CCD
diffractometer
695 independent reflections
Radiation source: fine-focus sealed tube630 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.027
ω scansθmax = 25.1°, θmin = 2.9°
Absorption correction: empirical (using intensity measurements)
(SADABS; Sheldrick, 1996)
h = 98
Tmin = 0.816, Tmax = 1.000k = 38
3627 measured reflectionsl = 1613
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)] = 0.035Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.086H-atom parameters constrained
S = 1.24 w = 1/[σ2(Fo2) + 18.7425P]
where P = (Fo2 + 2Fc2)/3
695 reflections(Δ/σ)max < 0.001
64 parametersΔρmax = 1.09 e Å3
0 restraintsΔρmin = 1.11 e Å3
Crystal data top
[Mo2)6(C4H4N2)]V = 785 (3) Å3
Mr = 367.98Z = 4
Orthorhombic, PbcaMo Kα radiation
a = 7.566 (16) ŵ = 3.20 mm1
b = 7.39 (2) ÅT = 293 K
c = 14.04 (3) Å0.10 × 0.10 × 0.06 mm
Data collection top
Siemens Smart CCD
diffractometer
695 independent reflections
Absorption correction: empirical (using intensity measurements)
(SADABS; Sheldrick, 1996)
630 reflections with I > 2σ(I)
Tmin = 0.816, Tmax = 1.000Rint = 0.027
3627 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0350 restraints
wR(F2) = 0.086H-atom parameters constrained
S = 1.24 w = 1/[σ2(Fo2) + 18.7425P]
where P = (Fo2 + 2Fc2)/3
695 reflectionsΔρmax = 1.09 e Å3
64 parametersΔρmin = 1.11 e Å3
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
Mo0.53153 (8)0.04406 (8)0.72799 (5)0.0094 (3)
N10.5163 (10)0.0231 (9)0.9018 (5)0.0180 (15)
O10.7602 (9)0.0276 (13)0.7470 (4)0.049 (2)
O20.5002 (13)0.2812 (8)0.7518 (5)0.049 (2)
O30.5142 (7)0.0367 (8)0.6086 (4)0.0177 (13)
C10.6160 (12)0.0961 (11)0.9494 (6)0.0179 (18)
H1A0.69820.16510.91620.021*
C20.3998 (11)0.1193 (11)0.9540 (6)0.0159 (17)
H2A0.32810.20380.92370.019*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Mo0.0079 (4)0.0078 (4)0.0124 (4)0.0002 (3)0.0009 (3)0.0004 (3)
N10.025 (4)0.017 (4)0.012 (3)0.000 (3)0.002 (3)0.002 (3)
O10.006 (3)0.121 (7)0.021 (3)0.003 (4)0.002 (3)0.001 (4)
O20.117 (7)0.007 (3)0.022 (3)0.003 (4)0.002 (4)0.001 (3)
O30.017 (3)0.021 (3)0.015 (3)0.000 (3)0.001 (2)0.001 (2)
C10.023 (5)0.008 (4)0.022 (4)0.003 (3)0.004 (4)0.003 (3)
C20.014 (4)0.013 (4)0.020 (4)0.004 (3)0.001 (3)0.003 (4)
Geometric parameters (Å, º) top
Mo—O31.682 (7)N1—C11.338 (11)
Mo—O11.755 (7)N1—C21.349 (11)
Mo—O21.799 (8)O1—Moiii2.086 (8)
Mo—O2i1.976 (9)O2—Moiv1.976 (9)
Mo—O1ii2.086 (8)C1—C2v1.372 (12)
Mo—N12.449 (8)C2—C1v1.372 (12)
O3—Mo—O1103.1 (3)O1—Mo—N183.7 (3)
O3—Mo—O2101.9 (3)O2—Mo—N182.5 (3)
O1—Mo—O299.7 (5)O2i—Mo—N177.8 (3)
O3—Mo—O2i95.9 (3)O1ii—Mo—N177.4 (2)
O1—Mo—O2i91.7 (4)C1—N1—C2116.3 (7)
O2—Mo—O2i156.01 (9)C1—N1—Mo120.9 (6)
O3—Mo—O1ii95.1 (3)C2—N1—Mo122.6 (5)
O1—Mo—O1ii160.1 (2)Mo—O1—Moiii172.6 (6)
O2—Mo—O1ii84.0 (4)Mo—O2—Moiv177.5 (4)
O2i—Mo—O1ii78.4 (4)N1—C1—C2v121.8 (8)
O3—Mo—N1171.0 (3)N1—C2—C1v121.9 (8)
Symmetry codes: (i) x+1, y1/2, z+3/2; (ii) x1/2, y, z+3/2; (iii) x+1/2, y, z+3/2; (iv) x+1, y+1/2, z+3/2; (v) x+1, y, z+2.

Experimental details

Crystal data
Chemical formula[Mo2)6(C4H4N2)]
Mr367.98
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)293
a, b, c (Å)7.566 (16), 7.39 (2), 14.04 (3)
V3)785 (3)
Z4
Radiation typeMo Kα
µ (mm1)3.20
Crystal size (mm)0.10 × 0.10 × 0.06
Data collection
DiffractometerSiemens Smart CCD
diffractometer
Absorption correctionEmpirical (using intensity measurements)
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.816, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
3627, 695, 630
Rint0.027
(sin θ/λ)max1)0.597
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.035, 0.086, 1.24
No. of reflections695
No. of parameters64
H-atom treatmentH-atom parameters constrained
w = 1/[σ2(Fo2) + 18.7425P]
where P = (Fo2 + 2Fc2)/3
Δρmax, Δρmin (e Å3)1.09, 1.11

Computer programs: SMART (Siemens, 1994), SMART, SHELXTL (Sheldrick, 1997), SHELXTL.

Selected geometric parameters (Å, º) top
Mo—O31.682 (7)Mo—O21.799 (8)
Mo—O11.755 (7)Mo—N12.449 (8)
O3—Mo—O1103.1 (3)O2—Mo—O1ii84.0 (4)
O3—Mo—O2101.9 (3)O2i—Mo—O1ii78.4 (4)
O1—Mo—O299.7 (5)O3—Mo—N1171.0 (3)
O3—Mo—O2i95.9 (3)O1—Mo—N183.7 (3)
O1—Mo—O2i91.7 (4)O2—Mo—N182.5 (3)
O2—Mo—O2i156.01 (9)O2i—Mo—N177.8 (3)
O3—Mo—O1ii95.1 (3)O1ii—Mo—N177.4 (2)
O1—Mo—O1ii160.1 (2)
Symmetry codes: (i) x+1, y1/2, z+3/2; (ii) x1/2, y, z+3/2.
 

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