Poly[aqua­[μ₃-(pyridin-1-ium-3,5-di­yl)diphospho­nato-κ³O:O′:O′′][μ₂-(pyri­din-1-ium-3,5-di­yl)diphospho­nato-κ²O:O′]calcium(II)]

The rigid organic ligand (pyridine-3,5-di­yl)diphospho­nic acid has been used to create the title novel three-dimensional coordination polymer, [Ca(C₅H₆NO₆P₂)₂(H₂O)]_n. The six-coordinate calcium ion is in a distorted octa­hedral environment, formed by five phospho­nate O atoms from five different (pyridin-1-ium-3,5-di­yl)diphospho­nate ligands, two of which are unique, and one water O atom. Two crystallographically independent acid monoanions, L1 and L2, serve to link metal centres using two different coordination modes, viz. η²μ₂ and η³μ₃, respectively. The latter ligand, L2, forms a strongly undulated two-dimensional framework parallel to the crystallographic bc plane, whereas the former ligand, L1, is utilized in the formation of one-dimensional helical chains in the [010] direction. The two sublattices of L1 and L2 inter­weave at the Ca²⁺ ions to form a three-dimensional framework. In addition, multiple O—H...O and N—H...O hydrogen bonds stabilize the three-dimensional coordination network. Topologically, the three-dimensional framework can be simplified as a very unusual (2,3,5)-connected three-nodal net represented by the Schläfli symbol (4·8²)(4·8⁸·10)(8).

S1. Comment

The design and synthesis of coordination polymers have attracted great attention not only for their impressive structural diversity, but also for their potential applications as functional materials in molecular adsorption, chemical separation, heterogeneous catalysis, ion exchange, drug delivery, magnetism and photoluminescence (Mueller et al., 2006; McKinlay et al., 2010; Kurmoo, 2009; Allendorf et al., 2009). To construct such materials, the rational design of a suitable organic linker is one of the various factors to be taken into account. From a crystal engineering point of view the ligand should be: (i) multidentate; (ii) structurally predisposed for extending the metal ions in different directions in order to form a multidimensional coordination network; (iii) relatively rigid allowing for a certain control of the steric consequences in the assembly process. The dinicotinic acid (pyridine-3,5-dicarboxylic acid) appears to be an interesting ligand because of the strong binding ability and versatile coordination modes of the functional groups. A search of the Cambridge Structural Database (CSD, Version 5.32; Allen, 2002) has revealed that the dinicotinic acid has been widely used to form inorganic–organic hybrid compounds with the main group metal ions Na⁺ (one compound), Ca²⁺ (three), Sr²⁺ (one), Ba²⁺ (one), In³⁺ (two), Tl⁺ (one), Sn⁴⁺ (three) and Pb²⁺ (one), as well as with transition metals (49) or rare earth metal ions (25). It has also been used as a ligand in 19 heterobimetallic metal–organic frameworks (MOFs). On the other hand, the phosphonic analogue of the dinicotinic acid, pyridine-3,5-dicarboxylic acid, is geometrically and topochemically predisposed for binding and extending metal ions in different, not necessarily planar, directions, forming a great variety of diverse coordination modes, dependent upon the deprotonation rate and the metal–ligand ratio. However, to the best of our knowledge, (pyridine-3,5-diyl)diphosphonic acid has not been used previously as a linker to form coordination polymers. We report here the crystal structure of the first such example, poly[aqua[µ₃-(pyridin-1-ium-3,5-diyl)diphosphonato-κ³O:O':O''][µ₂-(pyridin-1-ium-3,5-diyl)diphosphonato-κ²O:O']calcium(II)], (I).

The asymmetric unit of (I) contains one Ca^II ion, two symmetry-independent (pyridin-1-ium-3,5-diyl)diphosphonate monoanions and one coordinated water molecule. The calcium ion is six-coordinate with a distorted octahedral geometry. The coordination environment of the metal ion consists of five phosphonate O atoms located on five different (pyridin-1-ium-3,5-diyl)diphosphonate ligands, two of which are unique, and one water O atom (Fig. 1). Atoms O14ⁱ, O21ⁱⁱ, O22 and O25ⁱⁱⁱ bind as equatorial ligands and O11 and O1W act as axial ligands. The Ca—O bond lengths are in the range from 2.280 (2) to 2.450 (3) Å (symmetry codes as in Table 1).

Two singly ionized (pyridin-1-ium-3,5-diyl)diphosphonate moieties in the zwitterion form serve as η²µ₂ and η³µ₃ ligands, respectively, to extend the Ca ions into a three-dimensional framework. Each ligand uses both phosphonate sites to bind in a monodentate manner to the Ca²⁺ ions, linking them into C₂¹(8) helical chains along the b axis (Videnova-Adrabinska, 2007). Another O-atom site from one of the phosphonate groups in L2 is used to bridge metal ions from Ca–L2 helices aligned in the opposite direction, thus interweaving them into a two-dimensional coordination network via a 16-membered R₄²(16) ring, closed between two metal centres, two pyridine rings and four phosphonate groups. The Ca–L2 framework involves a large R₈⁴(24) motif, generated and located between four metal ions, two pyridine rings and six phosphonate groups (Fig. 2a). The Ca–L2 network is strongly folded and the pyridine rings, playing the role of linkers between the phosphonate sites, are tilted at an angle of 35.22 (10)° toward the mean bc plane of the framework. The folding of the two-dimensional network is supported by a pyridine–phosphonate hydrogen bond, viz. N21—H21···O25^v (symmetry code as in Table 2), established between the protonated N atom and the phosphonate O-atom site of adjacent glide-related monoanions and offset face-to-face (OFF) interactions established between neighbouring inversion-related pyridine rings [Cg2···Cg2^viii = 3.6861 Å and slippage = 1.208 Å; symmetry code: (viii) -x+2, -y+1, -z]. The aqua ligand, completing the coordination environment of the calcium ion, is arranged in the R₈⁴(24) ring and donates two water–phosphonate hydrogen bonds, viz. O1W—H1W···O24 and O1W—H2W···O22ⁱⁱ (symmetry code as in Table 2), which additionally stabilize the Ca–L2 framework.

The other acid monoanion, L1, connects the calcium ions in a η²µ₂ fashion, forming a one-dimensional helical C₂¹(8) chain along the b axis (Fig. 2b). Neighbouring Ca–L1 helices are linked together by two different hydrogen bonds to create a two-dimensional hydrogen-bonded network parallel to the crystallographic bc plane. The first hydrogen bond, O16—H16O···O12^vi (symmetry code as in Table 2), is established between phosphonate O-atom sites of adjacent inversion-related monodeprotonated ligands and forms an R₂²(16) hydrogen-bonded ring motif. The second hydrogen bond, N11—H11···O15^vii (symmetry code as in Table 2), is established between the protonated N atom and a phosphonate O-atom site of a neighbouring glide-related monoanion and serves to form an R₂²(28) hydrogen-bonded ring motif.

The Ca–L1 helical chains and the Ca–L2 network are interweaved at the metal ions in order to form a three-dimensional framework. Three phosphonate–phosphonate hydrogen-bond interactions, viz. O23—H23O···O15^iv, O26—H26O···O12ⁱⁱ and O13—H13O···O24ⁱⁱⁱ, and a pyridine–phosphonate hydrogen bond, viz. N11—H11···O23^vi (symmetry codes as in Table 2), established between the two different L1 and L2 ligands, stabilize the crystal framework.

However, the three-dimensional packing pattern of the compound can also be portrayed as a pillared bilayer structure. The L2 moieties are arranged in the interior and the Ca ions on the surfaces of the bilayers. The L1 moieties serve to connect the layers and act as pillars between them (Fig. 4a).

To get a better insight into the nature of the intricate coordination framework one can apply the topological approach, which allows to describe [facilitates a description of] multidimensional structures in terms of simple node-and-linker nets. One can consider the Ca²⁺ ion as a five-connected node (the terminal aqua ligand is disregarded during the simplification process) and the ligands L1 and L2 as two- and three-connected linkers (Figs. 3a and 3b). Hence, the three-dimensional network of (I) will be presented as a three-nodal (2,3,5)-connected net expressed by the Schläfli symbol (4.8²)(4.8⁸.10)(8) (Fig. 4b) (Blatov, 2006). To the best of our knowledge, this is a new type of network.

In summary, a novel three-dimensional coordination polymer, (I), featuring a unique (4.8²)(4.8⁸.10)(8) topology, is presented. It demonstrates an alternate arrangement of two-dimensional Ca–L2 frameworks and one-dimensional Ca–L1 helical chains that interweave at the metal ions. To the best of our knowledge, (I) is the first coordination polymer based on a phosphonic analogue of pyridine-3,5-dicarboxylic acid. To date, only three crystal structures of calcium complexes with the dinicotinate ligand have been reported. These are the zero-dimensional ionic complex [Ca₂(C₇H₄NO₄)₃(H₂O)₉](C₇H₄NO₄).2H₂O (Starosta et al., 2003), the zero-dimensional dinuclear complex [Ca₂(C₇H₃NO₄)₂(H₂O)₁₀].2H₂O (Starosta et al., 2002b) and the one-dimensional zigzag chain structure [Ca(C₇H₃NO₄)(H₂O)₅]_n (Starosta et al., 2002a).

Related literature

For related literature, see: Allen (2002); Allendorf et al. (2009); Blatov (2006); Kurmoo (2009); McKinlay et al. (2010); Mueller et al. (2006); Starosta et al. (2003); Starosta et al. (2002a,b); Videnova-Adrabinska (2007); Zon et al. (2011).

S2. Experimental

All chemicals were obtained commercially, with the exception of (pyridine-3,5-diyl)diphosphonic acid, which was prepared according to a published procedure (Zon et al., 2011). The title compound was synthesized by mixing calcium(II) nitrate tetrahydrate (15 mg, 0.06 mmol) dissolved in distilled water (0.5 ml) with (pyridine-3,5-diyl)diphosphonic acid (30 mg, 0.12 mmol) also dissolved in distilled water (2 ml). The resulting solution was placed in a tightly closed tube and then heated at 348 K for 2 d. The mixture was then cooled to room temperature and colourless parallelepiped-shaped crystals of (I) of sufficient quality for X-ray diffraction were grown.

S3. Refinement

The positions of H atoms attached to pyridine C atoms were constrained (C—H = 0.93 Å) with U_iso(H) = 1.2U_eq(C). The positions of H atoms involved in hydrogen bonds were refined with U_iso(H) = 1.5U_eq(O) or 1.2U_eq(N).

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis RED (Oxford Diffraction, 2006); data reduction: CrysAlis RED (Oxford Diffraction, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXS97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010).

Figures

	Fig. 1. The asymmetric unit and the coordination polyhedron of (I), together with the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level; the symmetry codes are as in Table 1.
	Fig. 2. The disentangled frameworks formed by the two unique ligands L1 and L2. (a) A view of the two-dimensional Co—L2 coordination framework, together with the folding N—H···O hydrogen bonds. The stabilizing O—H···O hydrogen bonds have been omitted for clarity. (b) A view of four Co—L1 helical chains interconnected by N—H···O and O—H···O hydrogen bonds, drawn as dashed lines (in the electronic version of the paper, blue for N—H···O and red for O—H···O). The pyridine (C)H atoms have been omitted for clarity.
	Fig. 3. A topological presentation of the simplified coordination frameworks (a) Co—L2 and (b) Co—L1.
	Fig. 4. (a) A view of the three-dimensional coordination framework. The L1—L1 (O16—H16O···O12^vi and N11—H11···O15^vii), L2—L2 (N21—H21···O25^v) and L1—L2 (O23—H23O···O15^iv, O26—H26O···O12^ii, O13—H13O···O24^iii and N11—H11···O23^vi) hydrogen bonds are drawn as dashed lines. The terminal aqua ligands and the pyridine (C)H atoms have been omitted. Symmetry codes are as given in Table 2. (b) A schematic presentation of the three-dimensional (2,3,5)-connected net with (4.8^2)(4.8^8.10)(8) topology.

Poly[aqua[µ₃-(pyridin-1-ium-3,5-diyl)diphosphonato- κ³O:O':O''][µ₂-(pyridin-1-ium-3,5- diyl)diphosphonato-κ²O:O']calcium(II)]

Crystal data

[Ca(C5H6NO6P2)2(H2O)]	F(000) = 1088
Mr = 534.19	Dx = 1.832 Mg m^−3 Dm = 1.83 Mg m^−3 Dm measured by flotation
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1076 reflections
a = 12.296 (2) Å	θ = 3.0–28.0°
b = 13.054 (3) Å	µ = 0.73 mm^−1
c = 12.308 (3) Å	T = 295 K
β = 101.33 (1)°	Paralellepiped, colourless
V = 1937.0 (8) Å^3	0.28 × 0.22 × 0.18 mm
Z = 4

Data collection

KUMA KM-4 diffractometer with CCD area detector	4673 independent reflections
Radiation source: fine-focus sealed tube	2710 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.084
Detector resolution: 1024x1024 with blocks 2x2 pixels mm^-1	θmax = 28.0°, θmin = 3.0°
ω scan	h = −16→16
Absorption correction: numerical (CrysAlis RED; Oxford Diffraction, 2006)	k = −18→17
Tmin = 0.824, Tmax = 0.882	l = −16→14
24330 measured reflections

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.063	H atoms treated by a mixture of independent and constrained refinement
S = 0.99	w = 1/[σ^2(Fo^2) + (0.012P)^2] where P = (Fo^2 + 2Fc^2)/3
4976 reflections	(Δ/σ)max = 0.001
295 parameters	Δρmax = 0.41 e Å^−3
0 restraints	Δρmin = −0.43 e Å^−3

Special details

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

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
Ca1	0.78030 (5)	0.22844 (5)	0.16490 (5)	0.02068 (17)
O1W	0.8440 (2)	0.3472 (2)	0.3183 (2)	0.0415 (8)
H1W	0.883 (3)	0.403 (3)	0.327 (3)	0.062*
H2W	0.833 (3)	0.336 (3)	0.381 (3)	0.062*
P11	0.74193 (8)	−0.01823 (7)	0.01980 (7)	0.0250 (2)
O11	0.72901 (18)	0.08895 (17)	0.05263 (16)	0.0345 (6)
O12	0.71879 (18)	−0.03975 (17)	−0.10300 (17)	0.0307 (6)
O13	0.8551 (2)	−0.06690 (19)	0.0733 (2)	0.0418 (7)
H13O	0.910 (3)	−0.027 (3)	0.103 (3)	0.063*
P12	0.46277 (8)	−0.11080 (7)	0.32022 (7)	0.0247 (2)
O14	0.38606 (18)	−0.19665 (18)	0.32949 (18)	0.0376 (7)
O15	0.55384 (17)	−0.09311 (16)	0.41900 (16)	0.0237 (5)
O16	0.4062 (2)	−0.0049 (2)	0.29137 (18)	0.0383 (7)
H16O	0.361 (3)	0.003 (3)	0.228 (3)	0.057*
N11	0.5583 (3)	−0.2600 (2)	0.0705 (3)	0.0382 (9)
H11	0.537 (3)	−0.321 (2)	0.030 (3)	0.046*
C12	0.6237 (3)	−0.1963 (3)	0.0304 (3)	0.0348 (10)
H12	0.6548	−0.2170	−0.0291	0.042*
C13	0.6472 (3)	−0.0995 (3)	0.0745 (2)	0.0261 (8)
C14	0.5975 (3)	−0.0728 (2)	0.1625 (3)	0.0245 (8)
H14	0.6107	−0.0083	0.1944	0.029*
C15	0.5282 (3)	−0.1405 (2)	0.2043 (2)	0.0242 (8)
C16	0.5102 (3)	−0.2342 (3)	0.1562 (3)	0.0346 (9)
H16	0.4645	−0.2809	0.1825	0.042*
P21	0.75879 (8)	0.39586 (7)	−0.07447 (7)	0.0208 (2)
O21	0.76999 (18)	0.38290 (16)	−0.19139 (16)	0.0325 (6)
O22	0.80369 (17)	0.31312 (16)	0.00497 (17)	0.0281 (6)
O23	0.6368 (2)	0.41634 (17)	−0.0625 (2)	0.0373 (7)
H23O	0.611 (3)	0.479 (3)	−0.074 (3)	0.056*
P22	0.94122 (8)	0.63141 (7)	0.28400 (7)	0.0229 (2)
O24	0.97066 (18)	0.52653 (16)	0.32952 (17)	0.0316 (6)
O25	1.02520 (16)	0.71498 (16)	0.31601 (16)	0.0252 (6)
O26	0.8289 (2)	0.66947 (18)	0.30952 (19)	0.0317 (7)
H26O	0.789 (3)	0.632 (3)	0.337 (3)	0.048*
N21	0.9413 (2)	0.6562 (2)	−0.0441 (2)	0.0252 (7)
H21	0.975 (2)	0.696 (2)	−0.080 (2)	0.030*
C22	0.8824 (3)	0.5768 (2)	−0.0879 (3)	0.0233 (8)
H22	0.8741	0.5642	−0.1634	0.028*
C23	0.8333 (2)	0.5125 (2)	−0.0243 (2)	0.0194 (7)
C24	0.8491 (3)	0.5358 (2)	0.0877 (3)	0.0246 (8)
H24	0.8147	0.4948	0.1328	0.030*
C25	0.9133 (2)	0.6166 (2)	0.1353 (2)	0.0178 (7)
C26	0.9592 (3)	0.6776 (2)	0.0646 (3)	0.0258 (8)
H26	1.0027	0.7336	0.0923	0.031*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ca1	0.0239 (4)	0.0181 (3)	0.0214 (3)	0.0034 (4)	0.0077 (3)	0.0023 (3)
O1W	0.052 (2)	0.0292 (16)	0.0438 (16)	−0.0045 (14)	0.0104 (16)	−0.0128 (15)
P11	0.0289 (6)	0.0248 (5)	0.0225 (5)	−0.0034 (5)	0.0081 (5)	0.0014 (5)
O11	0.0474 (17)	0.0267 (14)	0.0311 (14)	−0.0078 (13)	0.0121 (13)	−0.0036 (12)
O12	0.0352 (15)	0.0386 (16)	0.0215 (12)	0.0090 (13)	0.0133 (12)	0.0015 (12)
O13	0.0329 (18)	0.0346 (17)	0.0528 (17)	−0.0051 (13)	−0.0039 (14)	0.0057 (14)
P12	0.0241 (5)	0.0270 (5)	0.0246 (5)	−0.0038 (5)	0.0086 (4)	−0.0020 (5)
O14	0.0317 (15)	0.0450 (17)	0.0400 (15)	−0.0208 (13)	0.0162 (13)	−0.0113 (13)
O15	0.0274 (13)	0.0198 (12)	0.0226 (12)	−0.0056 (12)	0.0021 (11)	0.0042 (11)
O16	0.0410 (17)	0.0395 (16)	0.0291 (14)	0.0170 (14)	−0.0062 (13)	−0.0034 (13)
N11	0.054 (2)	0.0238 (18)	0.041 (2)	−0.0160 (18)	0.0180 (18)	−0.0127 (16)
C12	0.047 (3)	0.035 (2)	0.028 (2)	−0.012 (2)	0.0209 (19)	−0.0136 (18)
C13	0.032 (2)	0.028 (2)	0.0207 (17)	−0.0088 (19)	0.0112 (16)	−0.0045 (17)
C14	0.035 (2)	0.0144 (17)	0.0233 (18)	−0.0087 (17)	0.0046 (17)	−0.0006 (15)
C15	0.028 (2)	0.0261 (19)	0.0187 (17)	−0.0081 (18)	0.0054 (16)	−0.0025 (16)
C16	0.041 (2)	0.031 (2)	0.034 (2)	−0.018 (2)	0.0128 (19)	−0.0057 (19)
P21	0.0250 (5)	0.0164 (5)	0.0207 (5)	−0.0007 (5)	0.0040 (4)	0.0001 (4)
O21	0.0608 (18)	0.0215 (13)	0.0163 (12)	−0.0046 (13)	0.0103 (12)	−0.0059 (11)
O22	0.0308 (14)	0.0265 (13)	0.0263 (12)	0.0040 (12)	0.0040 (11)	0.0104 (11)
O23	0.0251 (16)	0.0205 (14)	0.0657 (18)	0.0028 (13)	0.0072 (14)	−0.0014 (15)
P22	0.0229 (5)	0.0236 (5)	0.0224 (5)	−0.0021 (5)	0.0050 (4)	−0.0028 (4)
O24	0.0330 (15)	0.0231 (13)	0.0357 (14)	0.0028 (13)	−0.0008 (12)	0.0063 (12)
O25	0.0225 (13)	0.0277 (13)	0.0262 (12)	−0.0082 (12)	0.0068 (11)	−0.0086 (11)
O26	0.0290 (16)	0.0324 (16)	0.0391 (16)	−0.0017 (13)	0.0197 (13)	0.0005 (12)
N21	0.0272 (18)	0.0217 (16)	0.0262 (17)	−0.0107 (15)	0.0044 (15)	0.0031 (14)
C22	0.028 (2)	0.0205 (18)	0.0216 (18)	0.0020 (17)	0.0047 (17)	0.0020 (16)
C23	0.0195 (18)	0.0197 (17)	0.0193 (17)	0.0036 (17)	0.0044 (15)	−0.0001 (16)
C24	0.024 (2)	0.024 (2)	0.0268 (18)	−0.0044 (17)	0.0085 (17)	0.0014 (17)
C25	0.0196 (17)	0.0193 (17)	0.0158 (15)	−0.0017 (17)	0.0010 (15)	0.0002 (15)
C26	0.028 (2)	0.0182 (18)	0.029 (2)	−0.0023 (18)	0.0001 (18)	−0.0032 (17)

Geometric parameters (Å, º)

Ca1—O14^i	2.280 (2)	C14—H14	0.9300
Ca1—O11	2.298 (2)	C15—C16	1.358 (4)
Ca1—O21^ii	2.312 (2)	C16—H16	0.9300
Ca1—O22	2.324 (2)	P21—O21	1.482 (2)
Ca1—O25^iii	2.363 (2)	P21—O22	1.488 (2)
Ca1—O1W	2.450 (3)	P21—O23	1.558 (2)
O1W—H1W	0.87 (4)	P21—C23	1.821 (3)
O1W—H2W	0.81 (3)	O21—Ca1^v	2.312 (2)
P11—O11	1.473 (2)	O23—H23O	0.87 (3)
P11—O12	1.508 (2)	P22—O24	1.497 (2)
P11—O13	1.553 (3)	P22—O25	1.501 (2)
P11—C13	1.801 (3)	P22—O26	1.557 (2)
O13—H13O	0.88 (4)	P22—C25	1.805 (3)
P12—O14	1.483 (2)	O25—Ca1^vi	2.363 (2)
P12—O15	1.500 (2)	O26—H26O	0.81 (3)
P12—O16	1.556 (2)	N21—C22	1.318 (4)
P12—C15	1.812 (3)	N21—C26	1.342 (4)
O14—Ca1^iv	2.280 (2)	N21—H21	0.84 (3)
O16—H16O	0.87 (3)	C22—C23	1.366 (4)
N11—C12	1.318 (4)	C22—H22	0.9300
N11—C16	1.349 (4)	C23—C24	1.388 (4)
N11—H11	0.95 (3)	C24—C25	1.377 (4)
C12—C13	1.384 (4)	C24—H24	0.9300
C12—H12	0.9300	C25—C26	1.380 (4)
C13—C14	1.389 (4)	C26—H26	0.9300
C14—C15	1.394 (4)
O14^i—Ca1—O11	102.49 (9)	C13—C14—H14	119.2
O14^i—Ca1—O21^ii	93.56 (8)	C15—C14—H14	119.2
O11—Ca1—O21^ii	84.96 (8)	C16—C15—C14	117.9 (3)
O14^i—Ca1—O22	94.75 (8)	C16—C15—P12	118.5 (3)
O11—Ca1—O22	86.13 (8)	C14—C15—P12	123.6 (3)
O21^ii—Ca1—O22	168.95 (8)	N11—C16—C15	120.5 (3)
O14^i—Ca1—O25^iii	157.68 (9)	N11—C16—H16	119.8
O11—Ca1—O25^iii	98.83 (8)	C15—C16—H16	119.8
O21^ii—Ca1—O25^iii	94.80 (8)	O21—P21—O22	117.50 (13)
O22—Ca1—O25^iii	80.11 (7)	O21—P21—O23	112.71 (14)
O14^i—Ca1—O1W	81.83 (10)	O22—P21—O23	107.58 (13)
O11—Ca1—O1W	166.77 (9)	O21—P21—C23	106.76 (13)
O21^ii—Ca1—O1W	82.28 (8)	O22—P21—C23	106.66 (13)
O22—Ca1—O1W	106.12 (8)	O23—P21—C23	104.72 (14)
O25^iii—Ca1—O1W	78.85 (9)	P21—O21—Ca1^v	147.59 (13)
Ca1—O1W—H1W	135 (2)	P21—O22—Ca1	144.08 (13)
Ca1—O1W—H2W	122 (3)	P21—O23—H23O	118 (2)
H1W—O1W—H2W	103 (3)	O24—P22—O25	117.61 (13)
O11—P11—O12	116.25 (13)	O24—P22—O26	112.05 (13)
O11—P11—O13	114.08 (14)	O25—P22—O26	107.88 (13)
O12—P11—O13	109.00 (14)	O24—P22—C25	105.39 (14)
O11—P11—C13	110.13 (14)	O25—P22—C25	109.16 (14)
O12—P11—C13	104.88 (14)	O26—P22—C25	103.83 (14)
O13—P11—C13	101.04 (15)	P22—O25—Ca1^vi	135.31 (13)
P11—O11—Ca1	152.34 (14)	P22—O26—H26O	122 (3)
P11—O13—H13O	119 (2)	C22—N21—C26	122.7 (3)
O14—P12—O15	116.02 (13)	C22—N21—H21	124 (2)
O14—P12—O16	115.22 (15)	C26—N21—H21	113 (2)
O15—P12—O16	106.08 (13)	N21—C22—C23	121.2 (3)
O14—P12—C15	106.64 (14)	N21—C22—H22	119.4
O15—P12—C15	107.15 (13)	C23—C22—H22	119.4
O16—P12—C15	104.93 (14)	C22—C23—C24	116.3 (3)
P12—O14—Ca1^iv	156.05 (15)	C22—C23—P21	124.7 (2)
P12—O16—H16O	119 (2)	C24—C23—P21	118.9 (2)
C12—N11—C16	121.9 (3)	C25—C24—C23	123.2 (3)
C12—N11—H11	117 (2)	C25—C24—H24	118.4
C16—N11—H11	120 (2)	C23—C24—H24	118.4
N11—C12—C13	121.6 (3)	C24—C25—C26	116.4 (3)
N11—C12—H12	119.2	C24—C25—P22	119.5 (2)
C13—C12—H12	119.2	C26—C25—P22	123.9 (2)
C12—C13—C14	116.4 (3)	N21—C26—C25	120.1 (3)
C12—C13—P11	119.4 (3)	N21—C26—H26	120.0
C14—C13—P11	124.1 (3)	C25—C26—H26	120.0
C13—C14—C15	121.6 (3)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1W···O24	0.87 (4)	1.94 (4)	2.800 (3)	174 (4)
O1W—H2W···O22^ii	0.81 (3)	2.55 (4)	3.218 (3)	140 (4)
O23—H23O···O15^v	0.87 (3)	1.65 (3)	2.515 (3)	172 (4)
O26—H26O···O12^ii	0.81 (3)	1.73 (3)	2.536 (3)	171 (4)
N21—H21···O25^vii	0.84 (3)	1.92 (3)	2.749 (3)	169 (3)
O13—H13O···O24^iii	0.88 (4)	1.68 (4)	2.550 (3)	168 (4)
O16—H16O···O12^viii	0.87 (3)	1.72 (3)	2.584 (3)	170 (4)
N11—H11···O15^ix	0.95 (3)	1.81 (3)	2.668 (4)	149 (3)
N11—H11···O23^viii	0.95 (3)	2.57 (3)	3.137 (4)	119 (2)

Symmetry codes: (ii) x, −y+1/2, z+1/2; (iii) −x+2, y−1/2, −z+1/2; (v) x, −y+1/2, z−1/2; (vii) x, −y+3/2, z−1/2; (viii) −x+1, −y, −z; (ix) x, −y−1/2, z−1/2.