catena-Poly[thorium(IV)-tetra­kis­(μ₂-3-carb­oxy­adamantane-1-carboxyl­ato)]: a quadruple helical strand driven by a synergy of coordination and hydrogen bonding

The title compound, [Th(C₁₂H₁₅O₄)₄]_n, is the first homoleptic thorium–carboxyl­ate coordination polymer. It has a one-dimensional structure supported by the bidentate bridging coordination of the singly charged 3-carb­oxy­adamantane-1-carboxyl­ate (HADC⁻) anions. The metal ion is situated on a fourfold axis (site symmetry 4) and possesses a square-anti­prismatic ThO₈ coordination, including four bonds to anionic carboxyl­ate groups [Th—O = 2.359 (2) Å] and four to neutral carboxyl groups [Th—O = 2.426 (2) Å], while a strong hydrogen bond between these two kinds of O-atom donor [O...O = 2.494 (3) Å] affords planar pseudo-chelated Th{CO₂...HO₂C} cycles. This combination of coordination and hydrogen bonding is responsible for the generation of quadruple helical strands of HADC⁻ ligands, which are wrapped around a linear chain of Th^IV ions [Th...Th = 7.5240 (4) Å] defining the helical axis.

S1. Comment

A particular issue of supramolecular chemistry is spontaneous self-assembly of chiral metal–organic architectures involving helical elements (Seeber et al., 2006). In recent years, different types of discrete helicates and infinite helices have been developed under an elegant approach utilizing polychelating ligands related to the oligopyridine family (Albrecht, 2001). In such systems, the preferred coordination geometry at the metal ions determines the helical twist and thus provides a necessary chiral prerequisite. This leads to the generation of single or multiple ligand strands wrapped around a set of metal ions, which define the helical axis (Lehn et al., 1987). Double-stranded helicates are common for tetrahedral Cu^I and Ag^I ions, and in the same fashion tris-chelate coordination of octahedral metal ions may be applied for the generation of triple-stranded helical arrays (Albrecht, 2001). In the present contribution, we report how a quadruple-stranded helical architecture can be designed without the need for complicated polychelating ligands, while utilizing the typical eight-fold coordination of Th^IV ions accompanied by strong interligand hydrogen-bonding interactions. In this context, we have prepared the title compound, Th⁴⁺(HADC^-)₄, (I), and describe its structure here. The bifunctional ADC^2- ligand (ADC^2- is the adamantane-1,3-dicarboxylate dianion) has been the subject of growing interest as a geometrically rigid angular connector to sustain the structures of metal–organic polymers, such as Zn²⁺ (Nielsen et al., 2008), Co²⁺ (Tang et al., 2009), Eu³⁺ (Millange et al., 2004) and UO₂²⁺ (Rusanova et al., 2010) complexes, whereas the particular supramolecular potential of the singly charged 3-carboxyadamantane-1-carboxylate (HADC^-) anion does not appear to have been considered.

Compound (I) is the first homoleptic Th carboxylate coordination polymer. A few examples of carboxylate/fluoride and carboxylate/aqua Th compounds involving isophthalic (Kim et al., 2003), trimesic (Ok et al., 2008), 1,3-adamantanediacetic (Ok & O'Hare, 2008) and some heteroaryl dicarboxylate anions (Frisch & Cahill, 2008; Ziegelgruber et al., 2008) have been characterized in the context of porous metal–organic framework materials.

The asymmetric unit of (I) contains an HADC^- anion and a Th⁴⁺ cation (Fig. 1), which is situated on a fourfold axis (site symmetry 4). The metal ion is eight-coordinated, ThO₈, and adopts a slightly distorted square-antiprismatic geometry, with the angle of twist between the upper and lower square faces [40.0 (3)°] approaching the value of 45° for an ideal square antiprism (Fig. 2). There are two different kinds of singly coordinated O-atom donor: four anionic carboxylate groups, –COO^-, and four neutral carboxylic acid groups, –COOH, constituting two square faces of the coordination polyhedron. Although the anionic groups adopt slightly shorter Th—O bond lengths [Th1—O1 = 2.359 (2) Å versus Th1—O3^vi = 2.426 (2) Å; symmetry code: (vi) x, y, z - 1] (Table 1), all the coordination interactions are rather uniform.

A salient feature of the alignment of the eight donors originates in a strong hydrogen bond between the coordinated —COO^- and —COOH groups: O4—H1···O2^vii = 2.494 (3) Å, H1···O2^vii = 1.64 Å, O4—H1···O2^vii = 178° [symmetry code: (vii) -y, x, 1 + z]. In this way, four pairs of anionic and neutral donor groups, which are related by a fourfold axis, yield four planar pseudochelated Th{CO₂H···O₂C} fragments (Fig. 2), and therefore the coordination around the Th^IV ion may be directly related to the simpler square-antiprismatic molecular tetrakis-chelates, for example Th malonate complexes, with a very similar distribution of Th—O bond lengths [2.337 (2)–2.450 (2) Å; Zhang et al., 2000].

Such an interplay of coordination and hydrogen-bonding interactions has a pronounced impact on the helical supramolecular structure of (I) and it could be considered as a design tool. This kind of supramolecular synthon is well known for molecular carboxylates. It is particularly important for the structure of hydrogen pivalate complexes, for example [Fe(^tBuCO₂)₃(^tBuCO₂H)₃] (Kiskin et al., 2006) and [Y₂(^tBuCO₂)₆(^tBuCO₂H)₆] (Kiseleva et al., 2006), since the bulky tert-butyl groups provide effective shielding of the complex unit and contribute to the stabilization of the coordination core involving such relatively poor donors as neutral carboxylic acid. This is exactly the case in the present dicarboxylate, featuring two tertiary donor groups installed on the bulky adamantane platform.

The organic ligands of (I) connect pairs of Th^IV ions at a distance of 7.5240 (4) Å [parameter c of the unit cell; symmetry code: (viii) x, y, 1 + z], giving a one-dimensional polymeric array along the c direction in which successive metal ions are linked by quadruple HADC^- bridges (Fig. 3). This motif may also be regarded as a chain of the above-mentioned tetrakis-pseudochelates interconnected by rigid angular 1,3-adamantanediyl spacers, similar to the discrete dinuclear lanthanide complexes with the angular 1,3-phenylene bis-diketonate ligand (Bassett et al., 2004). The resulting architecture is a quadruple-stranded hydrogen-bonded helix, with a pitch of 3c = 22.57 Å, wrapped around the infinite chain of Th^IV ions (Fig. 4). Thus, the chiral information is clearly embedded in the square-antiprismatic coordination geometry of the central atom and the angular configuration of the dicarboxylate linker. All the helical chains possess the same chirality. They are packed in a parallel fashion along the c direction (Fig. 4), with the shortest interchain contact observed between the methylene and carbonyl groups [C4···O2^x = 3.308 (3) Å, C4—H···O2^x = 131°; symmetry code: (x) 1/2 + y, 1/2 - x, 1/2 + z], which possibly indicates a very weak hydrogen bond. It is worth noting that, unlike the simpler double- and triple-stranded helical patterns constructed with polychelating ligands, quadruple helices are relatively uncommon. Recently, Xu & Raymond (2006) reported using Th tetrakis-chelate coordination with bifunctional 4-acyl-2-pyrazolin-5-one ligands for the assembly of discrete quadruple-stranded helicates.

In brief, our findings suggest new possibilities for the generation of multiple-stranded helical arrays while utilizing very simple and general ligand systems and synergy between coordination and hydrogen-bonding interactions.

S2. Experimental

Adamantane-1,3-dicarboxylic acid (H₂ADC) was synthesized by Koch–Haaf carboxylation of 1,3-dihydroxyadamantane (Stetter & Wulff, 1960). Crystals of the title compound were grown in a silica-gel medium. The gelling solution, prepared by neutralization of a 1:10 sodium silicate solution (density 1.39 g cm^-3) with 0.055 M HClO₄ to pH 5, was placed in a U-shaped tube and left for 2 d. Solutions of Th(NO₃)₄.4H₂O (5.5 mg, 0.01 mmol) in water (3 ml) and H₂ADC (9.0 mg, 0.04 mmol) in 0.05 M aqueous ammonia (3 ml) were then placed in two separate parts of the tube over the bottom gel layer. Small colourless prisms of the product, (I), grew in the gel as the initial solutions interdiffused over a period of three months. The crystals were separated from the gel by repeated slurrying in water followed by decantation (yield 7.3 mg, 65%).

S3. Refinement

All H atoms were located in difference maps and then refined as riding, with O—H = 0.85, C—H (CH₂) = 0.97 and C—H (CH) = 0.98 Å, and with U_iso(H) = 1.2U_eq(C) or 1.5U_eq(O).

Computing details

Data collection: IPDS Software (Stoe & Cie, 2000); cell refinement: IPDS Software (Stoe & Cie, 2000); data reduction: IPDS Software (Stoe & Cie, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Version 1.70.01; Farrugia, 1999).

Figures

	Fig. 1. The structure of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 40% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. The square-antiprismatic coordination polyhedron of the Th^IV ion of (I), showing the strong hydrogen bonding between the coordinated –CO2^- and –CO2H groups and the formation of pseudochelate cycles. [Symmetry codes: (i) -y, x, z; (ii) -x, -y, z; (iii) y, -x, z; (iv) -x, -y, z - 1; (v) -y, x, z - 1; (vi) x, y, z - 1; (vii) y, -x, z - 1.]
	Fig. 3. A fragment of the one-dimensional coordination polymer of (I), depicting the quadruple-stranded helical arrangement of the HADC^- ligands along the chain of Th^IV ions, which define the helical axis. A single ligand strand is shown with black bonds. [Symmetry codes: (vii) y, -x, z - 1; (viii) x, y, 1 + z; (ix) -y, x, 1 + z.]
	Fig. 4. A projection of the structure of (I) on the ab plane, showing the packing of the coordination chains. C-bound H atoms have been omitted for clarity. [Please check rephrasing]

catena-Poly[thorium(IV)-tetrakis(µ₂-3-carboxyadamantane-1- carboxylato)]

Crystal data

[Th(C12H15O4)4]	Dx = 1.756 Mg m^−3
Mr = 1125.00	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, I4	Cell parameters from 6302 reflections
a = 16.8182 (9) Å	θ = 2.4–28.0°
c = 7.5240 (4) Å	µ = 3.58 mm^−1
V = 2128.2 (2) Å^3	T = 294 K
Z = 2	Prism, colourless
F(000) = 1132	0.11 × 0.06 × 0.06 mm

Data collection

Stoe IPDS diffractometer	2498 independent reflections
Radiation source: fine-focus sealed tube	2472 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.036
ϕ oscillation scans	θmax = 28.0°, θmin = 2.4°
Absorption correction: numerical [X-RED (Stoe & Cie, 2001) and X-SHAPE (Stoe & Cie, 1999)]	h = −22→21
Tmin = 0.694, Tmax = 0.814	k = −22→20
6302 measured reflections	l = −9→9

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)] = 0.019	H-atom parameters constrained
wR(F^2) = 0.036	w = 1/[σ^2(Fo^2) + (0.0125P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.96	(Δ/σ)max < 0.001
2498 reflections	Δρmax = 0.46 e Å^−3
148 parameters	Δρmin = −0.40 e Å^−3
1 restraint	Absolute structure: Flack (1983), with how many Friedel pairs?
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.020 (6)

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
Th1	0.0000	0.0000	−0.2077	0.01669 (5)
O1	0.12030 (12)	−0.00437 (14)	−0.0466 (3)	0.0396 (6)
O2	0.21529 (13)	−0.09657 (13)	−0.0629 (3)	0.0405 (6)
O3	0.09419 (12)	0.07342 (13)	0.6115 (3)	0.0352 (6)
O4	0.18015 (13)	0.16655 (12)	0.6858 (3)	0.0377 (6)
H1	0.1509	0.1823	0.7709	0.057*
C1	0.22967 (14)	0.00491 (15)	0.1581 (4)	0.0165 (6)
C2	0.17111 (12)	0.03661 (13)	0.2990 (10)	0.0195 (6)
H2A	0.1332	0.0721	0.2430	0.023*
H2B	0.1419	−0.0074	0.3505	0.023*
C3	0.21601 (15)	0.08140 (15)	0.4462 (4)	0.0170 (6)
C4	0.26221 (16)	0.15183 (15)	0.3634 (4)	0.0223 (7)
H4A	0.2253	0.1884	0.3077	0.027*
H4B	0.2908	0.1803	0.4556	0.027*
C5	0.32105 (16)	0.12035 (16)	0.2245 (4)	0.0240 (7)
H5	0.3498	0.1653	0.1722	0.029*
C6	0.38035 (14)	0.06411 (16)	0.3100 (10)	0.0285 (10)
H6A	0.4104	0.0920	0.4007	0.034*
H6B	0.4174	0.0448	0.2211	0.034*
C7	0.33568 (16)	−0.00623 (17)	0.3936 (4)	0.0249 (7)
H7	0.3739	−0.0423	0.4499	0.030*
C8	0.28984 (15)	−0.05118 (15)	0.2484 (4)	0.0211 (10)
H8A	0.2620	−0.0960	0.3006	0.025*
H8B	0.3268	−0.0715	0.1606	0.025*
C9	0.27556 (16)	0.07592 (19)	0.0761 (4)	0.0214 (6)
H9A	0.3127	0.0567	−0.0127	0.026*
H9B	0.2386	0.1119	0.0184	0.026*
C10	0.27692 (17)	0.02440 (19)	0.5344 (4)	0.0242 (7)
H10A	0.3056	0.0523	0.6272	0.029*
H10B	0.2492	−0.0201	0.5882	0.029*
C11	0.18510 (15)	−0.03624 (16)	0.0071 (4)	0.0215 (6)
C12	0.15917 (15)	0.10853 (15)	0.5907 (4)	0.0199 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Th1	0.01563 (6)	0.01563 (6)	0.01880 (12)	0.000	0.000	0.000
O1	0.0274 (11)	0.0594 (14)	0.0321 (17)	0.0064 (10)	−0.0160 (10)	−0.0241 (12)
O2	0.0429 (12)	0.0479 (13)	0.0308 (17)	0.0164 (11)	−0.0163 (11)	−0.0283 (12)
O3	0.0343 (11)	0.0438 (12)	0.0275 (16)	−0.0157 (10)	0.0193 (10)	−0.0103 (11)
O4	0.0463 (12)	0.0404 (12)	0.0263 (15)	−0.0159 (10)	0.0220 (11)	−0.0249 (11)
C1	0.0182 (12)	0.0239 (13)	0.0074 (18)	−0.0001 (10)	−0.0009 (11)	−0.0055 (11)
C2	0.0180 (9)	0.0276 (10)	0.0130 (17)	−0.0030 (8)	0.010 (3)	−0.007 (3)
C3	0.0205 (13)	0.0243 (13)	0.0063 (17)	−0.0046 (10)	0.0051 (11)	−0.0037 (11)
C4	0.0294 (14)	0.0223 (12)	0.0153 (18)	−0.0079 (11)	0.0039 (11)	−0.0057 (11)
C5	0.0288 (14)	0.0292 (13)	0.014 (2)	−0.0115 (12)	0.0084 (11)	−0.0046 (11)
C6	0.0188 (10)	0.0496 (14)	0.017 (3)	−0.0044 (10)	−0.0015 (19)	−0.015 (2)
C7	0.0265 (14)	0.0360 (15)	0.0123 (18)	0.0090 (12)	−0.0070 (12)	−0.0034 (13)
C8	0.0288 (12)	0.0255 (12)	0.009 (3)	0.0061 (10)	−0.0009 (11)	−0.0039 (11)
C9	0.0256 (15)	0.0303 (16)	0.0084 (19)	0.0010 (12)	0.0013 (12)	0.0002 (13)
C10	0.0335 (16)	0.0277 (15)	0.012 (2)	0.0000 (13)	−0.0014 (13)	−0.0027 (13)
C11	0.0211 (13)	0.0320 (14)	0.0112 (19)	−0.0029 (11)	0.0022 (12)	−0.0059 (12)
C12	0.0234 (13)	0.0252 (13)	0.0111 (18)	−0.0013 (10)	0.0014 (12)	−0.0023 (12)

Geometric parameters (Å, º)

Th1—O1^i	2.359 (2)	C3—C12	1.518 (4)
Th1—O1^ii	2.359 (2)	C3—C4	1.548 (4)
Th1—O1	2.359 (2)	C3—C10	1.552 (4)
Th1—O1^iii	2.359 (2)	C4—C5	1.533 (4)
Th1—O3^iv	2.426 (2)	C4—H4A	0.9700
Th1—O3^v	2.426 (2)	C4—H4B	0.9700
Th1—O3^vi	2.426 (2)	C5—C6	1.517 (5)
Th1—O3^vii	2.426 (2)	C5—C9	1.546 (4)
O1—C11	1.280 (3)	C5—H5	0.9800
O2—C11	1.251 (3)	C6—C7	1.536 (5)
O3—C12	1.252 (3)	C6—H6A	0.9700
O3—Th1^viii	2.426 (2)	C6—H6B	0.9700
O4—C12	1.260 (3)	C7—C8	1.536 (4)
O4—H1	0.8500	C7—C10	1.537 (4)
C1—C11	1.527 (4)	C7—H7	0.9800
C1—C8	1.541 (4)	C8—H8A	0.9700
C1—C2	1.542 (5)	C8—H8B	0.9700
C1—C9	1.550 (4)	C9—H9A	0.9700
C2—C3	1.538 (6)	C9—H9B	0.9700
C2—H2A	0.9700	C10—H10A	0.9700
C2—H2B	0.9700	C10—H10B	0.9700
O1^i—Th1—O1^ii	74.71 (6)	C5—C4—C3	109.5 (2)
O1^i—Th1—O1	74.71 (6)	C5—C4—H4A	109.8
O1^ii—Th1—O1	118.20 (13)	C3—C4—H4A	109.8
O1^i—Th1—O1^iii	118.20 (13)	C5—C4—H4B	109.8
O1^ii—Th1—O1^iii	74.71 (6)	C3—C4—H4B	109.8
O1—Th1—O1^iii	74.71 (6)	H4A—C4—H4B	108.2
O1^i—Th1—O3^iv	138.14 (8)	C6—C5—C4	110.5 (4)
O1^ii—Th1—O3^iv	75.16 (9)	C6—C5—C9	109.3 (3)
O1—Th1—O3^iv	146.32 (8)	C4—C5—C9	109.9 (2)
O1^iii—Th1—O3^iv	80.28 (8)	C6—C5—H5	109.0
O1^i—Th1—O3^v	75.16 (9)	C4—C5—H5	109.0
O1^ii—Th1—O3^v	80.28 (8)	C9—C5—H5	109.1
O1—Th1—O3^v	138.14 (8)	C5—C6—C7	109.40 (19)
O1^iii—Th1—O3^v	146.31 (8)	C5—C6—H6A	109.8
O3^iv—Th1—O3^v	71.67 (6)	C7—C6—H6A	109.8
O1^i—Th1—O3^vi	80.28 (8)	C5—C6—H6B	109.8
O1^ii—Th1—O3^vi	146.32 (8)	C7—C6—H6B	109.8
O1—Th1—O3^vi	75.16 (9)	H6A—C6—H6B	108.2
O1^iii—Th1—O3^vi	138.14 (8)	C8—C7—C6	109.4 (3)
O3^iv—Th1—O3^vi	111.78 (11)	C8—C7—C10	109.4 (2)
O3^v—Th1—O3^vi	71.67 (6)	C6—C7—C10	109.8 (3)
O1^i—Th1—O3^vii	146.31 (8)	C8—C7—H7	109.4
O1^ii—Th1—O3^vii	138.14 (8)	C6—C7—H7	109.4
O1—Th1—O3^vii	80.28 (8)	C10—C7—H7	109.4
O1^iii—Th1—O3^vii	75.16 (9)	C7—C8—C1	110.0 (2)
O3^iv—Th1—O3^vii	71.67 (6)	C7—C8—H8A	109.7
O3^v—Th1—O3^vii	111.78 (11)	C1—C8—H8A	109.7
O3^vi—Th1—O3^vii	71.67 (6)	C7—C8—H8B	109.7
C11—O1—Th1	154.85 (19)	C1—C8—H8B	109.7
C12—O3—Th1^viii	151.7 (2)	H8A—C8—H8B	108.2
C12—O4—H1	120.4	C5—C9—C1	109.3 (2)
C11—C1—C8	111.9 (2)	C5—C9—H9A	109.8
C11—C1—C2	110.8 (2)	C1—C9—H9A	109.8
C8—C1—C2	109.1 (3)	C5—C9—H9B	109.8
C11—C1—C9	107.3 (2)	C1—C9—H9B	109.8
C8—C1—C9	108.7 (2)	H9A—C9—H9B	108.3
C2—C1—C9	109.0 (2)	C7—C10—C3	109.7 (3)
C3—C2—C1	110.54 (18)	C7—C10—H10A	109.7
C3—C2—H2A	109.5	C3—C10—H10A	109.7
C1—C2—H2A	109.5	C7—C10—H10B	109.7
C3—C2—H2B	109.5	C3—C10—H10B	109.7
C1—C2—H2B	109.5	H10A—C10—H10B	108.2
H2A—C2—H2B	108.1	O2—C11—O1	123.5 (3)
C12—C3—C2	110.7 (2)	O2—C11—C1	118.8 (2)
C12—C3—C4	112.0 (2)	O1—C11—C1	117.6 (2)
C2—C3—C4	109.3 (3)	O3—C12—O4	122.6 (3)
C12—C3—C10	107.2 (2)	O3—C12—C3	119.8 (2)
C2—C3—C10	109.2 (2)	O4—C12—C3	117.6 (2)
C4—C3—C10	108.3 (2)
O1^i—Th1—O1—C11	177.0 (5)	C6—C5—C9—C1	61.1 (3)
O1^ii—Th1—O1—C11	114.2 (6)	C4—C5—C9—C1	−60.4 (3)
O1^iii—Th1—O1—C11	51.4 (6)	C11—C1—C9—C5	179.3 (2)
O3^iv—Th1—O1—C11	7.9 (6)	C8—C1—C9—C5	−59.5 (3)
O3^v—Th1—O1—C11	−137.7 (5)	C2—C1—C9—C5	59.3 (3)
O3^vi—Th1—O1—C11	−99.2 (5)	C8—C7—C10—C3	−60.1 (3)
O3^vii—Th1—O1—C11	−25.8 (5)	C6—C7—C10—C3	60.1 (4)
C11—C1—C2—C3	−177.3 (3)	C12—C3—C10—C7	179.2 (2)
C8—C1—C2—C3	59.0 (3)	C2—C3—C10—C7	59.2 (3)
C9—C1—C2—C3	−59.5 (4)	C4—C3—C10—C7	−59.8 (3)
C1—C2—C3—C12	−176.7 (3)	Th1—O1—C11—O2	14.4 (8)
C1—C2—C3—C4	59.4 (3)	Th1—O1—C11—C1	−169.1 (4)
C1—C2—C3—C10	−58.9 (4)	C8—C1—C11—O2	−21.4 (4)
C12—C3—C4—C5	177.6 (2)	C2—C1—C11—O2	−143.5 (3)
C2—C3—C4—C5	−59.3 (3)	C9—C1—C11—O2	97.7 (3)
C10—C3—C4—C5	59.6 (3)	C8—C1—C11—O1	161.9 (3)
C3—C4—C5—C6	−60.5 (3)	C2—C1—C11—O1	39.9 (4)
C3—C4—C5—C9	60.2 (3)	C9—C1—C11—O1	−79.0 (3)
C4—C5—C6—C7	59.7 (4)	Th1^viii—O3—C12—O4	−57.4 (5)
C9—C5—C6—C7	−61.3 (5)	Th1^viii—O3—C12—C3	122.6 (4)
C5—C6—C7—C8	60.7 (4)	C2—C3—C12—O3	23.2 (4)
C5—C6—C7—C10	−59.4 (5)	C4—C3—C12—O3	145.5 (3)
C6—C7—C8—C1	−59.9 (3)	C10—C3—C12—O3	−95.9 (3)
C10—C7—C8—C1	60.5 (3)	C2—C3—C12—O4	−156.8 (3)
C11—C1—C8—C7	177.5 (2)	C4—C3—C12—O4	−34.4 (4)
C2—C1—C8—C7	−59.5 (3)	C10—C3—C12—O4	84.2 (3)
C9—C1—C8—C7	59.2 (3)

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