3-(2,4-Dichloro­anilino)iso­benzo­furan-1(3H)-one

Odabaşoğlu, M.; Büyükgüngör, O.

doi:10.1107/S1600536808007708

organic compounds

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ISSN: 2056-9890

Volume 64| Part 4| April 2008| Page o755

doi:10.1107/S1600536808007708

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3-(2,4-Dichloroanilino)isobenzofuran-1(3H)-one †

Mustafa Odabaşoğlu ^a and Orhan Büyükgüngör ^b ^*

^aDepartment of Chemistry, Faculty of Arts and Sciences, Ondokuz Mayıs University, TR-55139 Kurupelit Samsun, Turkey, and ^bDepartment of Physics, Faculty of Arts and Sciences, Ondokuz Mayıs University, TR-55139 Kurupelit Samsun, Turkey
^*Correspondence e-mail: orhanb@omu.edu.tr

(Received 19 March 2008; accepted 20 March 2008; online 29 March 2008)

In the molecule of the title compound, C₁₄H₉Cl₂NO₂, the essentially planar phthalide group is oriented at a dihedral angle of 63.23 (5)° with respect to the substituted aromatic ring. In the crystal structure, intermolecular C—H⋯O and N—H⋯O hydrogen bonds link the molecules, generating R₄⁴(21) ring motifs to form a three-dimensional network.

Related literature

For general background, see: Aoki et al. (1973 , 1974 ); Tsi & Tan (1997 ); Roy & Sarkar (2005 ); Bellasio (1974 , 1975 ). For related structures, see: Büyükgüngör & Odabaşoğlu (2006 ); Odabaşoğlu & Büyükgüngör (2006 ). For ring motif details, see: Bernstein et al. (1995 ); Etter (1990 ).

Experimental

Crystal data

C₁₄H₉Cl₂NO₂
M_r = 294.12
Monoclinic, P 2₁ /c
a = 7.7647 (4) Å
b = 23.9293 (12) Å
c = 7.3261 (4) Å
β = 102.768 (5)°
V = 1327.56 (12) Å³
Z = 4
Mo Kα radiation
μ = 0.48 mm⁻¹
T = 296 K
0.62 × 0.40 × 0.29 mm

Data collection

Stoe IPDSII diffractometer
Absorption correction: integration (X-RED32; Stoe & Cie, 2002 ) T_min = 0.486, T_max = 0.854
7695 measured reflections
2500 independent reflections
1860 reflections with I > 2σ(I)
R_int = 0.114

Refinement

R[F² > 2σ(F²)] = 0.048
wR(F²) = 0.113
S = 1.03
2500 reflections
176 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.38 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O1ⁱ	0.86 (3)	2.36 (3)	3.176 (2)	159 (2)
C4—H4⋯O2ⁱⁱ	0.93	2.57	3.387 (3)	147
Symmetry codes: (i) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (ii) $[x+1, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ .

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablock I. DOI: 10.1107/S1600536808007708/hk2436sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808007708/hk2436Isup2.hkl

checkCIF report

Comment top

Phthalides (isobenzofuranones) are five-membered lactones found in plants and they are known to show diverse biological activities, such as fungicidal, bactericidal, herbicidal, analgesic, pesticidal, hypotensive and vasorelaxant activities (Aoki et al., 1973, 1974; Tsi & Tan, 1997; Roy & Sarkar, 2005). In addition, phthalide derivatives are useful in the treatment of circulatory and heart-related diseases (Bellasio, 1974, 1975). As part of our ongoing research on 3-substituted phthalides (Büyükgüngör & Odabaşoğlu, 2006; Odabaşoǧlu & Büyükgüngör, 2006), the title compound, (I), has been synthesized and its crystal structure is reported here.

In the molecule of (I), (Fig. 1), rings A (C2-C7), B (C1/C2/C7/C8/O2) and C (C9-C14) are, of course, planar. The dihedral angles between them are A/B = 2.60 (5)°, A/C = 63.44 (4)° and B/C = 63.11 (5)°. So, rings A and B are also nearly coplanar. Ring C is oriented with respect to the coplanar ring system at a dihedral angle of 63.23 (5)°. The geometry of (I) does not show any significant difference from the average geometry found for 3-(4-chloroanilino)isobenzofuran-1(3H)-one (Büyükgüngör & Odabaşoğlu, 2006).

In the crystal structure, intermolecular C-H···O and N-H···O hydrogen bonds (Table 1) link the molecules, generating R₄⁴(21) (Fig. 2) ring motifs (Bernstein et al., 1995; Etter, 1990), to form a three-dimensional network, in which they may be effective in the stabilization of the structure.

Related literature top

For general background, see: Aoki et al. (1973, 1974); Tsi & Tan (1997); Roy & Sarkar (2005); Bellasio (1974, 1975). For related structures, see: Büyükgüngör & Odabaşoğlu (2006); Odabaşoğlu & Büyükgüngör (2006). For ring motif details, see: Bernstein et al. (1995); Etter (1990).

Experimental top

The title compound was prepared according to the method described by Odabaşoğlu & Büyükgüngör (2006), using phthalaldehydic acid and 2,4-dichloroaniline as starting materials (yield; 80%). Crystals of (I) suitable for X-ray analysis were obtained by slow evaporation of an ethanol-DMF (1:1) solution at room temperature.

Computing details top

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. A partial packing diagram of (I), showing the formation of R₄⁴(21) ring motif. Hydrogen bonds are shown as dashed lines [symmetry codes: (i) x, 1/2 - y, z + 1/2; (ii) x - 1, y, z; (iii) x - 1, 1/2 - y, 1/2 - z]. H atoms not involved in hydrogen bondings have been omitted for clarity.

3-(2,4-dichloroanilino)isobenzofuran-1(3H)-one top

Crystal data top

C₁₄H₉Cl₂NO₂	F(000) = 600
M_r = 294.12	D_x = 1.472 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 7695 reflections
a = 7.7647 (4) Å	θ = 1.7–26.1°
b = 23.9293 (12) Å	µ = 0.48 mm⁻¹
c = 7.3261 (4) Å	T = 296 K
β = 102.768 (5)°	Prism, colorless
V = 1327.56 (12) Å³	0.62 × 0.40 × 0.29 mm
Z = 4

Data collection top

Stoe IPDS II diffractometer	2500 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	1860 reflections with I > 2σ(I)
Plane graphite monochromator	R_int = 0.114
Detector resolution: 6.67 pixels mm^-1	θ_max = 25.7°, θ_min = 1.7°
w–scan rotation method	h = −9→9
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	k = −28→28
T_min = 0.486, T_max = 0.854	l = −8→8
7695 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.113	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ²(F_o²) + (0.0573P)² + 0.1182P] where P = (F_o² + 2F_c²)/3
2500 reflections	(Δ/σ)_max < 0.001
176 parameters	Δρ_max = 0.39 e Å⁻³
0 restraints	Δρ_min = −0.38 e Å⁻³

Crystal data top

C₁₄H₉Cl₂NO₂	V = 1327.56 (12) Å³
M_r = 294.12	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 7.7647 (4) Å	µ = 0.48 mm⁻¹
b = 23.9293 (12) Å	T = 296 K
c = 7.3261 (4) Å	0.62 × 0.40 × 0.29 mm
β = 102.768 (5)°

Data collection top

Stoe IPDS II diffractometer	2500 independent reflections
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	1860 reflections with I > 2σ(I)
T_min = 0.486, T_max = 0.854	R_int = 0.114
7695 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.048	0 restraints
wR(F²) = 0.113	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	Δρ_max = 0.39 e Å⁻³
2500 reflections	Δρ_min = −0.38 e Å⁻³
176 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 > 2sigma(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
Cl1	0.54932 (11)	0.44014 (3)	0.87525 (9)	0.0799 (3)
Cl2	0.05955 (13)	0.48298 (5)	0.25003 (14)	0.1281 (5)
O1	0.7384 (2)	0.18458 (7)	0.5396 (2)	0.0666 (4)
O2	0.69942 (18)	0.27650 (6)	0.4919 (2)	0.0552 (4)
H1	0.719 (3)	0.3623 (11)	0.752 (4)	0.069 (7)*
N1	0.7106 (3)	0.36695 (8)	0.6346 (3)	0.0570 (5)
C1	0.7958 (3)	0.23169 (9)	0.5653 (3)	0.0502 (5)
C2	0.9681 (3)	0.25091 (9)	0.6711 (3)	0.0468 (5)
C3	1.1115 (3)	0.22004 (10)	0.7623 (3)	0.0574 (6)
H3	1.1072	0.1812	0.7669	0.069*
C4	1.2615 (3)	0.24907 (13)	0.8465 (3)	0.0685 (7)
H4	1.3608	0.2296	0.9088	0.082*
C5	1.2657 (3)	0.30675 (14)	0.8391 (3)	0.0722 (7)
H5	1.3685	0.3253	0.8971	0.087*
C6	1.1218 (3)	0.33757 (11)	0.7482 (3)	0.0643 (6)
H6	1.1255	0.3764	0.7449	0.077*
C7	0.9719 (3)	0.30836 (9)	0.6624 (3)	0.0497 (5)
C8	0.8012 (3)	0.32888 (9)	0.5450 (3)	0.0506 (5)
H8	0.8241	0.3464	0.4318	0.061*
C9	0.5585 (3)	0.39413 (9)	0.5407 (3)	0.0518 (5)
C10	0.4694 (3)	0.43014 (9)	0.6373 (3)	0.0583 (6)
C11	0.3179 (3)	0.45773 (11)	0.5500 (4)	0.0716 (7)
H11	0.2602	0.4814	0.6177	0.086*
C12	0.2532 (3)	0.44977 (12)	0.3615 (4)	0.0730 (7)
C13	0.3382 (3)	0.41567 (11)	0.2614 (3)	0.0685 (6)
H13	0.2942	0.4110	0.1336	0.082*
C14	0.4896 (3)	0.38808 (10)	0.3495 (3)	0.0597 (6)
H14	0.5468	0.3649	0.2799	0.072*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.1151 (6)	0.0677 (4)	0.0658 (4)	0.0114 (4)	0.0389 (4)	−0.0076 (3)
Cl2	0.0912 (6)	0.1702 (11)	0.1280 (7)	0.0701 (6)	0.0349 (5)	0.0507 (7)
O1	0.0662 (10)	0.0565 (10)	0.0751 (10)	−0.0104 (8)	0.0116 (8)	−0.0096 (8)
O2	0.0437 (8)	0.0569 (9)	0.0613 (8)	0.0026 (7)	0.0036 (6)	−0.0052 (7)
N1	0.0652 (12)	0.0584 (11)	0.0487 (10)	0.0134 (9)	0.0153 (9)	−0.0014 (8)
C1	0.0471 (11)	0.0545 (13)	0.0509 (10)	−0.0004 (10)	0.0147 (9)	−0.0061 (9)
C2	0.0419 (10)	0.0541 (12)	0.0470 (10)	0.0009 (10)	0.0153 (8)	−0.0022 (8)
C3	0.0503 (12)	0.0652 (14)	0.0587 (12)	0.0101 (11)	0.0165 (10)	0.0023 (10)
C4	0.0434 (12)	0.098 (2)	0.0626 (13)	0.0103 (14)	0.0089 (10)	0.0015 (13)
C5	0.0426 (12)	0.103 (2)	0.0696 (14)	−0.0124 (14)	0.0087 (11)	−0.0137 (14)
C6	0.0552 (13)	0.0676 (15)	0.0710 (14)	−0.0150 (12)	0.0160 (11)	−0.0097 (11)
C7	0.0451 (11)	0.0574 (13)	0.0487 (10)	−0.0020 (10)	0.0152 (8)	−0.0032 (9)
C8	0.0511 (12)	0.0495 (12)	0.0527 (11)	0.0022 (10)	0.0147 (9)	−0.0008 (9)
C9	0.0580 (13)	0.0448 (11)	0.0569 (12)	0.0047 (10)	0.0219 (10)	0.0056 (9)
C10	0.0724 (15)	0.0471 (12)	0.0641 (13)	0.0061 (11)	0.0338 (12)	0.0062 (10)
C11	0.0778 (17)	0.0614 (14)	0.0886 (17)	0.0191 (14)	0.0463 (15)	0.0147 (13)
C12	0.0648 (15)	0.0764 (17)	0.0840 (17)	0.0203 (13)	0.0297 (14)	0.0266 (13)
C13	0.0671 (15)	0.0741 (16)	0.0656 (13)	0.0081 (13)	0.0175 (12)	0.0144 (12)
C14	0.0647 (14)	0.0591 (14)	0.0589 (12)	0.0133 (11)	0.0212 (11)	0.0046 (10)

Geometric parameters (Å, º) top

C1—O1	1.212 (3)	C8—O2	1.487 (3)
C1—O2	1.349 (3)	C8—H8	0.9800
C1—C2	1.465 (3)	C9—N1	1.390 (3)
C2—C7	1.377 (3)	C9—C14	1.392 (3)
C2—C3	1.379 (3)	C9—C10	1.392 (3)
C3—C4	1.379 (3)	C10—C11	1.376 (3)
C3—H3	0.9300	C10—Cl1	1.733 (2)
C4—C5	1.382 (4)	C11—C12	1.375 (4)
C4—H4	0.9300	C11—H11	0.9300
C5—C6	1.381 (4)	C12—C13	1.362 (4)
C5—H5	0.9300	C12—Cl2	1.737 (3)
C6—C7	1.384 (3)	C13—C14	1.378 (3)
C6—H6	0.9300	C13—H13	0.9300
C7—C8	1.494 (3)	C14—H14	0.9300
C8—N1	1.400 (3)	N1—H1	0.86 (3)

O1—C1—O2	121.7 (2)	O2—C8—H8	108.9
O1—C1—C2	129.5 (2)	C7—C8—H8	108.9
O2—C1—C2	108.85 (18)	N1—C9—C14	123.02 (19)
C7—C2—C3	122.3 (2)	N1—C9—C10	120.1 (2)
C7—C2—C1	108.35 (18)	C14—C9—C10	116.9 (2)
C3—C2—C1	129.3 (2)	C11—C10—C9	122.0 (2)
C4—C3—C2	117.3 (2)	C11—C10—Cl1	118.71 (17)
C4—C3—H3	121.4	C9—C10—Cl1	119.26 (18)
C2—C3—H3	121.4	C12—C11—C10	119.0 (2)
C3—C4—C5	120.7 (2)	C12—C11—H11	120.5
C3—C4—H4	119.6	C10—C11—H11	120.5
C5—C4—H4	119.6	C13—C12—C11	120.7 (2)
C6—C5—C4	121.9 (2)	C13—C12—Cl2	119.6 (2)
C6—C5—H5	119.1	C11—C12—Cl2	119.7 (2)
C4—C5—H5	119.1	C12—C13—C14	120.0 (2)
C5—C6—C7	117.3 (2)	C12—C13—H13	120.0
C5—C6—H6	121.3	C14—C13—H13	120.0
C7—C6—H6	121.3	C13—C14—C9	121.3 (2)
C2—C7—C6	120.5 (2)	C13—C14—H14	119.3
C2—C7—C8	109.26 (18)	C9—C14—H14	119.3
C6—C7—C8	130.2 (2)	C9—N1—C8	122.17 (18)
N1—C8—O2	112.22 (16)	C9—N1—H1	115.0 (17)
N1—C8—C7	114.69 (17)	C8—N1—H1	117.1 (17)
O2—C8—C7	103.07 (16)	C1—O2—C8	110.45 (15)
N1—C8—H8	108.9

O1—C1—C2—C7	−179.3 (2)	C14—C9—C10—C11	1.4 (3)
O2—C1—C2—C7	1.0 (2)	N1—C9—C10—Cl1	−0.5 (3)
O1—C1—C2—C3	2.9 (3)	C14—C9—C10—Cl1	−179.37 (17)
O2—C1—C2—C3	−176.77 (17)	C9—C10—C11—C12	−0.4 (4)
C7—C2—C3—C4	0.2 (3)	Cl1—C10—C11—C12	−179.66 (19)
C1—C2—C3—C4	177.70 (18)	C10—C11—C12—C13	−0.8 (4)
C2—C3—C4—C5	0.2 (3)	C10—C11—C12—Cl2	178.56 (19)
C3—C4—C5—C6	0.0 (4)	C11—C12—C13—C14	0.9 (4)
C4—C5—C6—C7	−0.5 (3)	Cl2—C12—C13—C14	−178.4 (2)
C3—C2—C7—C6	−0.8 (3)	C12—C13—C14—C9	0.1 (4)
C1—C2—C7—C6	−178.75 (17)	N1—C9—C14—C13	179.9 (2)
C3—C2—C7—C8	176.66 (16)	C10—C9—C14—C13	−1.2 (3)
C1—C2—C7—C8	−1.3 (2)	C14—C9—N1—C8	−3.5 (3)
C5—C6—C7—C2	0.9 (3)	C10—C9—N1—C8	177.7 (2)
C5—C6—C7—C8	−175.9 (2)	O2—C8—N1—C9	−69.0 (2)
C2—C7—C8—N1	123.40 (19)	C7—C8—N1—C9	173.83 (19)
C6—C7—C8—N1	−59.5 (3)	O1—C1—O2—C8	179.98 (18)
C2—C7—C8—O2	1.11 (19)	C2—C1—O2—C8	−0.3 (2)
C6—C7—C8—O2	178.20 (19)	N1—C8—O2—C1	−124.39 (18)
N1—C9—C10—C11	−179.7 (2)	C7—C8—O2—C1	−0.46 (19)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1ⁱ	0.86 (3)	2.36 (3)	3.176 (2)	159 (2)
C4—H4···O2ⁱⁱ	0.93	2.57	3.387 (3)	147

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

Experimental details

Crystal data
Chemical formula	C₁₄H₉Cl₂NO₂
M_r	294.12
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	296
a, b, c (Å)	7.7647 (4), 23.9293 (12), 7.3261 (4)
β (°)	102.768 (5)
V (Å³)	1327.56 (12)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.48
Crystal size (mm)	0.62 × 0.40 × 0.29

Data collection
Diffractometer	Stoe IPDS II diffractometer
Absorption correction	Integration (X-RED32; Stoe & Cie, 2002)
T_min, T_max	0.486, 0.854
No. of measured, independent and observed [I > 2σ(I)] reflections	7695, 2500, 1860
R_int	0.114
(sin θ/λ)_max (Å⁻¹)	0.609

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.048, 0.113, 1.03
No. of reflections	2500
No. of parameters	176
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.39, −0.38

Computer programs: X-AREA (Stoe & Cie, 2002), X-RED32 (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1ⁱ	0.86 (3)	2.36 (3)	3.176 (2)	159 (2)
C4—H4···O2ⁱⁱ	0.93	2.57	3.387 (3)	147.1

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

Footnotes

†3-Substituted phthalides. Part XXXV.

Acknowledgements

The authors acknowledge the Faculty of Arts and Sciences, Ondokuz Mayıs University, Turkey, for the use of the Stoe IPDSII diffractometer (purchased under grant F.279 of the University Research Fund).

References

Aoki, K., Furusho, T., Kimura, T., Satake, K. & Funayama, S. (1973). Jpn Patent No. 7 324 724. Google Scholar
Aoki, K., Furusho, T., Kimura, T., Satake, K. & Funayama, S. (1974). Chem. Abstr. 80, 129246. Google Scholar
Bellasio, E. (1974). German Patent No. 2 422 193. Google Scholar
Bellasio, E. (1975). Chem. Abstr. 83, 9788. Google Scholar
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Büyükgüngör, O. & Odabaşoğlu, M. (2006). Acta Cryst. E62, o2003–o2004. Web of Science CSD CrossRef IUCr Journals Google Scholar
Etter, M. C. (1990). Acc. Chem. Res. 23, 120–126. CrossRef CAS Web of Science Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Odabaşoğlu, M. & Büyükgüngör, O. (2006). Acta Cryst. E62, o1879–o1881. Web of Science CSD CrossRef IUCr Journals Google Scholar
Roy, H. N. & Sarkar, M. S. (2005). Synth. Commun. 35, 2177–2181. Web of Science CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Stoe & Cie (2002). X-AREA and X-RED32 . Stoe & Cie, Darmstadt, Germany. Google Scholar
Tsi, D. & Tan, B. K. H. (1997). Phytother. Res. 11, 576–582. CrossRef CAS Google Scholar