Supra­molecular hydrogen-bonded networks in adeninediium hemioxalate chloride and adeninium semioxalate hemi(oxalic acid) monohydrate

In 9H-adenine-1,7-diium hemioxalate chloride, C₅H₇N₅²⁺·0.5C₂O₄^2-·Cl^-, (I), adenine is doubly protonated, while in 7H-adenin-1-ium semioxalate hemi(oxalic acid) monohydrate, C₅H₆N₅⁺·C₂HO₄^-·0.5C₂H₂O₄·H₂O, (II), adenine and one oxalate anion are both monoprotonated. In (I), the adeninium cation forms R₂²(8) and R₁²(5) hydrogen-bonding motifs with the centrosymmetric oxalate anion, while in (II), the cation forms R₂¹(6) and R₁²(5) motifs with the centrosymmetric oxalic acid mol­ecule and R₁²(5)and R₂²(9) motifs with the monoprotonated oxalate anion. Linear hydrogen-bonded trimers are observed in (I) and (II). In both structures, the hydrogen bonds lead to the formation of two-dimensional supra­molecular hydrogen-bonded sheets in the crystal packing. The significance of this study lies in the analysis of the inter­actions occurring via hydrogen bonds and the diversity seen in the supra­molecular hydrogen-bonded networks as a result of such inter­actions.

S1. Comment

Adenine offers five available proton attachment sites (basicity order N9 > N1 > N7 > N3 > N10 exocyclic) which afford a wide range of neutral tautomers and protonated forms, and it has been the subject of numerous theoretical (Sponer et al., 2002; Turecek & Chen, 2005) and experimental investigations (Crespo-Hernandez et al., 2004; Chen & Shuhua, 2005). Carboxylic acids have been used widely as pattern-controlling functional groups for the rational design of organic solids (Desiraju, 1989; Melendez & Hamilton, 1998). Oxalic acid, in principle, exists in three ionization states, viz. singly charged (semi-oxalate), doubly charged (oxalate) and neutral (oxalic acid). The present study reports the structures of the title compounds, (I) and (II), as a continuation of our ongoing programme on the structure elucidation of adducts formed between nucleobases and carboxylic acids (Sridhar & Ravikumar, 2007a,b; 2008).

The asymmetric unit of (I) consists of one adeninium cation, half an oxalate anion lying across an inversion centre and one chloride anion (Fig. 1), while the asymmetric unit of (II) contains one adeninium cation, one monoprotonated oxalate anion and half an oxalic acid molecule lying across an inversion centre and one water molecule (Fig. 2). The water molecule is disordered over two sites (O7 and O7') with occupancies of 0.622 (19) and 0.378 (19), respectively.

Adeninium cations can be either mono- or diprotonated and the bond lengths and angles are dependent on the degree of protonation (Hingerty et al., 1981; Langer & Huml, 1978). This canonical tautomeric form contains three basic N atoms. The most basic site (pK_a = 4.2) is N1, which accepts the first proton, and the next protonation occurs at N7 and then at N3. In (I), atoms N1 and N7 are protonated, while in (II) only atom N1 is protonated. This is evident from the increase in the ring angle at the sites of protonation, namely N1 and N7. The internal angles at N1 and N7 (Tables 1 and 3) are increased from the reported values of 119.8 and 104.4°, respectively, in unprotonated adenine (Voet & Rich, 1970). The adenine base is nearly planar, with an r.m.s. deviation from the least-squares plane through the nine atoms (N1/C2/N3/C4–C6/N7/C8/N9) of the base of 0.002 Å in each structure. The maximum deviations from these planes are 0.005 (2) Å for atom C2 of (I) and 0.017 (2) Å for atom C5 of (II).

The oxalic acid and oxalate moieties of (I) and (II) are planar. In (II), the centrosymmetric oxalic acid molecule and the monoprotonated oxalate anion are linked by a short hydrogen bond, apparently symmetric, with its H atom centrally located. The refined isotropic atomic displacement parameter of atom H5O is somewhat larger than those of the amide H atoms, whose positions and atomic displacement parameters were also refined. A contoured difference Fourier map produced by PLATON (Spek, 2009), in which the site-occupation factor of atom H5O had been set to 0.001, clearly shows that the maximum of the electron density is at the atom H5O, but it is quite smeared out along the O···O axis (Fig. 3). In the crystal structure of a macrocycle, Linden et al. (2006) described a similar situation, stating that the refined position of the H atom does not necessarily truly represent the majority of the electron-density distribution and may give a misleading impression of the symmetric nature of the hydrogen bond. In the present structure, [(II)?], the O5—H5O···O2 hydrogen bond appears to be symmetrical, or disordered across the two possible `normal' sites closer to atoms O5 and O2. For O—H···O hydrogen bonds, as the O···O distance approaches 2.4 Å, the O—H and H···O distances both approach 1.2 Å. This then becomes a symmetric structure, with the H atom centred between the two heavy atoms. According to Alcock (1990), symmetric hydrogen bonds typically display a shorter (about 2.47 Å) O···O distance, whereas asymmetric hydrogen bonds have a longer O···O distance (about 2.5–3.0 Å). Similar hydrogen bonds are found in acid salts of dicarboxylic acids in which hydrogen dicarboxylate ions are linked by short hydrogen bonds into infinite chains (Speakman, 1972). Under this circumstance, it is not possible to distinguish between the neutral oxalic acid molecule and the monoprotonated oxalate anion in the present structure.

Hydrogen-bonded systems generated from organic cations and anions are of special interest because they would be expected to show stronger hydrogen bonds than neutral molecules (Reetz et al., 1994; Bertolasi et al., 2001; Mathew et al., 2002; Bulut et al., 2003). In (I), two types of hydrogen bonds are observed, N—H···O and N—H···Cl (Table 2), while in (II), three types of hydrogen bonds are observed, N—H···O, O—H···O and O—H···N (Table 4).

In (I), the Watson–Crick edge (atoms N1 and N10) of the adeninium cation links an oxalate anion through N—H···O hydrogen bonds, which results in a heterosynthon R₂²(8) hydrogen-bonding motif (Etter, 1990; Etter et al., 1990; Bernstein et al., 1995). This heterosynthon R₂²(8) motif is one of the classic motifs observed in adeninium carboxylate structures (Sridhar & Ravikumar, 2008a,b; Byres et al., 2009). The oxalate anion, lying across a centre of inversion, thus forms a linear trimer through hydrogen bonds with the two adjacent adeninium cations (Fig. 4). In (II), the Watson–Crick edge (atoms N1 and N10) forms hydrogen bonds with a centrosymmetric oxalic acid molecule and a water molecule. Interestingly, both atoms N1 and N10 are involved in a three-centred hydrogen-bonding pattern (Jeffrey & Saenger, 1991). The N—H···O hydrogen bonds with the oxalic acid molecule generate R₂¹(6) and R₁²(5) hydrogen-bonding motifs and combine with the centrosymmetric anion to give a linear hydrogen-bonded trimer (Fig. 5).

The Hoogsteen face (atoms N10 and N7) of (I) forms N—H···Cl hydrogen bonds with the Cl^- ion, thereby creating an R₂¹(7) motif. Furthermore, cation–anion trimers are interlinked by three-centred hydrogen bonds involving atom N9 of the adeninium cation and carboxylate atoms O1(-x + 1, y - 1/2, -z + 3/2) and O2(x - 1, -y + 1/2, z + 1/2) of a symmetry-related oxalate anion, thereby generating an R₁²(5) motif. In (II), the Hoogsteen face (atoms N10 and N7) links the oxalic acid molecule through N—H···O and O—H···N hydrogen bonds and forms an R₂²(9) motif. This R₂²(9) motif is interlinked by three-centred hydrogen bonds involving atom N9 of the adeninium cation and atoms O1 and O3 of the monoprotonated oxalate anion at (x - 1, -y + 3/2, z - 1/2), thereby generating an R₁²(5) motif. Furthermore, the oxalic acid molecule and the monoprotonated oxalate ion form a short three-segment centrosymmetric hydrogen-bonded linear rod.

In (I), the combination of N—H···O and N—H···Cl hydrogen bonds involving adeninium cations, oxalate anions and Cl^- ions leads to short hydrogen-bonded rods. Each rod is further interlinked to its adjacent glide-related rods by intermolecular three-centred N—H···O hydrogen bonds, thereby generating infinite two-dimensional hydrogen-bonded sheets parallel to the (102) plane (Fig. 4).

In (II), the R₂¹(6) and R₁²(5) motifs existing between the adeninium cation and centrosymmetric oxalic acid molecules form hydrogen-bonded trimers. These trimers are flanked by intermolecular N—H···O interactions through the three-centred hydrogen bonds involving the monoprotonated oxalate anions [R₁²(5) motif] and extend parallel to the b axis, thereby generating short hydrogen-bonded rods. Each such rod is further interlinked to its adjacent rods by intramolecular N—H···O, O—H···O and O—H···N hydrogen bonds (Fig. 5), thereby generating R₄⁴(18) and R₄⁴(22) motifs. Thus, the combination of N—H···O, O—H···O and O—H···N hydrogen bonds leads to the formation of infinite two-dimensional supramolecular hydrogen-bonded sheets which lie parallel to the (102) plane.

It is very interesting to note that in the present study, an adeninium–adeninium self-association base pair is not observed, which is one of the characteristic features observed in two previously reported structures (Sridhar & Ravikumar, 2007a,b)

S2. Experimental

To obtain suitable crystals of (I), adenine (0.135 g, 1 mmol) and oxalic acid (0.09 g, 1 mmol) were dissolved in a mixture of hydrochloric acid (2–3 drops) and water (10 ml) and the solution was allowed to evaporate slowly. Crystals of (II) were obtained by slow evaporation of an equimolar solution of adenine (0.135 g, 1 mmol) and oxalic acid (0.18 g, 2 mmol) in water (20 ml).

S3. Refinement

All N-bound H atoms of the adeninium cations of (I) and (II), and O-bound H atoms of the oxalic acid molecule and the monoprotonated oxalate ion of (II), were located in a difference Fourier map and their positions and isotropic displacement parameters were refined. All other H atoms were located in a difference density map, positioned geometrically and included as riding atoms, with C—H = 0.93 Å, and with U_iso(H) = 1.2U_eq(C). In (II), the water molecule is disordered over two sites (O7 and O7') and the site-occupation factors refined to 0.622 (19) and 0.378 (19), respectively. The anisotropic displacement parameters of atoms O7/O7' were restrained to be similar [SIMU instruction in SHELXL97 (Sheldrick, 2008)], and the direction of motion along the axis between these atoms was also restrained (DELU instruction in SHELXL97). The H atoms of the disordered molecule could not be located reliably. Contoured difference Fourier maps only indicate significant electron density at the location of one potential site for an H atom and the electron density of the disordered water molecule is smeared along the O7···O7' axis. Therefore, the water H atoms were not included in the model.

Computing details

For both compounds, data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. A view of the structure of (I), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. Hydrogen bonds are shown as dashed lines.[Symmetry code: (i) -x + 2, -y + 1, -z + 1.]
	Fig. 2. A view of the structure of (II), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. The minor component of the disordered water molecule O7' has been omitted for clarity. Hydrogen bonds are shown as dashed lines. [Symmetry code: (i) -x + 4, -y + 1, -z + 2.]
	Fig. 3. A contoured difference Fourier map slice in the plane of the carboxylic acid group of (II), with the site occupancy of atom H5O set to 0.001. The refined positions of the atoms are shown by + marks. The contour intervals are 0.1 e Å^-3.
	Fig. 4. A packing diagram for (I), viewed down the a axis. Dashed lines indicate N—H···O and N—H···Cl hydrogen bonds. H atoms not involved in hydrogen bonding have been omitted for clarity. Only atoms involved in the hydrogen bonding are labelled. [Symmetry codes: (i) x - 1, -y + 1/2, z + 1/2; (ii) -x + 1, y - 1/2, -z + 3/2.]
	Fig. 5. A packing diagram for (II), viewed down the a axis. Dashed lines indicate N—H···O, O—H···O and O—H···N hydrogen bonds. H atoms not involved in hydrogen bonding and the minor component of the disordered water molecule O7' have been omitted for clarity. Only atoms involved in the hydrogen bonding are labelled. [Symmetry codes: (i) -x + 2, -y + 1, -z + 1; (ii) x - 2, y, z - 1; (iii) x - 1, -y + 3/2, z - 1/2.]

(I) adeninium hemioxalate chloride

Crystal data

C5H7N5^2+·0.5C2O4^2^−·Cl^−	F(000) = 444
Mr = 216.62	Dx = 1.737 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 6694 reflections
a = 4.3758 (4) Å	θ = 2.2–28.0°
b = 17.1354 (15) Å	µ = 0.44 mm^−1
c = 11.1188 (10) Å	T = 294 K
β = 96.558 (2)°	Block, colourless
V = 828.24 (13) Å^3	0.21 × 0.18 × 0.13 mm
Z = 4

Data collection

Bruker SMART APEX CCD area-detector diffractometer	1411 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.027
Graphite monochromator	θmax = 25.0°, θmin = 2.2°
ω scans	h = −5→5
7683 measured reflections	k = −20→20
1455 independent reflections	l = −13→13

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.031	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.090	w = 1/[σ^2(Fo^2) + (0.0573P)^2 + 0.2435P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max = 0.001
1455 reflections	Δρmax = 0.30 e Å^−3
148 parameters	Δρmin = −0.22 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.009 (2)

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.

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

	x	y	z	Uiso*/Ueq
C2	0.4418 (4)	0.30240 (9)	0.74561 (15)	0.0351 (4)
H2	0.3835	0.3498	0.7768	0.042*
C4	0.4437 (3)	0.17406 (8)	0.74188 (13)	0.0275 (3)
C5	0.6286 (3)	0.17070 (8)	0.64958 (13)	0.0265 (3)
C6	0.7299 (3)	0.24110 (8)	0.60101 (13)	0.0265 (3)
C8	0.5215 (4)	0.05172 (9)	0.70087 (14)	0.0333 (4)
H8	0.5142	−0.0025	0.7031	0.040*
N1	0.6247 (3)	0.30542 (7)	0.65462 (12)	0.0317 (3)
H1N	0.687 (5)	0.3551 (13)	0.627 (2)	0.052 (6)*
N3	0.3406 (3)	0.23914 (8)	0.79321 (13)	0.0338 (3)
N7	0.6744 (3)	0.09282 (7)	0.62691 (13)	0.0296 (3)
H7N	0.766 (4)	0.0761 (11)	0.5728 (18)	0.036 (5)*
N9	0.3795 (3)	0.09876 (7)	0.77165 (13)	0.0311 (3)
H9N	0.278 (5)	0.0857 (11)	0.8292 (19)	0.043 (5)*
N10	0.9099 (3)	0.24850 (8)	0.51496 (12)	0.0330 (3)
H10B	0.956 (4)	0.2985 (12)	0.4859 (18)	0.041 (5)*
H10A	0.972 (5)	0.2036 (13)	0.4768 (19)	0.047 (5)*
C11	0.9450 (4)	0.45822 (8)	0.51377 (13)	0.0308 (4)
O1	0.7837 (3)	0.45117 (6)	0.59863 (11)	0.0451 (4)
O2	1.0250 (3)	0.40387 (6)	0.44905 (12)	0.0416 (3)
Cl1	1.02908 (10)	0.08391 (2)	0.40756 (4)	0.0401 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C2	0.0436 (9)	0.0248 (8)	0.0399 (9)	0.0000 (6)	0.0180 (7)	−0.0047 (6)
C4	0.0314 (7)	0.0242 (8)	0.0284 (7)	−0.0019 (5)	0.0092 (6)	0.0005 (6)
C5	0.0314 (7)	0.0209 (7)	0.0284 (7)	−0.0005 (5)	0.0086 (6)	−0.0009 (5)
C6	0.0303 (7)	0.0224 (7)	0.0277 (7)	−0.0016 (5)	0.0073 (6)	0.0000 (5)
C8	0.0409 (9)	0.0215 (8)	0.0394 (8)	−0.0013 (6)	0.0133 (7)	0.0007 (6)
N1	0.0402 (7)	0.0207 (7)	0.0369 (7)	−0.0022 (5)	0.0156 (6)	−0.0008 (5)
N3	0.0415 (8)	0.0257 (7)	0.0372 (7)	−0.0009 (5)	0.0172 (6)	−0.0035 (5)
N7	0.0372 (7)	0.0226 (7)	0.0317 (7)	−0.0003 (5)	0.0158 (6)	−0.0014 (5)
N9	0.0385 (7)	0.0240 (7)	0.0338 (7)	−0.0023 (5)	0.0166 (6)	0.0029 (5)
N10	0.0437 (8)	0.0243 (7)	0.0342 (7)	−0.0026 (5)	0.0179 (6)	0.0010 (5)
C11	0.0421 (9)	0.0232 (8)	0.0294 (8)	−0.0003 (6)	0.0138 (6)	0.0006 (6)
O1	0.0731 (9)	0.0247 (6)	0.0445 (7)	−0.0048 (5)	0.0373 (6)	−0.0002 (5)
O2	0.0626 (8)	0.0215 (6)	0.0467 (7)	−0.0039 (5)	0.0325 (6)	−0.0046 (5)
Cl1	0.0544 (3)	0.0273 (3)	0.0438 (3)	−0.00033 (15)	0.0274 (2)	0.00009 (15)

Geometric parameters (Å, º)

C2—N3	1.306 (2)	C8—N9	1.329 (2)
C2—N1	1.361 (2)	C8—H8	0.9300
C2—H2	0.9300	N1—H1N	0.95 (2)
C4—N3	1.3533 (19)	N7—H7N	0.81 (2)
C4—N9	1.3692 (19)	N9—H9N	0.85 (2)
C4—C5	1.379 (2)	N10—H10B	0.95 (2)
C5—N7	1.3770 (19)	N10—H10A	0.93 (2)
C5—C6	1.414 (2)	C11—O1	1.2471 (18)
C6—N10	1.313 (2)	C11—O2	1.2511 (19)
C6—N1	1.3582 (19)	C11—C11^i	1.552 (3)
C8—N7	1.321 (2)
N3—C2—N1	126.05 (14)	C6—N1—H1N	117.4 (13)
N3—C2—H2	117.0	C2—N1—H1N	119.0 (13)
N1—C2—H2	117.0	C2—N3—C4	111.62 (13)
N3—C4—N9	125.96 (13)	C8—N7—C5	107.94 (13)
N3—C4—C5	126.90 (13)	C8—N7—H7N	126.8 (14)
N9—C4—C5	107.14 (13)	C5—N7—H7N	125.0 (14)
N7—C5—C4	106.67 (12)	C8—N9—C4	107.80 (13)
N7—C5—C6	134.31 (13)	C8—N9—H9N	127.3 (13)
C4—C5—C6	119.02 (13)	C4—N9—H9N	124.7 (13)
N10—C6—N1	120.21 (13)	C6—N10—H10B	120.3 (12)
N10—C6—C5	126.95 (14)	C6—N10—H10A	118.8 (13)
N1—C6—C5	112.83 (12)	H10B—N10—H10A	120.5 (18)
N7—C8—N9	110.45 (14)	O1—C11—O2	125.65 (14)
N7—C8—H8	124.8	O1—C11—C11^i	116.97 (16)
N9—C8—H8	124.8	O2—C11—C11^i	117.37 (16)
C6—N1—C2	123.58 (13)
N3—C4—C5—N7	179.98 (14)	N3—C2—N1—C6	−0.6 (3)
N9—C4—C5—N7	−0.71 (17)	N1—C2—N3—C4	0.9 (2)
N3—C4—C5—C6	0.6 (2)	N9—C4—N3—C2	179.89 (15)
N9—C4—C5—C6	179.96 (13)	C5—C4—N3—C2	−0.9 (2)
N7—C5—C6—N10	−0.4 (3)	N9—C8—N7—C5	−0.50 (18)
C4—C5—C6—N10	178.75 (14)	C4—C5—N7—C8	0.74 (17)
N7—C5—C6—N1	−179.31 (16)	C6—C5—N7—C8	179.93 (16)
C4—C5—C6—N1	−0.2 (2)	N7—C8—N9—C4	0.05 (18)
N10—C6—N1—C2	−178.87 (15)	N3—C4—N9—C8	179.74 (15)
C5—C6—N1—C2	0.2 (2)	C5—C4—N9—C8	0.42 (17)

Symmetry code: (i) −x+2, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1	0.95 (2)	1.74 (2)	2.685 (2)	171 (2)
N7—H7N···Cl1	0.81 (2)	2.28 (2)	3.041 (1)	156 (2)
N9—H9N···O2^ii	0.85 (2)	1.83 (2)	2.645 (2)	159 (2)
N9—H9N···O1^iii	0.85 (2)	2.47 (2)	3.037 (2)	125 (2)
N10—H10B···O2	0.95 (2)	1.88 (2)	2.822 (2)	171 (2)
N10—H10A···Cl1	0.93 (2)	2.21 (2)	3.130 (2)	166 (2)

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

(II) adeninium oxalate hemi(oxalic acid) monohydrate

Crystal data

C5H6N5^+·C2HO4^−·0.5C2H2O4·H2O	F(000) = 596
Mr = 288.21	Dx = 1.711 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 6401 reflections
a = 3.6222 (3) Å	θ = 2.4–27.9°
b = 28.131 (3) Å	µ = 0.15 mm^−1
c = 11.1101 (10) Å	T = 294 K
β = 98.696 (2)°	Block, colourless
V = 1119.05 (17) Å^3	0.19 × 0.16 × 0.09 mm
Z = 4

Data collection

Bruker SMART APEX CCD area-detector diffractometer	1891 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.020
Graphite monochromator	θmax = 25.0°, θmin = 1.5°
ω scans	h = −4→4
10683 measured reflections	k = −33→33
1982 independent reflections	l = −13→13

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.103	H atoms treated by a mixture of independent and constrained refinement
S = 1.14	w = 1/[σ^2(Fo^2) + (0.049P)^2 + 0.5164P] where P = (Fo^2 + 2Fc^2)/3
1982 reflections	(Δ/σ)max = 0.001
215 parameters	Δρmax = 0.34 e Å^−3
6 restraints	Δρmin = −0.23 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.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
C2	0.3057 (5)	0.65002 (6)	0.01285 (16)	0.0312 (4)
H2	0.1722	0.6407	−0.0615	0.037*
C4	0.5714 (5)	0.70469 (6)	0.13987 (15)	0.0269 (4)
C5	0.7040 (4)	0.67218 (6)	0.22865 (15)	0.0255 (4)
C6	0.6187 (5)	0.62365 (6)	0.20749 (15)	0.0267 (4)
C8	0.8726 (5)	0.74063 (6)	0.29858 (16)	0.0325 (4)
H8	0.9765	0.7649	0.3495	0.039*
N1	0.4163 (4)	0.61531 (5)	0.09554 (13)	0.0297 (3)
H1N	0.343 (6)	0.5847 (9)	0.080 (2)	0.047 (6)*
N3	0.3710 (4)	0.69523 (5)	0.02899 (13)	0.0318 (4)
N7	0.8963 (4)	0.69541 (5)	0.32865 (13)	0.0298 (3)
N9	0.6815 (4)	0.74809 (5)	0.18611 (14)	0.0324 (4)
H9N	0.630 (7)	0.7751 (10)	0.153 (2)	0.063 (8)*
N10	0.7156 (5)	0.58903 (6)	0.28362 (15)	0.0382 (4)
H10	0.839 (7)	0.5947 (9)	0.356 (2)	0.053 (7)*
H11	0.658 (7)	0.5582 (9)	0.264 (2)	0.055 (7)*
C11	1.2953 (5)	0.63238 (6)	0.57708 (15)	0.0302 (4)
C12	1.5343 (5)	0.62201 (6)	0.70148 (16)	0.0295 (4)
O1	1.7325 (4)	0.65301 (4)	0.75259 (12)	0.0418 (4)
O2	1.4950 (4)	0.57968 (5)	0.73755 (12)	0.0440 (4)
O3	1.3244 (4)	0.67583 (4)	0.53995 (12)	0.0412 (4)
H3O	1.155 (10)	0.6778 (12)	0.461 (3)	0.113 (12)*
O4	1.1022 (4)	0.60221 (5)	0.52236 (12)	0.0457 (4)
C13	1.8746 (5)	0.50930 (6)	0.94231 (15)	0.0275 (4)
O5	1.8981 (4)	0.55387 (4)	0.92541 (11)	0.0359 (3)
H5O	1.704 (9)	0.5678 (12)	0.833 (3)	0.110 (11)*
O6	1.6739 (4)	0.48122 (4)	0.87839 (12)	0.0393 (4)
O7	0.697 (4)	0.50019 (15)	0.4161 (8)	0.112 (3)	0.622 (19)
O7'	0.939 (5)	0.4985 (2)	0.3730 (11)	0.089 (4)	0.378 (19)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C2	0.0344 (9)	0.0308 (9)	0.0261 (9)	−0.0027 (7)	−0.0028 (7)	−0.0023 (7)
C4	0.0286 (8)	0.0235 (8)	0.0273 (8)	0.0001 (7)	0.0001 (7)	0.0003 (7)
C5	0.0280 (8)	0.0225 (8)	0.0244 (8)	−0.0003 (6)	−0.0015 (6)	−0.0018 (6)
C6	0.0285 (8)	0.0239 (8)	0.0264 (8)	−0.0004 (6)	0.0000 (7)	−0.0012 (7)
C8	0.0384 (10)	0.0243 (9)	0.0322 (9)	−0.0025 (7)	−0.0031 (7)	−0.0043 (7)
N1	0.0356 (8)	0.0228 (8)	0.0281 (7)	−0.0035 (6)	−0.0033 (6)	−0.0032 (6)
N3	0.0373 (8)	0.0286 (8)	0.0264 (7)	−0.0001 (6)	−0.0051 (6)	0.0005 (6)
N7	0.0355 (8)	0.0245 (7)	0.0267 (7)	−0.0025 (6)	−0.0044 (6)	−0.0023 (6)
N9	0.0410 (9)	0.0201 (7)	0.0330 (8)	0.0004 (6)	−0.0044 (6)	0.0016 (6)
N10	0.0541 (10)	0.0216 (8)	0.0336 (9)	−0.0036 (7)	−0.0109 (7)	0.0024 (7)
C11	0.0349 (9)	0.0266 (9)	0.0273 (9)	0.0001 (7)	−0.0012 (7)	0.0012 (7)
C12	0.0333 (9)	0.0256 (9)	0.0277 (8)	−0.0004 (7)	−0.0015 (7)	0.0013 (7)
O1	0.0520 (8)	0.0299 (7)	0.0371 (7)	−0.0058 (6)	−0.0143 (6)	−0.0005 (6)
O2	0.0548 (9)	0.0301 (7)	0.0395 (8)	−0.0086 (6)	−0.0169 (6)	0.0121 (6)
O3	0.0566 (9)	0.0278 (7)	0.0329 (7)	−0.0072 (6)	−0.0137 (6)	0.0085 (5)
O4	0.0630 (9)	0.0310 (7)	0.0353 (7)	−0.0088 (6)	−0.0185 (7)	0.0033 (6)
C13	0.0334 (9)	0.0207 (8)	0.0264 (8)	−0.0025 (7)	−0.0020 (7)	0.0005 (7)
O5	0.0479 (8)	0.0213 (6)	0.0328 (7)	−0.0049 (5)	−0.0121 (6)	0.0050 (5)
O6	0.0510 (8)	0.0247 (6)	0.0352 (7)	−0.0070 (6)	−0.0162 (6)	0.0007 (5)
O7	0.188 (8)	0.0395 (19)	0.096 (4)	−0.020 (3)	−0.016 (5)	0.001 (2)
O7'	0.153 (10)	0.030 (3)	0.072 (5)	−0.008 (4)	−0.025 (5)	0.010 (3)

Geometric parameters (Å, º)

C2—N3	1.301 (2)	N9—H9N	0.85 (3)
C2—N1	1.359 (2)	N10—H10	0.87 (3)
C2—H2	0.9300	N10—H11	0.91 (3)
C4—N3	1.358 (2)	C11—O4	1.204 (2)
C4—N9	1.361 (2)	C11—O3	1.299 (2)
C4—C5	1.377 (2)	C11—C12	1.544 (2)
C5—N7	1.383 (2)	C12—O1	1.214 (2)
C5—C6	1.412 (2)	C12—O2	1.271 (2)
C6—N10	1.303 (2)	O2—H5O	1.25 (4)
C6—N1	1.365 (2)	O3—H3O	1.00 (4)
C8—N7	1.315 (2)	C13—O6	1.225 (2)
C8—N9	1.350 (2)	C13—O5	1.273 (2)
C8—H8	0.9300	C13—C13^i	1.546 (3)
N1—H1N	0.91 (2)	O5—H5O	1.22 (4)
N3—C2—N1	125.48 (16)	C8—N7—C5	104.32 (14)
N3—C2—H2	117.3	C8—N9—C4	106.86 (14)
N1—C2—H2	117.3	C8—N9—H9N	126.1 (18)
N3—C4—N9	127.17 (15)	C4—N9—H9N	126.9 (18)
N3—C4—C5	126.89 (15)	C6—N10—H10	120.6 (16)
N9—C4—C5	105.94 (15)	C6—N10—H11	121.6 (15)
C4—C5—N7	109.90 (14)	H10—N10—H11	118 (2)
C4—C5—C6	118.63 (15)	O4—C11—O3	124.86 (16)
N7—C5—C6	131.43 (15)	O4—C11—C12	121.54 (16)
N10—C6—N1	121.19 (16)	O3—C11—C12	113.61 (15)
N10—C6—C5	125.75 (16)	O1—C12—O2	127.72 (16)
N1—C6—C5	113.06 (14)	O1—C12—C11	119.65 (15)
N7—C8—N9	112.96 (15)	O2—C12—C11	112.63 (15)
N7—C8—H8	123.5	C12—O2—H5O	115.7 (16)
N9—C8—H8	123.5	C11—O3—H3O	105 (2)
C2—N1—C6	123.72 (15)	O6—C13—O5	126.64 (15)
C2—N1—H1N	120.4 (14)	O6—C13—C13^i	119.03 (18)
C6—N1—H1N	115.7 (14)	O5—C13—C13^i	114.32 (17)
C2—N3—C4	112.18 (14)	C13—O5—H5O	113.5 (16)
N3—C4—C5—N7	179.80 (16)	N9—C4—N3—C2	−178.96 (17)
N9—C4—C5—N7	−0.32 (19)	C5—C4—N3—C2	0.9 (3)
N3—C4—C5—C6	−2.2 (3)	N9—C8—N7—C5	−0.5 (2)
N9—C4—C5—C6	177.64 (15)	C4—C5—N7—C8	0.50 (19)
C4—C5—C6—N10	−178.13 (17)	C6—C5—N7—C8	−177.11 (18)
N7—C5—C6—N10	−0.7 (3)	N7—C8—N9—C4	0.3 (2)
C4—C5—C6—N1	1.8 (2)	N3—C4—N9—C8	179.89 (17)
N7—C5—C6—N1	179.20 (17)	C5—C4—N9—C8	0.0 (2)
N3—C2—N1—C6	−1.1 (3)	O4—C11—C12—O1	178.23 (18)
N10—C6—N1—C2	179.58 (17)	O3—C11—C12—O1	−2.0 (2)
C5—C6—N1—C2	−0.3 (2)	O4—C11—C12—O2	−1.4 (3)
N1—C2—N3—C4	0.8 (3)	O3—C11—C12—O2	178.41 (16)

Symmetry code: (i) −x+4, −y+1, −z+2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O6^ii	0.91 (2)	1.91 (2)	2.755 (2)	153 (2)
N1—H1N···O5^iii	0.91 (2)	2.34 (2)	3.002 (2)	130 (2)
N9—H9N···O3^iv	0.85 (3)	2.07 (3)	2.873 (2)	157 (2)
N9—H9N···O1^iv	0.85 (3)	2.31 (3)	2.877 (2)	124 (2)
N10—H10···O4	0.87 (3)	1.96 (3)	2.830 (2)	175 (2)
N10—H11···O6^ii	0.91 (3)	2.14 (3)	2.893 (2)	139 (2)
N10—H11···O7′	0.91 (3)	2.23 (3)	2.807 (6)	121 (2)
N10—H11···O7	0.91 (3)	2.34 (3)	2.906 (6)	120 (2)
O3—H3O···N7	1.00 (4)	1.69 (4)	2.668 (2)	166 (3)
O5—H5O···O2	1.22 (4)	1.25 (4)	2.469 (2)	176 (3)

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