Bis­(DL-me­thioninium) sulfate

In the title compound, 2 C₅H₁₂NO₂S⁺·SO₄^2-, the sulfate anions form strong hydrogen bonds with both the cations. A head-to-tail sequence is observed in both the mol­ecules. The three sulfate anions on threefold axes link the amino-N atom through normal hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.009 Å
• Disorder in solvent or counterion
• R factor = 0.051
• wR factor = 0.147
• Data-to-parameter ratio = 7.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level A:



REFI_021  Alert A _refine_ls_abs_structure_details is missing
          Absolute structure method and Friedel-pair number.
          This should be present as the _refine_ls_abs_structure_Flack or Roger
          field has been filled out.


 Alert Level B:



STRDE_01  Alert B A value for _refine_ls_abs_structure_flack has been given,
          without an explanantion in the _refine_ls_abs_structure_details
          field.


 Alert Level C:



PLAT_302  Alert C Anion/Solvent Disorder .......................       6.00 Perc.

General Notes



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           69.99
         From the CIF: _reflns_number_total               1786
         Count of symmetry unique reflns         1722
         Completeness (_total/calc)            103.72%
         TEST3: Check Friedels for noncentro structure
         Estimate of Friedel pairs measured        64
         Fraction of Friedel pairs measured     0.037
         Are heavy atom types Z>Si present          yes
          WARNING: Large fraction of Friedel related reflns may
                   be needed to determine absolute structure


 1 Alert Level A = Potentially serious problem

 1 Alert Level B = Potential problem

 1 Alert Level C = Please check

---

S1. Comment

Methionine is one of the few amino acids having sulfur; it also has straight-chain aliphatic α-amino acids. The crystal structure of DL-methionine (Mathieson, 1952), L-methionine (Torii & Iitaka, 1973), DL-methionine hydrochloride (Di Blasio et al., 1977), DL-methionine nitrate (Mostad & Natarajan, 1985) and bis(DL-methionine dihydrogen phosphate) (Asath Bahadur, 1992) have already been reported. In the present study, the structure of bis(DL-methioninium)sulfate (I) was determined.

The two crystallographically independent methionine cations (A and B) have similar geometries (Fig. 1). The C^γ and S^δ atoms of molecule B are disordered. The minor contributing disordered atoms are denoted as primed atoms. The conformation angle ψ² is -148.5 (5) and 166.7 (4) for molecules A and B, respectively, which agrees well with bis(DL-methionine dihydrogen phosphate). The χ¹ straight-chain conformation is in trans form [-154.7 (5) & -159.6 (9)] for both the A and B molecules. The χ² conformation is in gauche I form [63.1 (7)°] for molecule A, and in trans [161.4 (10)°] and gauche I [75 (2)°] forms for the unprimed and primed atoms of molecule B. The χ³ conformation is in gauche I form [70.8 (7)°] for molecule A, and in gauche II [-82 (2)°] and gauche I [70 (2)°] forms for the unprimed and primed atoms of molecule B (Lakshminarayanan et al., 1967).

The carboxyl groups of the methionine cations A and B (Fig. 2 and Table 2) form strong hydrogen bonds with the sulfate anions. The three sulfate anions sitting on the threefold axis link the amino N atom of both the molecules (A and B) and stabilize the structure. Bifurcated hydrogen bonds are observed in the case of the amino N atom and the sulfate- and carboxyl-O atoms of both the A and B molecules (Jeffrey & Saenger, 1991). Both the A and B molecules are engaged in a head-to-tail sequence since the hydrogen bonds N11—H11B···O12(-y + 1, x-y - 1, z) and N21—H21B···O22(-y, x-y - 1,z), connect the amino acids along xy plane (Vijayan, 1988).

S2. Experimental

The title compound crystallized in aqueous solution of methionine and sulfuric acid in stoichiometric ratio of 2:1. The density of the sample was measured by flotation technique using a liquid mixture of carbon tetrachloride and xylene.

S3. Refinement

In molecule B, the atoms C24, S21 are disordered; the site-occupation factor for C24 and S21 is 0.58 (1), and for C24' and S21' is 0.42 (1). Since the geometry of these disordered atoms differs significantly from expected values, the distances were fixed by DFIX and the disordered group of atoms (with the associated H atoms) was treated using a split model. All H atoms were fixed by geometric restraints using HFIX, and allowed to ride on the preceding atom.

Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: CAD-4 Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 1999); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. ORTEP (Johnson, 1976) plot of the molecular structures of the two independent DL-methionine cations showing the atomic numbering scheme with 50% probability displacement ellipsoids.
	Fig. 2. Packing diagram of the molecule viewed down the a axis

Bis(DL-Methioninium)sulfate

Crystal data

2C5H12NO2S^+·SO4^2^−	Dx = 1.459 Mg m^−3 Dm = 1.454 Mg m^−3 Dm measured by flotation
Mr = 396.49	Cu Kα radiation, λ = 1.5418 Å
Trigonal, P3	Cell parameters from 25 reflections
a = 10.281 (3) Å	θ = 14.5–23.4°
c = 14.788 (6) Å	µ = 4.12 mm^−1
V = 1353.5 (8) Å^3	T = 293 K
Z = 3	Needle, colourless
F(000) = 630	0.5 × 0.35 × 0.2 mm

Data collection

Enraf-Nonius sealed tube diffractometer	1690 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.066
Graphite monochromator	θmax = 70.0°, θmin = 5.0°
ω–2θ scans	h = 0→12
Absorption correction: ψ scan (North et al., 1968)	k = −12→10
Tmin = 0.221, Tmax = 0.438	l = 0→17
2818 measured reflections	25 standard reflections every 3 reflections
1786 independent reflections	intensity decay: none

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: inferred from neighbouring sites
wR(F^2) = 0.147	H-atom parameters not refined
S = 1.09	w = 1/[σ^2(Fo^2) + (0.1004P)^2 + 0.3922P] where P = (Fo^2 + 2Fc^2)/3
1786 reflections	(Δ/σ)max < 0.001
229 parameters	Δρmax = 0.60 e Å^−3
7 restraints	Δρmin = −0.51 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.

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	Occ. (<1)
S1	0.3333	0.6667	0.77391 (13)	0.0310 (4)
O1	0.3333	0.6667	0.8717 (5)	0.0434 (14)
O2	0.4427 (4)	0.8170 (4)	0.7397 (3)	0.0438 (9)
S2	1.0000	1.0000	0.98814 (13)	0.0305 (4)
O3	1.0000	1.0000	0.8912 (5)	0.062 (2)
O4	0.8825 (4)	0.8538 (4)	1.0219 (3)	0.0452 (9)
S3	0.6667	0.3333	0.86420 (13)	0.0314 (4)
O5	0.6667	0.3333	0.9608 (5)	0.0534 (17)
O6	0.5636 (6)	0.1826 (5)	0.8286 (4)	0.0715 (14)
O11	1.0169 (5)	0.3728 (5)	0.6607 (3)	0.0501 (9)
H11	1.0871	0.4506	0.6810	0.075*
O12	1.0378 (5)	0.2760 (5)	0.7908 (3)	0.0515 (10)
N11	0.7559 (5)	0.0500 (5)	0.7821 (3)	0.0437 (10)
H11A	0.8198	0.0413	0.8188	0.066*
H11B	0.6772	−0.0406	0.7715	0.066*
H11C	0.7249	0.1078	0.8080	0.066*
C11	0.9748 (6)	0.2651 (6)	0.7207 (4)	0.0399 (11)
C12	0.8326 (6)	0.1193 (5)	0.6949 (4)	0.0400 (10)
H12	0.8634	0.0524	0.6669	0.048*
C13	0.7291 (7)	0.1375 (7)	0.6291 (4)	0.0532 (14)
H13A	0.7296	0.2301	0.6428	0.064*
H13B	0.6273	0.0550	0.6375	0.064*
C14	0.7749 (9)	0.1408 (9)	0.5302 (5)	0.0708 (19)
H14A	0.8768	0.2231	0.5224	0.085*
H14B	0.7100	0.1609	0.4923	0.085*
S11	0.7659 (3)	−0.0287 (3)	0.49214 (15)	0.0864 (7)
C15	0.5623 (13)	−0.1487 (12)	0.4901 (8)	0.109 (4)
H15A	0.5370	−0.2475	0.4702	0.164*
H15B	0.5198	−0.1074	0.4493	0.164*
H15C	0.5228	−0.1545	0.5497	0.164*
O21	0.7156 (4)	0.0723 (5)	0.0797 (3)	0.0503 (10)
H21	0.7936	0.0769	0.0624	0.075*
O22	0.6232 (5)	−0.0585 (5)	−0.0462 (3)	0.0535 (10)
C21	0.6119 (6)	0.0030 (6)	0.0200 (4)	0.0366 (10)
C22	0.4706 (5)	0.0103 (5)	0.0384 (3)	0.0375 (10)
H22	0.4987	0.1148	0.0509	0.045*
N21	0.3763 (5)	−0.0402 (5)	−0.0446 (3)	0.0411 (10)
H21A	0.2925	−0.0367	−0.0353	0.062*
H21B	0.3528	−0.1339	−0.0576	0.062*
H21C	0.4270	0.0199	−0.0905	0.062*
C23	0.3778 (7)	−0.0877 (9)	0.1178 (4)	0.0641 (18)
H23A	0.3766	−0.1826	0.1179	0.077*	0.576 (10)
H23B	0.2753	−0.1074	0.1146	0.077*	0.576 (10)
H23C	0.2941	−0.0698	0.1240	0.077*	0.424 (10)
H23D	0.3353	−0.1905	0.0970	0.077*	0.424 (10)
C24	0.4590 (16)	0.007 (3)	0.2046 (6)	0.093 (7)	0.576 (10)
H24A	0.4908	0.1114	0.1938	0.112*	0.576 (10)
H24B	0.5479	−0.0006	0.2165	0.112*	0.576 (10)
C24'	0.432 (3)	−0.086 (2)	0.2133 (11)	0.079 (7)	0.424 (10)
H24C	0.5274	−0.0844	0.2126	0.095*	0.424 (10)
H24D	0.3595	−0.1749	0.2462	0.095*	0.424 (10)
S21	0.3392 (7)	−0.0573 (9)	0.3016 (3)	0.121 (3)	0.576 (10)
S21'	0.4523 (12)	0.0817 (10)	0.2647 (5)	0.126 (4)	0.424 (10)
C25	0.2501 (18)	0.038 (2)	0.2777 (9)	0.166 (8)
H25A	0.1459	−0.0318	0.2665	0.250*	0.576 (10)
H25B	0.2943	0.0988	0.2250	0.250*	0.576 (10)
H25C	0.2593	0.1009	0.3280	0.250*	0.576 (10)
H25D	0.1994	−0.0416	0.3210	0.250*	0.424 (10)
H25E	0.1998	0.0070	0.2204	0.250*	0.424 (10)
H25F	0.2492	0.1259	0.2983	0.250*	0.424 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0239 (5)	0.0239 (5)	0.0451 (10)	0.0119 (3)	0.000	0.000
O1	0.042 (2)	0.042 (2)	0.047 (3)	0.0208 (10)	0.000	0.000
O2	0.0301 (17)	0.0283 (17)	0.067 (2)	0.0100 (14)	0.0006 (15)	0.0090 (16)
S2	0.0256 (5)	0.0256 (5)	0.0403 (9)	0.0128 (3)	0.000	0.000
O3	0.071 (3)	0.071 (3)	0.043 (4)	0.0353 (15)	0.000	0.000
O4	0.0293 (16)	0.0269 (17)	0.079 (3)	0.0136 (14)	0.0040 (16)	0.0077 (17)
S3	0.0262 (5)	0.0262 (5)	0.0419 (10)	0.0131 (3)	0.000	0.000
O5	0.059 (3)	0.059 (3)	0.042 (3)	0.0295 (13)	0.000	0.000
O6	0.072 (3)	0.035 (2)	0.070 (3)	−0.002 (2)	−0.008 (2)	−0.003 (2)
O11	0.045 (2)	0.038 (2)	0.050 (2)	0.0078 (16)	−0.0025 (17)	0.0016 (17)
O12	0.044 (2)	0.053 (2)	0.059 (2)	0.0254 (18)	−0.0045 (17)	0.0022 (18)
N11	0.048 (3)	0.031 (2)	0.051 (3)	0.0185 (19)	0.0105 (19)	−0.0022 (18)
C11	0.042 (3)	0.034 (2)	0.047 (3)	0.022 (2)	0.006 (2)	0.000 (2)
C12	0.040 (3)	0.036 (2)	0.044 (2)	0.019 (2)	0.008 (2)	0.001 (2)
C13	0.042 (3)	0.052 (3)	0.058 (4)	0.018 (2)	−0.005 (2)	−0.003 (3)
C14	0.070 (5)	0.068 (4)	0.060 (4)	0.023 (4)	−0.007 (3)	0.007 (3)
S11	0.0890 (15)	0.0899 (15)	0.0657 (11)	0.0337 (12)	0.0030 (10)	−0.0215 (11)
C15	0.104 (8)	0.079 (6)	0.099 (7)	0.011 (6)	−0.015 (6)	−0.024 (5)
O21	0.0334 (19)	0.066 (3)	0.056 (2)	0.0283 (19)	−0.0085 (16)	−0.021 (2)
O22	0.042 (2)	0.073 (3)	0.054 (2)	0.035 (2)	−0.0054 (17)	−0.021 (2)
C21	0.030 (2)	0.030 (2)	0.045 (3)	0.0121 (18)	0.0041 (19)	0.0045 (18)
C22	0.033 (2)	0.037 (2)	0.043 (2)	0.019 (2)	0.003 (2)	−0.003 (2)
N21	0.032 (2)	0.049 (2)	0.045 (2)	0.0219 (19)	0.0037 (17)	0.0101 (18)
C23	0.053 (3)	0.104 (5)	0.043 (3)	0.045 (4)	0.017 (3)	0.016 (3)
C24	0.078 (10)	0.20 (2)	0.018 (5)	0.081 (14)	0.005 (5)	−0.004 (8)
C24'	0.098 (16)	0.098 (16)	0.066 (13)	0.067 (14)	0.017 (10)	0.031 (11)
S21	0.143 (5)	0.211 (7)	0.0429 (18)	0.114 (5)	0.034 (2)	0.043 (3)
S21'	0.199 (10)	0.139 (7)	0.065 (4)	0.103 (7)	−0.014 (4)	−0.021 (4)
C25	0.27 (2)	0.225 (19)	0.088 (8)	0.19 (2)	0.050 (11)	0.015 (10)

Geometric parameters (Å, º)

S1—O1	1.446 (7)	C15—H15C	0.9600
S1—O2^i	1.474 (3)	O21—C21	1.289 (7)
S1—O2	1.474 (3)	O21—H21	0.8200
S1—O2^ii	1.474 (3)	O22—C21	1.202 (7)
S2—O3	1.433 (8)	C21—C22	1.517 (7)
S2—O4^iii	1.466 (3)	C22—N21	1.486 (7)
S2—O4^iv	1.466 (3)	C22—C23	1.530 (8)
S2—O4	1.466 (3)	C22—H22	0.9800
S3—O5	1.429 (8)	N21—H21A	0.8900
S3—O6^v	1.469 (4)	N21—H21B	0.8900
S3—O6	1.469 (4)	N21—H21C	0.8900
S3—O6^vi	1.469 (4)	C23—C24'	1.517 (16)
O11—C11	1.312 (7)	C23—C24	1.574 (14)
O11—H11	0.8200	C23—H23A	0.9700
O12—C11	1.198 (7)	C23—H23B	0.9700
N11—C12	1.494 (7)	C23—H23C	0.9700
N11—H11A	0.8900	C23—H23D	0.9700
N11—H11B	0.8900	C24—S21	1.787 (12)
N11—H11C	0.8900	C24—H24A	0.9700
C11—C12	1.529 (7)	C24—H24B	0.9700
C12—C13	1.521 (8)	C24'—S21'	1.803 (17)
C12—H12	0.9800	C24'—H24C	0.9700
C13—C14	1.532 (10)	C24'—H24D	0.9700
C13—H13A	0.9700	S21—C25	1.678 (13)
C13—H13B	0.9700	S21'—C25	1.903 (15)
C14—S11	1.789 (9)	C25—H25A	0.9600
C14—H14A	0.9700	C25—H25B	0.9600
C14—H14B	0.9700	C25—H25C	0.9600
S11—C15	1.823 (12)	C25—H25D	0.9600
C15—H15A	0.9600	C25—H25E	0.9600
C15—H15B	0.9600	C25—H25F	0.9600
O1—S1—O2^i	110.08 (18)	C22—N21—H21C	109.5
O1—S1—O2	110.08 (19)	H21A—N21—H21C	109.5
O2^i—S1—O2	108.85 (19)	H21B—N21—H21C	109.5
O1—S1—O2^ii	110.08 (18)	C24'—C23—C22	127.2 (12)
O2^i—S1—O2^ii	108.85 (19)	C24'—C23—C24	32.4 (9)
O2—S1—O2^ii	108.85 (19)	C22—C23—C24	104.9 (8)
O3—S2—O4^iii	109.9 (2)	C24'—C23—H23A	80.0
O3—S2—O4^iv	109.9 (2)	C22—C23—H23A	110.8
O4^iii—S2—O4^iv	109.1 (2)	C24—C23—H23A	110.8
O3—S2—O4	109.9 (2)	C24'—C23—H23B	113.8
O4^iii—S2—O4	109.1 (2)	C22—C23—H23B	110.8
O4^iv—S2—O4	109.1 (2)	C24—C23—H23B	110.8
O5—S3—O6^v	111.0 (2)	H23A—C23—H23B	108.8
O5—S3—O6	111.0 (2)	C24'—C23—H23C	105.5
O6^v—S3—O6	107.9 (2)	C22—C23—H23C	105.5
O5—S3—O6^vi	111.0 (2)	C24—C23—H23C	93.0
O6^v—S3—O6^vi	107.9 (2)	H23A—C23—H23C	128.6
O6—S3—O6^vi	107.9 (2)	H23B—C23—H23C	21.6
C11—O11—H11	109.5	C24'—C23—H23D	105.5
C12—N11—H11A	109.5	C22—C23—H23D	105.5
C12—N11—H11B	109.5	C24—C23—H23D	137.8
H11A—N11—H11B	109.5	H23A—C23—H23D	29.8
C12—N11—H11C	109.5	H23B—C23—H23D	84.6
H11A—N11—H11C	109.5	H23C—C23—H23D	106.1
H11B—N11—H11C	109.5	C23—C24—S21	111.9 (10)
O12—C11—O11	124.9 (5)	C23—C24—H24A	109.2
O12—C11—C12	121.0 (5)	S21—C24—H24A	109.2
O11—C11—C12	114.1 (5)	C23—C24—H24B	109.2
N11—C12—C13	112.0 (5)	S21—C24—H24B	109.2
N11—C12—C11	105.7 (4)	H24A—C24—H24B	107.9
C13—C12—C11	115.1 (4)	C23—C24'—S21'	105.4 (10)
N11—C12—H12	107.9	C23—C24'—H24C	110.7
C13—C12—H12	107.9	S21'—C24'—H24C	110.7
C11—C12—H12	107.9	C23—C24'—H24D	110.7
C12—C13—C14	112.7 (5)	S21'—C24'—H24D	110.7
C12—C13—H13A	109.0	H24C—C24'—H24D	108.8
C14—C13—H13A	109.0	C25—S21—C24	95.3 (9)
C12—C13—H13B	109.0	C24'—S21'—C25	103.1 (11)
C14—C13—H13B	109.0	S21—C25—S21'	46.4 (5)
H13A—C13—H13B	107.8	S21—C25—H25A	109.5
C13—C14—S11	114.5 (5)	S21'—C25—H25A	147.1
C13—C14—H14A	108.6	S21—C25—H25B	109.5
S11—C14—H14A	108.6	S21'—C25—H25B	70.1
C13—C14—H14B	108.6	H25A—C25—H25B	109.5
S11—C14—H14B	108.6	S21—C25—H25C	109.5
H14A—C14—H14B	107.6	S21'—C25—H25C	101.0
C14—S11—C15	98.5 (5)	H25A—C25—H25C	109.5
S11—C15—H15A	109.5	H25B—C25—H25C	109.5
S11—C15—H15B	109.5	S21—C25—H25D	65.6
H15A—C15—H15B	109.5	S21'—C25—H25D	109.5
S11—C15—H15C	109.5	H25A—C25—H25D	63.4
H15A—C15—H15C	109.5	H25B—C25—H25D	167.0
H15B—C15—H15C	109.5	H25C—C25—H25D	83.5
C21—O21—H21	109.5	S21—C25—H25E	110.7
O22—C21—O21	125.3 (5)	S21'—C25—H25E	109.5
O22—C21—C22	121.2 (5)	H25A—C25—H25E	52.0
O21—C21—C22	113.4 (4)	H25B—C25—H25E	60.0
N21—C22—C21	108.0 (4)	H25C—C25—H25E	139.6
N21—C22—C23	108.7 (4)	H25D—C25—H25E	109.5
C21—C22—C23	113.7 (5)	S21—C25—H25F	138.5
N21—C22—H22	108.8	S21'—C25—H25F	109.5
C21—C22—H22	108.8	H25A—C25—H25F	102.9
C23—C22—H22	108.8	H25B—C25—H25F	82.3
C22—N21—H21A	109.5	H25C—C25—H25F	32.9
C22—N21—H21B	109.5	H25D—C25—H25F	109.5
H21A—N21—H21B	109.5	H25E—C25—H25F	109.5
O12—C11—C12—N11	30.7 (6)	N21—C22—C23—C24'	173.9 (10)
O11—C11—C12—N11	−148.4 (5)	C21—C22—C23—C24'	53.6 (12)
O12—C11—C12—C13	154.8 (5)	N21—C22—C23—C24	−159.6 (9)
O11—C11—C12—C13	−24.3 (6)	C21—C22—C23—C24	80.1 (10)
N11—C12—C13—C14	−154.7 (5)	C24'—C23—C24—S21	−60 (2)
C11—C12—C13—C14	84.5 (6)	C22—C23—C24—S21	161.4 (10)
C12—C13—C14—S11	63.1 (7)	C22—C23—C24'—S21'	74.6 (17)
C13—C14—S11—C15	70.8 (7)	C24—C23—C24'—S21'	21.0 (12)
O22—C21—C22—N21	−11.1 (7)	C23—C24—S21—C25	−82.4 (15)
O21—C21—C22—N21	166.7 (4)	C23—C24'—S21'—C25	70.0 (15)
O22—C21—C22—C23	109.5 (6)	C24—S21—C25—S21'	−37.2 (7)
O21—C21—C22—C23	−72.6 (6)	C24'—S21'—C25—S21	47.2 (8)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O11—H11···O2^iv	0.82	1.79	2.569 (6)	159
N11—H11A···O3^vii	0.89	2.36	3.233 (7)	169
N11—H11B···O2^vii	0.89	2.16	2.964 (6)	151
N11—H11B···O12^viii	0.89	2.33	2.816 (6)	115
N11—H11C···O6	0.89	2.17	2.989 (8)	153
N11—H11C···O6^v	0.89	2.49	3.209 (8)	138
O21—H21···O4^ix	0.82	1.76	2.576 (5)	171
N21—H21A···O4^x	0.89	2.11	2.956 (6)	159
N21—H21B···O1^xi	0.89	2.22	3.079 (6)	162
N21—H21B···O22^xii	0.89	2.65	3.083 (7)	111
N21—H21C···O6^xiii	0.89	1.96	2.839 (7)	168

Symmetry codes: (iv) −y+2, x−y+1, z; (v) −y+1, x−y, z; (vii) x, y−1, z; (viii) −y+1, x−y−1, z; (ix) −x+y+1, −x+1, z−1; (x) −y+1, x−y, z−1; (xi) x, y−1, z−1; (xii) −y, x−y−1, z; (xiii) x, y, z−1.