Crystal structure of the Anderson-type hetero-polyoxometalate; K2[H7Cr(III)Mo6O24]·8H2O: a redetermination revealing the position of the extra H atom in the polyanion.

The title compound contains a symmetric hydrogen bond in which the H atom does not lie on a crystallographic centre of symmetry. The structure of K2[H7Cr(III)Mo6O24]·8H2O, namely dipotassium hepta-hydrogen hexa-molybdochromate(III) octa-hydrate, previously reported by Lee [Acta Cryst. (2007), E63, i5-i7], has been redetermined in order to locate the position of the seventh H atom in the anion. Six of the H atoms are bonded to the six μ3-O atoms and form hydrogen bonds of medium strength either to water mol-ecules or to the terminal O atoms of other polyanions. The seventh H atom forms a very short hydrogen bond between two μ2-O atoms on adjacent polyanions. This short bond, together with two normal hydrogen bonds, link the two crystallographically distinct centrosymmetric polyanions into chains along [011], while the length of this bond [2.461 (3) Å] suggests that the H atom lies at its centre, but unusually for such a bond, this point is not a crystallographic centre of symmetry.

Chemical context

This redetermined structure of a typical Anderson-type heteropolyoxometalate (Anderson, 1937 ▸), K2[H7CrIIIMo6O24]·8H2O reveals the position of the extra or seventh H atom in the [HCrIII(OH)6Mo6O18]2− polyanion. This has not only an extra H atom but this atom also forms a very short hydrogen bond [2.461 (3) Å]; however, the H atom that contributes to the short hydrogen bond does not lie on a crystallographic centre of symmetry.

An example of a relatively short hydrogen bond in which the H atom does lie on a crystallographic centre of symmetry in an Anderson-type polyanion was reported in the polyoxometalate, viz. K7[H4.5α-PtMo6O24]2·11H2O (Lee et al., 2010 ▸). In this compound, the two polyanions form a dimer, viz. [(H4.5PtMo6O24)2]7− via seven hydrogen bonds, viz. four μ3-O—H⋯μ1–O (terminal Mo=O atom), two μ2-O—H⋯μ2-O and one central/symmetric μ3-O⋯H⋯μ3-O. The H atom of the central hydrogen bond lies on a crystallographic centre of symmetry (space group P : ½, 0, ½) with a μ3-O⋯H⋯μ3-O () distance of 2.553 (3) Å. In this way, the hydrogen bond is symmetric, O⋯H⋯O, and the donor and acceptor cannot be distinguished. The dimerization of the polyanion by these hydrogen bonds is possible because the μ3-O atoms in the polyanion are only partially protonated. The location of the H atom in the central μ3-O⋯H⋯μ3-O unit was determined from a centrosymmetric electron density map around the H-atom position. This centrosymmetric inter­pretation of the hydrogen bond is strongly supported by the bond-valence sums (BVS; Brown & Altermatt, 1985 ▸; Brese & O’Keeffe, 1991 ▸). The sum around the strongly bonded μ3-O atom is 1.92 valence units (v.u.) in the [(H4.5PtMo6O24)2]7− polyanion. The reasonable BVS values of very short or very long O—H bond distances can be obtained from the graphical correlation (Brown, 2001 ▸).

However, the title compound belongs to the B-series Anderson-type polyanions (Tsigdinos, 1978 ▸) viz. [X +(OH)6MoO18](12− (X = heteroatom), in which such dimerization is impossible because all six μ3-O atoms are fully protonated. The polyanion structure in the title compound is shown in Fig. 1 ▸.

Figure 1

The polyanion structure in the title compound. Displacement ellipsoids are drawn at the 50% probability level for non-H atoms. H atoms are shown as small spheres of arbitrary radius. [Symmetry codes: (i) −x + 1, −y, −z + 2; (ii) −x + 1, −y + 1, −z + 1.]

Structural commentary

This study was carried out to clearly identify the position of the seventh or extra H atom in the [HCrIII(OH)6Mo6O18]2− polyanion. After considering the electron density maps and BVS values of the protonated OB (O-bridged μ2-O atom) atoms in the previously reported structure (Lee, 2007 ▸), we came to the conclusion that the positional disorder model of the H atom was wrong. The electron density (Fig. 2 ▸) is not symmetric in the title compound, but we expect the H atoms to lie in the middle of the bond because of the short O⋯O distance of 2.461 (3) Å, which corresponds to a pseudosymmetric hydrogen bond. The description of the rest of the structure and the composition of the atoms in the polyanion are the same as in the previous report of the compound, viz. K2[H7CrIIIMo6O24]·8H2O (Lee, 2007 ▸). The O atoms of the polyoxometalate are designated as OT (terminal Mo=O atom), OB, and OC (centre of two Mo and one Cr atom, μ3-O atom), respectively.

Figure 2

Difference Fourier map around atom H5 where atom H5 is absent.

In the present case, the O5B⋯H5 and O16B i⋯H5 distances are both 1.23 Å (Table 1 ▸). However, since the H atom does not lie on a crystallographic centre of symmetry, the present structure is considered to be particularly significant. As a result, the H5 atom is co-shared as O5B⋯H5⋯O16B i, and the average equation of the polyanion is [CrIII(μ3-OH)6{μ2-O(0.5H)}2Mo6O17]2−.

Table 1

Hydrogen-bond geometry (, )

DHA	DH	HA	D A	DHA
O1CH1O22T i	0.70(6)	2.11(6)	2.789(4)	164(6)
O2CH2O27W	0.76(6)	2.01(6)	2.753(4)	166(6)
O3CH3O31W ii	0.82(6)	1.79(6)	2.604(4)	176(6)
O5BH5O16B iii	1.23(1)	1.23(1)	2.461(3)	175(5)
O13CH13O12T iii	0.70(5)	2.05(5)	2.734(4)	167(5)
O14CH14O32W	0.81(5)	2.01(5)	2.776(4)	158(5)
O15CH15O28W iv	0.76(6)	1.87(6)	2.619(4)	170(6)
O25WH25AO21T	0.92(3)	1.96(3)	2.838(4)	157(5)
O25WH25BO20T	0.93(3)	1.92(3)	2.819(4)	162(5)
O26WH26AO4B v	0.91(3)	1.89(3)	2.748(4)	158(5)
O26WH26BO24T iii	0.91(3)	1.91(3)	2.798(4)	164(5)
O27WH27AO18B	0.90(3)	1.95(4)	2.775(4)	151(5)
O27WH27BO32W	0.91(3)	1.92(3)	2.825(5)	171(5)
O28WH28AO12T vi	0.91(3)	2.00(4)	2.785(4)	144(5)
O28WH28BO31W iv	0.90(3)	1.82(3)	2.706(4)	170(5)
O29WH29AO11T v	0.95(3)	2.11(4)	2.949(5)	146(6)
O29WH29BO8T vii	0.96(3)	2.18(3)	3.126(5)	169(6)
O31WH31AO26W iv	0.90(3)	1.77(3)	2.665(4)	170(5)
O31WH31BO27W iv	0.92(3)	2.18(4)	2.952(4)	141(4)
O32WH32AO30W	0.89(3)	2.06(3)	2.947(6)	171(5)
O32WH32BO6B v	0.89(3)	2.39(5)	3.000(4)	126(5)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .

The calculated BVS for the O5B and O16B atoms are 1.59 and 1.57 v.u., respectively, if the valence of the O—H bond is not included. Since the BVS value around the μ2-O atom should be 2.0 v.u., the missing valences of O5B and O16B are 0.41 and 0.43 v.u., respectively, corresponding to the valence of the O—H bonds. The obtained graphical correlation valence of H5 from its distance, 1.232 (7) Å, is 0.41 v.u., which is sufficient to satisfy the sums around the O5B and O16B atoms. As a result, the valence sums around O5B and O16B are 2.00 and 1.98 v.u., respectively. The BVS around the unprotonated μ2-O atoms, viz. O4B, O6B, O17B and O18B are 1.98, 1.96, 2.13 and 2.02 v.u., respectively.

The positional disordered model in the previous report (Lee, 2007 ▸) showed unreasonable BVS values. The calculated BVS for the O5B and O16B atoms are 1.62 and 1.57 v.u., respectively, if the valence of the O—H bond is not included. The obtained graphical correlation valences of H5 and H16 from its distances [O5B—H5 = 0.71 (8), H5⋯O16B = 1.79 (8) Å and O16B—H16 = 0.83 (8), H16⋯O5B = 1.65 (8) Å] are 0.24 and 0.26 v.u. Therefore, the total BVS values of O5B and O16B are 1.86 and 1.83 v.u., respectively.

As a result, we consider that the present model of the title compound is more reasonable, and the one extra H atom is located at the mid-point between the O5B and O16B atoms, and shared equally by two discrete polyanions. All H atoms and hydrogen bonds are well-defined in the title compound (Table 1 ▸).

Supra­molecular features

Two discrete polyanions A and B are linked into chains along [011] by two normal, and one strong and pseudosymmetric hydrogen bonds (Table 1 ▸ and Fig. 3 ▸). The K+ ions are variously coordinated by O atoms as [K1(OT)4(OW)4]+ and [K2(OT)4(OB)(OW)3]+ in the distance range 2.722 (3)–3.075 (3) Å. Furthermore, the polyanions are three dimensionally linked via K⋯OT inter­actions. All water mol­ecules form hydrogen bonds with polyanions except for the O30W and O31W water mol­ecules.

Figure 3

Polyhedral view of the heteropolyanion in (I), with O⋯O contacts of the inter-polyanion hydrogen bonds shown as dashed lines. [Symmetry codes; (i) −x + 1, −y, −z + 1; (ii) x, y, z − 1; (iii) −x + 1, −y + 1, −z + 1; (iv) x, y + 1, z; (v) −x + 1, −y + 1, −z + 2.]

Synthesis and crystallization

The crude potassium salt of title compound was obtained from the reaction of an Na3[H6CrMo6O24]·8H2O (Perloff, 1970 ▸) solution and excess KCl solution. The title compound was obtained by recrystallization of crude K3[H6CrMo6O24]·8H2O at pH 1.80.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. All the H atoms in the polyanions and all water H atoms were positioned using difference Fourier maps. All H atoms in the polyanion were refined freely, but the H5 atoms were refined with a distance restraint of O5B—H5 and O16B iii—H5 (Table 1 ▸) using the SADI command in SHELXL97 (Sheldrick, 2008 ▸); σ = 0.01, the distances between the first and second named bonds were restrained to be equal with an effective standard deviation sigma in order to locate the H5 atom on the pseudocentre between the O5B and O16B atoms. The H atoms of all water mol­ecules (OW) were refined with a distance restraint of O—H = 0.95 (3) Å using the DFIX command, and were included in the refinement with U iso(H) = 1.5U eq(O). The highest peak in the difference map is 1.62 Å from O9T.

Table 2

Experimental details

Crystal data
Chemical formula	K2[H7CrMo6O24]8H2O
M r	1241.02
Crystal system, space group	Triclinic, P
Temperature (K)	446
a, b, c ()	10.4588(2), 10.8553(2), 12.6287(3)
, , ()	99.296(1), 94.469(1), 99.283(1)
V (3)	1388.44(5)
Z	2
Radiation type	Mo K
(mm1)	3.42
Crystal size (mm)	0.18 0.11 0.09
Data collection
Diffractometer	Bruker SMART APEXII CCD
Absorption correction	Multi-scan (SADABS; Sheldrick, 2008 ▸)
T min, T max	0.645, 0.746
No. of measured, independent and observed [I > 2(I)] reflections	23489, 6028, 5893
R int	0.025
(sin /)max (1)	0.639
Refinement
R[F 2 > 2(F 2)], wR(F 2), S	0.024, 0.064, 1.11
No. of reflections	6028
No. of parameters	450
No. of restraints	17
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
max, min (e 3)	1.58, 0.67

Computer programs: APEX2 and SAINT (Bruker, 2009 ▸), SHELXS97 and SHELXL97 (Sheldrick, 2008 ▸), ORTEP-3 for Windows (Farrugia, 2012 ▸), PLATON (Spek, 2009 ▸) and DIAMOND (Brandenburg, 1998 ▸).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989015000390/br2242sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015000390/br2242Isup2.hkl

CCDC reference: 1042715

Additional supporting information: crystallographic information; 3D view; checkCIF report

K2[H7CrMo6O24]·8H2O	Z = 2
Mr = 1241.02	F(000) = 1186
Triclinic, P1	Dx = 2.968 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 10.4588 (2) Å	Cell parameters from 9896 reflections
b = 10.8553 (2) Å	θ = 2.5–33.5°
c = 12.6287 (3) Å	µ = 3.42 mm−1
α = 99.296 (1)°	T = 446 K
β = 94.469 (1)°	Block, purple
γ = 99.283 (1)°	0.18 × 0.11 × 0.09 mm
V = 1388.44 (5) Å3

Bruker SMART APEXII CCD diffractometer	6028 independent reflections
Radiation source: Rotating Anode	5893 reflections with I > 2σ(I)
Graphite multilayer monochromator	Rint = 0.025
Detector resolution: 10.0 pixels mm-1	θmax = 27.0°, θmin = 1.6°
φ and ω scans	h = −13→13
Absorption correction: multi-scan (SADABS; Sheldrick, 2008)	k = −13→13
Tmin = 0.645, Tmax = 0.746	l = −16→16
23489 measured reflections

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.024	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.064	w = 1/[σ2(Fo2) + (0.0255P)2 + 6.3059P] where P = (Fo2 + 2Fc2)/3
S = 1.11	(Δ/σ)max = 0.001
6028 reflections	Δρmax = 1.58 e Å−3
450 parameters	Δρmin = −0.67 e Å−3
17 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.00391 (16)

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.

	x	y	z	Uiso*/Ueq
Cr1	0.5000	0.0000	1.0000	0.00813 (15)
Cr2	0.5000	0.5000	0.5000	0.00762 (15)
Mo1	0.23267 (3)	0.13627 (3)	0.99546 (2)	0.01127 (8)
Mo2	0.20792 (3)	−0.17249 (3)	0.90598 (2)	0.01086 (8)
Mo3	0.47636 (3)	−0.31129 (3)	0.92212 (2)	0.01051 (8)
Mo4	0.79232 (3)	0.42389 (3)	0.46268 (2)	0.00994 (8)
Mo5	0.52144 (3)	0.19391 (3)	0.43518 (2)	0.00938 (8)
Mo6	0.23147 (3)	0.27465 (3)	0.46825 (2)	0.00952 (8)
K1	0.06894 (8)	0.02275 (9)	0.66878 (7)	0.02014 (17)
K2	0.92835 (8)	0.58495 (9)	0.77823 (7)	0.02212 (18)
O1C	0.4157 (2)	0.1138 (2)	1.0986 (2)	0.0113 (5)
H1	0.414 (6)	0.100 (5)	1.151 (5)	0.033 (16)*
O2C	0.3526 (2)	0.0070 (2)	0.8952 (2)	0.0099 (5)
H2	0.362 (5)	0.029 (5)	0.842 (4)	0.028 (14)*
O3C	0.3916 (2)	−0.1598 (2)	1.0194 (2)	0.0109 (5)
H3	0.386 (5)	−0.166 (5)	1.083 (5)	0.034 (15)*
O4B	0.1720 (2)	−0.0378 (2)	1.0107 (2)	0.0137 (5)
O5B	0.3370 (2)	−0.2592 (2)	0.83029 (19)	0.0121 (5)
H5	0.334 (9)	−0.271 (9)	0.7314 (10)	0.12 (3)*
O6B	0.6225 (2)	−0.2660 (2)	1.0259 (2)	0.0131 (5)
O7T	0.1329 (3)	0.1463 (3)	0.8855 (2)	0.0196 (6)
O8T	0.1748 (3)	0.2124 (3)	1.1047 (2)	0.0201 (6)
O9T	0.1160 (3)	−0.1627 (3)	0.7911 (2)	0.0171 (5)
O10T	0.1270 (3)	−0.2975 (3)	0.9535 (2)	0.0192 (6)
O11T	0.3862 (3)	−0.4281 (3)	0.9735 (2)	0.0184 (5)
O12T	0.5387 (3)	−0.3860 (2)	0.8119 (2)	0.0158 (5)
O13C	0.4147 (2)	0.3516 (2)	0.3922 (2)	0.0099 (5)
H13	0.415 (5)	0.359 (5)	0.338 (4)	0.015 (12)*
O14C	0.3526 (2)	0.4487 (2)	0.5815 (2)	0.0100 (5)
H14	0.357 (5)	0.437 (5)	0.643 (4)	0.019 (12)*
O15C	0.3920 (2)	0.6197 (2)	0.4556 (2)	0.0096 (5)
H15	0.376 (5)	0.616 (5)	0.395 (5)	0.034 (15)*
O16B	0.6638 (2)	0.2882 (2)	0.36714 (19)	0.0110 (5)
O17B	0.8278 (2)	0.5773 (2)	0.56733 (19)	0.0113 (5)
O18B	0.3755 (2)	0.1934 (2)	0.5151 (2)	0.0116 (5)
O19T	0.8822 (3)	0.4581 (3)	0.3615 (2)	0.0179 (5)
O20T	0.8741 (3)	0.3335 (3)	0.5323 (2)	0.0187 (6)
O21T	0.6089 (2)	0.1094 (3)	0.5064 (2)	0.0165 (5)
O22T	0.4583 (3)	0.0957 (2)	0.3159 (2)	0.0157 (5)
O23T	0.1361 (2)	0.2368 (3)	0.5654 (2)	0.0155 (5)
O24T	0.1681 (3)	0.1718 (3)	0.3527 (2)	0.0176 (5)
O25W	0.8716 (3)	0.0732 (3)	0.5305 (2)	0.0206 (6)
H25A	0.783 (3)	0.069 (5)	0.535 (4)	0.031*
H25B	0.891 (5)	0.159 (3)	0.530 (4)	0.031*
O26W	0.8483 (3)	0.0653 (3)	0.7784 (2)	0.0235 (6)
H26A	0.863 (5)	0.051 (5)	0.847 (3)	0.035*
H26B	0.827 (5)	−0.012 (3)	0.735 (4)	0.035*
O27W	0.3568 (3)	0.1168 (3)	0.7134 (2)	0.0261 (7)
H27A	0.367 (6)	0.113 (5)	0.643 (2)	0.039*
H27B	0.337 (6)	0.194 (3)	0.739 (4)	0.039*
O28W	0.6802 (3)	0.4221 (3)	0.7521 (2)	0.0208 (6)
H28A	0.629 (4)	0.464 (5)	0.794 (4)	0.031*
H28B	0.669 (5)	0.345 (3)	0.770 (4)	0.031*
O29W	0.8747 (4)	0.5437 (4)	0.9821 (3)	0.0390 (8)
H29A	0.810 (5)	0.479 (5)	0.998 (5)	0.059*
H29B	0.851 (6)	0.611 (5)	0.948 (5)	0.059*
O30W	0.0221 (5)	0.3490 (4)	0.7849 (5)	0.0640 (14)
H30A	−0.019 (9)	0.333 (9)	0.716 (4)	0.096*
H30B	−0.022 (8)	0.268 (4)	0.786 (7)	0.096*
O31W	0.3602 (3)	0.8223 (3)	0.2192 (2)	0.0206 (6)
H31A	0.295 (4)	0.868 (5)	0.226 (4)	0.031*
H31B	0.432 (4)	0.870 (4)	0.261 (4)	0.031*
O32W	0.3044 (3)	0.3645 (3)	0.7732 (2)	0.0245 (6)
H32A	0.219 (3)	0.366 (5)	0.772 (4)	0.037*
H32B	0.346 (5)	0.392 (5)	0.839 (3)	0.037*

	U11	U22	U33	U12	U13	U23
Cr1	0.0082 (3)	0.0076 (4)	0.0084 (3)	0.0010 (3)	0.0006 (3)	0.0013 (3)
Cr2	0.0070 (3)	0.0074 (4)	0.0086 (3)	0.0013 (3)	0.0009 (3)	0.0015 (3)
Mo1	0.01095 (14)	0.01186 (15)	0.01156 (14)	0.00390 (11)	0.00131 (11)	0.00177 (11)
Mo2	0.00957 (14)	0.01067 (15)	0.01165 (14)	0.00013 (11)	0.00034 (10)	0.00198 (11)
Mo3	0.01252 (14)	0.00810 (15)	0.01083 (14)	0.00194 (11)	0.00182 (11)	0.00109 (11)
Mo4	0.00749 (13)	0.00962 (15)	0.01315 (14)	0.00208 (10)	0.00177 (10)	0.00245 (11)
Mo5	0.00942 (14)	0.00756 (14)	0.01113 (14)	0.00169 (10)	0.00103 (10)	0.00138 (10)
Mo6	0.00820 (14)	0.00838 (15)	0.01158 (14)	0.00012 (10)	0.00090 (10)	0.00201 (11)
K1	0.0189 (4)	0.0248 (4)	0.0182 (4)	0.0039 (3)	0.0019 (3)	0.0081 (3)
K2	0.0173 (4)	0.0303 (5)	0.0177 (4)	0.0012 (3)	0.0017 (3)	0.0040 (3)
O1C	0.0135 (12)	0.0115 (12)	0.0089 (12)	0.0027 (9)	0.0016 (9)	0.0011 (10)
O2C	0.0108 (11)	0.0116 (12)	0.0081 (11)	0.0022 (9)	0.0019 (9)	0.0036 (9)
O3C	0.0135 (12)	0.0103 (12)	0.0093 (11)	0.0018 (9)	0.0017 (9)	0.0024 (9)
O4B	0.0130 (12)	0.0148 (13)	0.0135 (12)	0.0022 (10)	0.0041 (9)	0.0022 (10)
O5B	0.0127 (12)	0.0128 (12)	0.0106 (11)	0.0036 (9)	0.0005 (9)	0.0004 (9)
O6B	0.0144 (12)	0.0117 (12)	0.0129 (12)	0.0024 (10)	−0.0009 (9)	0.0026 (9)
O7T	0.0159 (13)	0.0214 (15)	0.0212 (14)	0.0031 (11)	−0.0022 (10)	0.0058 (11)
O8T	0.0206 (14)	0.0200 (14)	0.0203 (13)	0.0046 (11)	0.0066 (11)	0.0019 (11)
O9T	0.0168 (13)	0.0182 (14)	0.0157 (13)	0.0024 (11)	−0.0004 (10)	0.0028 (10)
O10T	0.0184 (13)	0.0168 (14)	0.0230 (14)	0.0013 (11)	0.0040 (11)	0.0062 (11)
O11T	0.0199 (13)	0.0145 (13)	0.0219 (13)	0.0023 (11)	0.0037 (11)	0.0063 (11)
O12T	0.0198 (13)	0.0140 (13)	0.0136 (12)	0.0047 (10)	0.0029 (10)	0.0002 (10)
O13C	0.0118 (12)	0.0104 (12)	0.0073 (12)	0.0014 (9)	0.0006 (9)	0.0019 (9)
O14C	0.0086 (11)	0.0130 (12)	0.0088 (11)	0.0014 (9)	0.0007 (9)	0.0039 (9)
O15C	0.0110 (11)	0.0096 (12)	0.0082 (11)	0.0019 (9)	−0.0002 (9)	0.0021 (9)
O16B	0.0122 (11)	0.0120 (12)	0.0083 (11)	0.0014 (9)	0.0033 (9)	0.0003 (9)
O17B	0.0103 (11)	0.0106 (12)	0.0124 (11)	0.0013 (9)	−0.0005 (9)	0.0022 (9)
O18B	0.0112 (11)	0.0106 (12)	0.0140 (12)	0.0022 (9)	0.0029 (9)	0.0045 (9)
O19T	0.0144 (12)	0.0169 (14)	0.0225 (14)	0.0003 (10)	0.0089 (10)	0.0031 (11)
O20T	0.0147 (13)	0.0159 (14)	0.0263 (14)	0.0055 (10)	−0.0019 (11)	0.0055 (11)
O21T	0.0127 (12)	0.0150 (13)	0.0240 (14)	0.0046 (10)	0.0028 (10)	0.0075 (11)
O22T	0.0162 (12)	0.0136 (13)	0.0156 (12)	0.0005 (10)	0.0014 (10)	0.0001 (10)
O23T	0.0139 (12)	0.0150 (13)	0.0187 (13)	0.0008 (10)	0.0049 (10)	0.0065 (10)
O24T	0.0165 (13)	0.0187 (14)	0.0168 (13)	0.0050 (11)	−0.0018 (10)	0.0005 (10)
O25W	0.0178 (13)	0.0182 (14)	0.0278 (15)	0.0071 (11)	0.0016 (11)	0.0062 (12)
O26W	0.0302 (16)	0.0238 (16)	0.0165 (13)	0.0047 (13)	0.0058 (12)	0.0023 (12)
O27W	0.0351 (17)	0.0310 (17)	0.0174 (14)	0.0118 (14)	0.0055 (12)	0.0121 (13)
O28W	0.0271 (15)	0.0180 (14)	0.0195 (14)	0.0085 (12)	0.0042 (11)	0.0050 (11)
O29W	0.040 (2)	0.040 (2)	0.043 (2)	0.0083 (16)	0.0114 (16)	0.0201 (17)
O30W	0.046 (3)	0.038 (2)	0.117 (4)	0.015 (2)	0.013 (3)	0.030 (3)
O31W	0.0258 (15)	0.0192 (15)	0.0157 (13)	0.0010 (12)	0.0010 (11)	0.0034 (11)
O32W	0.0257 (15)	0.0305 (17)	0.0152 (13)	−0.0007 (13)	0.0019 (12)	0.0036 (12)

Cr1—O1Ci	1.970 (2)	Mo6—O18B	1.964 (2)
Cr1—O1C	1.970 (3)	Mo6—O14C	2.301 (2)
Cr1—O2C	1.971 (2)	Mo6—O13C	2.307 (3)
Cr1—O2Ci	1.971 (2)	K1—O25Wiii	2.722 (3)
Cr1—O3Ci	1.975 (2)	K1—O25Wiv	2.778 (3)
Cr1—O3C	1.975 (2)	K1—O9T	2.809 (3)
Cr2—O13Cii	1.970 (2)	K1—O7T	2.825 (3)
Cr2—O13C	1.970 (2)	K1—O26Wiv	2.844 (3)
Cr2—O15C	1.972 (2)	K1—O23T	2.862 (3)
Cr2—O15Cii	1.972 (2)	K1—O24Tv	2.950 (3)
Cr2—O14Cii	1.976 (2)	K1—O27W	2.997 (3)
Cr2—O14C	1.976 (2)	K2—O29W	2.767 (4)
Mo1—O8T	1.696 (3)	K2—O17B	2.769 (3)
Mo1—O7T	1.699 (3)	K2—O19Tvi	2.799 (3)
Mo1—O4B	1.939 (3)	K2—O8Tvii	2.855 (3)
Mo1—O6Bi	1.962 (3)	K2—O28W	2.858 (3)
Mo1—O1C	2.299 (3)	K2—O10Tviii	2.891 (3)
Mo1—O2C	2.321 (2)	K2—O30Wix	2.897 (4)
Mo2—O10T	1.701 (3)	K2—O9Tviii	3.074 (3)
Mo2—O9T	1.705 (3)	O1C—H1	0.70 (6)
Mo2—O4B	1.913 (3)	O2C—H2	0.76 (6)
Mo2—O5B	1.986 (2)	O3C—H3	0.82 (6)
Mo2—O3C	2.276 (2)	O5B—O16Biii	2.461 (3)
Mo2—O2C	2.296 (3)	O5B—H5	1.232 (7)
Mo3—O11T	1.701 (3)	O13C—H13	0.70 (5)
Mo3—O12T	1.722 (3)	O14C—H14	0.81 (5)
Mo3—O6B	1.879 (2)	O15C—H15	0.76 (6)
Mo3—O5B	2.001 (2)	O16B—H5iii	1.231 (7)
Mo3—O3C	2.233 (2)	O25W—H25A	0.92 (3)
Mo3—O1Ci	2.321 (3)	O25W—H25B	0.93 (3)
Mo4—O19T	1.698 (3)	O26W—H26A	0.91 (3)
Mo4—O20T	1.702 (3)	O26W—H26B	0.91 (3)
Mo4—O17B	1.916 (2)	O27W—H27A	0.90 (3)
Mo4—O16B	1.992 (2)	O27W—H27B	0.91 (3)
Mo4—O15Cii	2.275 (2)	O28W—H28A	0.91 (3)
Mo4—O14Cii	2.306 (2)	O28W—H28B	0.90 (3)
Mo5—O21T	1.703 (3)	O29W—H29A	0.95 (3)
Mo5—O22T	1.715 (3)	O29W—H29B	0.96 (3)
Mo5—O18B	1.894 (2)	O30W—H30A	0.92 (3)
Mo5—O16B	1.998 (2)	O30W—H30B	0.93 (3)
Mo5—O15Cii	2.264 (2)	O31W—H31A	0.90 (3)
Mo5—O13C	2.301 (2)	O31W—H31B	0.92 (3)
Mo6—O23T	1.700 (3)	O32W—H32A	0.89 (3)
Mo6—O24T	1.703 (3)	O32W—H32B	0.89 (3)
Mo6—O17Bii	1.919 (2)
O1Ci—Cr1—O1C	180.00 (13)	O23T—Mo6—O24T	106.46 (13)
O1Ci—Cr1—O2C	96.36 (11)	O23T—Mo6—O17Bii	102.39 (12)
O1C—Cr1—O2C	83.64 (10)	O24T—Mo6—O17Bii	98.17 (12)
O1Ci—Cr1—O2Ci	83.64 (10)	O23T—Mo6—O18B	95.85 (11)
O1C—Cr1—O2Ci	96.36 (11)	O24T—Mo6—O18B	100.31 (12)
O2C—Cr1—O2Ci	180.000 (1)	O17Bii—Mo6—O18B	149.10 (10)
O1Ci—Cr1—O3Ci	96.40 (11)	O23T—Mo6—O14C	92.72 (11)
O1C—Cr1—O3Ci	83.60 (11)	O24T—Mo6—O14C	160.17 (11)
O2C—Cr1—O3Ci	96.11 (10)	O17Bii—Mo6—O14C	72.22 (9)
O2Ci—Cr1—O3Ci	83.89 (10)	O18B—Mo6—O14C	82.29 (10)
O1Ci—Cr1—O3C	83.60 (11)	O23T—Mo6—O13C	158.88 (11)
O1C—Cr1—O3C	96.40 (11)	O24T—Mo6—O13C	92.55 (11)
O2C—Cr1—O3C	83.89 (10)	O17Bii—Mo6—O13C	83.47 (10)
O2Ci—Cr1—O3C	96.11 (10)	O18B—Mo6—O13C	71.21 (9)
O3Ci—Cr1—O3C	180.0	O14C—Mo6—O13C	69.50 (9)
O13Cii—Cr2—O13C	180.00 (11)	O25Wiii—K1—O25Wiv	76.62 (9)
O13Cii—Cr2—O15C	83.38 (10)	O25Wiii—K1—O9T	103.15 (9)
O13C—Cr2—O15C	96.62 (10)	O25Wiv—K1—O9T	139.32 (9)
O13Cii—Cr2—O15Cii	96.62 (10)	O25Wiii—K1—O7T	153.61 (9)
O13C—Cr2—O15Cii	83.38 (10)	O25Wiv—K1—O7T	123.85 (9)
O15C—Cr2—O15Cii	180.00 (14)	O9T—K1—O7T	72.86 (8)
O13Cii—Cr2—O14Cii	83.45 (11)	O25Wiii—K1—O26Wiv	140.01 (9)
O13C—Cr2—O14Cii	96.55 (10)	O25Wiv—K1—O26Wiv	68.70 (9)
O15C—Cr2—O14Cii	96.19 (10)	O9T—K1—O26Wiv	91.09 (9)
O15Cii—Cr2—O14Cii	83.81 (10)	O7T—K1—O26Wiv	66.28 (8)
O13Cii—Cr2—O14C	96.55 (10)	O25Wiii—K1—O23T	74.25 (8)
O13C—Cr2—O14C	83.45 (11)	O25Wiv—K1—O23T	64.14 (8)
O15C—Cr2—O14C	83.81 (10)	O9T—K1—O23T	156.00 (8)
O15Cii—Cr2—O14C	96.19 (10)	O7T—K1—O23T	98.65 (8)
O14Cii—Cr2—O14C	180.000 (1)	O26Wiv—K1—O23T	106.24 (9)
O8T—Mo1—O7T	106.84 (14)	O25Wiii—K1—O24Tv	91.73 (9)
O8T—Mo1—O4B	99.43 (12)	O25Wiv—K1—O24Tv	68.54 (8)
O7T—Mo1—O4B	100.45 (12)	O9T—K1—O24Tv	70.82 (8)
O8T—Mo1—O6Bi	101.16 (12)	O7T—K1—O24Tv	110.61 (8)
O7T—Mo1—O6Bi	96.54 (12)	O26Wiv—K1—O24Tv	57.72 (8)
O4B—Mo1—O6Bi	148.14 (11)	O23T—K1—O24Tv	132.52 (8)
O8T—Mo1—O1C	91.58 (12)	O25Wiii—K1—O27W	83.91 (9)
O7T—Mo1—O1C	160.03 (12)	O25Wiv—K1—O27W	134.40 (9)
O4B—Mo1—O1C	83.63 (10)	O9T—K1—O27W	84.97 (8)
O6Bi—Mo1—O1C	71.79 (10)	O7T—K1—O27W	69.83 (8)
O8T—Mo1—O2C	159.33 (12)	O26Wiv—K1—O27W	135.05 (9)
O7T—Mo1—O2C	93.25 (12)	O23T—K1—O27W	71.05 (8)
O4B—Mo1—O2C	71.53 (10)	O24Tv—K1—O27W	153.77 (8)
O6Bi—Mo1—O2C	80.83 (10)	O29W—K2—O17B	146.30 (10)
O1C—Mo1—O2C	69.32 (9)	O29W—K2—O19Tvi	137.95 (10)
O10T—Mo2—O9T	105.54 (13)	O17B—K2—O19Tvi	70.05 (8)
O10T—Mo2—O4B	98.88 (12)	O29W—K2—O8Tvii	67.52 (10)
O9T—Mo2—O4B	104.05 (12)	O17B—K2—O8Tvii	102.90 (8)
O10T—Mo2—O5B	98.79 (12)	O19Tvi—K2—O8Tvii	140.83 (9)
O9T—Mo2—O5B	95.15 (11)	O29W—K2—O28W	73.32 (10)
O4B—Mo2—O5B	149.26 (11)	O17B—K2—O28W	74.70 (8)
O10T—Mo2—O3C	93.09 (11)	O19Tvi—K2—O28W	121.69 (9)
O9T—Mo2—O3C	157.67 (11)	O8Tvii—K2—O28W	91.06 (9)
O4B—Mo2—O3C	84.69 (10)	O29W—K2—O10Tviii	63.77 (10)
O5B—Mo2—O3C	69.42 (9)	O17B—K2—O10Tviii	147.47 (8)
O10T—Mo2—O2C	161.78 (11)	O19Tvi—K2—O10Tviii	91.15 (8)
O9T—Mo2—O2C	92.28 (11)	O8Tvii—K2—O10Tviii	74.69 (8)
O4B—Mo2—O2C	72.55 (10)	O28W—K2—O10Tviii	137.05 (8)
O5B—Mo2—O2C	83.06 (10)	O29W—K2—O30Wix	79.00 (15)
O3C—Mo2—O2C	70.46 (9)	O17B—K2—O30Wix	107.05 (14)
O11T—Mo3—O12T	106.13 (13)	O19Tvi—K2—O30Wix	66.13 (12)
O11T—Mo3—O6B	100.61 (12)	O8Tvii—K2—O30Wix	146.33 (14)
O12T—Mo3—O6B	102.43 (12)	O28W—K2—O30Wix	82.43 (11)
O11T—Mo3—O5B	100.44 (12)	O10Tviii—K2—O30Wix	87.75 (13)
O12T—Mo3—O5B	92.82 (11)	O29W—K2—O9Tviii	110.89 (10)
O6B—Mo3—O5B	149.33 (11)	O17B—K2—O9Tviii	94.26 (7)
O11T—Mo3—O3C	92.56 (11)	O19Tvi—K2—O9Tviii	72.19 (8)
O12T—Mo3—O3C	156.92 (11)	O8Tvii—K2—O9Tviii	69.98 (8)
O6B—Mo3—O3C	86.90 (10)	O28W—K2—O9Tviii	155.67 (8)
O5B—Mo3—O3C	70.11 (9)	O10Tviii—K2—O9Tviii	53.95 (7)
O11T—Mo3—O1Ci	161.82 (11)	O30Wix—K2—O9Tviii	121.81 (11)
O12T—Mo3—O1Ci	91.92 (11)	Cr1—O1C—Mo1	103.93 (11)
O6B—Mo3—O1Ci	72.66 (10)	Cr1—O1C—Mo3i	101.37 (11)
O5B—Mo3—O1Ci	80.47 (10)	Mo1—O1C—Mo3i	91.53 (9)
O3C—Mo3—O1Ci	70.51 (9)	Cr1—O2C—Mo2	102.54 (11)
O19T—Mo4—O20T	106.50 (14)	Cr1—O2C—Mo1	103.10 (10)
O19T—Mo4—O17B	104.09 (12)	Mo2—O2C—Mo1	92.00 (9)
O20T—Mo4—O17B	98.21 (12)	Cr1—O3C—Mo3	104.32 (11)
O19T—Mo4—O16B	94.09 (12)	Cr1—O3C—Mo2	103.08 (11)
O20T—Mo4—O16B	99.92 (12)	Mo3—O3C—Mo2	97.93 (10)
O17B—Mo4—O16B	149.41 (10)	Mo2—O4B—Mo1	119.12 (13)
O19T—Mo4—O15Cii	156.61 (11)	Mo2—O5B—Mo3	117.13 (12)
O20T—Mo4—O15Cii	93.29 (11)	Mo2—O5B—O16Biii	121.72 (12)
O17B—Mo4—O15Cii	84.78 (10)	Mo3—O5B—O16Biii	121.01 (12)
O16B—Mo4—O15Cii	69.81 (9)	Mo3—O6B—Mo1i	118.98 (13)
O19T—Mo4—O14Cii	91.56 (11)	Cr2—O13C—Mo5	102.58 (10)
O20T—Mo4—O14Cii	161.32 (12)	Cr2—O13C—Mo6	103.49 (11)
O17B—Mo4—O14Cii	72.15 (9)	Mo5—O13C—Mo6	92.48 (9)
O16B—Mo4—O14Cii	83.13 (9)	Cr2—O14C—Mo6	103.53 (11)
O15Cii—Mo4—O14Cii	70.30 (9)	Cr2—O14C—Mo4ii	102.33 (10)
O21T—Mo5—O22T	106.65 (13)	Mo6—O14C—Mo4ii	91.61 (8)
O21T—Mo5—O18B	99.32 (12)	Cr2—O15C—Mo5ii	103.82 (10)
O22T—Mo5—O18B	102.90 (12)	Cr2—O15C—Mo4ii	103.53 (10)
O21T—Mo5—O16B	100.17 (11)	Mo5ii—O15C—Mo4ii	97.60 (9)
O22T—Mo5—O16B	93.06 (11)	Mo4—O16B—Mo5	117.72 (11)
O18B—Mo5—O16B	150.02 (10)	Mo4—O17B—Mo6ii	118.91 (12)
O21T—Mo5—O15Cii	93.02 (11)	Mo5—O18B—Mo6	119.24 (12)
O22T—Mo5—O15Cii	156.22 (11)	H25A—O25W—H25B	96 (5)
O18B—Mo5—O15Cii	86.51 (10)	H26A—O26W—H26B	107 (5)
O16B—Mo5—O15Cii	69.93 (9)	H27A—O27W—H27B	108 (5)
O21T—Mo5—O13C	161.33 (11)	H28A—O28W—H28B	104 (5)
O22T—Mo5—O13C	91.69 (11)	H29A—O29W—H29B	121 (6)
O18B—Mo5—O13C	72.50 (10)	H30A—O30W—H30B	83 (7)
O16B—Mo5—O13C	81.93 (10)	H31A—O31W—H31B	107 (5)
O15Cii—Mo5—O13C	70.11 (9)	H32A—O32W—H32B	112 (5)

D—H···A	D—H	H···A	D···A	D—H···A
O1C—H1···O22Tx	0.70 (6)	2.11 (6)	2.789 (4)	164 (6)
O2C—H2···O27W	0.76 (6)	2.01 (6)	2.753 (4)	166 (6)
O3C—H3···O31Wxi	0.82 (6)	1.79 (6)	2.604 (4)	176 (6)
O5B—H5···O16Biii	1.23 (1)	1.23 (1)	2.461 (3)	175 (5)
O13C—H13···O12Tiii	0.70 (5)	2.05 (5)	2.734 (4)	167 (5)
O14C—H14···O32W	0.81 (5)	2.01 (5)	2.776 (4)	158 (5)
O15C—H15···O28Wii	0.76 (6)	1.87 (6)	2.619 (4)	170 (6)
O25W—H25A···O21T	0.92 (3)	1.96 (3)	2.838 (4)	157 (5)
O25W—H25B···O20T	0.93 (3)	1.92 (3)	2.819 (4)	162 (5)
O26W—H26A···O4Bi	0.91 (3)	1.89 (3)	2.748 (4)	158 (5)
O26W—H26B···O24Tiii	0.91 (3)	1.91 (3)	2.798 (4)	164 (5)
O27W—H27A···O18B	0.90 (3)	1.95 (4)	2.775 (4)	151 (5)
O27W—H27B···O32W	0.91 (3)	1.92 (3)	2.825 (5)	171 (5)
O28W—H28A···O12Txii	0.91 (3)	2.00 (4)	2.785 (4)	144 (5)
O28W—H28B···O31Wii	0.90 (3)	1.82 (3)	2.706 (4)	170 (5)
O29W—H29A···O11Ti	0.95 (3)	2.11 (4)	2.949 (5)	146 (6)
O29W—H29B···O8Tvii	0.96 (3)	2.18 (3)	3.126 (5)	169 (6)
O31W—H31A···O26Wii	0.90 (3)	1.77 (3)	2.665 (4)	170 (5)
O31W—H31B···O27Wii	0.92 (3)	2.18 (4)	2.952 (4)	141 (4)
O32W—H32A···O30W	0.89 (3)	2.06 (3)	2.947 (6)	171 (5)
O32W—H32B···O6Bi	0.89 (3)	2.39 (5)	3.000 (4)	126 (5)