Synthesis and crystal structure of 2-amino-3-hy­droxy­pyridinium dioxido(pyridine-2,6-di­carboxyl­ato-[kappa]³O²,N,O⁶)vanadate(V) and its conversion to nanostructured V₂O₅

2-Amino-3-hy­droxy­pyridinium dioxido(pyridine-2,6-di­car­box­yl­ato-[kappa]³O²,N,O⁶)vanadate(V), (C₅H₇N₂O)[V(C₇H₃NO₄)O₂] or [H(amino-3-OH-py)][VO₂(dipic)], (I), was prepared by the reaction of VCl₃ with dipicolinic acid (dipicH₂) and 2-amino-3-hy­droxy­pyridine (amino-3-OH-py) in water. The compound was characterized by elemental analysis, IR spectroscopy and X-ray structure analysis, and consists of an anionic [VO₂(dipic)]^- complex and an H(amino-3-OH-py)⁺ counter-cation. The V^V ion is five-coordinated by one O,N,O'-tridentate dipic dianionic ligand and by two oxide ligands. Thermal decomposition of (I) in the presence of polyethyl­ene glycol led to the formation of nanoparticles of V₂O₅. Powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) were used to characterize the structure and morphology of the synthesized powder.

S1. Introduction

There has been increasing inter­est in the fundamental chemistry of vanadium. It has a range of accessible oxidation states, offering a wide variety of complexes with diverse coordination numbers and stereochemistries. Vanadium complexes with hydrazine derivatives are used to lower blood pressure (Ciba Ltd, 1962). Several vanadium(IV) complexes with N- and O-donor ligands, especially picolinate derivatives, have attracted inter­est and have been investigated as anti­diabetic agents (Sakurai et al., 2002, and references therein). Furthermore, some vanadium(V) complexes have been found to have insulin-like properties (Goldwaser et al., 2000). Among N- and O-donor ligands, dipicolinic acid (dipicH₂) is a desirable ligand for modelling potential pharmacologically active compounds because of its low toxicity and amphophilic nature. It displays a large number of coordination modes and can act as a bidentate or tridentate and terminal or bridging ligand with different metal ions (Tabatabaee et al., 2011; Tabatabaee, Bordbar et al., 2013 ?). Dipicolinic acid is known as a bio-ligand, due to it various biological functions, including activation–inactivation of some metalloenzymes and inhibition of electron transport (Murakami et al., 2003; Gonzalez-Baró et al., 2005). The insulin-like properties of the V^V dipicolinate complex, [VO₂dipic]^-, and the 4-hy­droxy­dipicolinate derivative, [VO₂dipic-OH]^-, have been investigated (Crans, Mahroof-Tahir et al., 2003; Crans, Yang et al., 2003). The results show that vanadium dipicolinate complexes are more effective than the ligand alone in the treatment of diabetes. Furthermore, the design and synthesis of novel coordination compounds is influenced by varying the reaction conditions, such as the metal-to-ligand ratio, temperature, pH value, solvents and counter-ions. As a part of our wider research programme on the synthesis of transition metal complexes with pyridine-2,6-di­carboxyl­ate, we have studied the effects of a variety of parameters, including the molar ratio of the reagents and the solvent used for re-crystallization, on the formation of iron(III) complexes with pyridine-2,6-di­carboxyl­ate and 2-amino-6-picoline (Tabatabaee, Dadkhodaee et al., 2013). Here, we report the synthesis and characterization of a new vanadium(V) complex, (Hamino-3-OH-py)[VO₂(dipic)], (I). Although several compounds containing the [VO₂(dipic)]^- anion and different counter-ions have been reported previously (Ranjbar, 2004; Aghabozorg & Sadr-khanlou, 2007), in this work 2-amino-3-hy­droxy­pyridinium was used as the counter-ion in the synthesis of (I), which was in turn used in the preparation of nano-sized V₂O₅ for the first time.

S2. Experimental

All purchased chemicals were of reagent grade and used without further purification. IR spectra were recorded using a Bruker Tensor 27 FT–IR spectrometer (KBr pellets, 4000–400 cm^-1). Elemental analysis was performed using a Costech ECS 4010 CHNS analyser. Powder X-ray diffraction (PXRD) measurements were performed using a Bruker Advance D8 instrument with Cu Kα radiation (λ = 1.5406 Å). The size distribution and morphology of the sample were analysed using a scanning electron microscope (SEM; Philips XL30).

S2.1. Synthesis and crystallization

S2.1.1. Synthesis of complex

For the preparation of (Hamino-3-OH-py)[VO₂(dipic)], (I), dipicolinic acid (0.334 g, 2 mmol), 2-amino-3-hy­droxy­pyridine (0.220 g, 2 mmol) and NaOH (0.080 g, 2 mmol) were dissolved in distilled water (20 ml) and the mixture was stirred for 30 min at room temperature. VCl₃ (0.315 g, 2 mmol) was then added to the solution and the reaction mixture was stirred for 4 h. The precipitate which formed was filtered off and the mother liquor was kept at 277 K until brown crystals of (I) suitable for X-ray diffraction were obtained (yield 0.567 g, 78%). Spectroscopic analysis: IR (KBr, ν, cm^-1): 3430–3205 (b), 1687 (s), 1569 (s), 1369 (s), 1346 (s), 1282 (m), 1089 (m), 1081 (s), 960 (s), 926 (s), 755 (s), 676 (m), 460 (m). Analysis, calculated for C₁₂H₁₀N₃O₇V (M_r = 359.17): C 40.09, H 2.78, N 11.69%; found: C 39.97, H 2.68, N 11.44%.

S2.1.2. Preparation of V2O5 nanoparticles

Crystals of (I) (0.360 g, 1 mmol) were mixed with polyethyl­ene glycol (0.2 g) and the mixture was calcined at 873 K for 2 h. The orange precipitate which formed was separated off and washed with ethanol and water. IR spectroscopy was used to confirm that complex (I) had decomposed completely.

S2.2. Refinement

Data collection and structure refinement details are summarized in Table 1. H atoms bonded to O and N atoms were refined independently with isotropic parameters. The N—H and O—H distances are sensible and the U_iso values are within the exptected ranges for a low-temperature structure. C-bound H atoms were included in calculated positions, with C—H = 0.95 Å, and allowed to refine in a riding-motion approximation, with U_iso(H) = 1.2U_eq(C). [Added text OK?]

S3. Results and discussion

Treatment of VCl₃ with dipicolinic acid and 2-amino-3-hy­droxy­pyridine in the molar ratio of 1:1:1 in aqueous solution gave complex (I) (see scheme). Complex (I) appears as brown plates and is stable in air and soluble in water. Vanadium is in oxidation state 5 in (I). The oxidation of V^III or V^IV to V^V can occur in the presence of molecular oxygen. This redox process is observed in the synthesis of other vanadium(V) complexes with the dipicolinate ligand (Gonzalez-Baró et al., 2005; Tabatabaee, Mahmoodikhah et al., 2013; Hakimi et al., 2011).

S3.1. Crystal structure

Table 1 shows the crystallographic data for (I). The molecular structure of (I) is depicted in Fig. 1. Selected bond lengths and angles and hydrogen-bond geometries are listed in Tables 2 and 3, respectively. Compound (I) consists of the anionic complex [VO2(dipic)]^- and, in the outer coordination sphere, an (Hamino-3-OH-py)⁺ counter-ion. The vanadium(V) cation is five-coordinated by one O,N,O'-tridentate dipicolinate anion and two oxido ligands. The coordination polyhedron cannot be described as either a square pyramid or a trigonal bipyramid, having a trigonality index τ = 0.40 [τ = (β – α)/60, where β and α are the largest angles in the coordination sphere (Addison et al. 1984); its value is 0 for a perfect square pyramid and 1 for a perfect trigonal bipyramid]. Since τ is close to 0.5, the coordination geometry for this complex is neither trigonal–bipyramidal nor square-pyramidal. Similar structures have been obtained for other known five-coordinate dipicolinato–vanadium(V) complexes (Smee et al. 2007).

The V—N and V—O distances are within the usual ranges for this kind of vanadium(V) complex. Two sets of V—O distances are observed in (I). The V1—O5 distances [1.6176 (15) Å] are short compared with the V1—O1 [1.9976 (18) Å] and V1—O3 [2.0012 (18) Å] distances. There are hydrogen bonds of O—H···O, N—H···O and C—H···O types in the crystal structure of (I) (Table 3). The carboxyl groups of pydc^2- and (Hamino-3-OH-py)⁺ are involved in inter­molecular O—H···O, N—H···O and C—H···O hydrogen bonding (Fig. 2). As shown in Fig. 3, four types of robust hydrogen-bond synthons are formed, namely R₂²(8) (denoted I), R₃³(14) (denoted II), R₅⁴(22) (denoted III) and C₂²(8) (denoted IV). These inter­molecular inter­actions connect the various components into a three-dimensional network. The anionic complexes are linked to each other via strong O—H···O hydrogen bonds to form a one-dimensional polymeric chain. The other hydrogen bonds join these chains into a two-diemnsional network. There are also notable C—O···π inter­actions between C1—O2 and Cg3 (Cg3 is the centroid of the N1/C2–C6 ring) and between C7—O4 and Cg4 (Cg4 is the centroid of the N2/C8–C12 ring), with O···centroid distances of 3.482 (9) and 3.201 (4) Å, respectively.

S3.2. IR spectra

In the IR spectrum of (I), the band associated with the anti­symmetric stretching vibrational mode, ν_as(–COO═), appears at 1687 cm^-1 in (I) and 1668 cm^-1 in (2) [This second datum refers to which compound? (2) has not been defined anywhere] (1700 cm^-1 in the spectrum of free dipicH₂). The ν_s (–COO═) band is at 1346 cm^-1 in (I) and 1350 cm^-1 in (2) [Again, please define compound (2)] (1326 cm^-1 in the spectrum of free dipicH₂). The value of Δ[ν_as(–COO═) - ν_s(–COO═)] is 341 cm^-1 for (I), indicating the presence of a carboxyl­ate group coordinated to the V^V cation in a unidentate mode, which is in agreement with the crystal structure of (I). The band at 960 can be assigned to V═O stretching. A V═O stretching band has been reported at 1002 cm^-1 (Kriza et al., 2010), but the higher vanadium oxidation state in (I) causes a decrease in the frequency of the V═O stretching (Hakimi et al., 2011).

S3.3. Characterization of the calcined product

The IR spectrum of the calcined product, obtained after heating (I), shows that the typical bands of the ligand are not present in the calcined product. The IR spectrum of prepared V₂O₅ shows two intense bands at 1020 and 820 cm^-1. Only a weak band is observed at around 440 cm^-1. The band appearing at 1020 cm^-1 corresponds to the V—O_v (vanadyl oxygen) stretching mode. The band at 820 cm^-1 is assigned to the anti­symmetric stretching vibration of the V—O_b—V group (O_b is the bridging oxygen) and the weak band at around 440 cm^-1 can be assigned to the V—O stretching vibration (Fomichev et al., 1997).

The powder X-ray diffraction pattern of the nanosized V₂O₅ is shown in Fig. 4. The strong and sharp diffraction peaks indicate that the synthesized powder is well crystalline. The V₂O₅ crystals grew in the orthorhombic crystal system. The entire d-line pattern matched with the reported values (JCPDS Card Pattern 09-0387). No characteristic peaks of other impurities were detected.

The particle size was calculated from the Debye–Scherrer formula, D = kλ/(βcosθ), where D is the crystallite size, k is a constant (= 0.9, assuming that the particles are spherical), λ is the wavelength of the X-ray radiation, β is the line width (obtained after correction for the instrumental broadening) and θ is the angle of diffraction. The average particle size obtained from the X-ray diffraction data is ~35 nm.

The morphology of the sample was examined by a scanning electron microscope (SEM). The SEM image of the nanosized powder is shown in Fig. 5. The results show that the product consists of spherical crystallites. The average size of the five labelled particles in the SEM image is 44 nm. [Added text OK? Numbers in image will be too small for the reader to see. Do you wish to comment on the difference in average sizes obtained with the two techniques?]

Related literature

For related literature, see: Ciba Ltd (1962); Gonzalez-Baró et al. (2005); Addison et al. (1984); Aghabozorg & Sadr-khanlou (2007); Crans, Mahroof-Tahir, Johnson, Wilkins, Yang, Robbins, Johnson, Alfano, Godzala, Austin & Willsky (2003); Crans, Yang, Alfano, Chi, Jing, Mahroof-Tahir, Robbins, Toloue, Chan, Plante, Grayson & Willsky (2003); Fomichev et al. (1997); Goldwaser et al. (2000); Hakimi et al. (2011); Kriza et al. (2010); Murakami et al. (2003); Ranjbar (2004); Sakurai et al. (2002); Sheldrick (2008); Tabatabaee et al. (2011); Tabatabaee, Bordbar, Ghassemzadeh, Tahriri, Tahrir, Mehri- Lighvan & Neumüller (2013); Tabatabaee, Dadkhodaee & Kukovec (2013); Tabatabaee, Mahmoodikhah, Ahadiat, Dušek & Pojarová (2013).

Computing details

Data collection: APEX2 (Bruker, 2007); cell refinement: APEX2 (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at 50% probability level.
	Fig. 2. A view of the variety of hydrogen-bond interactions in the crystal structure of (I). C—H···O hydrogen bonds are shown as red dashed lines and N—H···O as green dashed lines. [Added text OK? Also, please supply a version of the figure with atom labels not overlapping atoms and bonds, and with symmetry codes for the two O5 acceptor atoms.]
	Fig. 3. A view of the robust hydrogen-bond synthons, R2^2(8), denoted I, R3^3(14), denoted II, R5^4(22), denoted III, and C2^2(8), denoted IV, which link the anions and cations to form the two-dimensional network in (I). Dashed blue lines show the donor–acceptor parts of the hydrogen bonds.
	Fig. 4. The powder X-ray diffraction pattern of the synthesized nano-sized V2O5.
	Fig. 5. An SEM image of the nano-sized V2O5 powder. Some particle sizes are given in nanometres. [These figures are too small to read and it might be better if they were omitted. Please provide a revised image. The micrograph itself also looks to be out of focus. Is a sharper image available?]

2-Amino-3-hydroxypyridinium dioxido(pyridine-2,6-dicarboxylato-κ²O²,N,O⁶)vanadate(V)

Crystal data

(C5H7N2O)[V(C7H3NO4)O2]	F(000) = 728
Mr = 359.17	Dx = 1.768 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 4939 reflections
a = 26.173 (3) Å	θ = 2.6–27.5°
b = 6.3586 (7) Å	µ = 0.78 mm^−1
c = 8.1089 (8) Å	T = 147 K
V = 1349.5 (3) Å^3	Plate, brown
Z = 4	0.33 × 0.22 × 0.14 mm

Data collection

Bruker Kappa APEX-DUO CCD area-detector diffractometer	1698 independent reflections
Radiation source: fine-focus sealed tube	1592 reflections with I > 2σ(I)
Bruker Triumph monochromator	Rint = 0.025
ϕ and ω scans	θmax = 27.6°, θmin = 1.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −34→34
Tmin = 0.700, Tmax = 0.746	k = −8→6
6889 measured reflections	l = −8→10

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.083	H atoms treated by a mixture of independent and constrained refinement
S = 1.18	w = 1/[σ^2(Fo^2) + (0.0269P)^2 + 1.4082P] where P = (Fo^2 + 2Fc^2)/3
1698 reflections	(Δ/σ)max = 0.001
148 parameters	Δρmax = 0.32 e Å^−3
0 restraints	Δρmin = −0.46 e Å^−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
V1	0.391884 (15)	0.2500	0.32914 (5)	0.01700 (14)
O1	0.46797 (6)	0.2500	0.3099 (2)	0.0198 (4)
O2	0.54401 (7)	0.2500	0.4348 (2)	0.0259 (4)
O3	0.32960 (6)	0.2500	0.4723 (2)	0.0224 (4)
O4	0.29382 (7)	0.2500	0.7230 (2)	0.0244 (4)
O5	0.37900 (5)	0.4580 (3)	0.22208 (17)	0.0311 (3)
N1	0.41866 (7)	0.2500	0.5728 (2)	0.0138 (4)
C1	0.49706 (9)	0.2500	0.4375 (3)	0.0173 (5)
C2	0.46877 (9)	0.2500	0.5985 (3)	0.0155 (5)
C3	0.48881 (10)	0.2500	0.7568 (3)	0.0214 (5)
H3A	0.5247	0.2500	0.7750	0.026*
C4	0.45462 (10)	0.2500	0.8874 (3)	0.0255 (6)
H4A	0.4671	0.2500	0.9974	0.031*
C5	0.40203 (10)	0.2500	0.8585 (3)	0.0234 (6)
H5A	0.3784	0.2500	0.9475	0.028*
C6	0.38534 (9)	0.2500	0.6972 (3)	0.0164 (5)
C7	0.33135 (9)	0.2500	0.6334 (3)	0.0184 (5)
O6	0.10832 (7)	0.2500	0.3215 (2)	0.0236 (4)
N2	0.24348 (8)	0.2500	0.2795 (3)	0.0198 (5)
N3	0.19267 (9)	0.2500	0.5117 (3)	0.0275 (6)
C8	0.19712 (9)	0.2500	0.3493 (3)	0.0181 (5)
C9	0.15369 (9)	0.2500	0.2421 (3)	0.0183 (5)
C10	0.16107 (9)	0.2500	0.0753 (3)	0.0210 (5)
H10A	0.1325	0.2500	0.0032	0.025*
C11	0.21097 (10)	0.2500	0.0097 (3)	0.0255 (6)
H11A	0.2161	0.2500	−0.1063	0.031*
C12	0.25140 (10)	0.2500	0.1128 (3)	0.0247 (6)
H12A	0.2852	0.2500	0.0699	0.030*
H6O	0.0869 (15)	0.2500	0.261 (5)	0.033 (10)*
H2N	0.2678 (14)	0.2500	0.342 (4)	0.029 (9)*
H3NA	0.2175 (15)	0.2500	0.572 (5)	0.041 (11)*
H3NB	0.1630 (16)	0.2500	0.553 (5)	0.044 (11)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
V1	0.0117 (2)	0.0298 (3)	0.0095 (2)	0.000	−0.00042 (14)	0.000
O1	0.0146 (8)	0.0329 (11)	0.0120 (8)	0.000	0.0020 (6)	0.000
O2	0.0108 (8)	0.0429 (12)	0.0239 (10)	0.000	0.0022 (7)	0.000
O3	0.0106 (7)	0.0423 (12)	0.0143 (9)	0.000	0.0000 (6)	0.000
O4	0.0147 (8)	0.0383 (12)	0.0201 (9)	0.000	0.0067 (7)	0.000
O5	0.0276 (7)	0.0446 (9)	0.0212 (7)	0.0099 (7)	0.0015 (5)	0.0095 (7)
N1	0.0128 (9)	0.0176 (10)	0.0111 (9)	0.000	0.0001 (7)	0.000
C1	0.0146 (10)	0.0198 (12)	0.0174 (12)	0.000	0.0016 (9)	0.000
C2	0.0120 (10)	0.0179 (12)	0.0166 (12)	0.000	−0.0002 (9)	0.000
C3	0.0158 (11)	0.0292 (14)	0.0192 (13)	0.000	−0.0054 (9)	0.000
C4	0.0258 (13)	0.0368 (16)	0.0137 (12)	0.000	−0.0054 (10)	0.000
C5	0.0208 (12)	0.0362 (16)	0.0132 (12)	0.000	0.0017 (10)	0.000
C6	0.0144 (11)	0.0221 (12)	0.0128 (12)	0.000	0.0017 (9)	0.000
C7	0.0154 (11)	0.0247 (13)	0.0151 (12)	0.000	0.0022 (9)	0.000
O6	0.0102 (8)	0.0406 (12)	0.0202 (10)	0.000	0.0007 (7)	0.000
N2	0.0097 (9)	0.0307 (13)	0.0190 (11)	0.000	−0.0015 (8)	0.000
N3	0.0155 (10)	0.0500 (17)	0.0170 (11)	0.000	−0.0010 (9)	0.000
C8	0.0129 (11)	0.0228 (13)	0.0185 (12)	0.000	0.0001 (9)	0.000
C9	0.0119 (10)	0.0230 (13)	0.0200 (13)	0.000	0.0007 (9)	0.000
C10	0.0137 (11)	0.0311 (15)	0.0181 (13)	0.000	−0.0024 (9)	0.000
C11	0.0193 (12)	0.0428 (17)	0.0143 (12)	0.000	0.0035 (10)	0.000
C12	0.0148 (11)	0.0377 (16)	0.0215 (13)	0.000	0.0046 (10)	0.000

Geometric parameters (Å, º)

V1—O5^i	1.6176 (15)	C5—H5A	0.9500
V1—O5	1.6176 (15)	C6—C7	1.505 (3)
V1—O1	1.9976 (18)	O6—C9	1.351 (3)
V1—O3	2.0012 (18)	O6—H6O	0.74 (4)
V1—N1	2.096 (2)	N2—C8	1.339 (3)
O1—C1	1.285 (3)	N2—C12	1.367 (4)
O2—C1	1.229 (3)	N2—H2N	0.81 (4)
O3—C7	1.307 (3)	N3—C8	1.322 (4)
O4—C7	1.222 (3)	N3—H3NA	0.81 (4)
N1—C2	1.328 (3)	N3—H3NB	0.85 (4)
N1—C6	1.334 (3)	C8—C9	1.431 (3)
C1—C2	1.500 (3)	C9—C10	1.367 (4)
C2—C3	1.387 (3)	C10—C11	1.410 (3)
C3—C4	1.387 (4)	C10—H10A	0.9500
C3—H3A	0.9500	C11—C12	1.348 (4)
C4—C5	1.396 (4)	C11—H11A	0.9500
C4—H4A	0.9500	C12—H12A	0.9500
C5—C6	1.379 (3)
O5^i—V1—O5	109.70 (11)	C4—C5—H5A	120.9
O5^i—V1—O1	99.56 (6)	N1—C6—C5	120.7 (2)
O5—V1—O1	99.56 (6)	N1—C6—C7	110.7 (2)
O5^i—V1—O3	98.13 (6)	C5—C6—C7	128.6 (2)
O5—V1—O3	98.13 (6)	O4—C7—O3	124.5 (2)
O1—V1—O3	149.01 (7)	O4—C7—C6	123.4 (2)
O5^i—V1—N1	125.13 (6)	O3—C7—C6	112.1 (2)
O5—V1—N1	125.13 (6)	C9—O6—H6O	111 (3)
O1—V1—N1	74.94 (7)	C8—N2—C12	123.7 (2)
O3—V1—N1	74.07 (7)	C8—N2—H2N	116 (2)
C1—O1—V1	121.87 (15)	C12—N2—H2N	120 (2)
C7—O3—V1	123.45 (15)	C8—N3—H3NA	122 (3)
C2—N1—C6	121.8 (2)	C8—N3—H3NB	119 (3)
C2—N1—V1	118.55 (16)	H3NA—N3—H3NB	120 (4)
C6—N1—V1	119.63 (16)	N3—C8—N2	120.1 (2)
O2—C1—O1	125.3 (2)	N3—C8—C9	122.3 (2)
O2—C1—C2	120.6 (2)	N2—C8—C9	117.6 (2)
O1—C1—C2	114.1 (2)	O6—C9—C10	126.6 (2)
N1—C2—C3	121.3 (2)	O6—C9—C8	114.1 (2)
N1—C2—C1	110.6 (2)	C10—C9—C8	119.3 (2)
C3—C2—C1	128.2 (2)	C9—C10—C11	120.3 (2)
C2—C3—C4	117.6 (2)	C9—C10—H10A	119.9
C2—C3—H3A	121.2	C11—C10—H10A	119.9
C4—C3—H3A	121.2	C12—C11—C10	119.6 (2)
C3—C4—C5	120.5 (2)	C12—C11—H11A	120.2
C3—C4—H4A	119.7	C10—C11—H11A	120.2
C5—C4—H4A	119.7	C11—C12—N2	119.6 (2)
C6—C5—C4	118.1 (2)	C11—C12—H12A	120.2
C6—C5—H5A	120.9	N2—C12—H12A	120.2
O5^i—V1—O1—C1	−123.99 (6)	C1—C2—C3—C4	180.0
O5—V1—O1—C1	123.99 (6)	C2—C3—C4—C5	0.0
O3—V1—O1—C1	0.0	C3—C4—C5—C6	0.0
N1—V1—O1—C1	0.0	C2—N1—C6—C5	0.0
O5^i—V1—O3—C7	124.32 (6)	V1—N1—C6—C5	180.0
O5—V1—O3—C7	−124.31 (6)	C2—N1—C6—C7	180.0
O1—V1—O3—C7	0.0	V1—N1—C6—C7	0.0
N1—V1—O3—C7	0.0	C4—C5—C6—N1	0.0
O5^i—V1—N1—C2	91.20 (7)	C4—C5—C6—C7	180.0
O5—V1—N1—C2	−91.20 (7)	V1—O3—C7—O4	180.0
O1—V1—N1—C2	0.0	V1—O3—C7—C6	0.0
O3—V1—N1—C2	180.0	N1—C6—C7—O4	180.0
O5^i—V1—N1—C6	−88.80 (7)	C5—C6—C7—O4	0.0
O5—V1—N1—C6	88.80 (7)	N1—C6—C7—O3	0.0
O1—V1—N1—C6	180.0	C5—C6—C7—O3	180.0
O3—V1—N1—C6	0.0	C12—N2—C8—N3	180.0
V1—O1—C1—O2	180.0	C12—N2—C8—C9	0.0
V1—O1—C1—C2	0.0	N3—C8—C9—O6	0.0
C6—N1—C2—C3	0.0	N2—C8—C9—O6	180.0
V1—N1—C2—C3	180.0	N3—C8—C9—C10	180.0
C6—N1—C2—C1	180.0	N2—C8—C9—C10	0.0
V1—N1—C2—C1	0.0	O6—C9—C10—C11	180.0
O2—C1—C2—N1	180.0	C8—C9—C10—C11	0.0
O1—C1—C2—N1	0.0	C9—C10—C11—C12	0.0
O2—C1—C2—C3	0.0	C10—C11—C12—N2	0.0
O1—C1—C2—C3	180.0	C8—N2—C12—C11	0.0
N1—C2—C3—C4	0.0

Symmetry code: (i) x, −y+1/2, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O6—H6O···O2^ii	0.74 (4)	1.95 (4)	2.675 (3)	166 (4)
N2—H2N···O3	0.81 (4)	1.93 (4)	2.743 (3)	175 (3)
N3—H3NA···O4	0.81 (4)	2.34 (4)	3.153 (3)	175 (4)
N3—H3NB···O5^iii	0.85 (4)	2.56 (3)	3.143 (2)	128 (2)
N3—H3NB···O5^iv	0.85 (4)	2.56 (3)	3.143 (2)	128 (2)

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