Intra- and inter-molecular proton transfer in 2,6-diamino-pyridinium 4-hy-droxy-pyridin-1-ium-2,6-dicarboxyl-ate.

Chelidamic acid (4-hy-droxy-pyridine-2,6-dicarb-oxy-lic acid) and 2,6-diamino-pyridine react to form the title salt, C(5)H(8)N(3) (+)·C(7)H(4)NO(5) (-); there are two formula units in the asymmetric unit. The pyridine N atom of 2,6-diamino-pyridine is protonated whereas chelidamic acid is deprotonated at both carboxyl-ate groups but protonated at the N atom; the reaction involves intra- and inter-molecular proton transfer. In the crystal, each 2,6-diamino-pyridinium cation participates in five strong N-H⋯O hydrogen bonds (including one bifurcated hydrogen bond). The crystal structure also features strong O-H⋯O hydrogen bonds between the chelidamate anions, leading to chains along the a axis.

Related literature

For chelidamic acid, see: Tutughamiarso et al. (2012 ▶). For chelidamic acid monohydrate, see: Hall et al. (2000 ▶). For inter­action of chelidamic acid with heavy metal ions, see: Norkus et al. (2003 ▶). For supermolecular structures, see: Aakeröy et al. (2005 ▶); Brunsveld et al. (2001 ▶); Prins et al. (2001 ▶); Schmid & Mann (1954 ▶). For a description of the Cambridge Structural Database, see: Allen (2002 ▶).

Experimental

Crystal data

C5H8N3 +·C7H4NO5 −

M = 292.26

Orthorhombic,

a = 14.963 (3) Å

b = 8.500 (2) Å

c = 20.385 (4) Å

V = 2592.7 (9) Å3

Z = 8

Mo Kα radiation

μ = 0.12 mm−1

T = 173 K

0.40 × 0.30 × 0.20 mm

Data collection

Stoe IPDS II two-circle diffractometer

33672 measured reflections

2510 independent reflections

2243 reflections with I > 2σ(I)

R int = 0.071

Refinement

R[F 2 > 2σ(F 2)] = 0.036

wR(F 2) = 0.083

S = 1.04

2510 reflections

417 parameters

1 restraint

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.16 e Å−3

Δρmin = −0.23 e Å−3

Data collection: X-AREA (Stoe & Cie, 2001 ▶); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: Mercury (Macrae et al., 2008 ▶) and XP (Sheldrick, 2008 ▶); software used to prepare material for publication: publCIF (Westrip (2010 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812037580/ng5291sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812037580/ng5291Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812037580/ng5291Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C5H8N3+·C7H4NO5−	F(000) = 1216
Mr = 292.26	Dx = 1.497 Mg m−3
Orthorhombic, Pca21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2ac	Cell parameters from 35668 reflections
a = 14.963 (3) Å	θ = 3.4–25.6°
b = 8.500 (2) Å	µ = 0.12 mm−1
c = 20.385 (4) Å	T = 173 K
V = 2592.7 (9) Å3	Block, colourless
Z = 8	0.40 × 0.30 × 0.20 mm

Stoe IPDS II two-circle diffractometer	2243 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.071
Graphite monochromator	θmax = 25.6°, θmin = 3.4°
ω scans	h = −18→18
33672 measured reflections	k = −10→10
2510 independent reflections	l = −24→24

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.083	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ2(Fo2) + (0.0555P)2] where P = (Fo2 + 2Fc2)/3
2510 reflections	(Δ/σ)max < 0.001
417 parameters	Δρmax = 0.16 e Å−3
1 restraint	Δρmin = −0.23 e Å−3

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.

	x	y	z	Uiso*/Ueq
N1	0.28490 (16)	0.3325 (3)	0.29385 (13)	0.0189 (5)
H1N	0.327 (2)	0.296 (4)	0.3201 (19)	0.023*
O1	0.45940 (13)	0.3882 (3)	0.28520 (12)	0.0274 (5)
O2	0.23936 (14)	0.1442 (3)	0.39526 (12)	0.0290 (5)
O3	0.44259 (14)	0.5304 (3)	0.19256 (12)	0.0247 (5)
O4	0.09524 (13)	0.1412 (3)	0.36286 (12)	0.0284 (5)
O5	0.10342 (13)	0.5135 (3)	0.16602 (12)	0.0218 (5)
HO5	0.0514	0.4868	0.1767	0.033*
C2	0.31328 (18)	0.4270 (3)	0.24492 (15)	0.0179 (6)
C3	0.2527 (2)	0.4901 (4)	0.20125 (18)	0.0188 (7)
H3	0.2726	0.5567	0.1668	0.023*
C4	0.16070 (18)	0.4548 (4)	0.20811 (16)	0.0180 (6)
C5	0.13420 (18)	0.3556 (4)	0.26059 (15)	0.0179 (6)
H5	0.0728	0.3311	0.2667	0.021*
C6	0.19726 (18)	0.2947 (4)	0.30257 (14)	0.0180 (6)
C7	0.41412 (18)	0.4510 (4)	0.24134 (15)	0.0199 (6)
C8	0.17574 (19)	0.1826 (4)	0.35877 (15)	0.0216 (7)
N11	0.05045 (16)	−0.0540 (3)	0.46143 (14)	0.0211 (6)
H11A	0.077 (3)	0.005 (4)	0.426 (2)	0.025*
N21	−0.0790 (2)	−0.0368 (4)	0.40028 (18)	0.0333 (7)
H21A	−0.051 (3)	0.024 (6)	0.375 (3)	0.040*
H21B	−0.136 (3)	−0.060 (5)	0.395 (2)	0.040*
N22	0.18961 (18)	−0.0644 (4)	0.51078 (16)	0.0298 (7)
H22A	0.209 (3)	0.006 (5)	0.472 (2)	0.036*
H22B	0.222 (3)	−0.080 (5)	0.545 (2)	0.036*
C12	−0.0384 (2)	−0.0884 (4)	0.45527 (17)	0.0229 (7)
C13	−0.0804 (2)	−0.1742 (4)	0.50451 (18)	0.0297 (8)
H13	−0.1427	−0.1958	0.5027	0.036*
C14	−0.0283 (2)	−0.2278 (4)	0.55677 (17)	0.0310 (8)
H14	−0.0561	−0.2872	0.5906	0.037*
C15	0.0634 (2)	−0.1973 (4)	0.56117 (16)	0.0283 (7)
H15	0.0979	−0.2375	0.5965	0.034*
C16	0.1027 (2)	−0.1060 (4)	0.51205 (16)	0.0226 (7)
N1'	0.45633 (16)	0.8257 (3)	0.62319 (13)	0.0193 (5)
H1'N	0.420 (2)	0.782 (4)	0.5953 (19)	0.023*
O1'	0.27918 (14)	0.8557 (3)	0.63201 (12)	0.0289 (5)
O2'	0.50769 (14)	0.6478 (3)	0.52175 (12)	0.0322 (6)
O3'	0.29024 (14)	0.9805 (3)	0.72949 (13)	0.0273 (6)
O4'	0.65252 (14)	0.6636 (3)	0.55187 (13)	0.0323 (6)
O5'	0.62710 (14)	1.0323 (3)	0.75228 (13)	0.0272 (6)
HO5'	0.6794	1.0350	0.7373	0.041*
C2'	0.42327 (18)	0.9094 (4)	0.67481 (15)	0.0190 (6)
C3'	0.47987 (19)	0.9782 (4)	0.71856 (18)	0.0195 (7)
H3'	0.4569	1.0356	0.7548	0.023*
C4'	0.57377 (18)	0.9632 (4)	0.70940 (15)	0.0180 (6)
C5'	0.60514 (18)	0.8727 (4)	0.65626 (16)	0.0208 (7)
H5'	0.6675	0.8597	0.6494	0.025*
C6'	0.54480 (19)	0.8037 (4)	0.61458 (15)	0.0188 (6)
C7'	0.32115 (18)	0.9150 (4)	0.67830 (16)	0.0193 (6)
C8'	0.57095 (19)	0.6954 (4)	0.55701 (16)	0.0222 (7)
N11'	0.69417 (17)	0.4557 (3)	0.45602 (14)	0.0216 (6)
H11B	0.670 (3)	0.530 (5)	0.482 (2)	0.026*
N21'	0.55525 (19)	0.4508 (4)	0.40698 (16)	0.0290 (6)
H21C	0.538 (3)	0.514 (5)	0.436 (3)	0.035*
H21D	0.520 (3)	0.426 (5)	0.373 (2)	0.035*
N22'	0.82341 (19)	0.4676 (4)	0.51780 (17)	0.0304 (7)
H22C	0.788 (3)	0.512 (5)	0.551 (3)	0.036*
H22D	0.886 (3)	0.442 (5)	0.517 (2)	0.036*
C12'	0.6415 (2)	0.4059 (4)	0.40541 (16)	0.0221 (6)
C13'	0.6800 (2)	0.3114 (4)	0.35694 (16)	0.0279 (7)
H13'	0.6452	0.2723	0.3215	0.034*
C14'	0.7703 (2)	0.2761 (4)	0.36190 (18)	0.0314 (8)
H14'	0.7971	0.2140	0.3285	0.038*
C15'	0.8230 (2)	0.3275 (4)	0.41358 (18)	0.0298 (8)
H15'	0.8849	0.3027	0.4154	0.036*
C16'	0.7828 (2)	0.4164 (4)	0.46261 (16)	0.0225 (7)

	U11	U22	U33	U12	U13	U23
N1	0.0105 (11)	0.0253 (14)	0.0208 (13)	−0.0001 (10)	−0.0017 (10)	0.0004 (11)
O1	0.0146 (10)	0.0403 (14)	0.0275 (12)	−0.0003 (9)	−0.0053 (9)	0.0016 (10)
O2	0.0183 (10)	0.0420 (15)	0.0267 (12)	0.0010 (9)	−0.0020 (9)	0.0121 (11)
O3	0.0119 (10)	0.0352 (13)	0.0269 (13)	−0.0014 (8)	0.0029 (8)	0.0075 (10)
O4	0.0162 (10)	0.0398 (14)	0.0292 (12)	−0.0061 (9)	−0.0008 (9)	0.0118 (11)
O5	0.0100 (10)	0.0319 (13)	0.0233 (13)	0.0007 (8)	−0.0011 (9)	0.0082 (9)
C2	0.0142 (13)	0.0207 (15)	0.0187 (14)	−0.0009 (10)	0.0006 (11)	−0.0032 (12)
C3	0.0167 (15)	0.0236 (17)	0.0162 (17)	−0.0003 (12)	0.0007 (12)	0.0026 (12)
C4	0.0130 (14)	0.0209 (16)	0.0202 (16)	0.0043 (11)	0.0004 (11)	−0.0016 (13)
C5	0.0106 (12)	0.0206 (15)	0.0225 (15)	−0.0015 (10)	0.0003 (11)	−0.0018 (12)
C6	0.0114 (13)	0.0218 (16)	0.0208 (15)	0.0005 (11)	−0.0010 (11)	−0.0010 (12)
C7	0.0106 (12)	0.0265 (16)	0.0224 (15)	0.0010 (11)	−0.0006 (11)	−0.0038 (13)
C8	0.0201 (15)	0.0253 (17)	0.0195 (16)	0.0008 (12)	0.0025 (12)	−0.0001 (13)
N11	0.0178 (12)	0.0252 (15)	0.0203 (15)	−0.0013 (10)	0.0005 (10)	0.0053 (12)
N21	0.0213 (14)	0.0440 (19)	0.0345 (18)	−0.0053 (14)	−0.0044 (12)	0.0115 (17)
N22	0.0223 (14)	0.0395 (19)	0.0276 (17)	−0.0028 (12)	−0.0058 (12)	0.0064 (15)
C12	0.0200 (14)	0.0222 (17)	0.0264 (16)	−0.0006 (12)	−0.0004 (12)	−0.0014 (14)
C13	0.0250 (15)	0.0327 (19)	0.0315 (19)	−0.0076 (13)	0.0048 (13)	0.0032 (16)
C14	0.0383 (18)	0.031 (2)	0.0241 (18)	−0.0091 (15)	0.0017 (15)	0.0039 (15)
C15	0.0333 (17)	0.0291 (19)	0.0226 (18)	−0.0006 (14)	−0.0017 (14)	0.0035 (14)
C16	0.0253 (15)	0.0232 (16)	0.0193 (16)	0.0026 (13)	−0.0032 (12)	0.0000 (14)
N1'	0.0141 (11)	0.0254 (14)	0.0183 (13)	−0.0019 (10)	−0.0012 (10)	−0.0032 (11)
O1'	0.0160 (9)	0.0417 (15)	0.0289 (13)	0.0004 (9)	−0.0073 (9)	−0.0017 (11)
O2'	0.0238 (11)	0.0443 (15)	0.0286 (13)	−0.0032 (10)	0.0007 (10)	−0.0118 (11)
O3'	0.0122 (10)	0.0409 (14)	0.0288 (14)	0.0006 (9)	0.0015 (9)	−0.0072 (11)
O4'	0.0194 (10)	0.0435 (15)	0.0341 (13)	0.0019 (10)	0.0035 (10)	−0.0177 (12)
O5'	0.0110 (9)	0.0443 (14)	0.0263 (14)	−0.0065 (9)	0.0008 (9)	−0.0127 (11)
C2'	0.0137 (13)	0.0208 (15)	0.0225 (15)	0.0011 (11)	0.0015 (12)	0.0036 (13)
C3'	0.0112 (13)	0.0237 (16)	0.0237 (19)	0.0010 (11)	0.0025 (12)	−0.0017 (13)
C4'	0.0132 (14)	0.0249 (16)	0.0159 (16)	−0.0005 (12)	0.0008 (11)	−0.0007 (13)
C5'	0.0121 (14)	0.0257 (16)	0.0247 (16)	0.0008 (12)	0.0032 (11)	−0.0001 (13)
C6'	0.0142 (13)	0.0207 (16)	0.0215 (16)	0.0002 (11)	0.0039 (11)	0.0018 (12)
C7'	0.0138 (13)	0.0216 (15)	0.0225 (15)	−0.0005 (11)	−0.0011 (12)	0.0037 (13)
C8'	0.0185 (14)	0.0269 (17)	0.0213 (16)	−0.0038 (12)	0.0019 (12)	−0.0049 (13)
N11'	0.0196 (13)	0.0227 (15)	0.0225 (15)	0.0015 (11)	0.0006 (10)	−0.0039 (13)
N21'	0.0238 (14)	0.0394 (18)	0.0239 (16)	0.0041 (12)	−0.0062 (12)	−0.0083 (14)
N22'	0.0180 (14)	0.0435 (18)	0.0297 (18)	0.0012 (13)	−0.0043 (12)	−0.0067 (16)
C12'	0.0264 (15)	0.0209 (16)	0.0190 (16)	−0.0027 (12)	0.0018 (12)	0.0029 (14)
C13'	0.0363 (17)	0.0253 (18)	0.0222 (17)	−0.0002 (14)	−0.0042 (13)	−0.0022 (14)
C14'	0.0385 (19)	0.0288 (19)	0.0269 (18)	0.0083 (14)	0.0077 (14)	−0.0056 (15)
C15'	0.0248 (15)	0.0298 (19)	0.035 (2)	0.0060 (13)	0.0028 (14)	−0.0004 (15)
C16'	0.0214 (14)	0.0202 (16)	0.0258 (17)	−0.0016 (11)	0.0026 (12)	0.0019 (14)

N1—C2	1.349 (4)	N1'—C6'	1.348 (4)
N1—C6	1.362 (4)	N1'—C2'	1.363 (4)
N1—H1N	0.88 (4)	N1'—H1'N	0.87 (4)
O1—C7	1.242 (4)	O1'—C7'	1.241 (4)
O2—C8	1.251 (4)	O2'—C8'	1.256 (4)
O3—C7	1.275 (4)	O3'—C7'	1.270 (4)
O4—C8	1.258 (4)	O4'—C8'	1.254 (4)
O5—C4	1.311 (4)	O5'—C4'	1.322 (4)
O5—HO5	0.8400	O5'—HO5'	0.8400
C2—C3	1.379 (4)	C2'—C3'	1.362 (5)
C2—C7	1.524 (4)	C2'—C7'	1.530 (4)
C3—C4	1.416 (4)	C3'—C4'	1.423 (4)
C3—H3	0.9500	C3'—H3'	0.9500
C4—C5	1.419 (5)	C4'—C5'	1.409 (4)
C5—C6	1.375 (4)	C5'—C6'	1.372 (4)
C5—H5	0.9500	C5'—H5'	0.9500
C6—C8	1.524 (4)	C6'—C8'	1.542 (4)
N11—C12	1.367 (4)	N11'—C12'	1.365 (4)
N11—C16	1.368 (4)	N11'—C16'	1.374 (4)
N11—H11A	0.97 (4)	N11'—H11B	0.90 (4)
N21—C12	1.349 (5)	N21'—C12'	1.346 (4)
N21—H21A	0.84 (5)	N21'—H21C	0.84 (5)
N21—H21B	0.88 (5)	N21'—H21D	0.89 (5)
N22—C16	1.349 (4)	N22'—C16'	1.351 (5)
N22—H22A	1.04 (5)	N22'—H22C	0.94 (5)
N22—H22B	0.86 (5)	N22'—H22D	0.96 (4)
C12—C13	1.391 (5)	C12'—C13'	1.398 (5)
C13—C14	1.397 (5)	C13'—C14'	1.388 (5)
C13—H13	0.9500	C13'—H13'	0.9500
C14—C15	1.399 (5)	C14'—C15'	1.387 (5)
C14—H14	0.9500	C14'—H14'	0.9500
C15—C16	1.396 (5)	C15'—C16'	1.390 (5)
C15—H15	0.9500	C15'—H15'	0.9500
C2—N1—C6	122.7 (3)	C6'—N1'—C2'	121.9 (3)
C2—N1—H1N	116 (2)	C6'—N1'—H1'N	118 (2)
C6—N1—H1N	121 (2)	C2'—N1'—H1'N	120 (2)
C4—O5—HO5	109.5	C4'—O5'—HO5'	109.5
N1—C2—C3	120.1 (3)	C3'—C2'—N1'	120.3 (3)
N1—C2—C7	115.2 (3)	C3'—C2'—C7'	125.3 (3)
C3—C2—C7	124.6 (3)	N1'—C2'—C7'	114.5 (3)
C2—C3—C4	119.5 (3)	C2'—C3'—C4'	119.3 (3)
C2—C3—H3	120.2	C2'—C3'—H3'	120.3
C4—C3—H3	120.2	C4'—C3'—H3'	120.3
O5—C4—C3	119.4 (3)	O5'—C4'—C5'	123.4 (3)
O5—C4—C5	122.5 (3)	O5'—C4'—C3'	118.0 (3)
C3—C4—C5	118.2 (3)	C5'—C4'—C3'	118.6 (3)
C6—C5—C4	120.1 (2)	C6'—C5'—C4'	119.4 (3)
C6—C5—H5	120.0	C6'—C5'—H5'	120.3
C4—C5—H5	120.0	C4'—C5'—H5'	120.3
N1—C6—C5	119.4 (3)	N1'—C6'—C5'	120.4 (3)
N1—C6—C8	116.7 (2)	N1'—C6'—C8'	115.5 (3)
C5—C6—C8	123.9 (3)	C5'—C6'—C8'	124.0 (3)
O1—C7—O3	127.3 (3)	O1'—C7'—O3'	128.2 (3)
O1—C7—C2	116.6 (3)	O1'—C7'—C2'	117.2 (3)
O3—C7—C2	116.0 (3)	O3'—C7'—C2'	114.5 (3)
O2—C8—O4	128.1 (3)	O4'—C8'—O2'	128.0 (3)
O2—C8—C6	116.7 (3)	O4'—C8'—C6'	116.0 (3)
O4—C8—C6	115.3 (3)	O2'—C8'—C6'	115.9 (3)
C12—N11—C16	123.8 (3)	C12'—N11'—C16'	123.7 (3)
C12—N11—H11A	116 (2)	C12'—N11'—H11B	116 (3)
C16—N11—H11A	120 (2)	C16'—N11'—H11B	120 (3)
C12—N21—H21A	119 (3)	C12'—N21'—H21C	120 (3)
C12—N21—H21B	117 (3)	C12'—N21'—H21D	118 (3)
H21A—N21—H21B	123 (5)	H21C—N21'—H21D	121 (4)
C16—N22—H22A	116 (2)	C16'—N22'—H22C	118 (3)
C16—N22—H22B	119 (3)	C16'—N22'—H22D	110 (3)
H22A—N22—H22B	123 (4)	H22C—N22'—H22D	131 (4)
N21—C12—N11	116.4 (3)	N21'—C12'—N11'	116.6 (3)
N21—C12—C13	124.6 (3)	N21'—C12'—C13'	125.0 (3)
N11—C12—C13	119.0 (3)	N11'—C12'—C13'	118.4 (3)
C12—C13—C14	118.0 (3)	C14'—C13'—C12'	118.2 (3)
C12—C13—H13	121.0	C14'—C13'—H13'	120.9
C14—C13—H13	121.0	C12'—C13'—H13'	120.9
C13—C14—C15	122.4 (3)	C15'—C14'—C13'	122.8 (3)
C13—C14—H14	118.8	C15'—C14'—H14'	118.6
C15—C14—H14	118.8	C13'—C14'—H14'	118.6
C16—C15—C14	118.0 (3)	C14'—C15'—C16'	118.1 (3)
C16—C15—H15	121.0	C14'—C15'—H15'	121.0
C14—C15—H15	121.0	C16'—C15'—H15'	121.0
N22—C16—N11	116.9 (3)	N22'—C16'—N11'	115.9 (3)
N22—C16—C15	124.4 (3)	N22'—C16'—C15'	125.4 (3)
N11—C16—C15	118.7 (3)	N11'—C16'—C15'	118.7 (3)
C6—N1—C2—C3	0.2 (4)	C6'—N1'—C2'—C3'	2.1 (5)
C6—N1—C2—C7	−177.7 (3)	C6'—N1'—C2'—C7'	−177.1 (3)
N1—C2—C3—C4	−0.1 (5)	N1'—C2'—C3'—C4'	0.7 (5)
C7—C2—C3—C4	177.7 (3)	C7'—C2'—C3'—C4'	179.8 (3)
C2—C3—C4—O5	−179.2 (3)	C2'—C3'—C4'—O5'	179.4 (3)
C2—C3—C4—C5	0.4 (5)	C2'—C3'—C4'—C5'	−2.1 (5)
O5—C4—C5—C6	178.7 (3)	O5'—C4'—C5'—C6'	179.3 (3)
C3—C4—C5—C6	−0.9 (5)	C3'—C4'—C5'—C6'	0.8 (5)
C2—N1—C6—C5	−0.7 (4)	C2'—N1'—C6'—C5'	−3.4 (5)
C2—N1—C6—C8	178.2 (3)	C2'—N1'—C6'—C8'	175.3 (3)
C4—C5—C6—N1	1.0 (4)	C4'—C5'—C6'—N1'	1.9 (5)
C4—C5—C6—C8	−177.8 (3)	C4'—C5'—C6'—C8'	−176.7 (3)
N1—C2—C7—O1	−3.3 (4)	C3'—C2'—C7'—O1'	175.0 (3)
C3—C2—C7—O1	178.8 (3)	N1'—C2'—C7'—O1'	−5.8 (4)
N1—C2—C7—O3	175.0 (3)	C3'—C2'—C7'—O3'	−5.3 (4)
C3—C2—C7—O3	−2.8 (4)	N1'—C2'—C7'—O3'	173.9 (3)
N1—C6—C8—O2	5.3 (4)	N1'—C6'—C8'—O4'	−174.3 (3)
C5—C6—C8—O2	−175.9 (3)	C5'—C6'—C8'—O4'	4.4 (5)
N1—C6—C8—O4	−175.3 (3)	N1'—C6'—C8'—O2'	4.5 (4)
C5—C6—C8—O4	3.5 (5)	C5'—C6'—C8'—O2'	−176.8 (3)
C16—N11—C12—N21	−175.8 (3)	C16'—N11'—C12'—N21'	178.1 (3)
C16—N11—C12—C13	3.5 (5)	C16'—N11'—C12'—C13'	−0.9 (5)
N21—C12—C13—C14	176.2 (4)	N21'—C12'—C13'—C14'	179.6 (3)
N11—C12—C13—C14	−3.0 (5)	N11'—C12'—C13'—C14'	−1.5 (5)
C12—C13—C14—C15	0.4 (5)	C12'—C13'—C14'—C15'	1.6 (5)
C13—C14—C15—C16	1.8 (5)	C13'—C14'—C15'—C16'	0.9 (5)
C12—N11—C16—N22	178.9 (3)	C12'—N11'—C16'—N22'	−175.9 (3)
C12—N11—C16—C15	−1.2 (5)	C12'—N11'—C16'—C15'	3.4 (5)
C14—C15—C16—N22	178.4 (3)	C14'—C15'—C16'—N22'	176.0 (3)
C14—C15—C16—N11	−1.4 (5)	C14'—C15'—C16'—N11'	−3.2 (5)

D—H···A	D—H	H···A	D···A	D—H···A
O5—HO5···O3i	0.84	1.67	2.495 (3)	169
O5′—HO5′···O3′ii	0.84	1.67	2.487 (3)	163
N21—H21B···O2iii	0.88 (5)	2.00 (5)	2.869 (4)	170 (4)
N22—H22B···O1′iv	0.86 (5)	2.04 (5)	2.892 (4)	169 (4)
N22′—H22D···O2′v	0.96 (4)	1.98 (4)	2.928 (4)	170 (4)
N1—H1N···O1	0.88 (3)	2.25 (3)	2.660 (3)	108 (3)
N1—H1N···O2	0.88 (3)	2.39 (4)	2.702 (4)	101 (2)
N1′—H1′N···O1′	0.87 (3)	2.32 (3)	2.669 (3)	104 (3)
N1′—H1′N···O2′	0.87 (3)	2.30 (4)	2.675 (4)	106 (2)
N11—H11A···O4	1.01 (4)	1.71 (3)	2.691 (4)	163 (4)
N11′—H11B···O4′	0.86 (3)	1.88 (3)	2.707 (4)	161 (4)
N21—H21A···O4	0.84 (5)	2.42 (5)	3.109 (4)	140 (5)
N21′—H21C···O2′	0.84 (5)	2.13 (6)	2.964 (4)	170 (5)
N21′—H21D···O1	0.90 (4)	2.03 (4)	2.916 (4)	169 (4)
N22—H22A···O2	1.03 (4)	2.01 (4)	3.040 (4)	177 (4)
N22′—H22C···O4′	0.94 (5)	2.40 (4)	3.130 (4)	134 (4)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O5—HO5⋯O3i	0.84	1.67	2.495 (3)	169
O5′—HO5′⋯O3′ii	0.84	1.67	2.487 (3)	163
N21—H21B⋯O2iii	0.88 (5)	2.00 (5)	2.869 (4)	170 (4)
N22—H22B⋯O1′iv	0.86 (5)	2.04 (5)	2.892 (4)	169 (4)
N22′—H22D⋯O2′v	0.96 (4)	1.98 (4)	2.928 (4)	170 (4)
N1—H1N⋯O1	0.88 (3)	2.25 (3)	2.660 (3)	108 (3)
N1—H1N⋯O2	0.88 (3)	2.39 (4)	2.702 (4)	101 (2)
N1′—H1′N⋯O1′	0.87 (3)	2.32 (3)	2.669 (3)	104 (3)
N1′—H1′N⋯O2′	0.87 (3)	2.30 (4)	2.675 (4)	106 (2)
N11—H11A⋯O4	1.01 (4)	1.71 (3)	2.691 (4)	163 (4)
N11′—H11B⋯O4′	0.86 (3)	1.88 (3)	2.707 (4)	161 (4)
N21—H21A⋯O4	0.84 (5)	2.42 (5)	3.109 (4)	140 (5)
N21′—H21C⋯O2′	0.84 (5)	2.13 (6)	2.964 (4)	170 (5)
N21′—H21D⋯O1	0.90 (4)	2.03 (4)	2.916 (4)	169 (4)
N22—H22A⋯O2	1.03 (4)	2.01 (4)	3.040 (4)	177 (4)
N22′—H22C⋯O4′	0.94 (5)	2.40 (4)	3.130 (4)	134 (4)

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