L-Tryptophan formic acid solvate at 183 K

In the title compound, C₁₁H₁₂N₂O₂·CH₂O₂, at 183 K. L-­tryptophan appears in the zwitterionic form, while the formic acid molecule is neutral. The formic acid molecule is the donor in a strong O-H...O hydrogen bond to the carboxyl­ate group of the tryptophan mol­ecule, with a short O...O contact of 2.487 (2) Å.

S1. Comment

In conjunction with our ongoing work of comparative charge-density studies on the 20 naturally occurring amino acids, we have directed our interest to tryptophan, Trp, one of the essential α-amino acids for humans. Compared with other amino acids, there are only a few tryptophan structures listed in the Cambridge Structural Database (Version?; Allen & Kennard, 1993), due to the difficulty of obtaining good quality crystals. The only solvent-free non-substituted tryptophan structure is that of DL-tryptophane (Bakke & Mostad, 1980), where the authors reported that `crystals were not as good as could be wished'. While our attempts to obtain good quality crystals suitable for charge-density experiments also failed for pure tryptophan (for both the DL– and L-forms), we could obtain nicely diffracting crystals of L-tryptophan formic acid solvate, (I), the X-ray structure of which was still unknown. Only the crystal structure of DL-tryptophan formate has been reported previously (Bye et al., 1973), where it was shown that the tryptophan molecule was protonated and the formate anion had a deprotonated carboxyl group. \sch

In contrast with these results, we found from our X-ray analysis at 183 K that, in the present case, the L-tryptophan is zwitterionic, as are most amino acids in the crystal, and that the formic acid is neutral (Fig. 1). There is a strong O17—H17···O13 hydrogen bond from the formic acid to the carboxylate group of L-tryptophan, with a remarkably short O···O contact of 2.487 (2) Å (Table 2). In DL-tryptophan formate, a hydrogen bond with almost the same donor-acceptor O···O distance was seen (2.492 Å). However, as already mentioned, the role of donor and acceptor was inverted.

The opposite donor-acceptor situation is reflected in the C—O bond lengths at these sites. Normally, a charged carboxylate group has two more or less equal C—O bonds of ~1.23–1.25 Å, while in a neutral COOH group, the two C—O bond lengths differ by ~0.1 Å. Due to the strong hydrogen bonds in both the L– and the DL-Trp formic acid derivatives, the C—O bond lengths in the COOH groups are less different [1.281 (3) and 1.213 (3) Å in the formic acid of the L-Trp derivative, and 1.295 and 1.214 Å in the carboxyl group of the DL-Trp structure]. On the other hand, the accepting C—O bonds in the carboxylate groups are enlarged [1.273 (2) versus 1.237 (2) Å for L-Trp, and 1.255 versus 1.232 Å in the COO^- group in the formate anion of the DL-tryptophan derivative]. The other bond lengths in the zwitterionic and cationic forms of L– and DL-Trp are not affected and need no further discussion.

The overall molecular conformation, i.e. the relative orientation of the side chain with respect to the indole ring system, can best be described by the torsion angles along the bonds C3—C10 and C10—C11 (Table 3). While χ^2.1 = C2—C3—C10—C11 = -104.4 (2)° has a similar value to that of L-tryptophan in the DL-tryptophan structure, the torsion angles χ¹ and χ^1.2 [for nomenclature, see IUPAC-IUB (1970)] along C10—C11, indicating + and - gauche arrangements, are different from both the free tryptophan molecular structure and the tryptophan cation in DL-tryptophan formate. Bakke & Mostad (1980) have summarized torsion angles for tryptophan derivatives and found that, in most cases, C12 is trans to C3. The molecular conformation of (I) is roughly similar to that of the hydrochloride of DL-tryptophan ethyl ester (Vijayalakshmi & Srinivasan, 1975). Due to the cis arrangement of the carboxylate group relative to the ring system and the strong hydrogen bonding to the formic acid molecule, a U-shaped arrangement of the entire donor-acceptor complex is formed.

In addition to the above-mentioned strong O17—H17···O13 hydrogen bond from the formic acid to the tryptophan zwitterion, three further hydrogen bonds exist, having the H atoms of the amino group as donors. Two of them link tryptophan molecules and the third one is a further weaker tryptophan-formic acid hydrogen bond with the donor on the tryptophan side. These hydrogen bonds establish a network mainly in the x and y directions close to z = 1/4, while double layers of the indole residues assemble close to z = 0, z = 1/2, ··· (Fig 2). Neighbouring indole layers have weak N1—H1···Cⁱ linkages as short contacts, with H1···C7ⁱ 2.50 (3) Å [N1···C7ⁱ 3.314 (2) Å] and H1···C8ⁱ 2.56 (3) Å [N1···C8ⁱ 3.351 (2) Å] [symmetry code: (i) 1/2 + x, 1/2 - y, 2 - z]. An extensive overview of X—H···π interactions has been given by Desiraju & Steiner (1999), where N—H···π interactions are also discussed. No further close contacts of interest were found in (I).

Table 3. Selected torsion angles (°) for L-tryptophan formic acid solvate, (I), DL-tryptophan formate, (II), and DL-tryptophane, (III). All angles refer to the S configuration at C11, i.e. the L form.

S2. Experimental

Crystals of (I) were grown by cooling a hot solution of L-tryptophan (ex Sigma) in a mixture of propan-2-ol and formic acid (ex Merck AG) (ratio?).

S3. Refinement

All H atoms were found in difference Fourier maps and refined freely.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SMART; data reduction: SMART; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996) and SCHAKAL99 (Keller & Pierrard, 1999); software used to prepare material for publication: PLATON (Spek, 1990).

Figures

	Fig. 1. The molecular structure and atom-numbering scheme of (I). Displacement ellipsoids are plotted at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. Packing diagram (SCHAKAL99; Keller & Pierrard, 1999) for (I).

L-2-Amino-3-(1H-indol-3-yl)-propionic acid formic acid solvate

Crystal data

C11H12N2O2·CH2O2	F(000) = 528
Mr = 250.25	Dx = 1.410 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 5433 reflections
a = 5.3163 (3) Å	θ = 2.1–32.4°
b = 8.1348 (4) Å	µ = 0.11 mm^−1
c = 27.259 (2) Å	T = 183 K
V = 1178.87 (12) Å^3	Needle, colourless
Z = 4	0.2 × 0.1 × 0.1 mm

Data collection

Bruker AXS SMART CCD area-detector diffractometer	2492 independent reflections
Radiation source: fine-focus sealed tube	2104 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.064
ω and ϕ scans	θmax = 33.1°, θmin = 2.6°
Absorption correction: empirical (using intensity measurements) (SADABS; Blessing, 1995; Siemens, 1996)	h = −8→8
Tmin = 0.761, Tmax = 1.000	k = −11→12
14392 measured reflections	l = −41→41

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)] = 0.051	Hydrogen site location: difference Fourier map
wR(F^2) = 0.126	All H-atom parameters refined
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0702P)^2 + 0.0077P] where P = (Fo^2 + 2Fc^2)/3
2492 reflections	(Δ/σ)max < 0.001
219 parameters	Δρmax = 0.37 e Å^−3
0 restraints	Δρmin = −0.24 e Å^−3

Special details

Experimental. A Bruker AXS low-temerature device was used. The crystal-detector distance was 4 cm and each frame covered 0.3° in ω. The reciprocal space was explored by a combination of three different runs with 2θ = 30°. No intensity decay was observed. SADABS (Siemens, 1996) was used to correct for absorption.

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.

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

	x	y	z	Uiso*/Ueq
N1	0.8375 (4)	0.1803 (3)	0.95189 (6)	0.0285 (4)
C2	0.7169 (4)	0.0686 (3)	0.92251 (7)	0.0260 (4)
C3	0.5132 (4)	0.1397 (2)	0.90033 (6)	0.0206 (3)
C4	0.3415 (4)	0.4396 (3)	0.91063 (7)	0.0241 (4)
C5	0.3909 (4)	0.5876 (3)	0.93428 (7)	0.0283 (4)
C6	0.6012 (5)	0.6056 (3)	0.96504 (7)	0.0319 (5)
C7	0.7655 (4)	0.4768 (3)	0.97318 (7)	0.0288 (4)
C8	0.7143 (4)	0.3275 (3)	0.94962 (6)	0.0242 (4)
C9	0.5058 (4)	0.3075 (3)	0.91776 (6)	0.0209 (4)
C10	0.3366 (4)	0.0536 (2)	0.86617 (7)	0.0223 (4)
C11	0.3690 (4)	0.0946 (2)	0.81137 (6)	0.0198 (3)
C12	0.2877 (4)	0.2696 (2)	0.79913 (6)	0.0204 (3)
O13	0.0556 (3)	0.29944 (19)	0.80642 (5)	0.0255 (3)
O14	0.4480 (3)	0.36826 (19)	0.78453 (5)	0.0278 (3)
N15	0.6339 (3)	0.0692 (2)	0.79503 (6)	0.0221 (3)
H1	0.968 (6)	0.164 (3)	0.9700 (10)	0.035 (7)*
H2	0.795 (6)	−0.040 (4)	0.9198 (11)	0.039 (8)*
H4	0.208 (5)	0.429 (3)	0.8900 (9)	0.026 (6)*
H5	0.283 (6)	0.682 (4)	0.9283 (10)	0.035 (7)*
H6	0.635 (5)	0.711 (3)	0.9802 (9)	0.029 (7)*
H7	0.902 (5)	0.486 (3)	0.9933 (9)	0.021 (6)*
H11	0.273 (6)	0.019 (4)	0.7942 (9)	0.031 (7)*
H10A	0.355 (5)	−0.070 (3)	0.8708 (9)	0.026 (6)*
H10B	0.167 (5)	0.081 (3)	0.8746 (9)	0.027 (6)*
H15A	0.719 (5)	0.162 (3)	0.8003 (9)	0.026 (7)*
H15B	0.713 (7)	−0.018 (4)	0.8124 (10)	0.041 (8)*
H15C	0.627 (5)	0.040 (3)	0.7663 (10)	0.027 (7)*
O16	−0.2042 (5)	0.7887 (2)	0.84447 (7)	0.0525 (6)
O17	−0.0386 (4)	0.5973 (2)	0.79702 (6)	0.0362 (4)
C18	−0.1563 (5)	0.6461 (3)	0.83536 (8)	0.0329 (5)
H17	−0.018 (7)	0.478 (4)	0.8008 (11)	0.049 (10)*
H18	−0.195 (6)	0.557 (4)	0.8602 (10)	0.037 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0245 (8)	0.0381 (10)	0.0228 (7)	0.0063 (8)	−0.0043 (6)	0.0012 (7)
C2	0.0281 (10)	0.0301 (10)	0.0199 (7)	0.0063 (8)	0.0016 (7)	0.0018 (7)
C3	0.0218 (8)	0.0245 (9)	0.0156 (7)	0.0017 (7)	0.0026 (6)	0.0011 (6)
C4	0.0251 (9)	0.0253 (9)	0.0218 (7)	0.0024 (8)	0.0000 (7)	−0.0019 (7)
C5	0.0340 (11)	0.0233 (10)	0.0277 (9)	0.0014 (8)	0.0041 (8)	−0.0025 (7)
C6	0.0410 (12)	0.0297 (11)	0.0251 (8)	−0.0091 (10)	0.0054 (8)	−0.0051 (8)
C7	0.0270 (10)	0.0402 (12)	0.0192 (7)	−0.0085 (9)	0.0013 (7)	−0.0031 (7)
C8	0.0222 (8)	0.0329 (10)	0.0174 (7)	0.0003 (8)	0.0018 (7)	0.0003 (7)
C9	0.0221 (8)	0.0247 (9)	0.0158 (7)	−0.0001 (7)	0.0019 (6)	0.0002 (6)
C10	0.0250 (9)	0.0202 (9)	0.0216 (7)	−0.0014 (7)	0.0022 (7)	0.0013 (6)
C11	0.0207 (8)	0.0189 (8)	0.0197 (7)	0.0013 (7)	0.0010 (6)	−0.0028 (6)
C12	0.0231 (8)	0.0212 (9)	0.0168 (7)	0.0015 (7)	−0.0027 (6)	−0.0007 (6)
O13	0.0226 (6)	0.0239 (7)	0.0301 (7)	0.0036 (6)	−0.0006 (5)	−0.0037 (5)
O14	0.0278 (7)	0.0242 (7)	0.0314 (7)	0.0007 (6)	0.0024 (6)	0.0066 (6)
N15	0.0229 (7)	0.0223 (8)	0.0211 (7)	0.0033 (6)	0.0018 (6)	−0.0026 (6)
O16	0.0837 (16)	0.0243 (9)	0.0495 (10)	0.0205 (11)	−0.0049 (11)	−0.0030 (7)
O17	0.0496 (10)	0.0258 (8)	0.0332 (7)	0.0058 (7)	0.0076 (7)	0.0057 (6)
C18	0.0420 (12)	0.0233 (10)	0.0334 (10)	0.0091 (9)	−0.0024 (9)	0.0017 (8)

Geometric parameters (Å, º)

N1—C8	1.366 (3)	C8—C9	1.417 (3)
N1—C2	1.371 (3)	C10—C11	1.540 (3)
N1—H1	0.86 (3)	C10—H10A	1.01 (3)
C2—C3	1.368 (3)	C10—H10B	0.96 (3)
C2—H2	0.98 (3)	C11—N15	1.491 (3)
C3—C9	1.446 (3)	C11—C12	1.524 (3)
C3—C10	1.496 (3)	C11—H11	0.93 (3)
C4—C5	1.390 (3)	C12—O14	1.237 (2)
C4—C9	1.399 (3)	C12—O13	1.273 (2)
C4—H4	0.91 (3)	N15—H15A	0.89 (3)
C5—C6	1.405 (3)	N15—H15B	0.95 (3)
C5—H5	0.97 (3)	N15—H15C	0.82 (3)
C6—C7	1.382 (3)	O16—C18	1.213 (3)
C6—H6	0.97 (3)	O17—C18	1.281 (3)
C7—C8	1.400 (3)	O17—H17	0.99 (4)
C7—H7	0.91 (3)	C18—H18	1.01 (3)
O13···O17	2.487 (2)	C2···H7^ix	2.88 (3)
O13···N15^i	2.938 (2)	C2···H10B^ii	2.73 (3)
O13···C4	3.418 (2)	C2···H15B	3.08 (3)
O13···C18	3.137 (3)	C3···H15B	2.92 (3)
O14···C18^ii	3.384 (3)	C3···H15A	2.94 (2)
O14···N15^iii	2.750 (2)	C4···H18^ii	2.98 (3)
O14···O17	3.206 (3)	C5···H18^ii	3.00 (3)
O14···N15	2.641 (2)	C6···H1^ix	2.91 (3)
O14···C11^iii	3.342 (2)	C6···H18^ii	3.08 (3)
O16···C2^iv	3.144 (3)	C7···H1^ix	2.49 (3)
O16···C10^iv	3.310 (3)	C8···H1^ix	2.55 (3)
O16···N15^iv	2.786 (2)	C9···H1^ix	3.07 (3)
O17···C12^v	3.254 (2)	C9···H18^ii	3.02 (3)
O17···C12	3.181 (3)	C12···H4	2.83 (2)
O17···O13	2.487 (2)	C12···H15C^iii	2.87 (3)
O17···O14	3.206 (3)	C12···H17	2.35 (3)
O13···H17	1.51 (3)	C18···H4	3.01 (3)
O13···H4	2.64 (2)	C18···H15B^iv	2.89 (3)
O13···H18	2.88 (3)	H1···C6^vi	2.91 (3)
O13···H15A^i	2.12 (3)	H1···C7^vi	2.49 (3)
O13···H10B	2.64 (2)	H1···C8^vi	2.55 (3)
O14···H15C	2.88 (2)	H1···C9^vi	3.07 (3)
O14···H11^iii	2.88 (3)	H2···O16^vii	2.48 (3)
O14···H17	2.67 (4)	H4···O13	2.64 (2)
O14···H15A	2.25 (3)	H4···C12	2.83 (2)
O14···H15C^iii	2.01 (3)	H4···C18	3.01 (3)
O16···H2^iv	2.48 (3)	H7···C2^vi	2.88 (3)
O16···H10A^iv	2.71 (3)	H10A···O16^vii	2.71 (3)
O16···H15B^iv	1.85 (3)	H10B···O13	2.64 (2)
O17···H11^v	2.85 (3)	H10B···N1^i	2.86 (3)
O17···H15C^iii	2.83 (3)	H10B···H2^i	2.53 (4)
N1···C7^vi	3.314 (3)	H10B···C2^i	2.73 (3)
N1···C8^vi	3.350 (3)	H11···O17^x	2.85 (3)
N15···O16^vii	2.786 (2)	H11···O14^viii	2.88 (3)
N15···O13^ii	2.938 (2)	H15A···O13^ii	2.12 (3)
N15···O14^viii	2.750 (2)	H15A···O14	2.25 (3)
N15···O14	2.641 (2)	H15A···C3	2.94 (2)
N1···H10B^ii	2.86 (3)	H15B···O16^vii	1.85 (3)
C2···O16^vii	3.144 (3)	H15B···C2	3.08 (3)
C4···C12	3.351 (3)	H15B···C18^vii	2.89 (3)
C4···O13	3.418 (2)	H15B···C3	2.92 (3)
C4···C7^i	3.518 (3)	H15C···O14	2.88 (2)
C7···C4^ii	3.518 (3)	H15C···O17^viii	2.83 (3)
C7···N1^ix	3.314 (3)	H15C···C12^viii	2.87 (3)
C8···N1^ix	3.350 (3)	H15C···O14^viii	2.01 (3)
C9···C12	3.449 (2)	H17···O13	1.51 (3)
C10···O16^vii	3.310 (3)	H17···O14	2.67 (4)
C11···O14^viii	3.342 (2)	H17···C12	2.35 (3)
C12···O17^x	3.254 (2)	H18···O13	2.88 (3)
C12···C4	3.351 (3)	H18···C4^i	2.98 (3)
C12···C9	3.449 (2)	H18···C5^i	3.00 (3)
C12···O17	3.181 (3)	H18···C6^i	3.08 (3)
C18···O13	3.137 (3)	H18···C9^i	3.02 (3)
C18···O14^i	3.384 (3)
C8—N1—C2	109.31 (17)	C8—C9—C3	106.77 (17)
C8—N1—H1	123.1 (19)	C3—C10—C11	115.58 (16)
C2—N1—H1	127.6 (19)	C3—C10—H10A	108.9 (15)
C3—C2—N1	110.36 (19)	C11—C10—H10A	108.9 (14)
C3—C2—H2	133.1 (18)	C3—C10—H10B	109.4 (16)
N1—C2—H2	116.4 (18)	C11—C10—H10B	106.7 (15)
C2—C3—C9	105.98 (18)	H10A—C10—H10B	107 (2)
C2—C3—C10	125.00 (19)	N15—C11—C12	109.39 (16)
C9—C3—C10	129.00 (18)	N15—C11—C10	111.42 (15)
C5—C4—C9	118.88 (19)	C12—C11—C10	112.53 (15)
C5—C4—H4	120.9 (17)	N15—C11—H11	105.9 (19)
C9—C4—H4	120.1 (17)	C12—C11—H11	110.9 (19)
C4—C5—C6	121.1 (2)	C10—C11—H11	106.5 (17)
C4—C5—H5	119.7 (18)	O14—C12—O13	126.46 (19)
C6—C5—H5	119.1 (18)	O14—C12—C11	118.74 (17)
C7—C6—C5	121.3 (2)	O13—C12—C11	114.78 (18)
C7—C6—H6	119.2 (17)	C11—N15—H15A	108.3 (18)
C5—C6—H6	119.5 (17)	C11—N15—H15B	112 (2)
C6—C7—C8	117.4 (2)	H15A—N15—H15B	109 (2)
C6—C7—H7	122.4 (16)	C11—N15—H15C	106 (2)
C8—C7—H7	120.1 (16)	H15A—N15—H15C	115 (2)
N1—C8—C7	130.23 (19)	H15B—N15—H15C	106 (3)
N1—C8—C9	107.57 (18)	C18—O17—H17	106.0 (18)
C7—C8—C9	122.2 (2)	O16—C18—O17	124.4 (2)
C4—C9—C8	119.01 (19)	O16—C18—H18	120.4 (17)
C4—C9—C3	134.19 (18)	O17—C18—H18	114.9 (17)
C8—N1—C2—C3	0.1 (2)	H4—C4—C5—C6	−178.1 (19)
N1—C2—C3—C9	−0.7 (2)	H4—C4—C9—C8	179.2 (19)
C2—C3—C9—C8	1.0 (2)	H5—C5—C6—H6	1 (3)
C2—C3—C10—C11	−104.4 (2)	H6—C6—C7—H7	2 (3)
C5—C4—C9—C3	179.1 (2)	C3—C10—C11—H11	169 (2)
C5—C6—C7—C8	0.0 (3)	H10A—C10—C11—H11	46 (3)
N1—C8—C9—C3	−0.9 (2)	H10B—C10—C11—H11	−69 (3)
C7—C8—C9—C4	−1.8 (3)	H1—N1—C2—C3	179 (2)
N15—C11—C12—O13	172.45 (15)	H1—N1—C8—C9	−178 (2)
C10—C11—C12—O14	115.27 (19)	H15A—N15—C11—H11	156 (3)
C2—N1—C8—C7	179.7 (2)	H15B—N15—C11—H11	−83 (3)
N1—C2—C3—C10	−179.33 (18)	H15C—N15—C11—H11	32 (3)
C10—C3—C9—C4	1.6 (4)	C2—C3—C10—H10A	18.5 (15)
C9—C3—C10—C11	77.3 (3)	C9—C3—C10—H10B	−43.2 (16)
C5—C4—C9—C8	1.3 (3)	H4—C4—C5—H5	−1 (3)
C6—C7—C8—N1	−177.9 (2)	C4—C5—C6—H6	177.8 (17)
N1—C8—C9—C4	177.44 (18)	C5—C6—C7—H7	−179.3 (18)
C3—C10—C11—N15	53.5 (2)	H7—C7—C8—N1	1.4 (18)
N15—C11—C12—O14	−9.1 (2)	H10A—C10—C11—N15	−69.5 (16)
C2—N1—C8—C9	0.5 (2)	H10B—C10—C11—N15	175.4 (15)
C2—C3—C9—C4	−177.0 (2)	H11—C11—C12—O13	55.9 (19)
C10—C3—C9—C8	179.54 (18)	H1—N1—C2—H2	−5 (3)
C9—C4—C5—C6	−0.2 (3)	H15A—N15—C11—C10	−88.0 (17)
C4—C5—C6—C7	−0.4 (3)	H15B—N15—C11—C10	32 (2)
C6—C7—C8—C9	1.2 (3)	H15C—N15—C11—C10	147.9 (18)
C7—C8—C9—C3	179.83 (18)	H2—C2—C3—C9	−176 (3)
C3—C10—C11—C12	−69.8 (2)	C2—C3—C10—H10B	135.1 (15)
C10—C11—C12—O13	−63.2 (2)	C9—C4—C5—H5	177 (2)
C8—N1—C2—H2	177 (2)	H4—C4—C9—C3	−3.0 (19)
H1—N1—C8—C7	1 (2)	H5—C5—C6—C7	−178 (2)
H15A—N15—C11—C12	37.0 (17)	H6—C6—C7—C8	−178.3 (17)
H15B—N15—C11—C12	157 (2)	H7—C7—C8—C9	−179.5 (18)
H15C—N15—C11—C12	−87.1 (18)	H10A—C10—C11—C12	167.3 (16)
H2—C2—C3—C10	5 (3)	H10B—C10—C11—C12	52.2 (15)
C9—C3—C10—H10A	−159.8 (15)	H11—C11—C12—O14	−125.7 (19)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N15—H15A···O13^ii	0.89 (3)	2.12 (3)	2.938 (2)	153 (2)
N15—H15A···O14	0.89 (3)	2.25 (3)	2.641 (2)	106 (2)
N15—H15B···O16^vii	0.95 (3)	1.85 (3)	2.786 (2)	167 (3)
N15—H15C···O14^viii	0.82 (3)	2.01 (3)	2.750 (2)	151 (2)
O17—H17···O13	0.98 (3)	1.51 (3)	2.487 (2)	171 (4)

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