catena-Poly[[(2,2′-bipyridyl)­oxido­vanadium]-di-μ₂-oxido-[(2,2′-bipyridyl)­oxido­vanadium]-μ₃-selenito-bis­[(2,2′-bipyridyl)­dioxido­vanadium]-μ₃-selenito]

In the title compound, [V₄O₈(SeO₃)₂(C₁₀H₈N₂)₄], there are two distinct vanadium coordination environments. Alternating corner-shared VO₄N₂ octa­hedra and SeO₃ pyramids result in eight-membered centrosymmetric V₂Se₂O₄ rings. In addition, pairs of V centres form centrosymmetric V₂O₆N₄ clusters via edge-sharing. These two kinds of secondary building units are linked in an ABABAB fashion to give an infinite chain whose nature is unprecedented in Se–V–O systems.

S1. Comment

A number of vanadates and vanadium phosphates have been explored extensively as a result of their catalytic properties in organic oxidations and their intercalation properties (Centi, 1993; Cheetham et al., 1999; Chirayil et al., 1997; Ouellette et al., 2006; Sananes et al., 1995; Shan et al., 1999; Shi et al., 2000). In contrast, the known chemistry of vanadium selenites is very limited (Harrison et al., 1995; Halasyamini & O'Hare, 1997; Kim et al., 2001; Kim, Kwon & Lee, 1996; Kim, Lee et al., 1996; Kwon et al., 1996; Lee & Kwon, 1996; Lee et al., 1995; Vaughey et al., 1994). Recently, many planned attempts have been made to modify structurally and to design hybrid vanadium selenites through the introduction of organic species as templates, charge-compensating cations or space-filling agents (Choudhury et al., 2002; Dai, Chen et al., 2003; Dai et al., 2004, 2005; Dai, Shi, Li, Chen et al., 2003; Dai, Shi, Li, Zhang et al., 2003; De et al., 2003; Harrison et al., 2000; Pasha et al., 2003; Shi et al., 2002). This strategy appears to afford primitive control over the dimensionality of the solid through manipulation of the steric requirements and denticity of the ligand, and enjoys considerable success. In our previous work, we have successfully obtained a novel vanadyl selenite templated by an organic salt, [(VO)(H₂O)₂(SeO₃)]₂[(H₂piperazidine)SO₄] (Lian et al., 2004). As an extension of our work, we report here the synthesis and crystal structure of the title compound, (I), which exhibits an infinite chain motif whose nature is unprecedented in Se–V–O–L systems, where L is an organic ligand.

In the asymmetric unit of (I), there are two crystallographically independent V atoms and one distinct Se atom (Fig. 1). Each V centre has a distorted octahedral coordination environment defined by four O atoms and two cis-positioned N donors of the 2,2'-bipyridine ligand. Within the V[O₄N₂] environment of atom V1, atoms O1 and O2 occur as terminal V═O. The remaining O atoms are from two centrosymmetrically related SeO₃ groups, thus forming two V—O—Se linkages with one short and one long V—O bond (Table 1). In the case of atom V2, two centrosymmetrically related V2 atoms are asymmetrically bridged via two symmetry-related µ₂-O6 atoms to form a dimeric [V₂O₆N₄] unit, similar to that in (1,10-phenanthroline)₂V₂SeO₇ and [VO₂(2,2'-bipy)]₂(tp) (tp is terephthalate) (Dai, Shi, Li, Zhang et al., 2003; Yuan et al., 2003). Atom O7 is coordinated to atom V2 as terminal V═O. One O-atom donor from an SeO₃ group is coordinated to atom V2 to make a V—O—Se linkage.

The V—N bond lengths are in the range 2.142 (2)–2.289 (2) Å (Table 1), which is similar to those observed in similar compounds documented elsewhere (Dai, Shi, Li, Zhang et al., 2003., Yuan et al., 2003). The V—O bond lengths vary from 1.6084 (2) to 2.3511 (2) Å and are grouped into four types. The shortest bond lengths are around 1.62 Å and correspond to terminal V═ O. In the V—O—V linkages, the bridging O atoms are conected to two symmetry-related V atoms, with one short V—O bond corresponding with one long V—O bond. In the case of the V—O—Se linkages, similar patterns are observed, and longer V—O bonds correspond with shorter Se—O bonds. Given that the longest bridging V—O bond [V1—O4ⁱ; symmetry code: (i) 1 − x, 1 − y, 1 − z] is trans to a terminal V═l O bond, it is hypothesized that the trans effect plays an appreciable role in governing the V—O bond lengths in compound (I).

The [VO₄N₂] geometry for atom V1 is similar to those in (2,2'-bipyridine)VSeO₄ and [(VO)(H₂O)₂(SeO₃)]₂[(H₂piperazidine)SO₄] (Dai, Shi, Li, Zhang et al., 2003; Lian et al., 2004). In these two compounds, there are one V═O bond and three V—O bonds forming three V—O—Se linkages. The Se atom in (I) is tricoordinated by O atoms and exhibits pseudo-tetrahedral geometry, with the lone pair of electrons occupying the apical site. All of the O atoms around atom Se1 form Se—O—V linkages, with an average Se—O bond length of 1.704 (3) Å and an average O—Se—O bond angle 100.6 (2)°. Bond-valence sum calculations (Brown & Altermatt, 1985; Brown & Shannon, 1973; Brese & O'Keeffe, 1991) give values of 4.7, 4.8 and 4.2 for atoms V1, V2 and Se1, respectively, showing that the V1 and V2 sites are in the +5 oxidation state and the Se site is in the +4 oxidation state. In [(VO)(H₂O)₂(SeO₃)]₂[(H₂piperazidine)SO₄], the V centres are in the +4 oxidation state.

The coordination patterns described above result in the structure of the title compound consisting of infinite chains constructed from SeO₃ pyramids, V[O₄N₂] octahedra and [V₂O₆N₄] clusters (Fig. 2). Two of the O atoms from the SeO₃ pyramids are corner-shared by two symmetrically equivalent V1[O₄N₂] octahedra to form cyclic centrosymmetric eight-membered [V₂Se₂O₄] rings. Such rings can often be connected into an infinite chain via edge-shared or corner-shared bridges. The former type is well documented elsewhere (Pasha et al., 2003; Dai, Shi, Li, Zhang et al., 2003; Dai, Shi, Li, Chen et al., 2003; Dai et al., 2005), while the latter is only exemplified by K(VO)(SeO₃)₂H (Kim, Lee et al., 1996). These chains can be further developed into one-, two- and three-dimensional structures, similar to those in open-framework metal phosphates. In (I), the exocyclic non-terminal O atoms on each side of the [V₂O₆N₄] clusters are bonded to Se atoms. This connection results in the secondary units of [V₂Se₂O₁₀N₄] and [V₂O₆N₄] being linked in an ABABAB fashion into infinite chains. Here, the [V₄Se₂O₁₅N₈] unit can be viewed as the principal building block of the chain. To our knowledge, this type of chain has not previously been reported in Se–V–O systems.

In the case of the complex-linked vanadates, vanadium–oxygen polyhedra are assembled via corner-sharing or edge-sharing into building blocks. The metal complexes link these building blocks to result in zero-, one-, two- and three-dimensional frameworks (Debord et al., 1996; Zhang et al., 1997; Hagrman & Zubieta, 2001; Hui et al., 2004), where metal complex fragments act either as a bridge between the vanadium–oxygen polyhedra or as a capping motif. In comparison with these compounds, the overall structure of (I) may be best depicted as `isolated' V[O₄N₂] octahedra and [V₂O₆N₄] clusters bridged by SeO₃ in the µ₃ mode to form infinite chains.

In the packing arrangement of (I), the 2,2'-bipyridine ligands are arranged in a wave-like fashion. C20—H···π interactions with a C20···π distance of 3.59 Å occur within the infinite chains, while the chains are cross-linked by aromatic interactions between adjacent 2,2'-bipyridine rings with an interplanar spacing of 3.31 Å, and by C8—H···π interactions with a C8···π distance of 3.66 Å (Fig. 3).

S2. Experimental

A mixture of V₂O₅ (0.036 g, 0.2 mmol), SeO₂ (0.060 g, 0.4 mmol), 2,2'-bipyridine (0.032 g 0.2 mmol) and H₂O (5 ml) was stirred for about 30 min, and then sealed in a Teflon-lined stainless steel autoclave and heated to 393 K for 4 d. The container was cooled to ambient temperature spontaneously. An essentially quantitative yield (about 75%, based on V) of red block-shaped single crystals of (I) was recovered by vacuum filtration and drying in air.

S3. Refinement

All H atoms were positioned geometrically, with C—H = 0.93 Å, and refined using a riding model, with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: RAPID-AUTO (Rigaku, 2001); cell refinement: RAPID-AUTO (Rigaku, 2001); data reduction: TEXSAN (Molecular Structure Corporation, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL (Bruker, 1997).

Figures

	Fig. 1. The structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms have been omitted for clarity. [Symmetry codes: (A) −x, −y + 1, −z + 2; (B) −x + 1, −y + 1, −z + 1.]
	Fig. 2. The chain structure of (I), viewed down [101].
	Fig. 3. A view of the packing of the chains in (I) in the ac plane.

catena-Poly[[(2,2'-bipyridyl)oxidovanadium]-di-µ₂-oxido-[(2,2'- bipyridyl)oxidovanadium]-µ₃-selenito-bis[(2,2'-bipyridyl)dioxidovanadium]- µ₃-selenito]

Crystal data

[V4O8(SeO3)2(C10H8N2)4]	Z = 2
Mr = 605.21	F(000) = 600
Triclinic, P1	Dx = 1.957 Mg m^−3
a = 9.816 (2) Å	Mo Kα radiation, λ = 0.71069 Å
b = 10.026 (3) Å	Cell parameters from 3588 reflections
c = 11.090 (2) Å	θ = 12–18°
α = 87.53 (3)°	µ = 2.74 mm^−1
β = 75.49 (2)°	T = 298 K
γ = 76.41 (3)°	Block, red
V = 1027.0 (4) Å^3	0.46 × 0.43 × 0.39 mm

Data collection

Rigaku R-AXIS RAPID diffractometer	3588 independent reflections
Radiation source: rotor target	3458 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.040
RAXISCS3 scanner	θmax = 25.0°, θmin = 1.9°
Absorption correction: multi-scan (TEXSAN; Molecular Structure Corporation, 2001)	h = −11→11
Tmin = 0.302, Tmax = 0.361	k = −11→0
3588 measured reflections	l = −13→13

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.026	H-atom parameters constrained
wR(F^2) = 0.087	w = 1/[σ^2(Fo^2) + (0.0666P)^2 + 0.4497P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max = 0.001
3588 reflections	Δρmax = 0.89 e Å^−3
308 parameters	Δρmin = −0.57 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.064 (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 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 (Ų)

	x	y	z	Uiso*/Ueq
Se1	0.34836 (2)	0.48783 (2)	0.639577 (19)	0.01603 (13)
V1	0.59671 (4)	0.22075 (4)	0.52822 (4)	0.01738 (14)
V2	0.12052 (4)	0.52532 (4)	0.91059 (3)	0.01637 (14)
O1	0.6138 (2)	0.11717 (18)	0.64349 (17)	0.0288 (4)
O2	0.45288 (18)	0.20010 (18)	0.49037 (16)	0.0260 (4)
O3	0.52610 (17)	0.39875 (17)	0.61313 (15)	0.0201 (3)
O4	0.36319 (18)	0.64661 (16)	0.65168 (15)	0.0219 (4)
O5	0.29475 (17)	0.43883 (17)	0.79379 (15)	0.0219 (4)
O6	0.01439 (17)	0.40655 (16)	0.92701 (15)	0.0197 (3)
O7	0.06057 (18)	0.64205 (19)	0.82039 (16)	0.0265 (4)
N1	0.8212 (2)	0.2563 (2)	0.5106 (2)	0.0216 (4)
N2	0.7443 (2)	0.0766 (2)	0.39155 (18)	0.0209 (4)
N3	0.2467 (2)	0.3988 (2)	1.04116 (18)	0.0197 (4)
N4	0.2426 (2)	0.6546 (2)	0.97566 (18)	0.0197 (4)
C1	0.8514 (3)	0.3473 (3)	0.5790 (3)	0.0279 (5)
H1	0.7750	0.4078	0.6313	0.033*
C2	0.9910 (3)	0.3552 (3)	0.5751 (3)	0.0349 (7)
H2	1.0083	0.4205	0.6230	0.042*
C3	1.1040 (3)	0.2645 (3)	0.4990 (3)	0.0378 (7)
H3	1.1991	0.2670	0.4953	0.045*
C4	1.0746 (3)	0.1695 (3)	0.4281 (3)	0.0327 (6)
H4	1.1497	0.1069	0.3767	0.039*
C5	0.9314 (3)	0.1688 (2)	0.4347 (2)	0.0226 (5)
C6	0.8878 (3)	0.0716 (2)	0.3638 (2)	0.0225 (5)
C7	0.9847 (3)	−0.0211 (3)	0.2757 (3)	0.0359 (7)
H7	1.0826	−0.0216	0.2553	0.043*
C8	0.9346 (4)	−0.1130 (3)	0.2183 (3)	0.0403 (7)
H8	0.9985	−0.1762	0.1594	0.048*
C9	0.7897 (3)	−0.1097 (3)	0.2494 (3)	0.0346 (6)
H9	0.7543	−0.1719	0.2131	0.042*
C10	0.6965 (3)	−0.0125 (2)	0.3355 (2)	0.0260 (5)
H10	0.5979	−0.0091	0.3550	0.031*
C11	0.2456 (3)	0.2680 (3)	1.0684 (2)	0.0248 (5)
H11	0.1960	0.2233	1.0283	0.030*
C12	0.3147 (3)	0.1965 (3)	1.1531 (3)	0.0310 (6)
H12	0.3124	0.1052	1.1693	0.037*
C13	0.3876 (3)	0.2626 (3)	1.2139 (3)	0.0323 (6)
H13	0.4339	0.2170	1.2727	0.039*
C14	0.3906 (3)	0.3976 (3)	1.1859 (2)	0.0280 (6)
H14	0.4401	0.4440	1.2246	0.034*
C15	0.3186 (2)	0.4630 (2)	1.0992 (2)	0.0204 (5)
C16	0.3146 (2)	0.6075 (2)	1.0632 (2)	0.0207 (5)
C17	0.3818 (3)	0.6896 (3)	1.1156 (2)	0.0269 (5)
H17	0.4318	0.6549	1.1754	0.032*
C18	0.3728 (3)	0.8238 (3)	1.0769 (3)	0.0315 (6)
H18	0.4154	0.8811	1.1115	0.038*
C19	0.2998 (3)	0.8718 (3)	0.9864 (3)	0.0325 (6)
H19	0.2931	0.9615	0.9588	0.039*
C20	0.2369 (3)	0.7840 (3)	0.9376 (2)	0.0265 (5)
H20	0.1888	0.8160	0.8760	0.032*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Se1	0.01344 (17)	0.01957 (17)	0.01359 (17)	−0.00168 (10)	−0.00234 (10)	−0.00132 (10)
V1	0.0143 (2)	0.0189 (2)	0.0170 (2)	−0.00199 (16)	−0.00152 (16)	−0.00260 (16)
V2	0.0131 (2)	0.0216 (2)	0.0134 (2)	−0.00353 (16)	−0.00177 (16)	−0.00085 (15)
O1	0.0320 (10)	0.0280 (9)	0.0238 (10)	−0.0033 (8)	−0.0061 (8)	0.0015 (7)
O2	0.0203 (9)	0.0328 (10)	0.0260 (9)	−0.0081 (7)	−0.0058 (7)	0.0001 (7)
O3	0.0147 (8)	0.0231 (8)	0.0186 (8)	0.0013 (6)	−0.0013 (6)	−0.0052 (6)
O4	0.0243 (9)	0.0193 (8)	0.0190 (8)	−0.0031 (7)	−0.0013 (7)	−0.0004 (6)
O5	0.0198 (8)	0.0247 (8)	0.0158 (8)	−0.0019 (7)	0.0022 (6)	0.0011 (6)
O6	0.0173 (8)	0.0234 (8)	0.0177 (8)	−0.0057 (6)	−0.0011 (6)	−0.0055 (6)
O7	0.0207 (9)	0.0352 (10)	0.0211 (9)	−0.0034 (7)	−0.0046 (7)	0.0065 (7)
N1	0.0176 (10)	0.0225 (10)	0.0231 (11)	−0.0004 (8)	−0.0059 (8)	0.0002 (8)
N2	0.0242 (10)	0.0189 (9)	0.0169 (10)	−0.0021 (8)	−0.0029 (8)	0.0004 (7)
N3	0.0157 (9)	0.0242 (10)	0.0173 (10)	−0.0027 (8)	−0.0025 (8)	−0.0007 (8)
N4	0.0156 (9)	0.0251 (10)	0.0163 (10)	−0.0028 (8)	−0.0017 (8)	−0.0021 (8)
C1	0.0269 (13)	0.0280 (13)	0.0305 (14)	−0.0055 (10)	−0.0107 (11)	−0.0022 (10)
C2	0.0335 (15)	0.0371 (16)	0.0417 (17)	−0.0147 (13)	−0.0180 (13)	0.0051 (13)
C3	0.0239 (14)	0.0485 (17)	0.0455 (18)	−0.0135 (13)	−0.0145 (13)	0.0146 (14)
C4	0.0177 (12)	0.0398 (15)	0.0343 (16)	−0.0015 (11)	−0.0007 (11)	0.0064 (12)
C5	0.0199 (12)	0.0241 (12)	0.0206 (12)	−0.0016 (9)	−0.0032 (10)	0.0044 (9)
C6	0.0209 (12)	0.0206 (11)	0.0201 (12)	0.0010 (9)	−0.0001 (10)	0.0020 (9)
C7	0.0324 (15)	0.0308 (14)	0.0334 (16)	0.0004 (12)	0.0058 (12)	−0.0043 (12)
C8	0.0506 (18)	0.0287 (14)	0.0287 (15)	0.0019 (13)	0.0049 (13)	−0.0088 (11)
C9	0.0542 (18)	0.0248 (13)	0.0230 (14)	−0.0075 (12)	−0.0069 (13)	−0.0040 (10)
C10	0.0340 (14)	0.0216 (12)	0.0225 (12)	−0.0054 (10)	−0.0082 (10)	0.0000 (9)
C11	0.0234 (12)	0.0256 (12)	0.0233 (13)	−0.0039 (10)	−0.0026 (10)	−0.0034 (10)
C12	0.0319 (14)	0.0258 (13)	0.0285 (14)	0.0004 (11)	−0.0023 (11)	0.0039 (10)
C13	0.0358 (15)	0.0329 (14)	0.0229 (13)	0.0054 (12)	−0.0104 (11)	0.0029 (11)
C14	0.0271 (13)	0.0333 (14)	0.0232 (13)	−0.0010 (11)	−0.0106 (10)	−0.0040 (11)
C15	0.0170 (11)	0.0252 (12)	0.0168 (11)	−0.0020 (9)	−0.0018 (9)	−0.0040 (9)
C16	0.0168 (11)	0.0247 (12)	0.0185 (12)	−0.0027 (9)	−0.0020 (9)	−0.0031 (9)
C17	0.0282 (13)	0.0329 (14)	0.0216 (13)	−0.0065 (11)	−0.0099 (11)	−0.0035 (10)
C18	0.0359 (15)	0.0310 (14)	0.0300 (15)	−0.0128 (12)	−0.0064 (12)	−0.0072 (11)
C19	0.0389 (15)	0.0243 (13)	0.0338 (15)	−0.0086 (11)	−0.0062 (12)	−0.0020 (11)
C20	0.0277 (13)	0.0268 (13)	0.0235 (13)	−0.0045 (10)	−0.0055 (10)	0.0021 (10)

Geometric parameters (Å, º)

Se1—O4	1.6464 (16)	C3—C4	1.384 (4)
Se1—O3	1.7210 (17)	C3—H3	0.9300
Se1—O5	1.7439 (17)	C4—C5	1.391 (4)
V1—O1	1.6285 (19)	C4—H4	0.9300
V1—O2	1.6292 (17)	C5—C6	1.477 (4)
V1—O3	1.9466 (18)	C6—C7	1.386 (4)
V1—N2	2.142 (2)	C7—C8	1.384 (4)
V1—N1	2.274 (2)	C7—H7	0.9300
V1—O4^i	2.3511 (18)	C8—C9	1.370 (5)
V2—O7	1.6084 (18)	C8—H8	0.9300
V2—O6	1.7337 (16)	C9—C10	1.387 (4)
V2—O5	1.9093 (18)	C9—H9	0.9300
V2—O6^ii	1.9876 (18)	C10—H10	0.9300
V2—N4	2.210 (2)	C11—C12	1.374 (4)
V2—N3	2.289 (2)	C11—H11	0.9300
V2—V2^ii	2.8135 (12)	C12—C13	1.382 (4)
O4—V1^i	2.3511 (18)	C12—H12	0.9300
O6—V2^ii	1.9876 (18)	C13—C14	1.381 (4)
N1—C1	1.339 (3)	C13—H13	0.9300
N1—C5	1.345 (3)	C14—C15	1.386 (4)
N2—C10	1.341 (3)	C14—H14	0.9300
N2—C6	1.354 (3)	C15—C16	1.481 (3)
N3—C11	1.334 (3)	C16—C17	1.392 (3)
N3—C15	1.344 (3)	C17—C18	1.384 (4)
N4—C20	1.339 (3)	C17—H17	0.9300
N4—C16	1.346 (3)	C18—C19	1.382 (4)
C1—C2	1.382 (4)	C18—H18	0.9300
C1—H1	0.9300	C19—C20	1.383 (4)
C2—C3	1.376 (5)	C19—H19	0.9300
C2—H2	0.9300	C20—H20	0.9300
O4—Se1—O3	101.45 (8)	C3—C2—C1	118.5 (3)
O4—Se1—O5	103.77 (9)	C3—C2—H2	120.7
O3—Se1—O5	96.61 (8)	C1—C2—H2	120.7
O1—V1—O2	104.96 (10)	C2—C3—C4	119.3 (3)
O1—V1—O3	101.88 (8)	C2—C3—H3	120.3
O2—V1—O3	101.74 (8)	C4—C3—H3	120.3
O1—V1—N2	93.55 (9)	C3—C4—C5	119.2 (3)
O2—V1—N2	94.56 (9)	C3—C4—H4	120.4
O3—V1—N2	153.69 (8)	C5—C4—H4	120.4
O1—V1—N1	90.74 (9)	N1—C5—C4	121.3 (2)
O2—V1—N1	160.71 (9)	N1—C5—C6	114.9 (2)
O3—V1—N1	85.54 (8)	C4—C5—C6	123.7 (2)
N2—V1—N1	72.96 (8)	N2—C6—C7	120.9 (2)
O1—V1—O4^i	165.34 (8)	N2—C6—C5	115.4 (2)
O2—V1—O4^i	86.95 (8)	C7—C6—C5	123.6 (2)
O3—V1—O4^i	83.60 (7)	C8—C7—C6	119.5 (3)
N2—V1—O4^i	76.74 (7)	C8—C7—H7	120.2
N1—V1—O4^i	76.03 (7)	C6—C7—H7	120.2
O7—V2—O6	106.45 (9)	C9—C8—C7	119.2 (3)
O7—V2—O5	97.50 (9)	C9—C8—H8	120.4
O6—V2—O5	103.55 (8)	C7—C8—H8	120.4
O7—V2—O6^ii	99.98 (9)	C8—C9—C10	119.2 (3)
O6—V2—O6^ii	81.99 (8)	C8—C9—H9	120.4
O5—V2—O6^ii	159.32 (7)	C10—C9—H9	120.4
O7—V2—N4	93.00 (9)	N2—C10—C9	122.0 (3)
O6—V2—N4	155.09 (8)	N2—C10—H10	119.0
O5—V2—N4	88.80 (8)	C9—C10—H10	119.0
O6^ii—V2—N4	79.37 (7)	N3—C11—C12	122.9 (2)
O7—V2—N3	164.14 (8)	N3—C11—H11	118.5
O6—V2—N3	89.38 (8)	C12—C11—H11	118.5
O5—V2—N3	79.25 (7)	C11—C12—C13	118.9 (3)
O6^ii—V2—N3	80.93 (7)	C11—C12—H12	120.6
N4—V2—N3	71.51 (7)	C13—C12—H12	120.6
O7—V2—V2^ii	107.27 (7)	C14—C13—C12	118.8 (2)
O6—V2—V2^ii	44.39 (6)	C14—C13—H13	120.6
O5—V2—V2^ii	143.64 (6)	C12—C13—H13	120.6
O6^ii—V2—V2^ii	37.60 (5)	C13—C14—C15	119.0 (2)
N4—V2—V2^ii	115.38 (6)	C13—C14—H14	120.5
N3—V2—V2^ii	83.22 (6)	C15—C14—H14	120.5
Se1—O3—V1	122.48 (9)	N3—C15—C14	122.0 (2)
Se1—O4—V1^i	119.57 (9)	N3—C15—C16	114.8 (2)
Se1—O5—V2	125.06 (10)	C14—C15—C16	123.2 (2)
V2—O6—V2^ii	98.01 (8)	N4—C16—C17	121.9 (2)
C1—N1—C5	118.8 (2)	N4—C16—C15	115.8 (2)
C1—N1—V1	124.72 (17)	C17—C16—C15	122.3 (2)
C5—N1—V1	116.13 (16)	C18—C17—C16	118.7 (2)
C10—N2—C6	119.2 (2)	C18—C17—H17	120.6
C10—N2—V1	120.53 (17)	C16—C17—H17	120.6
C6—N2—V1	120.24 (16)	C19—C18—C17	119.3 (2)
C11—N3—C15	118.3 (2)	C19—C18—H18	120.3
C11—N3—V2	123.87 (16)	C17—C18—H18	120.3
C15—N3—V2	117.67 (16)	C18—C19—C20	118.8 (2)
C20—N4—C16	118.7 (2)	C18—C19—H19	120.6
C20—N4—V2	121.31 (16)	C20—C19—H19	120.6
C16—N4—V2	119.75 (16)	N4—C20—C19	122.6 (2)
N1—C1—C2	122.8 (3)	N4—C20—H20	118.7
N1—C1—H1	118.6	C19—C20—H20	118.7
C2—C1—H1	118.6

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