Hydrogen bonding, π–π stacking and van der Waals forces-dominated layered regions in the crystal structure of 4-amino­pyridinium hydrogen (9-phosphono­non­yl)phospho­nate

Megen, M. van; Reiss, G.J.; Frank, W.

doi:10.1107/S2056989016014298

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Volume 72| Part 10| October 2016| Pages 1456-1459

https://doi.org/10.1107/S2056989016014298

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Hydrogen bonding, π–π stacking and van der Waals forces-dominated layered regions in the crystal structure of 4-aminopyridinium hydrogen (9-phosphonononyl)phosphonate

Martin van Megen,^a Guido J. Reiss ^a ^* and Walter Frank ^a

^aInstitut für Anorganische Chemie und Strukturchemie, Lehrstuhl II: Material- und Strukturforschung, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
^*Correspondence e-mail: reissg@hhu.de

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 14 August 2016; accepted 8 September 2016; online 23 September 2016)

The asymmetric unit of the title molecular salt, [C₅H₇N₂⁺][(HO)₂OP(CH₂)₉PO₂(OH)⁻], consists of one 4-aminopyridinium cation and one hydrogen (9-phosphonononyl)phosphonate anion, both in general positions. As expected, the 4-aminopyridinium moieties are protonated exclusively at their endocyclic nitrogen atom due to a mesomeric stabilization by the imine form which would not be given in the corresponding double-protonated dicationic species. In the crystal, the phosphonyl (–PO₃H₂) and hydrogen phosphonate (–PO₃H) groups of the anions form two-dimensional O—H⋯O hydrogen-bonded networks in the ab plane built from 24-membered hydrogen-bonded ring motifs with the graph-set descriptor R⁶₆(24). These networks are pairwise linked by the anions' alkylene chains. The 4-aminopyridinium cations are stacked in parallel displaced face-to-face arrangements and connect neighboring anionic substructures via medium–strong charge-supported N—H⋯O hydrogen bonds along the c axis. The resulting three-dimensional hydrogen-bonded network shows clearly separated hydrophilic and hydrophobic structural domains.

Keywords: crystal structure; 4-aminopyridinium; bis(phosphonate); hydrogen bonding.

CCDC reference: 1503436

1. Chemical context

Salts of organophosphonic acids with organic cations, e.g. with protonated primary (Mahmoudkhani & Langer, 2002b ), secondary (Wheatley et al., 2001 ) and tertiary amines (Kan & Ma, 2011 ) are of growing interest in supramolecular chemistry and crystal engineering. Besides their interesting topologies and structural diversity, they seem to be feasible model compounds for metal phosphonates as they exhibit similar structural characteristics but are less difficult to crystallize. Mostly, these organic solids establish extended hydrogen-bonded networks which are characterized by a rich diversity of strong charge-supported hydrogen bonds (Aakeröy & Seddon, 1993 ) and can either be one-, two- or three-dimensional. This contribution forms part of our research on the principles of the arrangement of alkane-α,ω-diphosphonic acids (van Megen et al., 2015 ) and their organic aminium salts (van Megen et al., 2016 ). Moreover, aminopyridines and the related protonated cations are of crucial interest in the field of biochemistry (Muñoz-Caro & Niño, 2002 ; Bolliger et al., 2011 ) and are also used as counter-cations to stabilize complex salts (Reiss & Leske, 2014a ,b ), in crystal engineering (Sertucha et al., 1998 ; Surbella III et al., 2016 ) as well as in polymer chemistry (Deng et al., 2015 ).

2. Structural commentary

The asymmetric unit of the title compound, [C₅H₇N₂⁺][(HO)₂OP(CH₂)₉PO₂(OH)⁻], consists of one 4-aminopyridinium cation and one hydrogen (9-phosphonononyl)phosphonate anion, both in general positions (Fig. 1). Generally, the first protonation of the 4-aminopyridine can take place at the exo- as well as at the endocyclic nitrogen atom. In the literature, all monoprotonated 4-aminopyridines characterized to date are protonated at the endocyclic nitrogen atom. Geometric parameters derived from the single-crystal diffraction experiment for the title compound show a short exocyclic N—C bond length [1.324 (2) Å] and slightly longer C—C and C—N bond lengths of the six-membered ring [1.350 (3)–1.425 (2) Å]. The bonding properties of this cation are best described by a pair of mesomeric structures: the enamine and the imine form (Scheme 2), which have been discussed in detail before (Koleva et al., 2008 ).

Figure 1
The asymmetric unit of the title compound plus symmetry-related hydrogen-bonded atoms [displacement ellipsoids are drawn at the 50% probability level; hydrogen atoms are drawn as spheres with arbitrary radii; symmetry codes: (i) 1 + x, −1 + y, 1 + z; (ii) x, −1 + y, 1 + z; (iii) 1 − x, 2 − y, 1 − z; (iv) 1 − x, 1 − y, 1 − z; (v) −x, 1 − y, 1 − z; (vi) −1 + x, 1 + y, −1 + z, (vii) x, 1 + y, −1 + z].

For the designation of the title compound, the systematic name of the amino form is used throughout this article. The bond lengths and angles of the anion are unexceptional and lie within the expected ranges. The alkylene chain of the anion shows nearly antiperiplanar conformations. In detail, the P—OH distances of the phosphonate moieties have values between 1.5535 (13) and 1.5786 (14) Å, longer than the P=O distances [1.5045 (13)–1.5149 (12) Å].

3. Supramolecular features

Within the crystal of the title compound, the phosphonyl and hydrogen phosphonate groups of the anions form two-dimensional O—H⋯O hydrogen-bonded networks which propagate in the ab plane. These networks contain 24-membered rings classified as a third level graph set R₆⁶(24) (Etter et al., 1990 ; Fig. 2; Table 1). 24-Membered hydrogen-bonded rings have been well known for decades (e.g. Mootz & Poll, 1984 ). In particular, the R₆⁶(24) motif is very common (e.g. Gomathi & Muthiah, 2011 ; Maspoch et al., 2007 ). Along the c-axis direction, these networks are pairwise linked by the anions' alkylene chains to form a three-dimensional anionic substructure. The 4-aminopyridinium cations show π–π stacking interactions. The rings are oriented in parallel displaced face-to-face arrangements (Grimme, 2008 ; Fig. 3). The geometry of these π–π interactions is reflected by distances of 3.25 and 3.32 Å between neighbouring pyridinium rings and centroid offsets of 2.37 and 2.42 Å. These findings are comparable to those found for other compounds containing pyridyl moieties (Janiak, 2000 ). Anions and cations are connected by medium–strong, charge-supported N—H⋯O hydrogen bonds (Steiner, 2002 ; Table 2) along the c axis. For these connections, each nitrogen-bound hydrogen atom forms one unbifurcated hydrogen bond (Fig. 1). The resulting three-dimensional hydrogen-bonded network clearly shows separated hydrophilic and hydrophobic regions (Fig. 3).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O6ⁱ	0.78 (3)	1.85 (3)	2.6171 (18)	166 (3)
O5—H5⋯O1ⁱⁱ	0.88 (3)	1.64 (3)	2.5059 (18)	168 (3)
O4—H4⋯O2ⁱⁱⁱ	0.91 (3)	1.59 (3)	2.4977 (17)	178 (3)
N1—H1⋯O6	0.96 (2)	1.74 (3)	2.696 (2)	173 (2)
N2—H22⋯O2^iv	0.90 (3)	1.92 (3)	2.806 (2)	170 (2)
N2—H21⋯O1^v	0.88 (3)	2.14 (3)	2.965 (2)	156 (3)
Symmetry codes: (i) -x+1, -y+2, -z+1; (ii) -x, -y+1, -z+1; (iii) -x+1, -y+1, -z+1; (iv) x, y-1, z+1; (v) x+1, y-1, z+1.

Table 2
Experimental details

Crystal data
Chemical formula	C₅H₇N₂⁺·C₉H₂₁O₆P₂⁻
M_r	382.32
Crystal system, space group	Triclinic, P $[\overline{1}]$
Temperature (K)	123
a, b, c (Å)	6.7275 (4), 6.8963 (4), 20.0643 (10)
α, β, γ (°)	97.956 (4), 98.767 (4), 94.309 (5)
V (Å³)	906.73 (9)
Z	2
Radiation type	Mo Kα
μ (mm⁻¹)	0.27
Crystal size (mm)	0.33 × 0.07 × 0.03

Data collection
Diffractometer	Stoe IPDS
No. of measured, independent and observed [I > 2σ(I)] reflections	8855, 4131, 3674
R_int	0.029
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.038, 0.079, 1.02
No. of reflections	4131
No. of parameters	241
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.50, −0.36
Computer programs: X-AREA (Stoe & Cie, 2002 ), SHELXT (Sheldrick, 2015a ), SHELXL-2014/7 (Sheldrick, 2015b ) and DIAMOND (Brandenburg, 2015 ).

Figure 2
Two-dimensional hydrogen-bonded networks composed of phosphonyl and hydrogen phosphonate groups. The graph set R₆⁶(24) is indicated by blue bonds.

Figure 3
View along [010] of the title structure, showing the hydrogen bonding (red), π–π stacking (blue), and van der Waals forces (grey) dominated layered regions within the three-dimensional network.

4. Related structures

For related phosphonate and bis(phosphonate) salts, see: Ferguson et al. (1998 ); Fu et al. (2004 ); Fuller & Heimer (1995 ); Glidewell et al. (2000 ); Kan & Ma (2011); Mahmoudkhani & Langer (2002a ,b,c ); van Megen et al. (2016); Plabst et al. (2009 ); Wheatley et al. (2001). For related 4-aminopyridinium salts, see: Sertucha et al. (1998); Reiss & Leske (2014a,b); Surbella III et al. (2016).

5. Synthesis and crystallization

Equimolar quantities (0.5 mmol) of 4-aminopyridine (47.1 mg) and nonane-1,9-diphosphonic acid (144.1 mg) were dissolved in methanol, separately. The solutions were mixed and stored in an open petri dish. Within several days, colorless platelet-shaped crystals of the title compound were obtained by slow evaporation of the solvent. 4-Aminopyridine was purchased from commercial sources and nonane-1,9-diphosphonic acid was synthesized according to the literature (Schwarzenbach & Zurc, 1950 ; Moedritzer & Irani, 1961 ; Griffith et al., 1998 ). Elemental analysis: C₁₄H₂₈N₂O₆P₂ (382.3): calculated C 44.0, H 7.4, N 7.3; found C 43.6, H 7.9, N 7.1. M. p.: 157 °C. The IR and Raman spectra of the title compound are shown in Fig. 4.

Figure 4
The IR (blue) and Raman (red) spectra of the title compound.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. All hydrogen atoms bound to either nitrogen or oxygen atoms were identified in difference syntheses and refined without any geometric constraints or restraints with individual U_iso(H) values. Carbon-bound hydrogen atoms were included using a riding model (AFIX23 option of the SHELX program for the methylene groups and AFIX43 option for the methine groups).

Supporting information

CCDC reference: 1503436

Crystal structure: contains datablocks I, publication_text. DOI: https://doi.org/10.1107/S2056989016014298/hb7610sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989016014298/hb7610Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2056989016014298/hb7610Isup3.cml

checkCIF report

Computing details top

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-AREA (Stoe & Cie, 2002); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL-2014/7 (Sheldrick, 2015b); molecular graphics: DIAMOND (Brandenburg, 2015).

4-Aminopyridinium hydrogen (9-phosphonononyl)phosphonate top

Crystal data top

C₅H₇N₂⁺·C₉H₂₁O₆P₂⁻	Z = 2
M_r = 382.32	F(000) = 408
Triclinic, P1	D_x = 1.400 Mg m⁻³
a = 6.7275 (4) Å	Mo Kα radiation, λ = 0.71073 Å
b = 6.8963 (4) Å	Cell parameters from 6853 reflections
c = 20.0643 (10) Å	θ = 3.0–35.3°
α = 97.956 (4)°	µ = 0.27 mm⁻¹
β = 98.767 (4)°	T = 123 K
γ = 94.309 (5)°	Platelet, colourless
V = 906.73 (9) Å³	0.33 × 0.07 × 0.03 mm

Data collection top

Stoe IPDS diffractometer	R_int = 0.029
Radiation source: sealed tube	θ_max = 27.5°, θ_min = 3.0°
ω scans	h = −8→8
8855 measured reflections	k = −8→8
4131 independent reflections	l = −26→26
3674 reflections with I > 2σ(I)

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.038	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.079	w = 1/[σ²(F_o²) + (0.011P)² + 1.110P] where P = (F_o² + 2F_c²)/3
S = 1.02	(Δ/σ)_max = 0.001
4131 reflections	Δρ_max = 0.50 e Å⁻³
241 parameters	Δρ_min = −0.36 e Å⁻³
0 restraints

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
P1	0.29655 (6)	1.15924 (6)	0.22320 (2)	0.01579 (10)
O1	0.14667 (19)	1.0094 (2)	0.17549 (6)	0.0230 (3)
N1	0.5995 (3)	0.2836 (2)	0.92948 (8)	0.0257 (3)
H1	0.553 (4)	0.306 (4)	0.8838 (13)	0.036 (6)*
C1	0.2470 (3)	1.1616 (3)	0.30883 (8)	0.0179 (3)
H1A	0.3161	1.2802	0.3371	0.021*
H1B	0.1032	1.1663	0.3086	0.021*
P2	0.24757 (6)	0.29013 (6)	0.77082 (2)	0.01589 (10)
O2	0.51802 (18)	1.13618 (18)	0.22159 (6)	0.0199 (3)
N2	0.7740 (3)	0.1858 (3)	1.12583 (8)	0.0252 (3)
H21	0.901 (4)	0.169 (4)	1.1403 (14)	0.049 (8)*
H22	0.681 (4)	0.172 (4)	1.1527 (12)	0.035 (6)*
C2	0.3143 (3)	0.9827 (3)	0.34082 (8)	0.0191 (3)
H2A	0.2686	0.8640	0.3084	0.023*
H2B	0.4608	0.9929	0.3504	0.023*
O3	0.2486 (2)	1.3660 (2)	0.20293 (7)	0.0239 (3)
C3	0.2306 (3)	0.9668 (3)	0.40681 (8)	0.0191 (3)
H3A	0.2699	1.0891	0.4379	0.023*
H3B	0.0842	0.9503	0.3964	0.023*
H3	0.343 (5)	1.442 (5)	0.2068 (17)	0.070 (11)*
O4	0.24107 (19)	0.08343 (18)	0.72796 (6)	0.0188 (2)
C4	0.3028 (3)	0.7975 (3)	0.44244 (8)	0.0195 (3)
H4A	0.4490	0.8157	0.4542	0.023*
H4B	0.2664	0.6752	0.4112	0.023*
H4	0.330 (5)	0.006 (5)	0.7471 (16)	0.066 (9)*
O5	0.1083 (2)	0.27587 (19)	0.82576 (6)	0.0216 (3)
C5	0.2125 (3)	0.7822 (3)	0.50710 (9)	0.0195 (3)
H5A	0.2483	0.9055	0.5379	0.023*
H5B	0.0664	0.7648	0.4950	0.023*
H5	0.017 (5)	0.174 (5)	0.8191 (16)	0.064 (9)*
O6	0.45679 (19)	0.37295 (19)	0.80557 (6)	0.0220 (3)
C6	0.2806 (3)	0.6151 (3)	0.54491 (8)	0.0188 (3)
H6A	0.4264	0.6325	0.5579	0.023*
H6B	0.2450	0.4910	0.5146	0.023*
C7	0.1838 (3)	0.6074 (3)	0.60867 (8)	0.0179 (3)
H7A	0.0383	0.5858	0.5951	0.022*
H7B	0.2146	0.7341	0.6377	0.022*
C8	0.2526 (3)	0.4476 (3)	0.65035 (8)	0.0180 (3)
H8A	0.3972	0.4716	0.6661	0.022*
H8B	0.2261	0.3205	0.6214	0.022*
C9	0.1432 (3)	0.4431 (3)	0.71211 (8)	0.0175 (3)
H9A	0.0022	0.3966	0.6959	0.021*
H9B	0.1488	0.5762	0.7360	0.021*
C10	0.7973 (3)	0.2769 (3)	0.95325 (10)	0.0283 (4)
H10	0.8919	0.2928	0.9247	0.034*
C11	0.8604 (3)	0.2470 (3)	1.01867 (9)	0.0272 (4)
H11	0.9972	0.2420	1.0341	0.033*
C12	0.7189 (3)	0.2236 (3)	1.06310 (9)	0.0199 (3)
C13	0.5127 (3)	0.2384 (3)	1.03659 (9)	0.0214 (4)
H13	0.4144	0.2288	1.0642	0.026*
C14	0.4601 (3)	0.2665 (3)	0.97075 (10)	0.0242 (4)
H14	0.3249	0.2741	0.9537	0.029*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
P1	0.01293 (19)	0.0198 (2)	0.0158 (2)	0.00022 (16)	0.00233 (15)	0.00733 (16)
O1	0.0224 (6)	0.0286 (7)	0.0167 (6)	−0.0056 (5)	0.0023 (5)	0.0042 (5)
N1	0.0360 (9)	0.0236 (8)	0.0159 (7)	0.0009 (7)	−0.0008 (6)	0.0036 (6)
C1	0.0179 (8)	0.0202 (8)	0.0161 (8)	−0.0003 (6)	0.0038 (6)	0.0048 (6)
P2	0.0175 (2)	0.0167 (2)	0.01360 (19)	−0.00040 (16)	0.00111 (15)	0.00535 (15)
O2	0.0163 (6)	0.0239 (6)	0.0228 (6)	0.0042 (5)	0.0057 (5)	0.0111 (5)
N2	0.0187 (8)	0.0392 (10)	0.0194 (7)	0.0036 (7)	0.0035 (6)	0.0097 (7)
C2	0.0185 (8)	0.0237 (9)	0.0162 (8)	0.0015 (7)	0.0030 (6)	0.0072 (6)
O3	0.0158 (6)	0.0267 (7)	0.0328 (7)	0.0026 (5)	0.0047 (5)	0.0162 (6)
C3	0.0195 (8)	0.0229 (9)	0.0163 (8)	0.0003 (7)	0.0047 (6)	0.0066 (6)
O4	0.0190 (6)	0.0194 (6)	0.0178 (6)	0.0029 (5)	0.0014 (5)	0.0036 (5)
C4	0.0201 (8)	0.0239 (9)	0.0161 (8)	0.0009 (7)	0.0038 (6)	0.0079 (6)
O5	0.0280 (7)	0.0206 (6)	0.0170 (6)	−0.0021 (5)	0.0070 (5)	0.0041 (5)
C5	0.0209 (8)	0.0217 (8)	0.0169 (8)	0.0002 (7)	0.0039 (6)	0.0063 (6)
O6	0.0216 (6)	0.0228 (6)	0.0202 (6)	−0.0045 (5)	−0.0032 (5)	0.0091 (5)
C6	0.0193 (8)	0.0221 (8)	0.0161 (8)	0.0008 (7)	0.0041 (6)	0.0056 (6)
C7	0.0195 (8)	0.0199 (8)	0.0153 (7)	0.0014 (6)	0.0029 (6)	0.0060 (6)
C8	0.0191 (8)	0.0200 (8)	0.0157 (7)	0.0019 (6)	0.0027 (6)	0.0058 (6)
C9	0.0178 (8)	0.0198 (8)	0.0157 (7)	0.0020 (6)	0.0027 (6)	0.0054 (6)
C10	0.0305 (10)	0.0338 (11)	0.0206 (9)	0.0008 (8)	0.0077 (7)	0.0020 (8)
C11	0.0206 (9)	0.0390 (11)	0.0215 (9)	0.0018 (8)	0.0038 (7)	0.0032 (8)
C12	0.0212 (8)	0.0192 (8)	0.0184 (8)	0.0008 (7)	0.0025 (6)	0.0014 (6)
C13	0.0206 (8)	0.0207 (8)	0.0232 (9)	0.0010 (7)	0.0039 (7)	0.0047 (7)
C14	0.0249 (9)	0.0206 (9)	0.0254 (9)	0.0022 (7)	−0.0020 (7)	0.0046 (7)

Geometric parameters (Å, º) top

P1—O1	1.5088 (13)	C4—H4A	0.9700
P1—O2	1.5149 (12)	C4—H4B	0.9700
P1—O3	1.5786 (14)	O5—H5	0.88 (3)
P1—C1	1.7974 (17)	C5—C6	1.526 (2)
N1—C10	1.350 (3)	C5—H5A	0.9700
N1—C14	1.352 (3)	C5—H5B	0.9700
N1—H1	0.96 (2)	C6—C7	1.527 (2)
C1—C2	1.534 (2)	C6—H6A	0.9700
C1—H1A	0.9700	C6—H6B	0.9700
C1—H1B	0.9700	C7—C8	1.530 (2)
P2—O6	1.5045 (13)	C7—H7A	0.9700
P2—O4	1.5535 (13)	C7—H7B	0.9700
P2—O5	1.5601 (13)	C8—C9	1.537 (2)
P2—C9	1.7880 (17)	C8—H8A	0.9700
N2—C12	1.324 (2)	C8—H8B	0.9700
N2—H21	0.88 (3)	C9—H9A	0.9700
N2—H22	0.90 (3)	C9—H9B	0.9700
C2—C3	1.530 (2)	C10—C11	1.365 (3)
C2—H2A	0.9700	C10—H10	0.9300
C2—H2B	0.9700	C11—C12	1.415 (3)
O3—H3	0.78 (3)	C11—H11	0.9300
C3—C4	1.523 (2)	C12—C13	1.425 (2)
C3—H3A	0.9700	C13—C14	1.359 (3)
C3—H3B	0.9700	C13—H13	0.9300
O4—H4	0.91 (3)	C14—H14	0.9300
C4—C5	1.527 (2)

O1—P1—O2	116.41 (8)	C6—C5—C4	114.77 (15)
O1—P1—O3	105.96 (8)	C6—C5—H5A	108.6
O2—P1—O3	108.76 (7)	C4—C5—H5A	108.6
O1—P1—C1	109.09 (8)	C6—C5—H5B	108.6
O2—P1—C1	109.62 (7)	C4—C5—H5B	108.6
O3—P1—C1	106.51 (8)	H5A—C5—H5B	107.6
C10—N1—C14	120.49 (16)	C5—C6—C7	112.06 (14)
C10—N1—H1	121.8 (15)	C5—C6—H6A	109.2
C14—N1—H1	117.6 (15)	C7—C6—H6A	109.2
C2—C1—P1	113.66 (12)	C5—C6—H6B	109.2
C2—C1—H1A	108.8	C7—C6—H6B	109.2
P1—C1—H1A	108.8	H6A—C6—H6B	107.9
C2—C1—H1B	108.8	C6—C7—C8	114.51 (14)
P1—C1—H1B	108.8	C6—C7—H7A	108.6
H1A—C1—H1B	107.7	C8—C7—H7A	108.6
O6—P2—O4	113.40 (7)	C6—C7—H7B	108.6
O6—P2—O5	109.15 (7)	C8—C7—H7B	108.6
O4—P2—O5	108.70 (7)	H7A—C7—H7B	107.6
O6—P2—C9	111.12 (8)	C7—C8—C9	111.67 (14)
O4—P2—C9	105.43 (8)	C7—C8—H8A	109.3
O5—P2—C9	108.89 (8)	C9—C8—H8A	109.3
C12—N2—H21	119.9 (18)	C7—C8—H8B	109.3
C12—N2—H22	119.6 (16)	C9—C8—H8B	109.3
H21—N2—H22	120 (2)	H8A—C8—H8B	107.9
C3—C2—C1	112.06 (14)	C8—C9—P2	113.70 (12)
C3—C2—H2A	109.2	C8—C9—H9A	108.8
C1—C2—H2A	109.2	P2—C9—H9A	108.8
C3—C2—H2B	109.2	C8—C9—H9B	108.8
C1—C2—H2B	109.2	P2—C9—H9B	108.8
H2A—C2—H2B	107.9	H9A—C9—H9B	107.7
P1—O3—H3	115 (2)	N1—C10—C11	120.95 (18)
C4—C3—C2	113.89 (15)	N1—C10—H10	119.5
C4—C3—H3A	108.8	C11—C10—H10	119.5
C2—C3—H3A	108.8	C10—C11—C12	120.38 (18)
C4—C3—H3B	108.8	C10—C11—H11	119.8
C2—C3—H3B	108.8	C12—C11—H11	119.8
H3A—C3—H3B	107.7	N2—C12—C11	121.92 (17)
P2—O4—H4	113 (2)	N2—C12—C13	121.32 (17)
C3—C4—C5	112.68 (15)	C11—C12—C13	116.75 (16)
C3—C4—H4A	109.1	C14—C13—C12	119.77 (17)
C5—C4—H4A	109.1	C14—C13—H13	120.1
C3—C4—H4B	109.1	C12—C13—H13	120.1
C5—C4—H4B	109.1	N1—C14—C13	121.60 (18)
H4A—C4—H4B	107.8	N1—C14—H14	119.2
P2—O5—H5	117 (2)	C13—C14—H14	119.2

O1—P1—C1—C2	74.30 (14)	O6—P2—C9—C8	66.99 (14)
O2—P1—C1—C2	−54.24 (14)	O4—P2—C9—C8	−56.25 (14)
O3—P1—C1—C2	−171.74 (12)	O5—P2—C9—C8	−172.75 (12)
P1—C1—C2—C3	−167.86 (12)	C14—N1—C10—C11	1.9 (3)
C1—C2—C3—C4	−176.88 (14)	N1—C10—C11—C12	−0.4 (3)
C2—C3—C4—C5	−178.52 (15)	C10—C11—C12—N2	176.98 (19)
C3—C4—C5—C6	−179.83 (15)	C10—C11—C12—C13	−1.7 (3)
C4—C5—C6—C7	−179.62 (14)	N2—C12—C13—C14	−176.38 (18)
C5—C6—C7—C8	−177.72 (15)	C11—C12—C13—C14	2.3 (3)
C6—C7—C8—C9	−177.78 (14)	C10—N1—C14—C13	−1.3 (3)
C7—C8—C9—P2	−169.70 (12)	C12—C13—C14—N1	−0.9 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O6ⁱ	0.78 (3)	1.85 (3)	2.6171 (18)	166 (3)
O5—H5···O1ⁱⁱ	0.88 (3)	1.64 (3)	2.5059 (18)	168 (3)
O4—H4···O2ⁱⁱⁱ	0.91 (3)	1.59 (3)	2.4977 (17)	178 (3)
N1—H1···O6	0.96 (2)	1.74 (3)	2.696 (2)	173 (2)
N2—H22···O2^iv	0.90 (3)	1.92 (3)	2.806 (2)	170 (2)
N2—H21···O1^v	0.88 (3)	2.14 (3)	2.965 (2)	156 (3)

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

Acknowledgements

We thank E. Hammes and P. Roloff for technical support.

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