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The title compound, tetrakis(tetraethylammonium) cyclo-tetra-[mu]-oxo-tetrakis[dioxovanadium(V)] dihydrate, (C8H20N)4[V4O12]·2H2O, was obtained by reacting V2O5 with (C2H5)4NOH. It consists of a discrete centrosymmetric molecular anion, [V4O12]4-, where four tetrahedral VO4 units share two vertices with each other to form a ring. A water mol­ecule is attached on each side of the ring through hydrogen bonds.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102013008/ob1072sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270102013008/ob1072Isup2.hkl
Contains datablock I

CCDC reference: 195601

Comment top

Tetraalkylammonium salts of metavanadate, (R4N)[VO3], have been widely used as starting materials for the syntheses of polyvanadates in aprotic solvents since their first preparation (Abe et al., 1994; Abe, Akashi et al., 1996; Abe, Isobe et al., 1996; Akashi et al., 1991; Attanasio et al., 1993; Day et al., 1990; Hayashi et al., 2000, 2001; Kawanami et al., 2000; Nakano et al., 2001). However, (R4N)[VO3] itself has not been fully characterized to date. It is assumed to be a tetrameric compound with a ring structure, (R4N)4[V4O12], because it readily gives organometallic compounds that have a V4O12 ring, but this assumption has never been confirmed by an X-ray structure analysis. Trimeric (R4N)3[V3O9] has recently been isolated from an aged DMF solution, a solvent seldom used in the syntheses of polyvanadates (Hamilton et al., 2002). We have isolated the title metavanadate salt as a tetraethylammonium salt, (I), from an acetonitrile solution and found that the anion does have the expected V4O12 ring structure (Fig. 1). \sch

The V—O distances in (I) are all normal for a vanadate and compare well with those observed for other compounds that contain a V4O12 ring. The ring in (I) assumes a twisted-boat-chair conformation, similar to what is observed for {[(η3-C4H7)2Rh]2[V4O12]}2- (Akashi et al., 1991), [Zn(2,2'-bipy)3]2[V4O12].11H2O (2,2'-bipy is 2,2'-bipyridine; Zhang et al., 1997) and [Ni(2,2'-bipy)3]2[V4O12].11H2O (Yang et al., 1998), and not the twisted-chair conformation observed for {[(η-C8H12)Ir]2(V4O12)}2- (Day et al., 1990).

As can be seen in Fig. 1, two water molecules are attached to the [V4O12]4- anion through hydrogen bonds, one to each surface. Each water molecule bridges two terminal VO O atoms. The [(V4O12)(H2O)2]4- anion is surrounded by C8H20N+ cations, and no other interactions between the anions and/or water molecules are observed (Fig. 2).

The structure of the [(V4O12)(H2O)2]4- anion as a whole very closely resembles that of {[(η3-C4H7)2Rh]2(V4O12)}2-, a vanadate-supported organorhodium complex. It is interesting to note that the V1—O2 [1.659 (2) Å] and V2—O4 [1.665 (2) Å] distances in (I) are virtually the same as those between the V and O atoms that bridge the V and Rh atoms in {[(η3-C4H7)2Rh]2(V4O12)}2- [1.652 (5) and 1.670 (5) Å].

The [(V4O12)(H2O)2]4- anion observed here can be viewed as a vanadate-supported water complex. In fact, the same adsorption geometry is proposed for water molecules adsorbed on V2O5 (Ranea et al., 2000). A similar vanadate-supported water complex can be found in [Zn(2,2'-bipy)3]2[V4O12].11H2O, although the [V4O12]4- anion in that compound is also hydrogen-bonded to many other water molecules.

The water molecules in (I) are bound relatively tightly onto the surface of the [V4O12]4- anion. The compound does not lose these water molecules even if it is dried under vacuum over P2O5 for more than 12 h. The TG-DTA (please define) of (I) gives a well defined peak at around 373 K that accounts for a 3.8% weight loss. This is consistent with the dissociation of two water molecules. The dissociation enthalpy was determined to be 103 kJ mol-1, which allows us to estimate the binding energy of a water molecule on the [V4O12]4- surface to be ~51 kJ mol-1.

Experimental top

The crude product of (I) was prepared by dissolving V2O5 (2.0 g, 0.011 mmol) in a 10% aqueous solution of Et4NOH (35 ml, 0.022 mmol), stirring the solution for 18 h, evaporating it to dryness under vacuum, dissolving the resulting solid in warm acetonitrile (100 ml), filtering off a small amount of insoluble material, adding diethyl ether (800 ml) to the filtrate, collecting by filtration the white precipitate that formed, and drying it under vacuum for 8 h (yield 73%, 3.8 g, 4.0 mmol). Crystals of (I) suitable for X-ray diffraction were obtained by dissolving the crude product (0.10 g) in warm acetonitrile (7 ml), adding m-xylene (5 ml) with stirring, and allowing the mixture to stand at ambient temperature overnight. The crystals gave a satisfactory elemental analysis; analysis calculated (found) for C32H84N4V4O14: C 40.59 (40.33), H 8.79 (8.89), N 5.78 (5.88), V 21.6 (21.4)%.

Refinement top

Water H atoms were located from difference Fourier syntheses and no refinements were applied. The H atoms in the tetraethylammonium cations were treated by constrained refinements, with C—H distances in the range 0.98–0.99 Å. Is this added text OK?

Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996).

Figures top
[Figure 1] Fig. 1. A view of the [(V4O12)(H2O)2]4- anion of (I), with the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
[Figure 2] Fig. 2. A packing diagram for (I), viewed along b.
Tetrakis(tetraethylammonium) cyclo-tetra-µ-oxo-tetrakis[dioxovanadium(V)] dihydrate top
Crystal data top
(C8H20N)4[V4O12]·2H2OF(000) = 1016
Mr = 952.79Dx = 1.372 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 4000 reflections
a = 14.0187 (3) Åθ = 1.0–30.5°
b = 10.5729 (2) ŵ = 0.85 mm1
c = 16.0212 (4) ÅT = 90 K
β = 103.836 (1)°Plate, colourless
V = 2305.7 (1) Å30.40 × 0.30 × 0.02 mm
Z = 2
Data collection top
Bruker SMART CCD area-detector
diffractometer
7001 independent reflections
Radiation source: Rigaku Ultrax-18 rotating anode3962 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.114
ω scansθmax = 30.5°, θmin = 1.7°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1620
Tmin = 0.631, Tmax = 0.983k = 1415
22145 measured reflectionsl = 2122
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)] = 0.058Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.141H-atom parameters constrained
S = 0.92 w = 1/[σ2(Fo2) + (0.0673P)2]
where P = (Fo2 + 2Fc2)/3
7001 reflections(Δ/σ)max < 0.001
244 parametersΔρmax = 0.72 e Å3
0 restraintsΔρmin = 0.87 e Å3
Crystal data top
(C8H20N)4[V4O12]·2H2OV = 2305.7 (1) Å3
Mr = 952.79Z = 2
Monoclinic, P21/nMo Kα radiation
a = 14.0187 (3) ŵ = 0.85 mm1
b = 10.5729 (2) ÅT = 90 K
c = 16.0212 (4) Å0.40 × 0.30 × 0.02 mm
β = 103.836 (1)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
7001 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
3962 reflections with I > 2σ(I)
Tmin = 0.631, Tmax = 0.983Rint = 0.114
22145 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0580 restraints
wR(F2) = 0.141H-atom parameters constrained
S = 0.92Δρmax = 0.72 e Å3
7001 reflectionsΔρmin = 0.87 e Å3
244 parameters
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
V10.11611 (4)0.14752 (5)0.03933 (3)0.01153 (13)
V20.06027 (4)0.05252 (5)0.13271 (3)0.01176 (13)
O10.16926 (18)0.2866 (2)0.03968 (14)0.0178 (5)
O20.19662 (17)0.0456 (2)0.09524 (14)0.0167 (5)
O30.00201 (17)0.0213 (2)0.23230 (13)0.0167 (5)
O40.16905 (17)0.1148 (2)0.13378 (15)0.0178 (5)
O50.07585 (17)0.0937 (2)0.07161 (14)0.0153 (5)
O60.01091 (17)0.1636 (2)0.08590 (13)0.0151 (5)
O70.32751 (18)0.0695 (2)0.01205 (16)0.0230 (6)
H10.28220.03200.03930.034*
H20.28080.11740.03810.034*
N10.3428 (2)0.1750 (2)0.33564 (16)0.0130 (5)
C10.2362 (2)0.1484 (3)0.29060 (19)0.0156 (6)
H1A0.23410.11110.23350.019*
H1B0.20970.08480.32440.019*
C20.3965 (3)0.0502 (3)0.3373 (2)0.0206 (7)
H2A0.38610.01920.27750.025*
H2B0.36600.01200.36930.025*
C30.3874 (3)0.2768 (3)0.2900 (2)0.0175 (7)
H3A0.45640.29000.32180.021*
H3B0.35170.35690.29260.021*
C40.3515 (3)0.2252 (3)0.42608 (19)0.0171 (7)
H4A0.32400.31190.42190.021*
H4B0.42200.23120.45540.021*
C50.1705 (3)0.2637 (4)0.2785 (2)0.0256 (8)
H5A0.10350.23920.24930.038*
H5B0.19500.32650.24380.038*
H5C0.17060.30010.33480.038*
C60.5061 (3)0.0530 (4)0.3772 (3)0.0378 (11)
H6A0.53350.03190.37510.057*
H6B0.51780.08070.43720.057*
H6C0.53790.11190.34510.057*
C70.3860 (3)0.2499 (4)0.1964 (2)0.0218 (7)
H7A0.41620.32070.17280.033*
H7B0.31790.23940.16350.033*
H7C0.42300.17230.19280.033*
C80.2999 (3)0.1459 (3)0.4817 (2)0.0194 (7)
H8A0.30930.18510.53850.029*
H8B0.32780.06040.48790.029*
H8C0.22960.14120.45440.029*
N20.3596 (2)0.2502 (3)0.87870 (17)0.0171 (6)
C90.4009 (3)0.2293 (3)0.9744 (2)0.0197 (7)
H9A0.35590.26871.00600.024*
H9B0.40220.13730.98610.024*
C100.2550 (3)0.1984 (3)0.8593 (2)0.0200 (7)
H10A0.22030.23740.89980.024*
H10B0.25830.10620.87040.024*
C110.4217 (3)0.1843 (4)0.8257 (3)0.0292 (9)
H11A0.39100.19870.76400.035*
H11B0.48740.22450.83840.035*
C120.3602 (3)0.3897 (3)0.8552 (2)0.0232 (8)
H12A0.42900.41970.86760.028*
H12B0.33200.39910.79270.028*
C130.5035 (3)0.2820 (4)1.0096 (3)0.0281 (8)
H13A0.52450.26461.07140.042*
H13B0.50300.37361.00000.042*
H13C0.54930.24190.98010.042*
C140.1942 (3)0.2207 (4)0.7677 (2)0.0343 (10)
H14A0.12860.18430.76140.051*
H14B0.22650.18020.72680.051*
H14C0.18850.31170.75630.051*
C150.4350 (4)0.0436 (4)0.8406 (3)0.0418 (11)
H15A0.47570.00960.80400.063*
H15B0.37060.00200.82650.063*
H15C0.46720.02790.90110.063*
C160.3027 (3)0.4724 (3)0.9032 (3)0.0295 (9)
H16A0.30590.56060.88530.044*
H16B0.33110.46530.96520.044*
H16C0.23400.44480.89020.044*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
V10.0111 (3)0.0147 (3)0.0071 (2)0.0009 (2)0.00102 (19)0.0003 (2)
V20.0111 (3)0.0162 (3)0.0070 (2)0.0007 (2)0.00013 (19)0.0000 (2)
O10.0223 (14)0.0173 (12)0.0138 (11)0.0030 (10)0.0043 (10)0.0009 (9)
O20.0174 (12)0.0185 (12)0.0115 (11)0.0026 (10)0.0020 (9)0.0002 (9)
O30.0186 (13)0.0211 (12)0.0086 (11)0.0018 (10)0.0005 (9)0.0003 (9)
O40.0127 (12)0.0245 (13)0.0156 (12)0.0018 (10)0.0023 (9)0.0007 (9)
O50.0157 (12)0.0194 (11)0.0090 (10)0.0017 (10)0.0004 (9)0.0031 (9)
O60.0143 (12)0.0200 (12)0.0104 (11)0.0006 (9)0.0015 (9)0.0012 (9)
O70.0165 (13)0.0253 (14)0.0267 (14)0.0043 (11)0.0043 (11)0.0006 (11)
N10.0127 (14)0.0148 (13)0.0091 (12)0.0001 (10)0.0022 (10)0.0017 (10)
C10.0157 (16)0.0196 (16)0.0095 (14)0.0060 (14)0.0006 (12)0.0042 (13)
C20.027 (2)0.0168 (16)0.0153 (16)0.0079 (15)0.0001 (14)0.0033 (14)
C30.0144 (17)0.0219 (18)0.0144 (16)0.0056 (13)0.0001 (13)0.0013 (13)
C40.0222 (18)0.0180 (17)0.0079 (14)0.0003 (14)0.0029 (13)0.0035 (12)
C50.0151 (18)0.035 (2)0.0236 (19)0.0043 (16)0.0026 (14)0.0056 (16)
C60.029 (2)0.043 (2)0.032 (2)0.018 (2)0.0122 (17)0.011 (2)
C70.0193 (18)0.031 (2)0.0137 (16)0.0043 (16)0.0010 (13)0.0014 (14)
C80.0254 (19)0.0194 (17)0.0122 (15)0.0033 (15)0.0021 (13)0.0023 (13)
N20.0189 (15)0.0168 (14)0.0182 (14)0.0031 (12)0.0094 (12)0.0011 (11)
C90.0197 (19)0.0192 (17)0.0204 (17)0.0021 (14)0.0053 (14)0.0001 (14)
C100.0170 (18)0.0227 (18)0.0214 (18)0.0070 (14)0.0071 (14)0.0002 (14)
C110.026 (2)0.034 (2)0.033 (2)0.0041 (17)0.0181 (18)0.0145 (17)
C120.028 (2)0.0195 (17)0.0239 (19)0.0049 (15)0.0100 (16)0.0032 (14)
C130.018 (2)0.027 (2)0.037 (2)0.0019 (16)0.0020 (16)0.0012 (17)
C140.038 (3)0.045 (3)0.0162 (19)0.017 (2)0.0003 (17)0.0006 (17)
C150.047 (3)0.040 (3)0.037 (2)0.018 (2)0.008 (2)0.010 (2)
C160.035 (2)0.0201 (19)0.033 (2)0.0002 (16)0.0082 (18)0.0010 (16)
Geometric parameters (Å, º) top
V1—O11.648 (2)C7—H7B0.98
V1—O21.659 (2)C7—H7C0.98
V1—O61.813 (2)C8—H8A0.98
V1—O51.822 (2)C8—H8B0.98
V2—O31.643 (2)C8—H8C0.98
V2—O41.665 (2)N2—C91.521 (4)
V2—O51.815 (2)N2—C111.523 (4)
V2—O6i1.815 (2)N2—C121.523 (4)
O6—V2i1.815 (2)N2—C101.525 (4)
O7—H10.94C9—C131.520 (5)
O7—H21.04C9—H9A0.99
N1—C21.517 (4)C9—H9B0.99
N1—C31.518 (4)C10—C141.528 (5)
N1—C41.520 (4)C10—H10A0.99
N1—C11.521 (4)C10—H10B0.99
C1—C51.512 (5)C11—C151.511 (6)
C1—H1A0.99C11—H11A0.99
C1—H1B0.99C11—H11B0.99
C2—C61.517 (5)C12—C161.517 (5)
C2—H2A0.99C12—H12A0.99
C2—H2B0.99C12—H12B0.99
C3—C71.521 (4)C13—H13A0.98
C3—H3A0.99C13—H13B0.98
C3—H3B0.99C13—H13C0.98
C4—C81.526 (5)C14—H14A0.98
C4—H4A0.99C14—H14B0.98
C4—H4B0.99C14—H14C0.98
C5—H5A0.98C15—H15A0.98
C5—H5B0.98C15—H15B0.98
C5—H5C0.98C15—H15C0.98
C6—H6A0.98C16—H16A0.98
C6—H6B0.98C16—H16B0.98
C6—H6C0.98C16—H16C0.98
C7—H7A0.98
O1—V1—O2109.20 (12)H7B—C7—H7C109.5
O1—V1—O6109.07 (11)C4—C8—H8A109.5
O2—V1—O6110.73 (11)C4—C8—H8B109.5
O1—V1—O5108.44 (11)H8A—C8—H8B109.5
O2—V1—O5109.62 (11)C4—C8—H8C109.5
O6—V1—O5109.75 (10)H8A—C8—H8C109.5
O3—V2—O4108.26 (11)H8B—C8—H8C109.5
O3—V2—O5108.69 (11)C9—N2—C11111.4 (3)
O4—V2—O5110.50 (11)C9—N2—C12111.5 (3)
O3—V2—O6i109.67 (11)C11—N2—C12105.5 (3)
O4—V2—O6i110.10 (11)C9—N2—C10105.6 (2)
O5—V2—O6i109.60 (10)C11—N2—C10111.8 (3)
V2—O5—V1139.57 (13)C12—N2—C10111.0 (3)
V1—O6—V2i133.71 (13)C13—C9—N2114.8 (3)
H1—O7—H2101C13—C9—H9A108.6
C2—N1—C3111.5 (3)N2—C9—H9A108.6
C2—N1—C4111.1 (2)C13—C9—H9B108.6
C3—N1—C4105.3 (2)N2—C9—H9B108.6
C2—N1—C1105.9 (2)H9A—C9—H9B107.6
C3—N1—C1111.9 (2)N2—C10—C14115.4 (3)
C4—N1—C1111.3 (2)N2—C10—H10A108.4
C5—C1—N1114.2 (3)C14—C10—H10A108.4
C5—C1—H1A108.7N2—C10—H10B108.4
N1—C1—H1A108.7C14—C10—H10B108.4
C5—C1—H1B108.7H10A—C10—H10B107.5
N1—C1—H1B108.7C15—C11—N2115.3 (3)
H1A—C1—H1B107.6C15—C11—H11A108.5
N1—C2—C6116.1 (3)N2—C11—H11A108.5
N1—C2—H2A108.3C15—C11—H11B108.5
C6—C2—H2A108.3N2—C11—H11B108.5
N1—C2—H2B108.3H11A—C11—H11B107.5
C6—C2—H2B108.3C16—C12—N2113.5 (3)
H2A—C2—H2B107.4C16—C12—H12A108.9
N1—C3—C7115.6 (3)N2—C12—H12A108.9
N1—C3—H3A108.4C16—C12—H12B108.9
C7—C3—H3A108.4N2—C12—H12B108.9
N1—C3—H3B108.4H12A—C12—H12B107.7
C7—C3—H3B108.4C9—C13—H13A109.5
H3A—C3—H3B107.4C9—C13—H13B109.5
N1—C4—C8115.1 (3)H13A—C13—H13B109.5
N1—C4—H4A108.5C9—C13—H13C109.5
C8—C4—H4A108.5H13A—C13—H13C109.5
N1—C4—H4B108.5H13B—C13—H13C109.5
C8—C4—H4B108.5C10—C14—H14A109.5
H4A—C4—H4B107.5C10—C14—H14B109.5
C1—C5—H5A109.5H14A—C14—H14B109.5
C1—C5—H5B109.5C10—C14—H14C109.5
H5A—C5—H5B109.5H14A—C14—H14C109.5
C1—C5—H5C109.5H14B—C14—H14C109.5
H5A—C5—H5C109.5C11—C15—H15A109.5
H5B—C5—H5C109.5C11—C15—H15B109.5
C2—C6—H6A109.5H15A—C15—H15B109.5
C2—C6—H6B109.5C11—C15—H15C109.5
H6A—C6—H6B109.5H15A—C15—H15C109.5
C2—C6—H6C109.5H15B—C15—H15C109.5
H6A—C6—H6C109.5C12—C16—H16A109.5
H6B—C6—H6C109.5C12—C16—H16B109.5
C3—C7—H7A109.5H16A—C16—H16B109.5
C3—C7—H7B109.5C12—C16—H16C109.5
H7A—C7—H7B109.5H16A—C16—H16C109.5
C3—C7—H7C109.5H16B—C16—H16C109.5
H7A—C7—H7C109.5
Symmetry code: (i) x, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O7—H1···O20.941.852.792 (3)178
O7—H2···O41.041.912.853 (3)149

Experimental details

Crystal data
Chemical formula(C8H20N)4[V4O12]·2H2O
Mr952.79
Crystal system, space groupMonoclinic, P21/n
Temperature (K)90
a, b, c (Å)14.0187 (3), 10.5729 (2), 16.0212 (4)
β (°) 103.836 (1)
V3)2305.7 (1)
Z2
Radiation typeMo Kα
µ (mm1)0.85
Crystal size (mm)0.40 × 0.30 × 0.02
Data collection
DiffractometerBruker SMART CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.631, 0.983
No. of measured, independent and
observed [I > 2σ(I)] reflections
22145, 7001, 3962
Rint0.114
(sin θ/λ)max1)0.714
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.058, 0.141, 0.92
No. of reflections7001
No. of parameters244
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.72, 0.87

Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 1998), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPIII (Burnett & Johnson, 1996).

Selected bond lengths (Å) top
V1—O11.648 (2)V2—O31.643 (2)
V1—O21.659 (2)V2—O41.665 (2)
V1—O61.813 (2)V2—O51.815 (2)
V1—O51.822 (2)V2—O6i1.815 (2)
Symmetry code: (i) x, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O7—H1···O20.941.852.792 (3)178
O7—H2···O41.041.912.853 (3)149
 

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