Crystal structure of a compact three-dimensional metal–organic framework based on Cs⁺ and (4,5-di­cyano-1,2-phenyl­ene)bis­(phospho­nic acid)

The three-dimensional metal–organic framework compound prepared from Cs⁺ and the organic linker 4,5-di­cyano-1,2-phenyl­ene)bis­(phospho­nic acid is based on an irregular CsO₈N₂ coordination center comprising a single monodentate hydro­nium O-atom donor, together with multiple bridging links to the two phospho­nate O-atom donors and to the two nitrile N-atom donors.

Abstract

A new metal–organic framework compound, poly[[μ₇-dihydrogen (4,5-di­cyano-1,2-phenyl­ene)diphospho­nato]­(oxonium)caesium], [Cs(C₈H₄N₂O₆P₂)(H₃O)]_n (I), based on Cs⁺ and the organic linker 4,5-di­cyano-1,2-phenyl­ene)bis­(phospho­nic acid, (H₄cpp), containing two distinct coordinating functional groups, has been prepared by a simple diffusion method and its crystal structure is reported. The coordination polymeric structure is based on a CsO₈N₂ complex unit comprising a monodentate hydro­nium cation, seven O-atom donors from two phospho­nium groups of the (H₂cpp)²⁻ ligand, and two N-atom donors from bridging cyano groups. The high level of connectivity from both the metal cation and the organic linker allow the formation of a compact and dense three-dimensional network without any crystallization solvent. Topologically (I) is a seven-connected uninodal network with an overall Schäfli symbol of {4¹⁷.6⁴}. Metal cations form an undulating inorganic layer, which is linked by strong and highly directional O—H⋯O hydrogen-bonding inter­actions. These metallic layers are, in turn, connected by the organic ligands along the [010] direction to form the overall three-dimensional framework structure.

Chemical context  

The area of metal–organic frameworks (MOFs) and coordin­ation polymers (CPs) has proven to be of great importance, not only in academic research but also for industrial applications (Silva et al., 2015 ▸). The simple and easy preparation of these materials, allied with the enormous variety of building blocks (either metal atoms or organic linkers) make these materials ideal to be employed in different applications: gas sorption/separation (Sumida et al., 2012 ▸), as heterogeneous catalysts (Mendes et al., 2015 ▸), luminescence (Heine & Müller-Buschbaum, 2013 ▸), batteries and as corrosion inhibitors (Morozan & Jaouen, 2012 ▸), among many others. Most of these compounds are obtained by mixing transition metal cations with carb­oxy­lic acids. The use of other oxygen-based donor groups such as phospho­nic acids has seen a great resurgence in recent years. The use of mixed oxygen–nitro­gen donor organic linkers is relatively less common, as confirmed by a search of the Cambridge Structural Database (CSD) (Groom et al., 2016 ▸).

Although alkali-metal cations are of great inter­est due to their abundance in biological systems, there is a surprisingly small number of MOFs/CPs based on these elements. Cs⁺-based materials are not as common as other alkali metals, especially when coordinated by either phospho­nic or sulfonic acid residues. Reports on these structures are directed to solely structural descriptions rather than to applications. Nevertheless, these compounds can be used as functional materials in batteries, either as proton conductors (Bazaga-Garcia et al., 2015 ▸) or as insulators (Tominaka et al., 2013 ▸).

Following our inter­est in this field of research, we report the preparation of a new compact and dense MOF network, [Cs(H₂cpp)(H₃O)]_n, prepared by the self-assembly of Cs⁺ and the organic linker (4,5-di­cyano-1,2-phenyl­ene)bis­(phospho­nic acid), (H₄cpp), previously reported by our group (Venkatramaiah et al., 2015 ▸). The title compound, [Cs(H₂cpp)(H₃O)]_n (I), was assembled under atmospheric conditions and represents, to the best of our knowledge, the first reported MOF or CP based on an amino/cyano phospho­nate with caesium as the metal cation, and the crystal structure is reported herein.

Structural commentary  

The asymmetric unit of (I) comprises one Cs⁺ atom coordinated by a dianionic H₂cpp²⁻ ligand, together with a monodentate hydro­nium cation (Fig. 1 ▸). The irregular CsO₈N₂ coordination polyhedron is defined by the O atom of one monodentate hydronium molecule, six hydrogen phospho­nate O-atom donors and two cyano N-atom donors. The Cs—O bond-length range is 3.159 (4)–3.410 (3) Å and for Cs—N, 3.234 (7) and 3.334 (6) Å (Table 1 ▸). These values are in good agreement with those reported for other phospho­nate-based materials as found in a search in the Cambridge Structural Database (CSD; Groom et al., 2016 ▸): mean value of 3.24 Å for the Cs—O bond (CSD range, 3.01–3.41 Å), and 3.28 Å for the Cs—N bond (CSD range, 2.35–3.79 Å).

Figure 1.

The asymmetric unit of [Cs(H₂cpp)(H₃O)]_n (I) showing all non-hydrogen atoms represented as displacement ellipsoids drawn at the 50% probability level and hydrogen atoms as small spheres with arbitrary radius. The coordination sphere of Cs⁺ is completed by generating (through symmetry) the remaining oxygen and nitro­gen atoms. For symmetry codes, see Table 1 ▸.

Table 1. Selected bond lengths (Å).

Cs1—O1	3.400 (3)	Cs1—O6v	3.259 (4)
Cs1—O1W	3.388 (4)	Cs1—O5vi	3.159 (4)
Cs1—O4	3.269 (4)	P1—O1	1.499 (4)
Cs1—N1i	3.234 (7)	P1—O2	1.509 (4)
Cs1—N2ii	3.334 (6)	P1—O3	1.558 (4)
Cs1—O1iii	3.229 (3)	P2—O4	1.497 (4)
Cs1—O3iv	3.356 (4)	P2—O5	1.572 (4)
Cs1—O4v	3.410 (3)	P2—O6	1.495 (3)

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

The crystallographic independent H₂cpp²⁻ residue in (I) acts as a linker connecting seven symmetry-related Cs⁺ metal atoms. The coordination modes between cyano and phospho­nate groups are, as expected, different. While the cyano groups connect to two different metal atoms, each in a simple κ¹ coordination mode, the two phospho­nate groups coordinate to the remaining metals by κ¹-O, κ²-O and μ₂-O,O coordination modes. This high coordination of the phospho­nate groups is responsible for the formation of a metallic undulating inorganic layer lying in the ac plane of the unit cell. Within this layer, the inter­metallic Cs⋯Cs distances range from 5.7792 (4) to 7.8819 (5) Å (Fig. 2 ▸). The cyano groups are, on the other hand, responsible for the inter-layer connections along the [010] direction. In this case, the inter­metallic Cs⋯Cs distances between layers range from 9.7347 (6) to 9.9044 (6) Å. Although the organic linkers are stacked, the minimum inter-centroid distance of 4.6545 (3) Å (as calculated using PLATON: Spek, 2009 ▸) indicates the absence of any significant π–π stacking inter­actions.

Figure 2.

Schematic representation of the connectivity of (a) the anionic H₂cpp²⁻ ligand; (b) the Cs⁺ cation and (c) the seven-connected [Cs(H₂cpp)(H₃O)] uninodal network with an overall Schäfli symbol of {4¹⁷.6⁴}.

The unusual presence of a coordinating H₃O⁺ ion in this Cs⁺ structure is confirmed by the location of the three hydrogen atoms associated with this cation, which were clearly visible from difference-Fourier maps and by the presence of the double charge with respect to the delocalized P1—O1, P1—O2 and P2—O4, P1—O6 bonds [1.499 (4), 1.509 (3) Å and 1.497 (4), 1.495 (3) Å, respectively]. The P1—O3 and P2—O5 bond lengths for the protonated groups are 1.558 (4) and 1.572 (4) Å, respectively. In addition, although the distance between O1W and O4 is very short, suggesting a possible O4—H⋯O1W inter­action, a calculated site for such a hydrogen was found to be sterically impossible in the crowded environment about Cs. Not only that, but any attempts to refine this mol­ecule as a coordination water mol­ecule proved to be not as successful as the hydro­nium cation. When the proton is connected to the adjacent phospho­nic residue, the bond is only possible by restraining the O—H distance between O4 and the proton. Also there was still a residual charge near O1W, which corroborated the initial refinement.

Topology  

The various coordination modes of the ligand and the presence of a compact undulating inorganic layer formed by the metal atoms to form the MOF architecture can be better understood from a pure topological perspective. Based on the recommendations of Alexandrov et al. (2011 ▸), any moiety (ligand, atom or clusters of atoms) connecting more than two metallic centers (μ_n) should be considered as a network node. For (I), all crystallographically independent moieties comprising the asymmetric unit, both the Cs⁺ cation and the anionic H₂cpp²⁻ ligand, should therefore be considered as nodes. Using the software package TOPOS (Blatov & Shevchenko, 2006 ▸), (I) could be classified as a seven-connected uninodal network with an overall Schäfli symbol of {4¹⁷.6⁴}. Fig. 2 ▸ illustrates the breakdown of the network of (I) into nodes and connecting rods, with the individual connectivity of each node being superimposed into the crystal structure itself (Fig. 2 ▸ a and 2b). The metal atom and the organic linker are connected to each other in every direction of the unit cell (Fig. 2 ▸ c), forming a compact and robust three-dimensional network (Fig. 3 ▸). The absence of water mol­ecules of crystallization leads to this very compact structure having no solvent-accessible pores: only 0.2% of the unit cell volume [calculated using Mercury (Macrae et al., 2006 ▸)] corresponds to voids.

Figure 3.

Schematic representation of the crystal packing of [Cs(H₂cpp) (H₃O)]_n viewed in perspective (a) along [001] and (b) along [100]. The representations emphasize the connection of the undulating inorganic layers located in the ac plane of the unit cell (and formed by the metal cations) through the organic ligand. The bottom representation further emphasizes the stacking of the organic linkers with inter-centroid ring distances of 4.6545 (3) Å.

Supra­molecular features  

The lack of crystallization solvent mol­ecules in (I) results in a rather small number of crystallographically different hydrogen-bonding supra­molecular inter­actions (Table 2 ▸). Indeed, although the structure is rich in hydrogen-bonding acceptors, only the POH and the H₃O⁺ moieties can establish strong inter­actions. A total of five distinct hydrogen bonds are present, two of these involving the phospho­nic acid donor groups [O3—H3⋯O6^vii and O5—H5⋯O2) and three involving the H₃O⁺ moiety (O1W—H1X⋯O2^iv, O1W—H1Y⋯O1 and O1W—H1Z⋯O4ⁱⁱⁱ (for symmetry codes, see Tables 1 ▸ and 2 ▸)]. An overall three-dimensional network structure is generated in which there are 62 ų voids (though not solvent-accessible ones). No π–π ring inter­actions are present (minimum ring-centroid separation = 4.655 Å). These hydrogen bonds are confined within the inorganic undulating layer (Fig. 4 ▸).

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O6vii	0.95 (1)	1.59 (12)	2.528 (5)	172 (5)
O5—H5⋯O2	0.94 (1)	1.60 (12)	2.545 (5)	175 (5)
O1W—H1X⋯O2iv	0.95 (1)	1.64 (16)	2.553 (5)	160 (4)
O1W—H1Y⋯O1	0.96 (1)	1.66 (11)	2.526 (5)	149 (4)
O1W—H1Z⋯O4iii	0.95 (1)	1.56 (15)	2.485 (5)	162 (4)

Symmetry codes: (iii) ; (iv) ; (vii) .

Figure 4.

Schematic representation of a portion of the undulating inorganic layer comprising the crystal structure of (I), emphasizing the various strong and directional supra­molecular O—H⋯O hydrogen-bonding inter­actions (orange dashed lines) present within this layer. For geometrical details and symmetry codes, see Table 2 ▸.

Database survey  

Although unusual in the case of Cs, in the Cambridge Structural Database (CSD) a total of 45 structures in which coordination between the metal cation and the hydro­nium cation is present, e.g. among the metal complexes (Reyes-Martínez et al., 2009 ▸; Jennifer et al., 2014 ▸; Teng et al., 2016 ▸; Hu & Mak, 2013 ▸) and coordination polymer/metal–organic frameworks (Yotnoi et al., 2015 ▸; Wang et al., 2013 ▸; Humphrey et al., 2005 ▸). Wang et al. (2013 ▸) in fact reported the structures of an isotypic series of crystal materials involving lanthanides (Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er and Y), in which the presence of the coordinating hydro­nium cation was confirmed.

Synthesis and crystallization  

Chemicals were purchased from commercial sources and used without any further purification steps. (4,5-Di­cyano-1,2-phenyl­ene)bis­(phospho­nic acid) (H₄cpp) was prepared according to published procedures (Venkatramaiah et al., 2015 ▸).

Synthesis of [Cs(H₂cpp)(H₃O)]_n, (I): H₄cpp (29 mg, 0.1 mM) was dissolved in 4 ml of methanol. A 1 ml aliquot of a methano­lic caesium hydroxide solution (45 mg, 0.3 mM; Sigma Aldrich, puriss p.a. ≥ 96%) was added slowly. The resulting mixture was stirred at ambient temperature for 10 min for uniform mixing. The final solution was allowed to slowly evaporate at ambient temperature. White transparent crystals of the title compound were obtained after one week. Crystals were filtered and dried under vacuum.

Refinement  

Crystal data, data collection and structure refinement details are summarized in Table 3 ▸. Hydrogen atoms bound to carbon were placed at idealized positions with C—H = 0.95 Å and included in the final structural model in a riding-motion approximation with the isotropic displacement parameters fixed at 1.2U _eq(C). Hydrogen atoms associated with the H₃O⁺ moiety and the phospho­nate groups were clearly located from difference-Fourier maps and were included in the refinement with the O—H and H⋯H (only for the cation) distances restrained to 0.95 (1) and 1.55 (1) Å, respectively, in order to ensure a chemically reasonable environment for these moieties. These hydrogen atoms were modelled with the isotropic displacement parameters fixed at 1.5U _eq(O). In order to avoid a close proximity between the H atoms associated with the POH group and the H₃O⁺ cation and the central Cs⁺ ion in the crystal structure, an anti­bump restraint [3.5 (1) Å)] was included in the overall refinement.

Table 3. Experimental details.

Crystal data
Chemical formula	[Cs(C8H4N2O6P2)(H3O)]
M r	438.01
Crystal system, space group	Monoclinic, P21/c
Temperature (K)	180
a, b, c (Å)	7.8819 (5), 24.5497 (14), 7.3137 (4)
β (°)	98.739 (2)
V (Å3)	1398.76 (14)
Z	4
Radiation type	Mo Kα
μ (mm−1)	2.91
Crystal size (mm)	0.15 × 0.06 × 0.02
Data collection
Diffractometer	Bruker D8 QUEST
Absorption correction	Multi-scan (SADABS; Bruker 2012 ▸)
T min, T max	0.647, 0.747
No. of measured, independent and observed [I > 2σ(I)] reflections	27787, 2550, 2499
R int	0.021
(sin θ/λ)max (Å−1)	0.602
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.031, 0.080, 1.50
No. of reflections	2550
No. of parameters	196
No. of restraints	10
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)	0.70, −0.60

Computer programs: APEX2 and SAINT (Bruker, 2012 ▸), SHELXS (Sheldrick, 2008 ▸), SHELXL2014 (Sheldrick, 2015 ▸) and DIAMOND (Brandenburg, 1999 ▸).

Supplementary Material

CCDC reference: 1510674

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

supplementary crystallographic information

Crystal data

[Cs(C8H4N2O6P2)(H3O)]	F(000) = 840
Mr = 438.01	Dx = 2.080 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.8819 (5) Å	Cell parameters from 9290 reflections
b = 24.5497 (14) Å	θ = 2.7–36.7°
c = 7.3137 (4) Å	µ = 2.91 mm−1
β = 98.739 (2)°	T = 180 K
V = 1398.76 (14) Å3	Plate, colourless
Z = 4	0.15 × 0.06 × 0.02 mm

Data collection

Bruker D8 QUEST diffractometer	2550 independent reflections
Radiation source: Sealed tube	2499 reflections with I > 2σ(I)
Multi-layer X-ray mirror monochromator	Rint = 0.021
Detector resolution: 10.4167 pixels mm-1	θmax = 25.4°, θmin = 3.6°
ω/φ scans	h = −9→9
Absorption correction: multi-scan (SADABS; Bruker 2012)	k = −29→29
Tmin = 0.647, Tmax = 0.747	l = −8→8
27787 measured reflections

Refinement

Refinement on F2	10 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.031	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.080	w = 1/[σ2(Fo2) + (0.0134P)2 + 6.7796P] where P = (Fo2 + 2Fc2)/3
S = 1.50	(Δ/σ)max = 0.002
2550 reflections	Δρmax = 0.70 e Å−3
196 parameters	Δρmin = −0.60 e Å−3

Special details

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.

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

	x	y	z	Uiso*/Ueq
Cs1	0.78119 (4)	0.56625 (2)	0.69290 (4)	0.02080 (11)
O1W	0.3543 (5)	0.54753 (15)	0.6850 (5)	0.0224 (8)
H1X	0.330 (6)	0.5549 (18)	0.806 (3)	0.034*
H1Y	0.3732 (16)	0.5092 (4)	0.675 (6)	0.034*
H1Z	0.258 (4)	0.5572 (15)	0.597 (5)	0.034*
P1	0.56069 (15)	0.42656 (5)	0.83441 (16)	0.0139 (2)
P2	0.97399 (15)	0.40970 (5)	0.72111 (17)	0.0147 (3)
O1	0.5083 (4)	0.45821 (14)	0.6597 (5)	0.0197 (7)
O2	0.6914 (4)	0.45406 (14)	0.9768 (5)	0.0186 (7)
O3	0.4048 (4)	0.41059 (15)	0.9310 (5)	0.0185 (7)
H3	0.311 (5)	0.403 (2)	0.837 (6)	0.028*
O4	0.8955 (4)	0.44573 (15)	0.5659 (5)	0.0237 (8)
O5	0.9966 (4)	0.44125 (15)	0.9103 (5)	0.0217 (8)
H5	0.886 (3)	0.4463 (14)	0.943 (7)	0.033*
O6	1.1438 (4)	0.38507 (14)	0.7016 (5)	0.0203 (7)
N1	0.4101 (9)	0.1823 (3)	0.7906 (11)	0.0603 (19)
N2	0.9099 (8)	0.1597 (2)	0.7224 (8)	0.0435 (14)
C1	0.6536 (6)	0.36144 (19)	0.7793 (6)	0.0143 (9)
C2	0.8230 (6)	0.3543 (2)	0.7429 (6)	0.0160 (10)
C3	0.8843 (6)	0.3016 (2)	0.7237 (7)	0.0189 (10)
H3A	0.9990	0.2968	0.7014	0.023*
C4	0.7834 (7)	0.2561 (2)	0.7360 (6)	0.0201 (10)
C5	0.6129 (7)	0.2632 (2)	0.7663 (7)	0.0222 (11)
C6	0.5506 (6)	0.3153 (2)	0.7867 (7)	0.0194 (10)
H6A	0.4350	0.3198	0.8061	0.023*
C7	0.5014 (8)	0.2170 (2)	0.7777 (9)	0.0333 (14)
C8	0.8522 (8)	0.2021 (2)	0.7244 (8)	0.0294 (12)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cs1	0.02062 (17)	0.02091 (18)	0.02049 (17)	−0.00137 (12)	0.00196 (12)	−0.00099 (12)
O1W	0.0225 (18)	0.0260 (19)	0.0182 (18)	0.0044 (15)	0.0015 (15)	−0.0030 (15)
P1	0.0117 (6)	0.0164 (6)	0.0135 (6)	0.0012 (5)	0.0021 (4)	−0.0005 (5)
P2	0.0109 (6)	0.0189 (6)	0.0142 (6)	−0.0009 (5)	0.0014 (5)	−0.0007 (5)
O1	0.0225 (18)	0.0222 (18)	0.0151 (17)	0.0047 (14)	0.0051 (14)	0.0011 (14)
O2	0.0139 (16)	0.0240 (18)	0.0177 (17)	0.0003 (14)	0.0020 (13)	−0.0046 (14)
O3	0.0126 (16)	0.0276 (19)	0.0156 (17)	0.0001 (14)	0.0034 (13)	−0.0003 (14)
O4	0.0198 (18)	0.0239 (19)	0.0257 (19)	−0.0040 (15)	−0.0019 (15)	0.0079 (16)
O5	0.0160 (17)	0.028 (2)	0.0216 (18)	−0.0040 (14)	0.0041 (14)	−0.0063 (15)
O6	0.0136 (17)	0.0279 (19)	0.0187 (18)	0.0005 (14)	0.0003 (14)	−0.0020 (15)
N1	0.067 (4)	0.037 (3)	0.082 (5)	−0.024 (3)	0.029 (4)	−0.006 (3)
N2	0.054 (3)	0.029 (3)	0.045 (3)	0.012 (3)	0.000 (3)	−0.003 (2)
C1	0.018 (2)	0.014 (2)	0.010 (2)	0.0009 (18)	−0.0006 (18)	0.0020 (18)
C2	0.013 (2)	0.018 (2)	0.015 (2)	−0.0004 (19)	−0.0017 (18)	−0.0024 (19)
C3	0.017 (2)	0.023 (3)	0.015 (2)	0.005 (2)	−0.0022 (19)	0.000 (2)
C4	0.029 (3)	0.021 (3)	0.008 (2)	0.004 (2)	−0.002 (2)	−0.0014 (19)
C5	0.026 (3)	0.020 (3)	0.020 (3)	−0.006 (2)	0.003 (2)	−0.002 (2)
C6	0.017 (2)	0.022 (3)	0.019 (3)	−0.002 (2)	0.0028 (19)	−0.001 (2)
C7	0.040 (3)	0.023 (3)	0.039 (4)	−0.006 (3)	0.015 (3)	−0.004 (3)
C8	0.037 (3)	0.024 (3)	0.026 (3)	0.002 (2)	0.002 (2)	−0.004 (2)

Geometric parameters (Å, º)

Cs1—O1	3.400 (3)	O1W—H1X	0.95 (3)
Cs1—O1W	3.388 (4)	O1W—H1Y	0.957 (11)
Cs1—O4	3.269 (4)	O1W—H1Z	0.95 (3)
Cs1—N1i	3.234 (7)	O3—H3	0.95 (4)
Cs1—N2ii	3.334 (6)	O5—H5	0.95 (3)
Cs1—O1iii	3.229 (3)	N1—C7	1.128 (9)
Cs1—O3iv	3.356 (4)	N2—C8	1.137 (7)
Cs1—O4v	3.410 (3)	C1—C2	1.412 (7)
Cs1—O6v	3.259 (4)	C1—C6	1.399 (7)
Cs1—O5vi	3.159 (4)	C2—C3	1.396 (7)
P1—O1	1.499 (4)	C3—C4	1.382 (7)
P1—O2	1.509 (4)	C4—C8	1.440 (7)
P1—O3	1.558 (4)	C4—C5	1.406 (8)
P1—C1	1.829 (5)	C5—C7	1.445 (8)
P2—O4	1.497 (4)	C5—C6	1.386 (7)
P2—O5	1.572 (4)	C3—H3A	0.9500
P2—O6	1.495 (3)	C6—H6A	0.9500
P2—C2	1.830 (5)
O1—Cs1—O1W	43.71 (8)	O2—P1—C1	106.8 (2)
O1—Cs1—O4	58.15 (8)	O3—P1—C1	104.5 (2)
O1—Cs1—N1i	113.35 (14)	O4—P2—O5	110.8 (2)
O1—Cs1—N2ii	170.46 (11)	O4—P2—O6	116.1 (2)
O1—Cs1—O1iii	55.63 (9)	O4—P2—C2	107.8 (2)
O1—Cs1—O3iv	80.81 (9)	O5—P2—O6	107.5 (2)
O1—Cs1—O4v	114.27 (8)	O5—P2—C2	106.1 (2)
O1—Cs1—O6v	114.88 (9)	O6—P2—C2	108.1 (2)
O1—Cs1—O5vi	106.05 (9)	Cs1—O1—P1	104.72 (16)
O1W—Cs1—O4	100.85 (9)	Cs1—O1—Cs1iii	124.37 (11)
O1W—Cs1—N1i	69.68 (14)	Cs1iii—O1—P1	130.85 (18)
O1W—Cs1—N2ii	142.36 (12)	Cs1iv—O3—P1	143.32 (19)
O1iii—Cs1—O1W	51.81 (9)	Cs1—O4—P2	114.80 (18)
O1W—Cs1—O3iv	58.71 (8)	Cs1—O4—Cs1v	119.82 (11)
O1W—Cs1—O4v	143.40 (9)	Cs1v—O4—P2	96.45 (15)
O1W—Cs1—O6v	110.36 (8)	Cs1vi—O5—P2	138.83 (19)
O1W—Cs1—O5vi	114.73 (9)	Cs1v—O6—P2	102.81 (17)
O4—Cs1—N1i	163.38 (15)	H1X—O1W—H1Z	109 (3)
O4—Cs1—N2ii	116.78 (11)	H1Y—O1W—H1Z	108 (3)
O1iii—Cs1—O4	78.26 (9)	Cs1—O1W—H1Z	132 (2)
O3iv—Cs1—O4	124.05 (9)	Cs1—O1W—H1X	107 (3)
O4—Cs1—O4v	60.18 (9)	Cs1—O1W—H1Y	88.2 (9)
O4—Cs1—O6v	89.17 (9)	H1X—O1W—H1Y	108 (4)
O4—Cs1—O5vi	94.02 (9)	P1—O3—H3	108 (3)
N1i—Cs1—N2ii	73.64 (16)	Cs1iv—O3—H3	104 (3)
O1iii—Cs1—N1i	85.23 (15)	P2—O5—H5	108 (3)
O3iv—Cs1—N1i	63.64 (15)	Cs1vi—O5—H5	100 (3)
O4v—Cs1—N1i	119.25 (15)	Cs1vii—N1—C7	167.2 (6)
O6v—Cs1—N1i	81.85 (15)	Cs1viii—N2—C8	155.5 (5)
O5vi—Cs1—N1i	102.33 (15)	P1—C1—C2	124.9 (4)
O1iii—Cs1—N2ii	133.14 (12)	C2—C1—C6	118.5 (4)
O3iv—Cs1—N2ii	97.40 (12)	P1—C1—C6	116.4 (4)
O4v—Cs1—N2ii	64.93 (12)	P2—C2—C3	116.1 (4)
O6v—Cs1—N2ii	71.74 (12)	P2—C2—C1	124.8 (4)
O5vi—Cs1—N2ii	65.30 (12)	C1—C2—C3	119.1 (4)
O1iii—Cs1—O3iv	110.02 (8)	C2—C3—C4	122.1 (5)
O1iii—Cs1—O4v	92.16 (8)	C3—C4—C5	118.9 (5)
O1iii—Cs1—O6v	64.05 (8)	C5—C4—C8	120.1 (5)
O1iii—Cs1—O5vi	161.55 (9)	C3—C4—C8	121.0 (5)
O3iv—Cs1—O4v	157.79 (8)	C6—C5—C7	119.3 (5)
O3iv—Cs1—O6v	145.49 (9)	C4—C5—C7	121.1 (5)
O3iv—Cs1—O5vi	60.47 (8)	C4—C5—C6	119.6 (5)
O4v—Cs1—O6v	44.67 (8)	C1—C6—C5	121.7 (5)
O4v—Cs1—O5vi	98.52 (8)	N1—C7—C5	177.0 (7)
O5vi—Cs1—O6v	133.23 (8)	N2—C8—C4	177.2 (6)
O1—P1—O2	115.3 (2)	C2—C3—H3A	119.00
O1—P1—O3	112.52 (19)	C4—C3—H3A	119.00
O1—P1—C1	109.5 (2)	C1—C6—H6A	119.00
O2—P1—O3	107.6 (2)	C5—C6—H6A	119.00
O1W—Cs1—O1—P1	−114.0 (2)	O1—Cs1—O5vi—P2vi	−110.8 (3)
O1W—Cs1—O1—Cs1iii	68.38 (14)	O1W—Cs1—O5vi—P2vi	−64.9 (3)
O4—Cs1—O1—P1	79.83 (17)	O4—Cs1—O5vi—P2vi	−168.8 (3)
O4—Cs1—O1—Cs1iii	−97.75 (14)	O1—P1—C1—C2	79.5 (4)
N1i—Cs1—O1—P1	−116.3 (2)	O1—P1—C1—C6	−105.0 (4)
N1i—Cs1—O1—Cs1iii	66.1 (2)	O2—P1—C1—C2	−46.0 (4)
O1iii—Cs1—O1—P1	177.6 (2)	O2—P1—C1—C6	129.6 (4)
O1iii—Cs1—O1—Cs1iii	−0.02 (14)	O3—P1—C1—C2	−159.8 (4)
O3iv—Cs1—O1—P1	−60.36 (16)	O3—P1—C1—C6	15.7 (4)
O3iv—Cs1—O1—Cs1iii	122.06 (13)	O3—P1—O1—Cs1	132.24 (17)
O4v—Cs1—O1—P1	102.56 (17)	C1—P1—O1—Cs1	−112.09 (19)
O4v—Cs1—O1—Cs1iii	−75.03 (14)	O2—P1—O1—Cs1iii	−174.33 (19)
O6v—Cs1—O1—P1	151.95 (15)	O3—P1—O1—Cs1iii	−50.4 (3)
O6v—Cs1—O1—Cs1iii	−25.63 (15)	C1—P1—O1—Cs1iii	65.3 (3)
O5vi—Cs1—O1—P1	−4.83 (18)	O1—P1—O3—Cs1iv	−111.9 (3)
O5vi—Cs1—O1—Cs1iii	177.59 (11)	O2—P1—O1—Cs1	8.3 (2)
O1—Cs1—O4—P2	−89.90 (19)	C1—P1—O3—Cs1iv	129.5 (3)
O1—Cs1—O4—Cs1v	156.05 (16)	O2—P1—O3—Cs1iv	16.2 (4)
O1W—Cs1—O4—P2	−99.61 (18)	O4—P2—C2—C3	121.5 (4)
O1W—Cs1—O4—Cs1v	146.34 (11)	O5—P2—C2—C1	59.4 (4)
N2ii—Cs1—O4—P2	80.8 (2)	O6—P2—C2—C1	174.4 (4)
N2ii—Cs1—O4—Cs1v	−33.23 (17)	O6—P2—C2—C3	−4.7 (4)
O1iii—Cs1—O4—P2	−146.54 (19)	O5—P2—C2—C3	−119.8 (4)
O1iii—Cs1—O4—Cs1v	99.41 (12)	O4—P2—C2—C1	−59.4 (4)
O3iv—Cs1—O4—P2	−40.2 (2)	O5—P2—O4—Cs1	−4.8 (2)
O3iv—Cs1—O4—Cs1v	−154.24 (10)	O6—P2—O4—Cs1	−127.67 (19)
O4v—Cs1—O4—P2	114.1 (2)	C2—P2—O4—Cs1	110.9 (2)
O4v—Cs1—O4—Cs1v	−0.02 (9)	O5—P2—O4—Cs1v	122.33 (16)
O6v—Cs1—O4—P2	149.81 (18)	O6—P2—O4—Cs1v	−0.5 (2)
O6v—Cs1—O4—Cs1v	35.76 (12)	C2—P2—O4—Cs1v	−121.95 (17)
O5vi—Cs1—O4—P2	16.53 (19)	O4—P2—O5—Cs1vi	−158.3 (2)
O5vi—Cs1—O4—Cs1v	−97.52 (12)	O6—P2—O5—Cs1vi	−30.5 (3)
O1W—Cs1—N2ii—C8ii	−38.5 (13)	C2—P2—O5—Cs1vi	85.0 (3)
O4—Cs1—N2ii—C8ii	140.8 (11)	O4—P2—O6—Cs1v	0.6 (2)
O1—Cs1—O1iii—Cs1iii	0.00 (10)	O5—P2—O6—Cs1v	−124.03 (17)
O1—Cs1—O1iii—P1iii	176.9 (3)	C2—P2—O6—Cs1v	121.81 (17)
O1W—Cs1—O1iii—Cs1iii	−54.81 (12)	P1—C1—C2—P2	−6.5 (6)
O1W—Cs1—O1iii—P1iii	122.1 (3)	P1—C1—C2—C3	172.7 (4)
O4—Cs1—O1iii—Cs1iii	59.28 (12)	C6—C1—C2—P2	178.1 (4)
O4—Cs1—O1iii—P1iii	−123.8 (2)	C6—C1—C2—C3	−2.8 (7)
O1—Cs1—O3iv—P1iv	−14.9 (3)	P1—C1—C6—C5	−173.3 (4)
O1W—Cs1—O3iv—P1iv	25.8 (3)	C2—C1—C6—C5	2.5 (7)
O4—Cs1—O3iv—P1iv	−55.9 (3)	P2—C2—C3—C4	−179.6 (4)
O1—Cs1—O4v—Cs1v	−22.22 (15)	C1—C2—C3—C4	1.2 (7)
O1—Cs1—O4v—P2v	101.24 (17)	C2—C3—C4—C5	0.9 (7)
O1W—Cs1—O4v—Cs1v	−65.93 (19)	C2—C3—C4—C8	−177.0 (5)
O1W—Cs1—O4v—P2v	57.5 (2)	C3—C4—C5—C6	−1.2 (7)
O4—Cs1—O4v—Cs1v	0.00 (10)	C3—C4—C5—C7	179.1 (5)
O4—Cs1—O4v—P2v	123.46 (19)	C8—C4—C5—C6	176.7 (5)
O1—Cs1—O6v—P2v	−99.78 (17)	C8—C4—C5—C7	−2.9 (7)
O1W—Cs1—O6v—P2v	−147.10 (15)	C4—C5—C6—C1	−0.5 (7)
O4—Cs1—O6v—P2v	−45.83 (17)	C7—C5—C6—C1	179.2 (5)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O6ix	0.95 (1)	1.59 (12)	2.528 (5)	172 (5)
O5—H5···O2	0.94 (1)	1.60 (12)	2.545 (5)	175 (5)
O1W—H1X···O2iv	0.95 (1)	1.64 (16)	2.553 (5)	160 (4)
O1W—H1Y···O1	0.96 (1)	1.66 (11)	2.526 (5)	149 (4)
O1W—H1Z···O4iii	0.95 (1)	1.56 (15)	2.485 (5)	162 (4)

Symmetry codes: (iii) −x+1, −y+1, −z+1; (iv) −x+1, −y+1, −z+2; (ix) x−1, y, z.