4-Nitro­aniline–picric acid (2/1)

Li, Y.

doi:10.1107/S1600536809037416

organic compounds

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ISSN: 2056-9890

Volume 65| Part 10| October 2009| Page o2566

doi:10.1107/S1600536809037416

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4-Nitroaniline–picric acid (2/1)

Yan-jun Li ^a ^*

^aCollege of Chemical Engineering and Technology, Wuhan University of Science and Technology, Wuhan 430081, People's Republic of China
^*Correspondence e-mail: yanwatercn@wust.edu.cn

(Received 3 August 2009; accepted 16 September 2009; online 30 September 2009)

In the title adduct, C₆H₃N₃O₇·0.5C₆H₆N₂O₂, the complete 4-nitroaniline molecule is generated by a crystallographic twofold axis with two C atoms and two N atoms lying on the axis. The molecular components are linked into two dimensional corrugated layers running parallel to the (001) plane by a combination of intermolecular N—H⋯O and C—H⋯O hydrogen bonds. The phenolic oxygen and two sets of nitro oxygen atoms in the picric acid were found to be disordered with occupancies of 0.81 (2):0.19 (2) and 0.55 (3):0.45 (3) and 0.77 (4):0.23 (4), respectively.

Related literature

For background to picrate derivatives, see: Harrison et al. (2007 ); Pascard et al. (1982 ); Pearson et al. (2007 ); Wang et al. (2003 ).

Experimental

Crystal data

C₆H₃N₃O₇·0.5C₆H₆N₂O₂
M_r = 298.18
Orthorhombic, P b c n
a = 23.534 (2) Å
b = 9.3318 (8) Å
c = 10.5047 (9) Å
V = 2307.0 (3) Å³
Z = 8
Mo Kα radiation
μ = 0.16 mm⁻¹
T = 298 K
0.30 × 0.20 × 0.10 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: none
16332 measured reflections
2855 independent reflections
2154 reflections with I > 2σ(I)
R_int = 0.033

Refinement

R[F² > 2σ(F²)] = 0.046
wR(F²) = 0.136
S = 1.06
2855 reflections
241 parameters
18 restraints
H-atom parameters constrained
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3⋯O2ⁱ	0.93	2.55	3.442 (10)	161
C9—H9⋯O5ⁱⁱ	0.93	2.53	3.286 (4)	139
N4—H4A⋯O6	0.86	2.44	3.2677 (16)	161
O1—H1A⋯O7	0.82	1.85	2.553 (2)	143
Symmetry codes: (i) $[-x+{\script{3\over 2}}, y-{\script{1\over 2}}, z]$ ; (ii) x, y+1, z.

Data collection: SMART (Bruker, 2001 ); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009 ); software used to prepare material for publication: PLATON.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809037416/bg2290sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809037416/bg2290Isup2.hkl

checkCIF report

Comment top

Picric acid has been early used in the characterization of organic bases because of the ease of crystallization and hence purification when picrate derivatives were produced (Pascard et al., 1982; Wang et al., 2003; Pearson et al., 2007; Harrison et al., 2007). Here, we report the crystal structure of the title adduct, 2(C₆H₃N₃O₇).C₆H₆N₂O₂, (I), where the hydrogen atom was not transferred from the picric acid to the nitroaniline molecule, as expected, thus forming a neutral 1:2 molecular adduct (acid to base) (Fig.1). The 4-nitroaniline molecule is bisected by a mirror plane through the N4-C7···C10-N5 line, and the picric acid unit presents a number of disordered sites (see refinement section for details). In the latter acid group, the parameters of C1—O1 = 1.347 (4)Å and C6—C1—C2=115.2 (3)° are indicative of the proton presence, confirmed by the difference electron density map.

In the crystal packing, the molecular components are linked into a dimensional zigzag-like layer (Fig.2) running parallel to the (001) plane by a combination of intermolecular N—H···O, O—H···N and C—H···O hydrogen bonds (Table 1).

Related literature top

For backgrounto picrate derivatives, see: Harrison et al. (2007); Pascard et al. (1982); Pearson et al. (2007); Wang et al. (2003).

Experimental top

Picric acid (0.6873 g, 3 mmol) and 4-nitroaniline (0.4144 g, 3 mmol) were mixed in 10 ml e thanol.The mixture was kept at room temperature for two weeks,after which time needle like yellow crystals (0.40 x 0.08 x 0.03 mm) suitable for single-crystal X-ray diffraction were obtained.

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).

Figures top

	Fig. 1. The title molecule with the atom-numbering scheme. The displacement ellipsoids are drawn at the 30% probability level. Hydrogen bonds are shown as blue dashed lines. Symmetry code a: 1-x, y, -z+1/2
	Fig. 2. Section of the title structure, showing the two-dimensional (001) layer. Hydrogen bonds are shown as dashed lines. For the sake of clarity, the H atoms not involved in the hydrogen-bonds pattern have been omitted.

4-Nitroaniline–picric acid (2/1) top

Crystal data top

C₆H₃N₃O₇·0.5C₆H₆N₂O₂	F(000) = 1216
M_r = 298.18	D_x = 1.717 Mg m⁻³
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2ab	Cell parameters from 5243 reflections
a = 23.534 (2) Å	θ = 2.4–27.1°
b = 9.3318 (8) Å	µ = 0.16 mm⁻¹
c = 10.5047 (9) Å	T = 298 K
V = 2307.0 (3) Å³	Block, red
Z = 8	0.30 × 0.20 × 0.10 mm

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	2154 reflections with I > 2σ(I)
Radiation source: fine focus sealed Siemens Mo tube	R_int = 0.033
Graphite monochromator	θ_max = 28.3°, θ_min = 2.4°
0.3° wide ω exposures scans	h = −30→31
16332 measured reflections	k = −12→12
2855 independent reflections	l = −13→8

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.046	H-atom parameters constrained
wR(F²) = 0.136	w = 1/[σ²(F_o²) + (0.0712P)² + 0.2759P] where P = (F_o² + 2F_c²)/3
S = 1.06	(Δ/σ)_max < 0.001
2855 reflections	Δρ_max = 0.22 e Å⁻³
241 parameters	Δρ_min = −0.26 e Å⁻³
18 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0032 (9)

Crystal data top

C₆H₃N₃O₇·0.5C₆H₆N₂O₂	V = 2307.0 (3) Å³
M_r = 298.18	Z = 8
Orthorhombic, Pbcn	Mo Kα radiation
a = 23.534 (2) Å	µ = 0.16 mm⁻¹
b = 9.3318 (8) Å	T = 298 K
c = 10.5047 (9) Å	0.30 × 0.20 × 0.10 mm

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	2154 reflections with I > 2σ(I)
16332 measured reflections	R_int = 0.033
2855 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.046	18 restraints
wR(F²) = 0.136	H-atom parameters constrained
S = 1.06	Δρ_max = 0.22 e Å⁻³
2855 reflections	Δρ_min = −0.26 e Å⁻³
241 parameters

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
C1	0.66852 (7)	0.40572 (18)	0.75606 (17)	0.0504 (4)
H1	0.6733	0.5023	0.7753	0.061*	0.194 (3)
C2	0.69244 (6)	0.29633 (18)	0.83061 (16)	0.0496 (4)
C3	0.68653 (7)	0.15487 (18)	0.80130 (17)	0.0517 (4)
H3	0.7032	0.0852	0.8524	0.062*
C4	0.65585 (7)	0.11617 (18)	0.69592 (17)	0.0511 (4)
C5	0.63050 (7)	0.21640 (19)	0.61822 (16)	0.0508 (4)
H5	0.6098	0.1890	0.5468	0.061*	0.806 (3)
C6	0.63686 (6)	0.35912 (17)	0.65015 (16)	0.0488 (4)
C7	0.5000	0.6849 (3)	0.2500	0.0505 (5)
C8	0.52386 (7)	0.76184 (19)	0.35141 (16)	0.0533 (4)
H8	0.5397	0.7127	0.4198	0.064*
C9	0.52404 (7)	0.90824 (19)	0.35084 (15)	0.0533 (4)
H9	0.5403	0.9585	0.4181	0.064*
C10	0.5000	0.9812 (3)	0.2500	0.0515 (6)
N4	0.5000	0.5397 (3)	0.2500	0.0760 (7)
H4A	0.5148	0.4936	0.3127	0.091*
N5	0.5000	1.1374 (3)	0.2500	0.0705 (6)
N1	0.72518 (7)	0.33052 (17)	0.94650 (15)	0.0607 (4)
N2	0.64972 (8)	−0.03633 (18)	0.66686 (19)	0.0733 (5)
N3	0.60883 (7)	0.46447 (16)	0.56958 (16)	0.0598 (4)
O1	0.67753 (7)	0.54438 (16)	0.78695 (17)	0.0670 (6)	0.81 (2)
H1A	0.6603	0.5962	0.7370	0.080*	0.806 (3)
O2	0.7225 (5)	0.4511 (5)	0.9832 (7)	0.084 (2)	0.55 (3)
O3	0.7584 (9)	0.2434 (12)	0.980 (2)	0.130 (5)	0.55 (3)
O5	0.6212 (4)	−0.0676 (7)	0.5744 (6)	0.100 (2)	0.77 (4)
O4	0.6739 (6)	−0.1218 (7)	0.7350 (9)	0.108 (2)	0.77 (4)
O1'	0.6057 (3)	0.1603 (7)	0.5099 (6)	0.079 (3)	0.19 (2)
H1'	0.6101	0.0731	0.5088	0.119*	0.194 (3)
O2'	0.7386 (8)	0.4462 (8)	0.9798 (8)	0.093 (3)	0.45 (3)
O3'	0.7319 (7)	0.2298 (7)	1.0257 (8)	0.082 (3)	0.45 (3)
O4'	0.6609 (16)	−0.120 (3)	0.752 (2)	0.106 (8)	0.23 (4)
O5'	0.6331 (17)	−0.077 (3)	0.5624 (14)	0.108 (8)	0.23 (4)
O6	0.58058 (7)	0.42228 (16)	0.48088 (16)	0.0820 (5)
O7	0.61414 (7)	0.59241 (15)	0.59443 (18)	0.0839 (5)
O8	0.52462 (9)	1.20034 (17)	0.33516 (17)	0.1041 (7)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0482 (8)	0.0479 (9)	0.0552 (10)	−0.0025 (6)	0.0033 (7)	−0.0010 (7)
C2	0.0454 (8)	0.0525 (9)	0.0508 (9)	−0.0017 (7)	−0.0013 (7)	−0.0044 (7)
C3	0.0508 (8)	0.0497 (9)	0.0545 (10)	0.0053 (7)	−0.0042 (7)	−0.0011 (7)
C4	0.0519 (9)	0.0474 (9)	0.0541 (10)	0.0002 (7)	−0.0010 (7)	−0.0065 (7)
C5	0.0465 (8)	0.0576 (10)	0.0483 (9)	−0.0035 (7)	−0.0009 (7)	−0.0014 (8)
C6	0.0445 (8)	0.0505 (9)	0.0515 (10)	−0.0010 (7)	0.0029 (7)	0.0063 (7)
C7	0.0487 (11)	0.0499 (12)	0.0531 (13)	0.000	0.0063 (10)	0.000
C8	0.0554 (9)	0.0604 (10)	0.0441 (9)	0.0068 (7)	−0.0050 (7)	0.0052 (7)
C9	0.0587 (10)	0.0594 (10)	0.0417 (9)	0.0001 (7)	−0.0079 (7)	−0.0046 (7)
C10	0.0584 (13)	0.0478 (12)	0.0482 (13)	0.000	−0.0035 (10)	0.000
N4	0.1002 (18)	0.0528 (13)	0.0750 (17)	0.000	−0.0071 (14)	0.000
N5	0.0951 (17)	0.0549 (13)	0.0614 (14)	0.000	−0.0084 (13)	0.000
N1	0.0598 (9)	0.0596 (9)	0.0626 (10)	−0.0030 (7)	−0.0093 (7)	−0.0083 (8)
N2	0.0863 (12)	0.0529 (9)	0.0805 (13)	0.0035 (9)	−0.0180 (10)	−0.0131 (9)
N3	0.0598 (9)	0.0540 (9)	0.0657 (10)	−0.0041 (7)	−0.0051 (8)	0.0115 (7)
O1	0.0826 (12)	0.0428 (8)	0.0757 (12)	−0.0040 (7)	−0.0190 (9)	−0.0021 (7)
O2	0.103 (4)	0.060 (2)	0.090 (3)	0.002 (3)	−0.024 (2)	−0.039 (3)
O3	0.137 (8)	0.103 (4)	0.149 (9)	0.046 (4)	−0.097 (7)	−0.042 (4)
O5	0.110 (3)	0.066 (2)	0.124 (5)	0.015 (2)	−0.059 (3)	−0.038 (3)
O4	0.151 (4)	0.047 (2)	0.127 (5)	0.0128 (19)	−0.064 (4)	−0.011 (3)
O1'	0.093 (5)	0.075 (5)	0.070 (5)	−0.001 (4)	−0.025 (4)	0.002 (4)
O2'	0.123 (7)	0.084 (4)	0.073 (3)	−0.062 (4)	−0.037 (3)	0.030 (4)
O3'	0.110 (6)	0.058 (3)	0.078 (4)	0.012 (3)	−0.040 (3)	−0.002 (2)
O4'	0.20 (2)	0.045 (7)	0.068 (8)	0.000 (9)	0.011 (13)	0.001 (5)
O5'	0.174 (18)	0.098 (13)	0.052 (8)	−0.035 (11)	0.004 (10)	−0.026 (7)
O6	0.1017 (11)	0.0681 (9)	0.0763 (10)	−0.0034 (8)	−0.0344 (9)	0.0128 (7)
O7	0.0925 (10)	0.0513 (8)	0.1079 (12)	−0.0020 (7)	−0.0244 (9)	0.0104 (8)
O8	0.1598 (18)	0.0609 (9)	0.0916 (12)	−0.0151 (10)	−0.0387 (11)	−0.0121 (9)

Geometric parameters (Å, º) top

C1—O1	1.351 (2)	C9—C10	1.381 (2)
C1—C2	1.404 (2)	C9—H9	0.9300
C1—C6	1.408 (2)	C10—C9ⁱ	1.381 (2)
C1—H1	0.9300	C10—N5	1.457 (3)
C2—C3	1.363 (2)	N4—H4A	0.8600
C2—N1	1.476 (2)	N5—O8ⁱ	1.2169 (18)
C3—C4	1.370 (2)	N5—O8	1.2169 (18)
C3—H3	0.9300	N1—O2'	1.178 (6)
C4—C5	1.377 (2)	N1—O3	1.182 (5)
C4—N2	1.463 (2)	N1—O2	1.191 (5)
C5—C6	1.382 (2)	N1—O3'	1.265 (5)
C5—O1'	1.382 (6)	N2—O4	1.214 (5)
C5—H5	0.9300	N2—O5	1.216 (4)
C6—N3	1.455 (2)	N2—O4'	1.221 (10)
C7—N4	1.355 (3)	N2—O5'	1.225 (10)
C7—C8	1.402 (2)	N3—O6	1.210 (2)
C7—C8ⁱ	1.402 (2)	N3—O7	1.228 (2)
C8—C9	1.366 (2)	O1—H1A	0.8200
C8—H8	0.9300	O1'—H1'	0.8200

O1—C1—C2	119.97 (16)	C10—C9—H9	120.2
O1—C1—C6	124.67 (16)	C9—C10—C9ⁱ	120.9 (2)
C2—C1—C6	115.35 (15)	C9—C10—N5	119.56 (11)
C2—C1—H1	122.3	C9ⁱ—C10—N5	119.56 (11)
C6—C1—H1	122.3	C7—N4—H4A	120.0
C3—C2—C1	122.50 (16)	O8ⁱ—N5—O8	122.3 (3)
C3—C2—N1	116.69 (15)	O8ⁱ—N5—C10	118.85 (13)
C1—C2—N1	120.81 (15)	O8—N5—C10	118.85 (13)
C2—C3—C4	119.45 (16)	O2'—N1—O3	111.4 (6)
C2—C3—H3	120.3	O3—N1—O2	126.1 (5)
C4—C3—H3	120.3	O2'—N1—O3'	116.8 (5)
C3—C4—C5	121.88 (16)	O2—N1—O3'	119.7 (6)
C3—C4—N2	118.49 (16)	O2'—N1—C2	125.7 (5)
C5—C4—N2	119.63 (16)	O3—N1—C2	116.3 (4)
C4—C5—C6	117.63 (16)	O2—N1—C2	116.3 (4)
C4—C5—O1'	114.4 (3)	O3'—N1—C2	116.6 (4)
C6—C5—O1'	127.7 (3)	O4—N2—O5	124.9 (4)
C4—C5—H5	121.2	O5—N2—O4'	123.6 (15)
C6—C5—H5	121.2	O4—N2—O5'	118.4 (16)
C5—C6—C1	123.16 (15)	O4'—N2—O5'	122.1 (15)
C5—C6—N3	117.44 (15)	O4—N2—C4	118.0 (4)
C1—C6—N3	119.39 (15)	O5—N2—C4	117.0 (3)
N4—C7—C8	120.81 (11)	O4'—N2—C4	116.7 (13)
N4—C7—C8ⁱ	120.81 (11)	O5'—N2—C4	121.3 (13)
C8—C7—C8ⁱ	118.4 (2)	O6—N3—O7	122.38 (16)
C9—C8—C7	120.67 (16)	O6—N3—C6	118.48 (15)
C9—C8—H8	119.7	O7—N3—C6	119.13 (16)
C7—C8—H8	119.7	C1—O1—H1A	109.5
C8—C9—C10	119.70 (16)	C5—O1'—H1'	109.5
C8—C9—H9	120.2

O1—C1—C2—C3	−177.52 (17)	C9—C10—N5—O8ⁱ	−175.18 (14)
C6—C1—C2—C3	1.3 (2)	C9ⁱ—C10—N5—O8ⁱ	4.82 (14)
O1—C1—C2—N1	3.0 (2)	C9—C10—N5—O8	4.82 (14)
C6—C1—C2—N1	−178.16 (14)	C9ⁱ—C10—N5—O8	−175.18 (14)
C1—C2—C3—C4	−0.5 (3)	C3—C2—N1—O2'	173.0 (10)
N1—C2—C3—C4	179.01 (15)	C1—C2—N1—O2'	−7.5 (10)
C2—C3—C4—C5	−0.1 (3)	C3—C2—N1—O3	24.2 (17)
C2—C3—C4—N2	−179.55 (16)	C1—C2—N1—O3	−156.3 (17)
C3—C4—C5—C6	−0.1 (3)	C3—C2—N1—O2	−168.1 (6)
N2—C4—C5—C6	179.26 (16)	C1—C2—N1—O2	11.4 (6)
C3—C4—C5—O1'	174.3 (4)	C3—C2—N1—O3'	−18.2 (9)
N2—C4—C5—O1'	−6.3 (5)	C1—C2—N1—O3'	161.3 (9)
C4—C5—C6—C1	1.1 (2)	C3—C4—N2—O4	−2.7 (9)
O1'—C5—C6—C1	−172.5 (5)	C5—C4—N2—O4	177.9 (9)
C4—C5—C6—N3	−178.51 (15)	C3—C4—N2—O5	178.4 (6)
O1'—C5—C6—N3	7.9 (5)	C5—C4—N2—O5	−1.0 (6)
O1—C1—C6—C5	177.14 (16)	C3—C4—N2—O4'	16 (2)
C2—C1—C6—C5	−1.6 (2)	C5—C4—N2—O4'	−163 (2)
O1—C1—C6—N3	−3.3 (3)	C3—C4—N2—O5'	−165 (2)
C2—C1—C6—N3	177.95 (14)	C5—C4—N2—O5'	15 (2)
N4—C7—C8—C9	179.68 (12)	C5—C6—N3—O6	1.5 (2)
C8ⁱ—C7—C8—C9	−0.32 (12)	C1—C6—N3—O6	−178.11 (17)
C7—C8—C9—C10	0.6 (2)	C5—C6—N3—O7	−179.18 (17)
C8—C9—C10—C9ⁱ	−0.31 (12)	C1—C6—N3—O7	1.2 (2)
C8—C9—C10—N5	179.68 (12)

Symmetry code: (i) −x+1, y, −z+1/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O2ⁱⁱ	0.93	2.55	3.442 (10)	161
C9—H9···O5ⁱⁱⁱ	0.93	2.53	3.286 (4)	139
N4—H4A···O6	0.86	2.44	3.2677 (16)	161
O1—H1A···O7	0.82	1.85	2.553 (2)	143

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

Experimental details

Crystal data
Chemical formula	C₆H₃N₃O₇·0.5C₆H₆N₂O₂
M_r	298.18
Crystal system, space group	Orthorhombic, Pbcn
Temperature (K)	298
a, b, c (Å)	23.534 (2), 9.3318 (8), 10.5047 (9)
V (Å³)	2307.0 (3)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.16
Crystal size (mm)	0.30 × 0.20 × 0.10

Data collection
Diffractometer	Bruker SMART APEX CCD area-detector diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	16332, 2855, 2154
R_int	0.033
(sin θ/λ)_max (Å⁻¹)	0.667

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.046, 0.136, 1.06
No. of reflections	2855
No. of parameters	241
No. of restraints	18
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.22, −0.26

Computer programs: SMART (Bruker, 2001), SAINT-Plus (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O2ⁱ	0.93	2.55	3.442 (10)	160.5
C9—H9···O5ⁱⁱ	0.93	2.53	3.286 (4)	139.0
N4—H4A···O6	0.86	2.44	3.2677 (16)	161.2
O1—H1A···O7	0.82	1.85	2.553 (2)	142.8

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

Acknowledgements

The author thanks Wuhan University of Science and Technology for supporting this study.

References

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