Hydrogen bonding in nitroaniline analogues: a hydrogen-bonded chain of rings in 2-amino-4-butylamino-6-methoxy-5-nitropyrimidine

In the title compound, C₉H₁₅N₅O₃, in which the mol­ecules exhibit orientational disorder, the mol­ecules of the major component are linked by paired N-H...O hydrogen bonds [H...O = 2.37 and 2.39 Å, N...O = 2.974 (3) and 3.011 (3) Å, and N-H...O = 126 and 128°] to form a C(8)C(8)[R(6)] chain of rings along [010]. The minor component (6.5% of the mol­ecules) forms a similar chain running in the opposite direction.

S1. Comment

An important mode of supramolecular aggregation in 4-nitroanilines is based on the formation of N—H···O hydrogen bonds, with each molecule acting as both a double donor and a double acceptor in these bonds. The resulting supramolecular structures can be two-dimensional (Tonogaki et al., 1993; Glidewell et al., 2002) or three-dimensional (Ferguson et al., 2001). An alternative aggregation mode can occur when there are bulky substituents present, which sometimes force an alternative one-dimensional aggregation mode, in which the molecules are linked by paired N—H···O hydrogen bonds to form an R₂²(6) (Bernstein et al., 1995) motif (McWilliam et al., 2001; Glidewell et al., 2002).

Continuing our study (Glidewell et al., 2003) of 2-amino-5-nitropyrimidines, which are closely analogous to 4-nitroanilines but which also offer the possibility that intermolecular N—H···N hydrogen bonds might be in competition with N—H···O hydrogen bonds, we report here the molecular and supramolecular structure of 2-amino-4-butylamino-6-methoxy-5-nitropyrimidine, (I). \sch

The molecules of (I), which lie in general positions, exhibit orientational disorder. The two components, whose site occupancy factors are 0.935 and 0.065, are related by an apparent rotation of 180° approximately around the N4···O6 line (Fig. 1). Within the molecules of the major component, the bond lengths (Table 1) show clear evidence of extensive bond fixation consequent upon the polarization of the molecular-electronic structure. Thus, the exocyclic bonds C2—N2 and C5—N5 are both very short for their types; the mean literature values for bonds of these types are 1.355 and 1.468 Å, respectively (Allen et al., 1987). The nitro group is essentially coplanar with the pyrimidine ring (Table 1), and the N—O distances are both longer than the mean literature value of 1.217 Å. It is noteworthy that the C2—N3 bond is shorter than C2—N1, and that N1—C6 is shorter than N3—C4, while N5—O52 is shorter than N5—O51. These observations taken together indicate that the polarized forms, (Ia), (Ib) and (Ic), are all significant contributors to the overall electronic structure.

The nature of the hydrogen bonding in (I) means that the supramolecular structures of the major and minor components are essentially the same, differing only in the direction of the chain formation (Table 2), and hence we discuss here only the major form. There is an intramolecular N—H···O hydrogen bond involving atoms N4 and O51, typical of those found in 2-nitroanilines (Dhaneshwar et al., 1978; Ellena et al., 1999; Cannon et al., 2001), but the principal interest in (I) lies in the intermolecular hydrogen bonding. The amino atom N2 in the molecule at (x, y, z) acts as a hydrogen-bond donor, via atoms H11 and H22, respectively, to atoms O51 and O52 in the molecule at (x, 1 + y, z), so generating a C(8) C(8)[R₂²(6)] chain of rings (Bernstein et al., 1995) running parallel to the [010] direction (Fig. 2). The R₂²(6) ring is effectively planar, with a sum of internal angles of 718°. It is notable that the supramolecular aggregation in (I) involves only N—H···O hydrogen bonds, whereas in the analogous 2-amino-4,6-dimethoxy-5-nitropyrimidine (Glidewell et al., 2003), both N—H···O and N—H···N hydrogen bonds contribute to the supramolecular structure.

Eight chains of rings pass through each unit cell of (I), but there are neither hydrogen bonds nor aromatic π–π stacking interactions between adjacent chains, so that the supramolecular structure defined by the direction-specific interactions is just one-dimensional. The total number of hydrogen bonds within the structure is maximized if the orientation of the molecules is fully correlated within a given chain. There is no necessary correlation between the molecular orientations in different chains, and chains containing the minor orientation are thus likely to be randomly distributed throughout the structure.

In the previously observed examples of such a chain of rings, the chains in the triclinic polymorph of 2-iodo-4-nitroaniline are linked into sheets by means of a two-centre iodo···nitro interaction (McWilliam et al., 2002), and in 2-trifluoromethyl-4-nitroaniline, a single C—H···O hydrogen bond links the molecules into a ladder generated by a 2₁ screw axis (Glidewell et al., 2002). It seems probable that direction-specific interactions between the chains in (I) are prevented by the presence of the N-butyl substituent which, in both components, adopts the usual all-trans chain-extended conformation (Table 1).

S2. Experimental

A sample of 2-amino-4-butylamino-6-methoxy-5-nitrosopyrimidine (Marchal, 2001) Is a clause missing here? and then converted into (I) by oxidation using 3-chloroperoxobenzoic acid (1.1 molar equivalents) in acetonitrile solution. After recrystallization from ethyl acetate, (I) had a melting point of 378 K. Spectroscopic analysis: ¹H NMR (δ, DMSO-d₆, p.p.m.): 0.90 (t, 3H, C—CH₃, J = 7.41 Hz), 1.32 (m, 2H, CH₂), 1.55 (m, 2H, CH₂), 3.45 (m, 2H, CH₂), 3.88 (s, 3H, O—CH₃), 7.37 (bs, 2H, NH₂, exchanges with H₂O), 8.84 (t, 1H, NH, J = 5.49 Hz); ¹³C NMR (δ, DMSO-d₆, p.p.m.): 13.6, 19.5, 30.7, 54.2, 109.2, 157.9, 160.6, 165.3. Crystals of (I) suitable for single-crystal X-ray diffraction were grown by slow evaporation of a solution in water-ethanol-acetonitrile (1:1:1 v/v).

S3. Refinement

The systematic absences permitted Cc and C2/c as possible space groups; C2/c was selected, and confirmed by the successful structure analysis. It was apparent at an early stage that the structure contained a small proportion of molecules adopting an alternative orientation. The bond distances in the minor component were constrained using DFIX commands, and the non-H atoms were assigned a common isotropic displacement parameter. Refinement of the site occupancy factors for the two components, constrained to sum to unity, gave values of 0.912 (4) and 0.088 (4) for the major and minor components, respectively. However, in these circumstances, the common U_iso for the minor component was more than double the mean value of the U_eq values for the major component. Refinements were then carried out with a series of fixed values for the site occupancy factors, still constrained to sum to unity. The most satisfactory outcome, in terms of the values of U_iso and the mean U_eq for the two components, was achieved when the occupancies were 0.935 and 0.065, and accordingly the occupancies were thereafter fixed at these values. H atoms were treated as riding, with C—H distances of 0.98 (CH₃) and 0.99 Å (CH₂), and N—H distances of 0.88 Å.

Computing details

Data collection: KappaCCD Server Software (Nonius, 1997); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2002); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).

Figures

Fig. 1. The molecular components of compound (I), showing the atom-labelling scheme and the relative orientation of the two components; full lines indicate the major component, broken lines the minor component. For the sake of clarity, H atoms have been omitted. Displacement parameters are drawn at the 30% probability level. For the minor component, non-H atoms were assigned a common isotropic displacement parameter.

Fig. 2. Part of the crystal structure of (I), showing the formation of a chain of rings along [010]. For the sake of clarity, only the major orientation is shown. The atoms marked with an asterisk (*) or hash sign (#) are at the symmetry positions (x, 1 + y, z) and (x, y − 1, z), respectively.

2-Amino-4-butylamino-6-methoxy-5-nitropyrimidine

Crystal data

C9H15N5O3	F(000) = 1024
Mr = 241.26	Dx = 1.442 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 2482 reflections
a = 20.5825 (13) Å	θ = 3.2–27.4°
b = 8.8102 (4) Å	µ = 0.11 mm^−1
c = 13.0289 (11) Å	T = 120 K
β = 109.810 (3)°	Plate, colourless
V = 2222.8 (3) Å^3	0.22 × 0.08 × 0.02 mm
Z = 8

Data collection

Nonius KappaCCD area-detector diffractometer	2482 independent reflections
Radiation source: fine-focus sealed X-ray tube	1151 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.124
ϕ scans, and ω scans with κ offsets	θmax = 27.4°, θmin = 3.2°
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997)	h = −26→26
Tmin = 0.911, Tmax = 0.998	k = −10→11
16040 measured reflections	l = −16→16

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)] = 0.063	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.163	H-atom parameters constrained
S = 0.94	w = 1/[σ^2(Fo^2) + (0.0759P)^2] where P = (Fo^2 + 2Fc^2)/3
2482 reflections	(Δ/σ)max < 0.001
211 parameters	Δρmax = 0.32 e Å^−3
26 restraints	Δρmin = −0.31 e Å^−3

Special details

Experimental. The program DENZO-SMN (Otwinowski & Minor, 1997) uses a scaling algorithm [Fox, G·C. & Holmes, K·C. (1966). Acta Cryst. 20, 886–891] which effectively corrects for absorption effects. High-redundancy data were used in the scaling program, hence the `multi-scan' code word was used.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
N1	0.31025 (15)	0.4567 (3)	−0.0483 (2)	0.0213 (8)	0.935
C2	0.34067 (15)	0.5240 (3)	0.0504 (2)	0.0201 (7)	0.935
N2	0.33616 (13)	0.6742 (3)	0.0514 (2)	0.0281 (7)	0.935
N3	0.37390 (13)	0.4557 (3)	0.14522 (19)	0.0203 (7)	0.935
C4	0.37663 (14)	0.3035 (3)	0.1449 (2)	0.0198 (7)	0.935
N4	0.4105 (2)	0.2373 (3)	0.2402 (2)	0.0209 (7)	0.935
C41	0.44135 (16)	0.3238 (3)	0.3408 (2)	0.0238 (7)	0.935
C42	0.47305 (17)	0.2170 (3)	0.4360 (2)	0.0222 (8)	0.935
C43	0.50891 (16)	0.3031 (3)	0.5407 (2)	0.0236 (7)	0.935
C44	0.54224 (19)	0.2029 (4)	0.6395 (3)	0.0321 (8)	0.935
N5	0.34632 (13)	0.0596 (3)	0.0420 (2)	0.0224 (6)	0.935
O51	0.37716 (12)	−0.0112 (2)	0.12942 (17)	0.0316 (6)	0.935
O52	0.31783 (12)	−0.0102 (2)	−0.04284 (16)	0.0300 (6)	0.935
C5	0.34477 (15)	0.2192 (3)	0.0452 (2)	0.0183 (7)	0.935
C6	0.31325 (14)	0.3075 (3)	−0.0496 (2)	0.0195 (7)	0.935
C61	0.25712 (17)	0.3330 (4)	−0.2406 (2)	0.0323 (8)	0.935
O6	0.28453 (14)	0.2378 (3)	−0.14489 (17)	0.0242 (7)	0.935
N1A	0.310 (2)	0.0532 (19)	−0.0515 (14)	0.026 (3)*	0.065
C2A	0.336 (2)	−0.0156 (17)	0.0480 (15)	0.026 (3)*	0.065
N2A	0.3339 (16)	−0.1667 (16)	0.0456 (19)	0.026 (3)*	0.065
N3A	0.372 (2)	0.0514 (19)	0.1435 (14)	0.026 (3)*	0.065
N4A	0.405 (4)	0.271 (3)	0.238 (2)	0.026 (3)*	0.065
C4A	0.376 (2)	0.2028 (19)	0.1414 (15)	0.026 (3)*	0.065
C41A	0.438 (2)	0.185 (3)	0.3385 (15)	0.026 (3)*	0.065
C42A	0.479 (3)	0.279 (4)	0.437 (2)	0.026 (3)*	0.065
C43A	0.504 (2)	0.181 (5)	0.539 (3)	0.026 (3)*	0.065
C44A	0.539 (3)	0.286 (6)	0.634 (3)	0.026 (3)*	0.065
C5A	0.347 (3)	0.2896 (16)	0.0455 (18)	0.026 (3)*	0.065
O51A	0.3776 (18)	0.525 (4)	0.134 (2)	0.026 (3)*	0.065
O52A	0.318 (2)	0.513 (5)	−0.038 (3)	0.026 (3)*	0.065
N5A	0.347 (2)	0.4477 (17)	0.048 (2)	0.026 (3)*	0.065
C6A	0.313 (2)	0.1991 (19)	−0.0559 (14)	0.026 (3)*	0.065
O6A	0.297 (3)	0.266 (3)	−0.1520 (17)	0.026 (3)*	0.065
C61A	0.259 (2)	0.175 (4)	−0.2441 (15)	0.026 (3)*	0.065
H21	0.3546	0.7245	0.1128	0.034*	0.935
H22	0.3147	0.7236	−0.0094	0.034*	0.935
H4	0.4144	0.1377	0.2426	0.025*	0.935
H41A	0.4055	0.3868	0.3551	0.029*	0.935
H41B	0.4774	0.3924	0.3327	0.029*	0.935
H42A	0.4364	0.1521	0.4460	0.027*	0.935
H42B	0.5069	0.1500	0.4194	0.027*	0.935
H43A	0.4748	0.3700	0.5563	0.028*	0.935
H43B	0.5449	0.3688	0.5294	0.028*	0.935
H44A	0.5072	0.1367	0.6512	0.048*	0.935
H44B	0.5628	0.2666	0.7040	0.048*	0.935
H44C	0.5783	0.1407	0.6269	0.048*	0.935
H61A	0.2210	0.3990	−0.2319	0.048*	0.935
H61B	0.2375	0.2689	−0.3052	0.048*	0.935
H61C	0.2943	0.3954	−0.2494	0.048*	0.935
H21A	0.3555	−0.2191	0.1049	0.032*	0.065
H22A	0.3109	−0.2142	−0.0153	0.032*	0.065
H4A	0.4047	0.3703	0.2418	0.032*	0.065
H41C	0.4689	0.1083	0.3241	0.032*	0.065
H41D	0.4015	0.1295	0.3572	0.032*	0.065
H42C	0.5198	0.3236	0.4234	0.032*	0.065
H42D	0.4504	0.3628	0.4477	0.032*	0.065
H43C	0.5362	0.1025	0.5316	0.032*	0.065
H43D	0.4637	0.1299	0.5502	0.032*	0.065
H44D	0.5748	0.3450	0.6173	0.040*	0.065
H44E	0.5602	0.2262	0.6999	0.040*	0.065
H44F	0.5049	0.3560	0.6450	0.040*	0.065
H61D	0.2886	0.0947	−0.2556	0.040*	0.065
H61E	0.2422	0.2388	−0.3094	0.040*	0.065
H61F	0.2193	0.1289	−0.2300	0.040*	0.065

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0222 (16)	0.022 (2)	0.0177 (14)	−0.0008 (13)	0.0048 (12)	−0.0012 (12)
C2	0.0167 (17)	0.0202 (18)	0.0218 (17)	0.0002 (13)	0.0043 (13)	0.0019 (14)
N2	0.0355 (16)	0.0179 (15)	0.0241 (15)	0.0005 (11)	0.0010 (12)	0.0006 (10)
N3	0.0221 (15)	0.0156 (15)	0.0194 (15)	0.0015 (11)	0.0022 (11)	0.0010 (11)
C4	0.0157 (16)	0.0252 (19)	0.0165 (17)	−0.0033 (12)	0.0027 (13)	−0.0031 (11)
N4	0.0263 (17)	0.0118 (14)	0.0186 (13)	0.0011 (16)	−0.0002 (10)	−0.0012 (11)
C41	0.0307 (19)	0.0176 (17)	0.0173 (17)	−0.0027 (12)	0.0006 (14)	−0.0031 (11)
C42	0.0220 (18)	0.0210 (19)	0.0225 (17)	−0.0034 (14)	0.0059 (13)	−0.0003 (12)
C43	0.0231 (18)	0.0264 (18)	0.0194 (17)	−0.0013 (13)	0.0046 (14)	−0.0038 (13)
C44	0.041 (2)	0.0314 (19)	0.0190 (17)	−0.0012 (16)	0.0042 (15)	0.0024 (14)
N5	0.0229 (14)	0.0220 (14)	0.0192 (14)	0.0004 (11)	0.0029 (11)	−0.0011 (12)
O51	0.0436 (15)	0.0182 (13)	0.0238 (13)	0.0042 (11)	−0.0004 (11)	0.0012 (9)
O52	0.0405 (15)	0.0233 (13)	0.0180 (12)	−0.0028 (11)	−0.0007 (10)	−0.0073 (9)
C5	0.0205 (16)	0.0132 (16)	0.0218 (16)	−0.0003 (14)	0.0082 (13)	−0.0019 (12)
C6	0.0173 (17)	0.0227 (19)	0.0175 (18)	−0.0021 (12)	0.0045 (14)	−0.0037 (11)
C61	0.040 (2)	0.0343 (19)	0.0169 (18)	0.0014 (14)	0.0018 (15)	0.0052 (13)
O6	0.0263 (17)	0.0297 (14)	0.0146 (11)	−0.0032 (10)	0.0044 (9)	−0.0008 (10)

Geometric parameters (Å, º)

N1—C2	1.361 (4)	N1A—C6A	1.290 (5)
C2—N3	1.335 (4)	N1A—C2A	1.365 (5)
N3—C4	1.342 (4)	C2A—N2A	1.333 (5)
C4—C5	1.446 (4)	C2A—N3A	1.349 (5)
C5—C6	1.418 (4)	N2A—H21A	0.88
C6—N1	1.316 (4)	N2A—H22A	0.88
C2—N2	1.327 (4)	N3A—C4A	1.337 (5)
C4—N4	1.335 (4)	N4A—C4A	1.343 (5)
C5—N5	1.407 (4)	N4A—C41A	1.458 (5)
N5—O51	1.265 (3)	N4A—H4A	0.88
N5—O52	1.227 (3)	C4A—C5A	1.414 (10)
C6—O6	1.330 (4)	C41A—C42A	1.520 (5)
N2—H21	0.88	C41A—H41C	0.99
N2—H22	0.88	C41A—H41D	0.99
N4—C41	1.463 (4)	C42A—C43A	1.517 (5)
N4—H4	0.88	C42A—H42C	0.99
C41—C42	1.517 (4)	C42A—H42D	0.99
C41—H41A	0.99	C43A—C44A	1.522 (5)
C41—H41B	0.99	C43A—H43C	0.99
C42—C43	1.516 (4)	C43A—H43D	0.99
C42—H42A	0.99	C44A—H44D	0.98
C42—H42B	0.99	C44A—H44E	0.98
C43—C44	1.520 (4)	C44A—H44F	0.98
C43—H43A	0.99	C5A—N5A	1.393 (5)
C43—H43B	0.99	C5A—C6A	1.495 (10)
C44—H44A	0.98	O51A—N5A	1.274 (5)
C44—H44B	0.98	O52A—N5A	1.223 (5)
C44—H44C	0.98	C6A—O6A	1.322 (5)
C61—O6	1.449 (4)	O6A—C61A	1.440 (5)
C61—H61A	0.98	C61A—H61D	0.98
C61—H61B	0.98	C61A—H61E	0.98
C61—H61C	0.98	C61A—H61F	0.98
C6—N1—C2	116.1 (3)	H21A—N2A—H22A	120.0
N2—C2—N3	117.2 (3)	C4A—N3A—C2A	115.7 (5)
N2—C2—N1	115.6 (3)	C4A—N4A—C41A	122.4 (7)
N3—C2—N1	127.2 (3)	C4A—N4A—H4A	118.8
C2—N2—H21	120.0	C41A—N4A—H4A	118.8
C2—N2—H22	120.0	N3A—C4A—N4A	115.8 (6)
H21—N2—H22	120.0	N3A—C4A—C5A	123.3 (5)
C2—N3—C4	117.1 (3)	N4A—C4A—C5A	120.8 (9)
N4—C4—N3	116.3 (3)	N4A—C41A—C42A	115 (2)
N4—C4—C5	123.1 (3)	N4A—C41A—H41C	108.4
N3—C4—C5	120.6 (3)	C42A—C41A—H41C	108.4
C4—N4—C41	122.5 (3)	N4A—C41A—H41D	108.4
C4—N4—H4	118.8	C42A—C41A—H41D	108.4
C41—N4—H4	118.8	H41C—C41A—H41D	107.5
N4—C41—C42	110.2 (3)	C43A—C42A—C41A	111 (2)
N4—C41—H41A	109.6	C43A—C42A—H42C	109.5
C42—C41—H41A	109.6	C41A—C42A—H42C	109.5
N4—C41—H41B	109.6	C43A—C42A—H42D	109.5
C42—C41—H41B	109.6	C41A—C42A—H42D	109.5
H41A—C41—H41B	108.1	H42C—C42A—H42D	108.1
C43—C42—C41	111.6 (2)	C42A—C43A—C44A	107 (3)
C43—C42—H42A	109.3	C42A—C43A—H43C	110.3
C41—C42—H42A	109.3	C44A—C43A—H43C	110.3
C43—C42—H42B	109.3	C42A—C43A—H43D	110.3
C41—C42—H42B	109.3	C44A—C43A—H43D	110.3
H42A—C42—H42B	108.0	H43C—C43A—H43D	108.6
C42—C43—C44	114.4 (3)	C43A—C44A—H44D	109.5
C42—C43—H43A	108.7	C43A—C44A—H44E	109.5
C44—C43—H43A	108.7	H44D—C44A—H44E	109.5
C42—C43—H43B	108.7	C43A—C44A—H44F	109.5
C44—C43—H43B	108.7	H44D—C44A—H44F	109.5
H43A—C43—H43B	107.6	H44E—C44A—H44F	109.5
O52—N5—O51	120.3 (3)	N5A—C5A—C4A	121.4 (17)
O52—N5—C5	121.3 (3)	N5A—C5A—C6A	123.6 (17)
O51—N5—C5	118.4 (3)	C4A—C5A—C6A	115.0 (4)
N5—C5—C6	122.0 (3)	O51A—N5A—O52A	120 (3)
N5—C5—C4	122.2 (3)	O52A—N5A—C5A	117 (3)
C6—C5—C4	115.8 (2)	O51A—N5A—C5A	124 (3)
N1—C6—O6	117.7 (3)	N1A—C6A—O6A	119.3 (7)
N1—C6—C5	123.1 (3)	N1A—C6A—C5A	120.5 (5)
O6—C6—C5	119.2 (3)	O6A—C6A—C5A	119.4 (13)
C6—O6—C61	117.2 (3)	C6A—O6A—C61A	115.4 (10)
C6A—N1A—C2A	118.4 (5)	O6A—C61A—H61D	109.5
N2A—C2A—N3A	117.5 (8)	O6A—C61A—H61E	109.5
N2A—C2A—N1A	115.0 (7)	H61D—C61A—H61E	109.5
N3A—C2A—N1A	126.7 (6)	O6A—C61A—H61F	109.5
C2A—N2A—H21A	120.0	H61D—C61A—H61F	109.5
C2A—N2A—H22A	120.0	H61E—C61A—H61F	109.5
C6—N1—C2—N2	−178.7 (3)	C6A—N1A—C2A—N2A	−177 (4)
C6—N1—C2—N3	1.0 (5)	C6A—N1A—C2A—N3A	−7 (7)
N2—C2—N3—C4	178.0 (3)	N2A—C2A—N3A—C4A	177 (4)
N1—C2—N3—C4	−1.7 (5)	N1A—C2A—N3A—C4A	8 (7)
C2—N3—C4—N4	179.5 (4)	C2A—N3A—C4A—N4A	173 (6)
C2—N3—C4—C5	0.1 (4)	C2A—N3A—C4A—C5A	−3 (7)
N3—C4—N4—C41	1.8 (6)	C41A—N4A—C4A—N3A	6 (10)
C5—C4—N4—C41	−178.8 (4)	C41A—N4A—C4A—C5A	−178 (6)
C4—N4—C41—C42	177.3 (4)	C4A—N4A—C41A—C42A	170 (7)
N4—C41—C42—C43	176.9 (3)	N4A—C41A—C42A—C43A	173 (5)
C41—C42—C43—C44	−179.7 (3)	C41A—C42A—C43A—C44A	−175 (4)
C4—C5—N5—O51	−0.5 (4)	N3A—C4A—C5A—N5A	175 (5)
C4—C5—N5—O52	178.5 (3)	N4A—C4A—C5A—N5A	−1 (8)
C6—C5—N5—O51	178.0 (3)	N3A—C4A—C5A—C6A	−2 (7)
C6—C5—N5—O52	−3.0 (4)	N4A—C4A—C5A—C6A	−178 (6)
N4—C4—C5—N5	1.0 (5)	C4A—C5A—N5A—O51A	6 (8)
N3—C4—C5—N5	−179.7 (3)	C6A—C5A—N5A—O51A	−177 (5)
N4—C4—C5—C6	−177.6 (4)	C4A—C5A—N5A—O52A	−177 (5)
N3—C4—C5—C6	1.8 (4)	C6A—C5A—N5A—O52A	0 (7)
C2—N1—C6—O6	−179.5 (3)	C2A—N1A—C6A—O6A	171 (5)
C2—N1—C6—C5	1.2 (4)	C2A—N1A—C6A—C5A	1 (6)
N5—C5—C6—N1	178.9 (3)	N5A—C5A—C6A—N1A	−174 (5)
C4—C5—C6—N1	−2.5 (4)	C4A—C5A—C6A—N1A	3 (7)
N5—C5—C6—O6	−0.4 (4)	N5A—C5A—C6A—O6A	16 (7)
C4—C5—C6—O6	178.2 (3)	C4A—C5A—C6A—O6A	−167 (4)
N1—C6—O6—C61	4.7 (4)	N1A—C6A—O6A—C61A	17 (7)
C5—C6—O6—C61	−175.9 (3)	C5A—C6A—O6A—C61A	−173 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4···O51	0.88	1.93	2.583 (3)	130
N2—H21···O51^i	0.88	2.37	2.974 (3)	126
N2—H22···O52^i	0.88	2.39	3.011 (3)	128
N4A—H4A···O51A	0.88	1.90	2.56 (4)	133
N2A—H21A···O51A^ii	0.88	2.31	3.00 (4)	132
N2A—H22A···O52A^ii	0.88	2.43	3.02 (4)	123

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