Bis(2,6-diamino-1H-purin-3-ium) di-μ-croconato-κ³O,O′:O′′;κ³O:O′,O′′-bis­[tetra­aqua­(croconato-κ²O,O′)neodymium(III)]

The structure of the ionic title compound, (C₅H₇N₆)₂[Nd₂(C₅O₅)₄(H₂O)₈], consists of anionic dimers built around an inversion centre and is made up of an Nd^III cation, two croconate (croco) dianions and four water mol­ecules (plus their inversion images), with two noncoordinated symmetry-related 2,6-diamino-1H-purin-3-ium (Hdap⁺) cations providing charge balance. Each Nd^III atom is bound to nine O atoms from four water and three croco units. The coordination polyhedron has the form of a rather regular monocapped square anti­prism. The croconate anions are regular and the Hdap⁺ cation presents a unique, thus far unreported, proton­ation state. The abundance of hydrogen-bonding donors and acceptors gives rise to a complex packing scheme consisting of dimers inter­linked along the three crystallographic directions and defining anionic `cages' where the unbound Hdap⁺ cations lodge, linking to the mainframe via (N—H)_Hdap...O_water/croco and (O—H)_water...N_Hdap inter­ac­tions.

S1. Comment

2,6-Diaminopurine (dap) is a highly interactive entity that, because of its many active sites, can take part in complex hydrogen-bonding interaction networks, either as a donor or acceptor. In spite of these capabilities, few structures surveying the molecule are known so far. We have recently reported (Atria et al., 2010) two structures in which the molecule acts as a free base [(2,6-diamino-9H-purine monohydrate, (IIa)] and as a cation [bis(2,6-diamino-9H-purin-1-ium) 2-(2-carboxylatophenyl)acetate heptahydrate, (IIb)] and in both a complicated hydrogen-bonding scheme builds up as a result of the intermolecular interactions.

Croconate (croco), the dianion of 4,5-dihydroxy-4-cyclopentene -1,2,3-trione, C₅O₅ ^2-, is a member of the cyclic oxocarbons family of general formula C_nO_n (n = 3, deltate; n = 4, squarate; n = 5, croconate; and n = 6, rhodizonate). It can act as a versatile polydentate ligand owing to its five different coordination sites, thus enabling it to bind to metal ions via an impressive number of different coordination modes, many of them only recently reported. Fig. 1 presents an updated survey of the 22 different modes adopted by croconate in complexes [source: Cambridge Structural Database (CSD), version 5.31, Allen, 2002], sorted in ascending order of coordination number and covering the range 1 to 5 plus an amazing outlier with µ = 8.

In pursuit of our current interest in lanthanide metal–organic frameworks (MOFs) with profuse hydrogen-bonding interactions, the inclusion of both dap and croco was an appealing prospect both from the coordination as well as the hydrogen-bonding point of view. Herein we present the first successful results in this series, with Nd as the lanthanide. The Nd–croconate complex obtained {[Nd^III(croco)₂(H₂O)₄]₂} ^2-.2Hdap ⁺, (I), even if not a polymer as expected, presents an attractive dimeric structure with tight non-covalent interlinkage, leading to a `nested' hydrogen-bonding structure.

Dinuclear units of (I) are built up around an inversion centre (Fig. 2), the independent part consisting of a Nd^III centre, two croconate anions and four water molecules. The two negative charges of the resulting dimer are balanced by two non-coordinated, symmetry-related Hdap⁺ cations. Each Hdap⁺ is coordinated by nine oxygen atoms in total (Table 1), four of them water molecules [O1W → O4W, Nd—O_water range: 2.439 (2)–2.555 (2) Å], the remaining five provided by three croco groups [O12, O22, O11, O21, O31ⁱ, (i): -x + 2, -y + 2, -z + 1, Nd—O_croco range: 2.455 (2)–2.570 (2) Å]. The coordination polyhedron has the form of a rather regular monocapped square antiprism (Fig. 2, inset), with O1W in the capping position and (O12, O22, O3W , O31ⁱ ) and (O11, O21, O2W, O4W) defining the upper/lower bases, respectively. One of the croco anions (trailing label 2) acts in a simple κ²O,O' chelating fashion though O12 and O22, while the remaining one (trailing label 1), in addition to chelation via O11 and O21, also involves a third oxygen (O31) displaying a final µ₂κ³ O,O':O" coordination mode. This results in the formation of large (Nd–O–C–C–O)₂ centrosymmetric bridging rings, linking individual Nd(croco)₂(H₂O)₄ monomers into the dimeric structural units shown in Fig. 2.

The binding modes observed in I occur with different frequency in the literature. The first one is the most common (1a in Fig. 1) and 26 of the 66 entries in the CSD show this pattern, while the second one is among the rarest (mode 2g in Fig. 1) with only one appearance (Ghoshal et al., 2005). In this latter structure, however, the bridging mode gives rise to an infinite, corrugated two-dimensional assembly of copper coordination polyhedra instead of the isolated dimers found in (I).

The geometry of the croco ligands is regular and both moieties display symmetries close to D_2h. C—O bond lengths within each unit present maximum percentage differences of 1.6 and 2.9%, respectively, which can be considered small when compared with other croco complexes in the literature (for example Chen et al., 1990, with differences larger than 10.3% and symmetries closer to C_2v).

The Hdap⁺ cation is planar, with a mean deviation of 0.0193 (12) Å and a maximum departure from the least-squares plane (for atom C23) of 0.0431 (14) Å. Planarity extends to the two amino groups, coplanar with the rest of the molecule and in this respect similar to the only other Hdap⁺ unit so far reported [structure (IIb), Atria et al., 2010] but different from the neutral, unprotonated ones presented either in the same paper or in Atria et al. (2009), in both of which one of the two amines is significantly pyramidal; this different degree of planarity in the NH₂ groups is not uncommon in diamino aromatic groups and might be due to the ability of the delocalized π-system of the ring to accommodate charge from one amino group, but not both, in the extended resonance structure (Linden, 2010).

Notwithstanding these analogies, there are also significant differences between the Hdap⁺ ions in (I) and (IIb). Protonation of the diaminopurine takes place at different nitrogen sites, both at the imidazole [N2 in (I), N1 in (IIb)] as well as the pyrimidine groups [N4 in (I), N3 in (IIb); see Scheme 2]. This forces rearrangement of the charge distribution and the positioning of single/double bonds along the rings (Scheme 2). The outstanding hydrogen-bonding capability of Hdap, however, does not seem to be modified by the different H disposition, as shown in Table 2. The table presents the 15 hydrogen bonds in the structure, which define a tight three-dimensional hydrogen-bonding network consisting of an (anionic) mesh of dimeric units (where all the water H atoms except H2WB, see below, are involved), giving rise to columnar `cages' where the Hdap⁺ cations reside.

The mesh can be imagined as built up in a two-step process. Firstly, through six (O—H)_water···O_croco interactions (Table 2, entries 2–3, 5–8) giving rise to six types of R_n^m rings (Bernstein et al., 1995) and defining broad two-dimensional structures parallel to (100) (Fig. 3). Secondly, through the connection of these `planes' along [100] via the hydrogen bonds involving O1W (Table 2 , entries 1–2 and Fig. 4 ).

These interconnections define the columnar `cages' centred at x \sim 0.5, z ~0.0 and evolving along [010]; O2W is the only water molecule not entirely devoted to `mesh building', but it acts instead as a bridge joining both ion types. Thus, the Hdap⁺ counterions in the `cages' link to the mainframe through this latter (O—H)<sub>water</sub>···N<sub>Hdap</sub> bond (Table 2, entry 4), one (N—H)<sub>Hdap</sub>···O<sub>water</sub> (Table 2, entry 13) and six (N—H)<sub>Hdap</sub>···O<sub>croco</sub> interactions (Table 2, entries 9–12, 14–15). This gives rise to a large number of hydrogen-bonding rings, displayed in Fig. 5, where the nearest-neighbour environment of one such Hdap<sup>+</sup> cation is shown. This is a strikingly planar two-dimensional substructure where all aromatic rings (both the free Hdaps as well as the coordinated crocos) lay [lie?] almost parallel to each other with a mean deviation of 0.196 (8) Å from their least-squares plane, parallel to (1 0 1). These planar arrays are a direct consequence of the extreme directionality of the hydrogen bonds connecting the intervening aromatic units. Similarly, planar dispositions have already been described in a number of structures containing dap or Hdap derivatives, either crystallizing alone [for example (IIa) in Atria et al., 2010] or with aromatic partners [for example Sakore et al., 1969, (IIb) in Atria et al., 2010]. In all these cases, these planes dispose in pairs, parallel to each other at a graphitic distance from one another, usually the result of a number of π···π interactions connecting planes. In the present case, however, even if a similar `multilayer' structure of such planes exists (Fig. 6), the possibility of optimizing stacking interactions appears precluded by coordination of the croco ligands, which anchors them relative to the cation sites in detriment of an optimal stacking geometry. This was confirmed with the help of the program PLATON (Spek, 2009), which did not indicate any relevant π···π contacts between layers.

The most appealing aspects of compound (I), as in related dap/Hdap structures which we have studied so far (Atria et al., 2009, 2010), reside in the rich supramolecular structure arising from the ensemble of simple but highly interacting molecular units. We are currently working towards obtaining new members of this lanthanide–(dap/Hdap) family.

Related literature

For related literature, see: Allen (2002); Atria et al. (2009, 2010); Bernstein et al. (1995); Chen et al. (1990); Ghoshal et al. (2005); Linden (2010); Perec & Baggio (2010); Sakore et al. (1969); Spek (2009).

S2. Experimental

An ethanolic solution of croconic acid (0.050 g, 0.035 mmol) and 2,6-diaminopurine (0.070 g, 0.47 mmol) was added to an aqueous solution (400 ml) of neodymium nitrate (0.1539 g, 0.35 mmol), previously heated to about 343–353 K for 10 min under a nitrogen atmosphere. The reaction mixture was refluxed for 24 h, cooled to room temperature and filtered. Crystals adequate for X-ray diffraction analysis were obtained within a few days by slow evaporation of the solution. The whole process was carried out in the dark.

S3. Refinement

The two largest residual electron-density peaks (circa 3.30 e Å^-3) lie opposite each other at 0.85 Å from atom Nd1. All H atoms were clearly visible in a difference Fourier, but they were treated differently in the refinement: H atoms attached to C atoms were repositioned at their calculated locations and allowed to ride (C—H = 0.95 Å). Those attached to O and N atoms were further refined with a restrained O/N—H distance of 0.85 (2) Å (an s.u. of 0.01 Å was used to restrain the O—H distances in waters O3W and O4W). In all cases, U_iso(H) values were taken as 1.2U_eq(host). There is an artifact regarding refinement, which is not unique to the present structure but has already been observed in other complexes we recently reported (Perec & Baggio, 2010). Although there is clear synthetic and analytical evidence for the composition of the title compound (see Experimental section), significantly lower R indices can be obtained when the structure is refined with a different metallic species (in the present case, for instance, La instead of Nd). However, despite many indicators favouring the substituting cation (lower R factors, smaller residual electron-density peaks etc.), the Hirshfeld tests implemented in PLATON checkCIF generate a high number of alerts for the La refinement but none for the Nd refinement, thus indicating an incorrect assignment of atom type in the former case. We have no simple explanation for this paradox.

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures

	Fig. 1. The binding modes shown by the croconate ligand. Explanation of the [Mκ(n)] symbol: M, coordination number; κ, a sequential label within the M group; (n), number of entries found in the CSD for the Mκ mode.
	Fig. 2. Displacement ellipsoid plot of the dimeric structure in (I) drawn at the 50% probability level, with independent (symmetry-related) atoms in heavy (hollow) bonds and filled (empty) ellipsoids. Inset: schematic of the coordination polyhedron. [Symmetry code: (i) -x + 2, -y + 2, -z + 1.]
	Fig. 3. Packing plot of the two-dimensional structure parallel to the (100) plane and determined by interdimeric hydrogen bonds. Contiguous dimers are drawn in different shading for clarity. Hydrogen-bonding rings: `A' is R4^4(14); `B' is R2^2(14); `C' is R2^2(8); `D' is R2^2(9); `E' is R2^2(7); `F' is R2^1(11). [Symmetry codes: (ii) x + 1, y, z; (iii) -x + 2, -y + 1, -z + 1; (iv) -x + 2, -y + 1, -z + 2; (v) -x + 1, -y + 1, -z + 1; (vi) x, y + 1, z.]
	Fig. 4. Projection down [001] showing the way in which the two-dimensional (100) dimeric structures shown in Fig. 3 interact. `G' represents the R4^2(8) hydrogen-bonding ring. [Symmetry codes: (ii) x + 1, y, z; (iii) -x + 2, -y + 1, -z + 1.]
	Fig. 5. Interaction scheme of a single Hdap^+ cation, generating planar arrays paralell to (101). Hydrogen-bonding rings: `H' is R2^2(9); `I' is R3^2(8)' `J' is R2^1(7); `K' is R1^2(5); `F' is R3^3(13). [Symmetry codes: (v) -x + 1, -y + 1, -z + 1; (vi) x, y + 1, z; (vii) x - 1, y, z - 1; (viii) -x + 1, -y + 2, -z + 1; (ix) x - 1, y + 1, z - 1.]
	Fig. 6. Packing plot along [010], showing in projection (heavy lining) the planar structures shown in Fig. 5.

Bis(2,6-diamino-1H-purin-3-ium) di-µ-croconato- κ³O,O':O'';κ³O:O',O''- bis[tetraaqua(croconato-κ²O,O')neodymium(III)]

Crystal data

(C5H7N6)2[Nd2(C5O5)(H2O)8]	Z = 1
Mr = 1295.14	F(000) = 638
Triclinic, P1	Dx = 2.154 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 9.0999 (5) Å	Cell parameters from 4368 reflections
b = 9.5912 (5) Å	θ = 2.3–25.8°
c = 12.3272 (7) Å	µ = 2.70 mm^−1
α = 89.133 (3)°	T = 150 K
β = 69.418 (2)°	Polyhedron, pink
γ = 82.740 (3)°	0.24 × 0.19 × 0.16 mm
V = 998.66 (9) Å^3

Data collection

Bruker SMART CCD area-detector diffractometer	4379 independent reflections
Radiation source: fine-focus sealed tube	4089 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
CCD rotation images, thin slices scans	θmax = 27.8°, θmin = 1.8°
Absorption correction: multi-scan (SADABS in SAINT-NT; Bruker, 2002)	h = −11→11
Tmin = 0.55, Tmax = 0.65	k = −12→12
16172 measured reflections	l = −15→15

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)] = 0.031	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.082	H atoms treated by a mixture of independent and constrained refinement
S = 1.11	w = 1/[σ^2(Fo^2) + (0.0568P)^2 + 0.2868P] where P = (Fo^2 + 2Fc^2)/3
4379 reflections	(Δ/σ)max = 0.004
371 parameters	Δρmax = 3.30 e Å^−3
14 restraints	Δρmin = −0.87 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Nd1	1.016870 (19)	0.730138 (16)	0.663204 (14)	0.01342 (8)
C11	0.7520 (4)	0.7752 (3)	0.5468 (3)	0.0143 (6)
C21	0.8014 (4)	0.9148 (3)	0.5415 (3)	0.0139 (6)
C31	0.7495 (4)	0.9952 (3)	0.4563 (3)	0.0143 (6)
C41	0.6529 (4)	0.9072 (3)	0.4185 (3)	0.0153 (6)
C51	0.6552 (4)	0.7714 (3)	0.4758 (3)	0.0143 (6)
O11	0.7941 (3)	0.6772 (2)	0.6029 (2)	0.0189 (5)
O21	0.8804 (3)	0.9504 (2)	0.5990 (2)	0.0161 (5)
O31	0.7810 (3)	1.1127 (2)	0.4191 (2)	0.0181 (5)
O41	0.5852 (3)	0.9363 (3)	0.3486 (2)	0.0228 (5)
O51	0.5880 (3)	0.6720 (2)	0.4582 (2)	0.0190 (5)
C12	1.0474 (4)	0.4145 (3)	0.7584 (3)	0.0137 (6)
C22	1.1047 (4)	0.4934 (3)	0.8305 (3)	0.0142 (6)
C32	1.1595 (4)	0.3972 (3)	0.9051 (3)	0.0154 (6)
C42	1.1261 (4)	0.2546 (3)	0.8832 (3)	0.0170 (7)
C52	1.0529 (4)	0.2676 (3)	0.7912 (3)	0.0147 (6)
O12	0.9999 (3)	0.4694 (2)	0.6805 (2)	0.0169 (5)
O22	1.1041 (3)	0.6249 (2)	0.8264 (2)	0.0168 (5)
O32	1.2226 (3)	0.4268 (2)	0.9742 (2)	0.0179 (5)
O42	1.1511 (4)	0.1474 (3)	0.9328 (2)	0.0286 (6)
O52	1.0038 (3)	0.1733 (2)	0.7510 (2)	0.0194 (5)
C13	0.4579 (4)	0.5532 (4)	0.2601 (3)	0.0213 (7)
H13	0.4846	0.4870	0.3104	0.026*
C23	0.4222 (4)	0.7514 (4)	0.1785 (3)	0.0154 (6)
C33	0.3982 (4)	0.8909 (4)	0.1416 (3)	0.0160 (6)
C43	0.2992 (4)	0.8025 (4)	0.0101 (3)	0.0184 (7)
C53	0.3781 (4)	0.6434 (4)	0.1301 (3)	0.0160 (6)
N13	0.3999 (3)	0.5189 (3)	0.1796 (3)	0.0186 (6)
N23	0.4746 (3)	0.6898 (3)	0.2627 (3)	0.0180 (6)
H23	0.507 (5)	0.734 (4)	0.308 (3)	0.022*
N33	0.3360 (4)	0.9119 (3)	0.0574 (3)	0.0181 (6)
N43	0.3180 (4)	0.6674 (3)	0.0428 (3)	0.0173 (6)
H43	0.296 (5)	0.601 (3)	0.009 (3)	0.021*
N53	0.4314 (4)	1.0024 (3)	0.1858 (3)	0.0183 (6)
H53A	0.480 (4)	0.994 (4)	0.233 (3)	0.020 (11)*
H53B	0.396 (5)	1.079 (3)	0.162 (4)	0.035 (13)*
N63	0.2411 (4)	0.8282 (3)	−0.0750 (3)	0.0246 (7)
H63A	0.231 (6)	0.911 (3)	−0.101 (4)	0.041 (14)*
H63B	0.212 (5)	0.768 (4)	−0.108 (3)	0.023 (11)*
O1W	1.2873 (3)	0.6014 (3)	0.5853 (2)	0.0210 (5)
H1WA	1.359 (4)	0.646 (4)	0.545 (3)	0.025*
H1WB	1.316 (5)	0.519 (3)	0.558 (4)	0.025*
O2W	0.7592 (3)	0.7128 (3)	0.8325 (2)	0.0176 (5)
H2WB	0.706 (4)	0.652 (4)	0.823 (4)	0.021*
H2WA	0.770 (5)	0.696 (4)	0.896 (2)	0.021*
O3W	1.1048 (3)	0.7164 (3)	0.4435 (2)	0.0216 (5)
H3WA	1.118 (5)	0.786 (3)	0.403 (3)	0.026*
H3WB	1.067 (5)	0.663 (4)	0.411 (3)	0.026*
O4W	0.9831 (3)	0.9063 (2)	0.8136 (2)	0.0184 (5)
H4WB	0.907 (4)	0.912 (5)	0.876 (2)	0.022*
H4WA	0.998 (5)	0.990 (2)	0.798 (4)	0.022*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Nd1	0.01946 (12)	0.00861 (11)	0.01694 (11)	−0.00465 (7)	−0.01140 (8)	0.00260 (7)
C11	0.0178 (16)	0.0125 (15)	0.0131 (14)	−0.0037 (12)	−0.0054 (13)	0.0018 (12)
C21	0.0164 (15)	0.0110 (15)	0.0163 (15)	−0.0036 (12)	−0.0076 (13)	0.0003 (12)
C31	0.0149 (15)	0.0123 (15)	0.0163 (15)	−0.0029 (12)	−0.0058 (13)	0.0012 (12)
C41	0.0177 (16)	0.0116 (15)	0.0171 (15)	−0.0029 (12)	−0.0063 (13)	0.0002 (12)
C51	0.0165 (15)	0.0105 (15)	0.0182 (16)	−0.0046 (12)	−0.0078 (13)	−0.0001 (12)
O11	0.0248 (13)	0.0152 (12)	0.0232 (12)	−0.0072 (10)	−0.0150 (11)	0.0066 (10)
O21	0.0203 (12)	0.0131 (11)	0.0198 (12)	−0.0046 (9)	−0.0124 (10)	0.0007 (9)
O31	0.0221 (12)	0.0097 (11)	0.0260 (13)	−0.0054 (9)	−0.0116 (10)	0.0039 (9)
O41	0.0292 (14)	0.0193 (13)	0.0292 (14)	−0.0061 (11)	−0.0210 (11)	0.0050 (10)
O51	0.0219 (12)	0.0123 (12)	0.0281 (13)	−0.0054 (9)	−0.0143 (11)	−0.0009 (10)
C12	0.0161 (15)	0.0113 (15)	0.0155 (15)	−0.0029 (12)	−0.0074 (13)	0.0019 (12)
C22	0.0165 (15)	0.0111 (15)	0.0190 (16)	−0.0050 (12)	−0.0101 (13)	0.0029 (12)
C32	0.0176 (16)	0.0135 (16)	0.0166 (15)	−0.0042 (12)	−0.0072 (13)	0.0029 (12)
C42	0.0230 (17)	0.0119 (16)	0.0179 (16)	−0.0032 (13)	−0.0091 (14)	0.0024 (12)
C52	0.0167 (16)	0.0114 (15)	0.0156 (15)	−0.0043 (12)	−0.0042 (13)	0.0010 (12)
O12	0.0251 (12)	0.0107 (11)	0.0206 (12)	−0.0056 (9)	−0.0143 (10)	0.0025 (9)
O22	0.0256 (13)	0.0086 (11)	0.0232 (12)	−0.0053 (9)	−0.0163 (10)	0.0029 (9)
O32	0.0260 (13)	0.0143 (12)	0.0188 (12)	−0.0055 (10)	−0.0136 (10)	0.0027 (9)
O42	0.0504 (17)	0.0140 (13)	0.0325 (15)	−0.0058 (12)	−0.0282 (13)	0.0078 (11)
O52	0.0301 (14)	0.0118 (12)	0.0214 (12)	−0.0071 (10)	−0.0138 (11)	0.0008 (9)
C13	0.0256 (18)	0.0182 (17)	0.0250 (18)	−0.0065 (14)	−0.0139 (15)	0.0056 (14)
C23	0.0172 (16)	0.0153 (16)	0.0179 (16)	−0.0057 (12)	−0.0101 (13)	0.0023 (12)
C33	0.0164 (15)	0.0146 (16)	0.0179 (16)	−0.0041 (12)	−0.0066 (13)	0.0004 (12)
C43	0.0205 (17)	0.0155 (16)	0.0238 (17)	−0.0041 (13)	−0.0130 (14)	0.0017 (13)
C53	0.0170 (16)	0.0156 (16)	0.0187 (16)	−0.0055 (12)	−0.0091 (13)	0.0007 (12)
N13	0.0222 (15)	0.0154 (14)	0.0215 (14)	−0.0050 (11)	−0.0111 (12)	0.0020 (11)
N23	0.0217 (15)	0.0177 (15)	0.0201 (14)	−0.0069 (12)	−0.0127 (12)	0.0017 (11)
N33	0.0240 (15)	0.0144 (14)	0.0220 (15)	−0.0069 (11)	−0.0141 (12)	0.0025 (11)
N43	0.0233 (15)	0.0131 (14)	0.0205 (14)	−0.0059 (11)	−0.0128 (12)	−0.0001 (11)
N53	0.0251 (15)	0.0149 (15)	0.0222 (15)	−0.0071 (12)	−0.0158 (13)	0.0027 (11)
N63	0.0382 (19)	0.0165 (16)	0.0314 (17)	−0.0080 (14)	−0.0261 (15)	0.0022 (13)
O1W	0.0203 (13)	0.0113 (12)	0.0297 (14)	−0.0032 (10)	−0.0065 (11)	0.0030 (10)
O2W	0.0248 (13)	0.0152 (12)	0.0188 (12)	−0.0100 (10)	−0.0125 (10)	0.0041 (9)
O3W	0.0291 (14)	0.0217 (14)	0.0193 (12)	−0.0088 (11)	−0.0133 (11)	0.0012 (10)
O4W	0.0289 (13)	0.0097 (11)	0.0189 (12)	−0.0065 (10)	−0.0099 (10)	0.0009 (9)

Geometric parameters (Å, º)

Nd1—O4W	2.439 (2)	C52—O52	1.239 (4)
Nd1—O31^i	2.455 (2)	C13—N13	1.339 (5)
Nd1—O1W	2.472 (3)	C13—N23	1.340 (5)
Nd1—O11	2.501 (2)	C13—H13	0.9500
Nd1—O12	2.526 (2)	C23—C53	1.371 (5)
Nd1—O3W	2.540 (3)	C23—N23	1.383 (4)
Nd1—O2W	2.555 (2)	C23—C33	1.423 (5)
Nd1—O22	2.560 (2)	C33—N53	1.321 (4)
Nd1—O21	2.570 (2)	C33—N33	1.347 (4)
C11—O11	1.259 (4)	C43—N63	1.338 (4)
C11—C51	1.446 (5)	C43—N33	1.340 (4)
C11—C21	1.459 (4)	C43—N43	1.359 (4)
C21—O21	1.251 (4)	C53—N13	1.357 (4)
C21—C31	1.468 (4)	C53—N43	1.373 (4)
C31—O31	1.239 (4)	N23—H23	0.85 (2)
C31—C41	1.480 (5)	N43—H43	0.85 (2)
C41—O41	1.234 (4)	N53—H53A	0.84 (2)
C41—C51	1.474 (4)	N53—H53B	0.86 (2)
C51—O51	1.256 (4)	N63—H63A	0.86 (2)
O31—Nd1^i	2.455 (2)	N63—H63B	0.84 (2)
C12—O12	1.267 (4)	O1W—H1WA	0.83 (2)
C12—C22	1.443 (4)	O1W—H1WB	0.84 (2)
C12—C52	1.459 (4)	O2W—H2WB	0.83 (2)
C22—O22	1.261 (4)	O2W—H2WA	0.83 (2)
C22—C32	1.457 (4)	O3W—H3WA	0.82 (2)
C32—O32	1.237 (4)	O3W—H3WB	0.83 (2)
C32—C42	1.487 (5)	O4W—H4WB	0.83 (2)
C42—O42	1.225 (4)	O4W—H4WA	0.84 (2)
C42—C52	1.500 (5)
O4W—Nd1—O31^i	72.92 (8)	C22—C12—C52	109.2 (3)
O4W—Nd1—O1W	113.46 (9)	O22—C22—C12	123.1 (3)
O31^i—Nd1—O1W	67.54 (8)	O22—C22—C32	127.8 (3)
O4W—Nd1—O11	122.78 (8)	C12—C22—C32	109.1 (3)
O31^i—Nd1—O11	130.78 (8)	O32—C32—C22	127.0 (3)
O1W—Nd1—O11	123.67 (9)	O32—C32—C42	125.5 (3)
O4W—Nd1—O12	129.36 (8)	C22—C32—C42	107.5 (3)
O31^i—Nd1—O12	138.50 (8)	O42—C42—C32	126.2 (3)
O1W—Nd1—O12	71.14 (8)	O42—C42—C52	126.7 (3)
O11—Nd1—O12	71.62 (7)	C32—C42—C52	107.1 (3)
O4W—Nd1—O3W	137.56 (8)	O52—C52—C12	125.8 (3)
O31^i—Nd1—O3W	70.83 (8)	O52—C52—C42	127.2 (3)
O1W—Nd1—O3W	71.37 (9)	C12—C52—C42	106.9 (3)
O11—Nd1—O3W	69.89 (8)	C12—O12—Nd1	113.4 (2)
O12—Nd1—O3W	92.78 (8)	C22—O22—Nd1	112.4 (2)
O4W—Nd1—O2W	70.23 (8)	N13—C13—N23	113.5 (3)
O31^i—Nd1—O2W	141.82 (8)	N13—C13—H13	123.2
O1W—Nd1—O2W	138.02 (8)	N23—C13—H13	123.2
O11—Nd1—O2W	66.07 (8)	C53—C23—N23	104.9 (3)
O12—Nd1—O2W	75.66 (8)	C53—C23—C33	119.5 (3)
O3W—Nd1—O2W	135.90 (8)	N23—C23—C33	135.4 (3)
O4W—Nd1—O22	68.26 (8)	N53—C33—N33	117.6 (3)
O31^i—Nd1—O22	100.15 (8)	N53—C33—C23	124.0 (3)
O1W—Nd1—O22	68.88 (8)	N33—C33—C23	118.4 (3)
O11—Nd1—O22	129.02 (7)	N63—C43—N33	117.8 (3)
O12—Nd1—O22	67.56 (7)	N63—C43—N43	118.1 (3)
O3W—Nd1—O22	139.53 (8)	N33—C43—N43	124.1 (3)
O2W—Nd1—O22	75.18 (8)	N13—C53—C23	112.2 (3)
O4W—Nd1—O21	76.61 (8)	N13—C53—N43	127.0 (3)
O31^i—Nd1—O21	73.05 (8)	C23—C53—N43	120.8 (3)
O1W—Nd1—O21	133.03 (8)	C13—N13—C53	103.1 (3)
O11—Nd1—O21	67.67 (7)	C13—N23—C23	106.2 (3)
O12—Nd1—O21	139.28 (7)	C13—N23—H23	129 (3)
O3W—Nd1—O21	72.35 (8)	C23—N23—H23	125 (3)
O2W—Nd1—O21	88.95 (8)	C43—N33—C33	120.0 (3)
O22—Nd1—O21	144.56 (7)	C43—N43—C53	117.1 (3)
O11—C11—C51	128.2 (3)	C43—N43—H43	121 (3)
O11—C11—C21	123.2 (3)	C53—N43—H43	122 (3)
C51—C11—C21	108.6 (3)	C33—N53—H53A	121 (3)
O21—C21—C11	122.6 (3)	C33—N53—H53B	112 (3)
O21—C21—C31	128.9 (3)	H53A—N53—H53B	127 (4)
C11—C21—C31	108.4 (3)	C43—N63—H63A	122 (4)
O31—C31—C21	128.1 (3)	C43—N63—H63B	125 (3)
O31—C31—C41	125.1 (3)	H63A—N63—H63B	113 (5)
C21—C31—C41	106.8 (3)	Nd1—O1W—H1WA	117 (3)
O41—C41—C51	124.2 (3)	Nd1—O1W—H1WB	129 (3)
O41—C41—C31	127.7 (3)	H1WA—O1W—H1WB	104 (4)
C51—C41—C31	108.0 (3)	Nd1—O2W—H2WB	115 (3)
O51—C51—C11	128.9 (3)	Nd1—O2W—H2WA	115 (3)
O51—C51—C41	123.2 (3)	H2WB—O2W—H2WA	106 (4)
C11—C51—C41	107.8 (3)	Nd1—O3W—H3WA	123 (3)
C11—O11—Nd1	112.1 (2)	Nd1—O3W—H3WB	121 (3)
C21—O21—Nd1	109.8 (2)	H3WA—O3W—H3WB	105 (4)
C31—O31—Nd1^i	148.1 (2)	Nd1—O4W—H4WB	121 (3)
O12—C12—C22	123.3 (3)	Nd1—O4W—H4WA	122 (3)
O12—C12—C52	127.5 (3)	H4WB—O4W—H4WA	105 (4)
O11—C11—C21—O21	−5.1 (5)	O32—C32—C42—C52	−178.7 (3)
C51—C11—C21—O21	176.6 (3)	C22—C32—C42—C52	1.3 (4)
O11—C11—C21—C31	172.1 (3)	O12—C12—C52—O52	−3.8 (6)
C51—C11—C21—C31	−6.1 (4)	C22—C12—C52—O52	175.7 (3)
O21—C21—C31—O31	4.3 (6)	O12—C12—C52—C42	177.1 (3)
C11—C21—C31—O31	−172.7 (3)	C22—C12—C52—C42	−3.4 (4)
O21—C21—C31—C41	−177.2 (3)	O42—C42—C52—O52	1.0 (6)
C11—C21—C31—C41	5.8 (4)	C32—C42—C52—O52	−177.8 (3)
O31—C31—C41—O41	−2.4 (6)	O42—C42—C52—C12	−180.0 (3)
C21—C31—C41—O41	179.0 (3)	C32—C42—C52—C12	1.3 (4)
O31—C31—C41—C51	175.2 (3)	C22—C12—O12—Nd1	0.3 (4)
C21—C31—C41—C51	−3.3 (4)	C52—C12—O12—Nd1	179.7 (3)
O11—C11—C51—O51	2.8 (6)	O4W—Nd1—O12—C12	−33.2 (3)
C21—C11—C51—O51	−179.1 (3)	O31^i—Nd1—O12—C12	77.6 (2)
O11—C11—C51—C41	−174.1 (3)	O1W—Nd1—O12—C12	72.1 (2)
C21—C11—C51—C41	4.0 (4)	O11—Nd1—O12—C12	−150.9 (2)
O41—C41—C51—O51	0.2 (5)	O3W—Nd1—O12—C12	141.4 (2)
C31—C41—C51—O51	−177.5 (3)	O2W—Nd1—O12—C12	−81.8 (2)
O41—C41—C51—C11	177.4 (3)	O22—Nd1—O12—C12	−2.1 (2)
C31—C41—C51—C11	−0.4 (4)	O21—Nd1—O12—C12	−152.8 (2)
C51—C11—O11—Nd1	164.5 (3)	C12—C22—O22—Nd1	−5.8 (4)
C21—C11—O11—Nd1	−13.3 (4)	C32—C22—O22—Nd1	174.6 (3)
O4W—Nd1—O11—C11	71.3 (2)	O4W—Nd1—O22—C22	158.6 (2)
O31^i—Nd1—O11—C11	−24.1 (3)	O31^i—Nd1—O22—C22	−134.5 (2)
O1W—Nd1—O11—C11	−112.3 (2)	O1W—Nd1—O22—C22	−73.5 (2)
O12—Nd1—O11—C11	−163.2 (2)	O11—Nd1—O22—C22	43.3 (3)
O3W—Nd1—O11—C11	−63.0 (2)	O12—Nd1—O22—C22	4.0 (2)
O2W—Nd1—O11—C11	114.8 (2)	O3W—Nd1—O22—C22	−62.2 (3)
O22—Nd1—O11—C11	158.7 (2)	O2W—Nd1—O22—C22	84.3 (2)
O21—Nd1—O11—C11	15.5 (2)	O21—Nd1—O22—C22	150.5 (2)
C11—C21—O21—Nd1	19.5 (4)	C53—C23—C33—N53	177.4 (3)
C31—C21—O21—Nd1	−157.1 (3)	N23—C23—C33—N53	2.5 (6)
O4W—Nd1—O21—C21	−152.1 (2)	C53—C23—C33—N33	−1.6 (5)
O31^i—Nd1—O21—C21	132.0 (2)	N23—C23—C33—N33	−176.6 (4)
O1W—Nd1—O21—C21	98.2 (2)	N23—C23—C53—N13	0.1 (4)
O11—Nd1—O21—C21	−17.7 (2)	C33—C23—C53—N13	−176.2 (3)
O12—Nd1—O21—C21	−15.8 (3)	N23—C23—C53—N43	179.4 (3)
O3W—Nd1—O21—C21	57.2 (2)	C33—C23—C53—N43	3.1 (5)
O2W—Nd1—O21—C21	−82.2 (2)	N23—C13—N13—C53	−0.6 (4)
O22—Nd1—O21—C21	−144.4 (2)	C23—C53—N13—C13	0.3 (4)
C21—C31—O31—Nd1^i	49.1 (6)	N43—C53—N13—C13	−179.0 (3)
C41—C31—O31—Nd1^i	−129.2 (4)	N13—C13—N23—C23	0.6 (4)
O12—C12—C22—O22	4.1 (5)	C53—C23—N23—C13	−0.4 (4)
C52—C12—C22—O22	−175.4 (3)	C33—C23—N23—C13	175.0 (4)
O12—C12—C22—C32	−176.2 (3)	N63—C43—N33—C33	−178.5 (3)
C52—C12—C22—C32	4.3 (4)	N43—C43—N33—C33	1.1 (5)
O22—C22—C32—O32	−3.8 (6)	N53—C33—N33—C43	−179.5 (3)
C12—C22—C32—O32	176.5 (3)	C23—C33—N33—C43	−0.4 (5)
O22—C22—C32—C42	176.3 (3)	N63—C43—N43—C53	179.8 (3)
C12—C22—C32—C42	−3.4 (4)	N33—C43—N43—C53	0.2 (5)
O32—C32—C42—O42	2.6 (6)	N13—C53—N43—C43	176.8 (3)
C22—C32—C42—O42	−177.5 (3)	C23—C53—N43—C43	−2.3 (5)

Symmetry code: (i) −x+2, −y+2, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1WA···O51^ii	0.83 (2)	2.03 (3)	2.798 (4)	154 (4)
O1W—H1WB···O51^iii	0.84 (2)	1.91 (2)	2.704 (3)	158 (4)
O2W—H2WA···O32^iv	0.83 (2)	1.99 (3)	2.761 (3)	154 (4)
O2W—H2WB···N13^v	0.83 (2)	2.01 (2)	2.833 (4)	168 (4)
O3W—H3WA···O52^iii	0.82 (2)	2.52 (4)	3.028 (3)	121 (4)
O3W—H3WB···O12^iii	0.83 (2)	1.99 (2)	2.820 (3)	174 (4)
O4W—H4WA···O52^vi	0.84 (2)	1.84 (2)	2.673 (3)	170 (4)
O4W—H4WB···O42^iv	0.83 (2)	2.31 (3)	2.993 (4)	140 (4)
N23—H23···O51	0.86 (2)	2.27 (3)	2.931 (4)	134 (4)
N23—H23···O41	0.86 (2)	2.27 (3)	3.025 (4)	147 (4)
N43—H43···O32^vii	0.85 (2)	1.99 (2)	2.807 (4)	163 (4)
N53—H53A···O41	0.84 (2)	2.02 (2)	2.847 (4)	169 (4)
N53—H53B···O2W^viii	0.86 (2)	2.28 (3)	3.095 (4)	159 (4)
N63—H63A···O42^ix	0.86 (2)	2.29 (3)	3.062 (4)	149 (5)
N63—H63B···O22^vii	0.84 (2)	2.10 (2)	2.930 (4)	172 (4)

Symmetry codes: (ii) x+1, y, z; (iii) −x+2, −y+1, −z+1; (iv) −x+2, −y+1, −z+2; (v) −x+1, −y+1, −z+1; (vi) x, y+1, z; (vii) x−1, y, z−1; (viii) −x+1, −y+2, −z+1; (ix) x−1, y+1, z−1.