Tris(2,2′-bipyridine)­cobalt(II) μ6-oxido-dodeca-μ2-oxido-hexa­oxidohexa­molydate(VI)

Ying Liu; Xianxi Zhang; Zechun Xue; Jian Sheng

doi:10.1107/S1600536810020775

. 2010 Jun 5;66(Pt 7):m756–m757. doi: 10.1107/S1600536810020775

Tris(2,2′-bipyridine)cobalt(II) μ₆-oxido-dodeca-μ₂-oxido-hexaoxidohexamolydate(VI)

Ying Liu ^a,^*, Xianxi Zhang ^a, Zechun Xue ^a, Jian Sheng ^a

PMCID: PMC3006945 PMID: 21587692

Abstract

In the title compound, [Co(C₁₀H₈N₂)₃][Mo₆O₁₉], the Co²⁺ cation is surrounded in a distorted octahedral coordination by six N atoms from three 2,2′-bipyridine ligands. The distribution of Mo—O bond lengths in the Lindqvist isopolyanion is consistent with other structures containing the same unit. In the crystal, the cations and anions are linked by C—H⋯O interactions.

Related literature

For general background to polyoxometalates, see: Pope & Müller (1991 ▶). For polyoxometalates modified with amines, see: Zhang, Dou et al. (2009 ▶); Zhang, Wei et al. (2009 ▶). For another structure containing the μ6-oxido-dodecakis-μ2-oxido-hexaoxidohexamolydate(VI) anion see: Dahlstrom et al. (1982 ▶). For Co—N bond lengths in a related structure, see: Li & Xu (2009 ▶).

Experimental

Crystal data

[Co(C₁₀H₈N₂)₃][Mo₆O₁₉]
M _r = 1407.12
Monoclinic,
a = 12.310 (2) Å
b = 18.979 (4) Å
c = 17.150 (4) Å
β = 100.895 (3)°
V = 3934.4 (14) Å³
Z = 4
Mo Kα radiation
μ = 2.35 mm⁻¹
T = 296 K
0.12 × 0.10 × 0.08 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.766, T _max = 0.834
25652 measured reflections
6500 independent reflections
4649 reflections with I > 2σ(I)
R _int = 0.041

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.092
S = 1.00
6500 reflections
559 parameters
H-atom parameters constrained
Δρ_max = 0.65 e Å⁻³
Δρ_min = −0.54 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT-Plus (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: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810020775/hb5476sup1.cif

e-66-0m756-sup1.cif^{(29.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810020775/hb5476Isup2.hkl

e-66-0m756-Isup2.hkl^{(318.1KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected bond lengths (Å).

Co1—N5	2.075 (5)
Co1—N6	2.078 (5)
Co1—N1	2.079 (5)
Co1—N4	2.081 (5)
Co1—N2	2.091 (5)
Co1—N3	2.100 (5)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯O11ⁱ	0.93	2.36	3.166 (9)	145
C4—H4⋯O17ⁱⁱ	0.93	2.52	3.165 (9)	127
C11—H11⋯O4ⁱⁱⁱ	0.93	2.51	3.400 (8)	161
C12—H12⋯O2ⁱⁱⁱ	0.93	2.47	3.277 (10)	145
C20—H20⋯O14^iv	0.93	2.53	3.159 (9)	125
C22—H22⋯O8^v	0.93	2.54	3.230 (9)	132
C26—H26⋯O18	0.93	2.58	3.459 (8)	157

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) .

Acknowledgments

Financial support from the 973 Key Program of the MOST (2006CB932905 and 2007CB81532), the National Natural Science Foundation of China (20501011), the Chinese Academy of Sciences (KJCX2-YW—M02), Shandong Provincial Education Department and Qilu Normal University is gratefully acknowledged.

supplementary crystallographic information

Comment

There has been extensive interest in heteropolyoxometalates, owing to their fascinating properties and great potential applications in many fields such as, catalysis, material science, medicine, and magnetochemistry (Pope et al., 1991). The organic amines, such as 3-(2-pyridyl)pyrazole and pyrazine, are used to effectively modify heteropolyoxomolybdates under hydrothermal condictions (Zhang, Dou et al., 2009; Zhang, Wei, Sun et al., 2009). 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 [Co(C₁₀H₈N₂)₃]²⁺ cation, one typical Lindqvist isopolyanion [Mo₆O₁₉]^2- anion (Dahlstrom et al., 1982). The Co²⁺ cation is surrounded in a distorted octahedral coordination by six N atoms from three chelating 2,2'-bipyridine ligands. The Co—N bond lengths are in the range of 2.075 (5)—2.100 (5) Å, respectively, compared to reported one (Li & Xu, 2009).

The [Mo₆O₁₉]^2- polyoxoanion, possessing well known Lindquist structure, is formed by six MoO₆ octahedra connected with each other through edge-sharing oxygen atoms and thus exhibits approximate Oh symmetry. Three kinds of oxygen atoms exist in the cluster, that is, terminal Oa, double-bridging oxygen Ob, and central oxygen Oc. Therefore, Mo—O band lengths can be grouped into three sets: Mo—Oa 1.669 (5)—1.682 (5) Å; Mo—Ob 1.888 (4)—1.951 (5) Å; and Mo—Oc 2.299 (4)—2.318 (4) Å; these bond distances have a rule of Mo—Oa<Mo—Ob<Mo—Oc. Comparing Mo=O bond distances with that of Lindqvist isopolyanion salt (Dahlstrom, 1982), Mo=O distances have no obvious change.

Experimental

A mixture of 2,2'-bipyridine (0.5 mmoL, 0.07 g), molybdenum(VI) oxide (1 mmol, 0.14 g), oxalic aicd (10 mmol, 0.09), p-carboxyphenylboronic acid (0.3 mmoL, 0.05 g), and cobalt(II) sulfate heptahydrate (0.2 mmol, 0.05 g) in 14 ml distilled water was sealed in a 25 ml Teflon-lined stainless steel autoclave and was kept at 433 K for three days. Upon cooling, red blocks of (I) were obtained. Anal. Calc. for C₃₀H₂₄CoMo₆N₆O₁₉: C, 25.58; H, 1.71; N, 5.97. Found: C, 22.38; H, 1.52; N, 5.78%.