A three-dimensional inorganic/organic hybrid vanadium oxide complex with pentacoordinate Co^II, [CoV₂O₆(4,4'-bipy)]

The title compound, poly[[cobalt(II)-[mu]-(hexaoxodivanadium-O:O')]-[mu]-bipyridine-N:N'], [CoV₂O₆(C₁₀H₈N₂)], has been prepared hydro­thermally and characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction. The structure consists of bimetallic oxide layers, [Co₂V₄O₁₂], linked through 4,4'-bipyridine ligands into a three-dimensional network.

S1. Comment

Considerable attention has been focused on inorganic/organic hybrid materials, owing to their rich structural chemistry (Hagrman et al., 1999) and unique electrochemical and magnetic properties (Leroux et al., 1996; Lira-Cantú & Gómez-Romero, 1998). Of these materials, vanadate/ML_n (M is Co, Ni, Cu, Zn etc; L is an organic ligand) compounds are regarded as V/M-bimetallic oxides coordinated by L, showing one-dimensional, two-dimensional and three-dimensional extended network structures, with different coordination numbers and geometries for M and different shapes for L. Four examples in the vanadate/CoL_n system are known, [{Co(3,3'-bipy)₂}₂V₄O₁₂] (LaDuca et al., 2000), [Co(Hdpa)₂V₄O₁₂] (LaDuca et al., 2001), [{Co(phen)₂}₂V₆O₇]_n (Zhang et al., 2000) and [Co(2,2'-bipy)]₂[V₁₂O₃₂] (Ollivier et al., 1998) (3,3'-bypy is 3,3'-bipyridine, Hdpa is?, phen is 1,10-phenanthroline and 2,2'-bipy is 2,2'-bipyridine. Query.). All the Co^II atoms in these complexes achieve octahedral sixfold coordination with O and N atoms. We report here the crystal structure of the title complex, [Co(4,4'-bipy)V₂O₆], (I), which is the first example of Co^II in a trigonal-bipyramidal pentacoordinate geometry in the vanadate/CoL_n system. \sch

The structure of (I) is composed of bimetallic oxide [Co₂V₄O₁₂] layers of corner-shared V-centred tetrahedra and Co-centred trigonal bipyramids (Figs. 1, 2 and 3). Within the layers are infinite chains of the type –O—Co—O—V—O—V–, which are cross-linked to other similar chains by O bridges, leaving only one terminal O atom (O3 of the V2 tetrahedron). This gives rise to four distinct centrosymmetric rings; two 12-membered [Co₂V₄O₆] rings (Co—V1—V2ⁱⁱⁱ—Coⁱⁱⁱ—V1ⁱⁱⁱ—V2 and Co—V2—V1ⁱⁱ—Coⁱⁱ—V2ⁱ—V1ⁱ) and two eight-membered [V₄O₄] and [Co₂V₂O₄] rings (V2—V1ⁱⁱⁱ—V2ⁱⁱ—V1ⁱⁱ and Co—V1ⁱ—Coⁱ—V1, respectively) [symmetry codes: (i) -x, -1 - y, -2 - z; (ii) x, 1 + y, z; (iii) 1 - x, -1 - y, -2 - z]. The apical positions of the Co trigonal bipyramid are occupied by atoms N1 and N2 from different bipyridyl ligands, which thereby join the polyhedral layers.

In the trigonal bipyramid, the mean axial Co—N bond length (2.139 Å) is significantly longer than the mean basal Co—O distance (1.984 Å). The axial N1—Co—N2 angle is almost linear [179.3 (1)°]. The O—Co—O angles lie between 109.8 (1) and 128.7 (1)°. The O—Co—N bond angles vary between 88.5 (1) and 91.8 (1)°. The V1O₄ tetrahedron corner-shares atoms O1 and O5ⁱ from two CoN₂O₃ polyhedra, and O4 and O6 from two V2O₄ tetrahedra. The V2O₄ tetrahedron is corner-shared with two V1O₄ tetrahedra and only one CoN₂O₃ polyhedron through atom O2 and this leaves one terminal atom, O3.

Similar [V₄O₁₂] rings have also been observed in other vanadate/CoL_n complexes, where every VO₄ group has one terminal O atom. Bimetallic oxide [Co₂V₄O₁₂] layers with a different structure have been observed in [{Co(3,3'-bipy)₂}₂V₄O₁₂] (LaDuca et al., 2000), where the layers are composed of CoN₄O₂ octahedra and [V₄O₁₂] groups, forming large 24-membered [Co₄V₈O₁₂] rings. As shown in Figs. 1 and 3, atoms Co and Co^vi [with a Co—Co^vi separation of 11.38 Å; symmetry code: (vi) x - 1, y, 1 + z] in two adjacent layers of the bimetallic oxide are cross-linked by a 4,4'-bipyridyl ligand to form a three-dimensional network (Fig. 3). The two pyridine rings, N1,C1—C5 and N2^vi,C6^vi—C9^vi,C10, in the 4,4'-bipyridyl ligand are twisted relative to each other by 37.9 (2)° (Fig.1).

Related literature

For related literature, see: Hagrman et al. (1999); LaDuca, Brodkin, Finn & Zubieta (2000); LaDuca, Rarig & Zubieta (2001); Leroux et al. (1996); Lira-Cantú & Gómez-Romero (1998); Ollivier et al. (1998); Zhang et al. (2000).

S2. Experimental

All reagents were of analytical grade and used without further purification. Hydrothermal reaction of CoCl₂ (0.0962 g), NH₄VO₃ (0.0433 g), 4,4'-bipyridine (0.1157 g), (CH₃)₄NOH (0.0338 g) and H₂O (10 ml) in a 20 ml Teflon-lined steel autoclave at 453 K for 72 h gave black plate-shaped crystals of (I) (yield 0.04 g). Found: H 1.92, C 28.75, N 6.67, V 24.82, Co 15.24%; calculated for CoV₂O₆C₁₀N₂H₈: H 1.95, C 29.08, N 6.78, V 24.67, Co 14.27%. The IR spectrum exhibits bands in the range 1000–1610 cm^-1, corresponding to 4,4'-bipyridyl, and other bands in the range 920–500 cm^-1, attributed to V═O or V—O—V stretching. The thermogravimetric analysis shows a weight loss of 44.48% in the range 301–703 K, corresponding to the decomposition of 4,4'-bipyridine.

S3. Refinement

All H atoms in the 4,4'-bipy group were placed in fixed positions with ideal C—H distances (1.07–1.08 Å) and constant U_iso parameters (0.033 Ų).

Computing details

Data collection: PROCESS-AUTO (Rigaku, 1998); cell refinement: PROCESS-AUTO; data reduction: TEXSAN (Molecular Structure Corporation, 1999); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: TEXSAN (Molecular Structure Corporation, 1985); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: TEXSAN (Molecular Structure Corporation, 1999).

Figures

	Fig. 1. The molecular view of (I) with displacement ellipsoids drawn at the 50% probability level. H atoms have been omitted [symmetry codes: (i) -x, -1 - y, -2 - z; (ii) x, 1 + y, z; (iii) 1 - x, -1 - y, -2 - z; (iv) 1 + x, y, z - 1; (v) x, y - 1, z; (vi) x - 1, y, 1 + z].
	Fig. 2. A ball-and-stick model of the [Co2V4O12] layer in (I). Symmetry codes are as in Fig. 1.
	Fig. 3. A perspective view of (I). H atoms have been omitted.

(I)

Crystal data

[Co(C10H8N2)V2O6]	Z = 2
Mr = 412.99	F(000) = 406
Triclinic, P1	Dx = 2.055 Mg m^−3
a = 8.1634 (9) Å	Mo Kα radiation, λ = 0.7107 Å
b = 8.572 (1) Å	Cell parameters from 3503 reflections
c = 10.171 (1) Å	θ = 3.1–27.5°
α = 87.079 (5)°	µ = 2.63 mm^−1
β = 75.833 (4)°	T = 296 K
γ = 75.233 (6)°	Plate, black
V = 667.2 (2) Å^3	0.2 × 0.2 × 0.1 mm

Data collection

Rigaku RAXIS-RAPID imaging-plate diffractometer	2174 reflections with F^2 > 2σ(F^2)
Detector resolution: 10.00 pixels mm^-1	Rint = 0.032
ω scans	θmax = 27.5°
Absorption correction: multi-scan (software?; Higashi, 1995)	h = −10→10
Tmin = 0.597, Tmax = 0.769	k = −11→10
3920 measured reflections	l = −13→13
2961 independent reflections

Refinement

Refinement on F^2	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.044	w = 1/[σ^2(Fo^2) + {0.085[Max(Fo^2,0) + 2Fc^2]/3}^2]
wR(F^2) = 0.174	(Δ/σ)max = 0.002
S = 1.92	Δρmax = 0.93 e Å^−3
2340 reflections	Δρmin = −0.82 e Å^−3
190 parameters

Special details

Refinement. Refinement using reflections with F² > 1.0 σ(F²). The weighted R-factor (wR) and goodness of fit (S) are based on F². R-factor (gt) are based on F. The threshold expression of F² > 2.0 σ(F²) is used only for calculating R-factor (gt).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Co	0.15624 (4)	−0.33906 (5)	−0.94205 (3)	0.0149 (1)
V1	0.23138 (5)	−0.77366 (6)	−0.96987 (4)	0.0161 (1)
V2	0.37325 (5)	−0.09006 (6)	−0.80229 (4)	0.0150 (1)
O1	0.2178 (2)	−0.5793 (3)	−0.9527 (2)	0.0230 (5)
O2	0.2707 (2)	−0.1978 (3)	−0.8703 (2)	0.0219 (5)
O3	0.3483 (3)	−0.1289 (3)	−0.6422 (2)	0.0261 (5)
O4	0.2811 (2)	−0.8774 (3)	−0.8225 (2)	0.0219 (5)
O5	−0.0414 (2)	−0.2058 (3)	−1.0122 (2)	0.0241 (5)
O6	0.3953 (2)	−0.8565 (3)	−1.1148 (2)	0.0227 (5)
N1	−0.0205 (3)	−0.3466 (3)	−0.7485 (2)	0.0220 (6)
N2	0.3334 (3)	−0.3351 (3)	−1.1342 (2)	0.0170 (5)
C1	−0.0876 (4)	−0.4734 (4)	−0.7077 (3)	0.0285 (8)
C2	−0.2165 (4)	−0.4741 (4)	−0.5889 (3)	0.0244 (7)
C3	−0.2807 (3)	−0.3344 (4)	−0.5066 (3)	0.0206 (7)
C4	−0.2121 (4)	−0.2035 (4)	−0.5482 (3)	0.0254 (7)
C5	−0.0828 (4)	−0.2136 (4)	−0.6687 (3)	0.0231 (7)
C6	0.3272 (4)	−0.2039 (4)	−1.2104 (3)	0.0230 (7)
C7	0.4490 (4)	−0.1956 (4)	−1.3333 (3)	0.0238 (7)
C8	0.4621 (3)	−0.4661 (4)	−1.1791 (3)	0.0209 (7)
C9	0.5889 (3)	−0.4702 (4)	−1.3004 (3)	0.0235 (7)
C10	−0.4169 (3)	−0.3331 (4)	−0.3789 (3)	0.0198 (7)
H1	−0.2629	−0.5802	−0.5582	0.0330*
H2	−0.2516	−0.1051	−0.4763	0.0330*
H3	−0.0239	−0.1138	−0.6984	0.0330*
H4	−0.0547	−0.5725	−0.7778	0.0330*
H5	0.4602	−0.5693	−1.1143	0.0330*
H6	0.6811	−0.5872	−1.3214	0.0330*
H7	0.4386	−0.0808	−1.3831	0.0330*
H8	0.2379	−0.0889	−1.1787	0.0330*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co	0.0141 (2)	0.0166 (3)	0.0124 (2)	−0.0029 (2)	−0.0006 (2)	−0.0019 (2)
V1	0.0128 (2)	0.0169 (3)	0.0162 (2)	−0.0014 (2)	−0.0008 (2)	−0.0009 (2)
V2	0.0148 (2)	0.0174 (3)	0.0114 (2)	−0.0019 (2)	−0.0020 (2)	−0.0023 (2)
O1	0.0258 (9)	0.0143 (8)	0.023 (1)	−0.0009 (8)	0.0014 (8)	−0.0019 (9)
O2	0.0197 (10)	0.025 (1)	0.024 (1)	−0.0109 (8)	−0.0035 (8)	−0.0053 (9)
O3	0.039 (1)	0.023 (1)	0.0127 (8)	−0.0044 (9)	−0.0040 (8)	0.0018 (9)
O4	0.0249 (10)	0.017 (1)	0.0222 (9)	0.0016 (8)	−0.0097 (8)	−0.0005 (8)
O5	0.0164 (9)	0.030 (1)	0.023 (1)	−0.0017 (8)	−0.0035 (7)	0.0026 (9)
O6	0.0172 (8)	0.024 (1)	0.0241 (10)	−0.0036 (8)	−0.0005 (7)	−0.0078 (9)
N1	0.0178 (10)	0.032 (1)	0.0139 (10)	−0.0067 (9)	0.0023 (7)	−0.0068 (10)
N2	0.0144 (9)	0.020 (1)	0.0157 (10)	−0.0087 (8)	0.0038 (7)	−0.0019 (8)
C1	0.027 (1)	0.031 (2)	0.024 (1)	−0.013 (1)	0.010 (1)	−0.014 (1)
C2	0.032 (1)	0.019 (2)	0.021 (1)	−0.014 (1)	0.0043 (10)	0.001 (1)
C3	0.017 (1)	0.030 (2)	0.012 (1)	−0.006 (1)	0.0017 (9)	−0.002 (1)
C4	0.022 (1)	0.026 (2)	0.024 (1)	−0.007 (1)	0.0046 (9)	−0.006 (1)
C5	0.028 (1)	0.011 (1)	0.024 (1)	−0.006 (1)	0.0051 (10)	0.001 (1)
C6	0.024 (1)	0.019 (1)	0.021 (1)	0.001 (1)	−0.0024 (9)	−0.0037 (10)
C7	0.027 (1)	0.021 (2)	0.021 (1)	−0.005 (1)	−0.0017 (10)	−0.001 (1)
C8	0.018 (1)	0.022 (2)	0.018 (1)	−0.0050 (10)	0.0048 (9)	0.004 (1)
C9	0.014 (1)	0.032 (2)	0.020 (1)	−0.005 (1)	0.0041 (9)	0.000 (1)
C10	0.015 (1)	0.030 (2)	0.013 (1)	−0.005 (1)	−0.0001 (8)	−0.007 (1)

Geometric parameters (Å, º)

Co—O1	1.994 (3)	C1—C2	1.396 (5)
Co—O2	1.968 (3)	C1—H4	1.074
Co—O5	1.990 (3)	C2—C3	1.406 (6)
Co—N1	2.145 (3)	C2—H1	1.075
Co—N2	2.132 (3)	C3—C4	1.382 (6)
V1—O1	1.657 (3)	C3—C10	1.487 (5)
V1—O4	1.783 (3)	C4—C5	1.398 (5)
V1—O5^i	1.658 (3)	C4—H2	1.076
V1—O6	1.768 (3)	C5—H3	1.080
V2—O2	1.666 (3)	C6—C7	1.405 (6)
V2—O3	1.619 (3)	C6—H8	1.076
V2—O4^ii	1.809 (3)	C7—C10^iv	1.398 (5)
V2—O6^iii	1.819 (3)	C7—H7	1.077
N1—C1	1.342 (6)	C8—C9	1.398 (5)
N1—C5	1.347 (5)	C8—H5	1.077
N2—C6	1.330 (6)	C9—C10^iv	1.384 (6)
N2—C8	1.338 (5)	C9—H6	1.084
O1—Co—O2	128.8 (1)	C6—N2—C8	117.5 (3)
O1—Co—O5	121.4 (1)	N1—C1—C2	123.8 (4)
O1—Co—N1	89.8 (1)	N1—C1—H4	117.6
O1—Co—N2	89.5 (1)	C2—C1—H4	117.9
O2—Co—O5	109.8 (1)	C1—C2—C3	118.6 (4)
O2—Co—N1	91.9 (1)	C1—C2—H1	121.2
O2—Co—N2	88.5 (1)	C3—C2—H1	120.2
O5—Co—N1	89.4 (1)	C2—C3—C4	117.9 (4)
O5—Co—N2	91.2 (1)	C2—C3—C10	119.4 (4)
N1—Co—N2	179.2 (1)	C4—C3—C10	122.7 (4)
O1—V1—O4	109.2 (1)	C3—C4—C5	119.7 (4)
O1—V1—O5^i	108.8 (1)	C3—C4—H2	115.6
O1—V1—O6	110.7 (1)	C5—C4—H2	124.2
O4—V1—O5^i	109.9 (1)	N1—C5—C4	123.0 (4)
O4—V1—O6	109.5 (1)	N1—C5—H3	117.2
O5^i—V1—O6	108.7 (1)	C4—C5—H3	119.7
O2—V2—O3	109.3 (2)	N2—C6—C7	123.7 (4)
O2—V2—O4^ii	109.6 (1)	N2—C6—H8	123.3
O2—V2—O6^iii	109.5 (1)	C7—C6—H8	112.6
O3—V2—O4^ii	109.0 (1)	C6—C7—C10^iv	118.3 (4)
O3—V2—O6^iii	109.3 (1)	C6—C7—H7	117.8
O4^ii—V2—O6^iii	110.1 (1)	C10^iv—C7—H7	123.8
Co—O1—V1	168.6 (2)	N2—C8—C9	123.2 (4)
Co—O2—V2	175.6 (2)	N2—C8—H5	114.5
V1—O4—V2^v	128.9 (2)	C9—C8—H5	122.3
Co—O5—V1^i	136.5 (2)	C8—C9—C10^iv	119.2 (4)
V1—O6—V2^iii	147.3 (2)	C8—C9—H6	112.9
Co—N1—C1	122.9 (3)	C10^iv—C9—H6	127.9
Co—N1—C5	119.6 (3)	C3—C10—C7^vi	122.0 (4)
C1—N1—C5	117.1 (3)	C3—C10—C9^vi	119.8 (4)
Co—N2—C6	122.7 (3)	C7^vi—C10—C9^vi	118.2 (4)
Co—N2—C8	119.8 (3)

Symmetry codes: (i) −x, −y−1, −z−2; (ii) x, y+1, z; (iii) −x+1, −y−1, −z−2; (iv) x+1, y, z−1; (v) x, y−1, z; (vi) x−1, y, z+1.