4-Chloro-2-((E)-{3-[1-(hydroxy­imino)eth­yl]phen­yl}imino­meth­yl)phenol

Xu, L.; Wu, L.

doi:10.1107/S1600536809045942

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 65| Part 12| December 2009| Page o3021

doi:10.1107/S1600536809045942

Open

access

4-Chloro-2-((E)-{3-[1-(hydroxyimino)ethyl]phenyl}iminomethyl)phenol

Li Xu ^a ^* and Lei Wu ^a

^aSchool of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, People's Republic of China
^*Correspondence e-mail: xuli@mail.lzjtu.cn

(Received 15 October 2009; accepted 2 November 2009; online 7 November 2009)

The title compound, C₁₅H₁₃ClN₂O₂, adopts an E conformation with respect to the azomethine C=N bond. The aniline and phenol rings are almost coplanar, making a dihedral angle of 3.33 (2)°. In the crystal, the molecules lie about inversion centers, forming dimers that are connected by intermolecular O—H⋯N hydrogen bonds, resulting in six-membered rings with graph-set motif R₂²(6). In addition, there is a strong intermolecular O—H⋯N hydrogen-bonding interaction, resulting in an S(6) ring motif. Weak π–π interactions between the benzene rings [centroid–centroid distance = 3.809 (1) Å] further stabilize the crystal structure.

Related literature

For background to Schiff bases, see: Dong et al. (2007 , 2008 , 2009 ); Eltayeb et al. (2008 ). For related crystal strcutures, see: Butcher et al. (2005 ); Golovnia et al. (2009 ); Xu et al. (2008 ); Rafiq et al. (2008 ); Zhao et al. (2009 ).

Experimental

Crystal data

C₁₅H₁₃ClN₂O₂
M_r = 288.72
Monoclinic, P 2₁ /c
a = 16.7139 (16) Å
b = 5.9983 (6) Å
c = 13.3902 (11) Å
β = 96.328 (2)°
V = 1334.3 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.29 mm⁻¹
T = 298 K
0.40 × 0.12 × 0.07 mm

Data collection

Siemens SMART 1000 CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.893, T_max = 0.980
6410 measured reflections
2349 independent reflections
1398 reflections with I > 2σ(I)
R_int = 0.053

Refinement

R[F² > 2σ(F²)] = 0.044
wR(F²) = 0.092
S = 1.04
2349 reflections
182 parameters
H-atom parameters constrained
Δρ_max = 0.17 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯N2	0.82	1.87	2.601 (3)	147
O1—H1⋯N1ⁱ	0.82	2.06	2.789 (3)	149
Symmetry code: (i) -x, -y+3, -z.

Data collection: SMART (Siemens, 1996 ); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809045942/pv2220sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809045942/pv2220Isup2.hkl

checkCIF report

Comment top

Schiff base ligands have numerous applications in chemistry, biology, physics and advanced materials and catalysis (Dong et al., 2007; Dong et al., 2008; Eltayeb et al., 2008). The pressence of Schiff base functional group together with oxime (–C═N—OH) may result in significant increase of chelating efficiency and ability to form polynuclear complexes (Golovnia et al., 2009; Dong et al., 2009; Xu et al., 2008). Owing to the importance of oxime-type compounds, we report in this article the synthesis and crystal structure of the title compound, (I), which contains both the functional groups.

In the structure of the title compound (Fig. 1), the bond lengths and bond angles are in normal ranges and agree well with the coresponding bond lengths and angles reported for the crystal structures related to the title compound, e.g., (Butcher et al., 2005; Golovnia et al., 2009; Xu et al., 2008; Rafiq et al., 2008; Zhao et al., 2009). The molecule of (I) adopts an E conformation with respect to the azomethine C═N bond. The aniline (C3—C8) and phenol rings (C10—C15) are almost coplanar with each other, making a dihedral angle of 3.33 (2)°; the torsion angles O1—N1—C2—C3 and C5—N2—C9—C10 are 178.4 (2) and -178.9 (2)°, respectively. The molecules of (I) lie about inversion centers forming dimers that are connected by intermolecular hydrogen bonds of the type O—H···N resulting in six-membered rings which can be described in graph-set notation as R₂²(6) motif. In addition, there is a strong intermolecular hydrogen bonding interaction of the type O—H···N resulting in an S(6) ring motif (Table 1). Moreover, weak π–π interactions between the benzene rings (centroid-centroid distance = 3.809 (1) Å) further stabilize the crystal structure (Fig. 2).

Related literature top

For background to Schiff bases, see: Dong et al. (2007, 2008, 2009); Eltayeb et al. (2008). For related crystal strcutures, see: Butcher et al. (2005); Golovnia et al. (2009); Xu et al. (2008); Rafiq et al. (2008); Zhao et al. (2009).

Experimental top

To an ethanol solution (5 ml) of 3-aminophenylethanone oxime (150.2 mg, 1.00 mmol) was added dropwise an ethanol solution (5 ml) of 5-chlorinebenzaldehyde (156.8 mg, 1.00 mmol). Immediately, a yellow precipitate was obtained. The mixture solution was stirred at 328–333 K for 5 h. After cooling to room temperature, the precipitate was filtered off, dried in vacuo and purified by recrystallization from ethanol to a solid material. Yellow needle-like single crystals suitable for X-ray diffraction studies were obtained by slow evaporation from a solution of dichloromethane at room temperature in about two weeks.

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT (Siemens, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The molecule structure of the title compound with atomic numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. Part of the supramolecular structure of the title compound, showing a dimer formed by intermolecular O—H···O and O—H···N hydrogen bonds as well as π–π stacking interactions. H atoms not involved in hydrogen bonding have been omitted for clarity.

4-Chloro-2-((E)-{3-[1-(hydroxyimino)ethyl]phenyl}iminomethyl)phenol top

Crystal data top

C₁₅H₁₃ClN₂O₂	F(000) = 600
M_r = 288.72	D_x = 1.437 Mg m⁻³
Monoclinic, P2₁/c	Melting point = 454–456 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 16.7139 (16) Å	Cell parameters from 1148 reflections
b = 5.9983 (6) Å	θ = 3.1–25.3°
c = 13.3902 (11) Å	µ = 0.29 mm⁻¹
β = 96.328 (2)°	T = 298 K
V = 1334.3 (2) Å³	Needle, yellow
Z = 4	0.40 × 0.12 × 0.07 mm

Data collection top

Siemens SMART 1000 CCD area-detector diffractometer	2349 independent reflections
Radiation source: fine-focus sealed tube	1398 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.053
ϕ and ω scans	θ_max = 25.0°, θ_min = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −18→19
T_min = 0.893, T_max = 0.980	k = −7→7
6410 measured reflections	l = −15→11

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.092	H-atom parameters constrained
S = 1.04	w = 1/[σ²(F_o²) + (0.0246P)²] where P = (F_o² + 2F_c²)/3
2349 reflections	(Δ/σ)_max < 0.001
182 parameters	Δρ_max = 0.17 e Å⁻³
0 restraints	Δρ_min = −0.18 e Å⁻³

Crystal data top

C₁₅H₁₃ClN₂O₂	V = 1334.3 (2) Å³
M_r = 288.72	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 16.7139 (16) Å	µ = 0.29 mm⁻¹
b = 5.9983 (6) Å	T = 298 K
c = 13.3902 (11) Å	0.40 × 0.12 × 0.07 mm
β = 96.328 (2)°

Data collection top

Siemens SMART 1000 CCD area-detector diffractometer	2349 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	1398 reflections with I > 2σ(I)
T_min = 0.893, T_max = 0.980	R_int = 0.053
6410 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.044	0 restraints
wR(F²) = 0.092	H-atom parameters constrained
S = 1.04	Δρ_max = 0.17 e Å⁻³
2349 reflections	Δρ_min = −0.18 e Å⁻³
182 parameters

Special details top

Experimental. m. p. 454–456 K. Anal. Calc.: C, 62.40; H, 4.54; N, 9.70. Found: C, 62.10; H, 4.59; N, 9.89.

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
Cl1	0.47005 (4)	−0.34472 (13)	0.16802 (5)	0.0679 (3)
N1	0.04965 (12)	1.3024 (4)	−0.03178 (14)	0.0492 (6)
N2	0.25468 (11)	0.4873 (4)	0.02923 (14)	0.0459 (5)
O1	0.01107 (10)	1.4271 (3)	−0.11173 (11)	0.0660 (6)
H1	−0.0105	1.5364	−0.0895	0.099*
O2	0.29783 (10)	0.2627 (3)	−0.12216 (12)	0.0714 (6)
H2	0.2760	0.3628	−0.0934	0.107*
C1	0.08207 (16)	1.0646 (5)	−0.16879 (17)	0.0649 (9)
H1A	0.0436	1.1557	−0.2087	0.097*
H1B	0.0670	0.9107	−0.1768	0.097*
H1C	0.1344	1.0862	−0.1903	0.097*
C2	0.08394 (13)	1.1288 (4)	−0.06072 (16)	0.0397 (6)
C3	0.12822 (12)	0.9899 (4)	0.01858 (16)	0.0368 (6)
C4	0.16997 (12)	0.8025 (4)	−0.00603 (17)	0.0414 (6)
H4	0.1693	0.7636	−0.0734	0.050*
C5	0.21285 (13)	0.6705 (4)	0.06599 (18)	0.0403 (6)
C6	0.21285 (14)	0.7264 (5)	0.16624 (18)	0.0512 (7)
H6	0.2406	0.6389	0.2159	0.061*
C7	0.17157 (15)	0.9121 (5)	0.19178 (18)	0.0552 (8)
H7	0.1719	0.9499	0.2592	0.066*
C8	0.12969 (14)	1.0435 (4)	0.11943 (17)	0.0465 (7)
H8	0.1023	1.1688	0.1384	0.056*
C9	0.29415 (13)	0.3476 (4)	0.08762 (19)	0.0462 (7)
H9	0.2948	0.3651	0.1567	0.055*
C10	0.33755 (13)	0.1644 (4)	0.04994 (18)	0.0410 (6)
C11	0.33784 (14)	0.1268 (5)	−0.05337 (19)	0.0491 (7)
C12	0.37878 (14)	−0.0525 (5)	−0.08613 (19)	0.0572 (8)
H12	0.3789	−0.0767	−0.1547	0.069*
C13	0.41961 (14)	−0.1967 (5)	−0.0189 (2)	0.0547 (7)
H13	0.4473	−0.3176	−0.0417	0.066*
C14	0.41926 (13)	−0.1606 (4)	0.08297 (19)	0.0459 (7)
C15	0.37940 (13)	0.0169 (4)	0.11697 (18)	0.0462 (7)
H15	0.3801	0.0399	0.1857	0.055*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.0726 (5)	0.0574 (5)	0.0723 (5)	0.0192 (4)	0.0021 (4)	0.0118 (4)
N1	0.0631 (13)	0.0413 (15)	0.0398 (12)	0.0115 (12)	−0.0090 (11)	0.0044 (11)
N2	0.0427 (12)	0.0397 (15)	0.0543 (13)	0.0036 (11)	0.0008 (10)	0.0030 (11)
O1	0.0957 (14)	0.0518 (14)	0.0464 (11)	0.0267 (11)	−0.0102 (10)	0.0062 (9)
O2	0.0864 (13)	0.0763 (16)	0.0495 (11)	0.0282 (12)	−0.0015 (10)	0.0080 (10)
C1	0.086 (2)	0.070 (2)	0.0373 (15)	0.0267 (17)	0.0000 (15)	0.0016 (14)
C2	0.0442 (14)	0.0391 (17)	0.0347 (14)	0.0009 (13)	−0.0003 (12)	0.0000 (12)
C3	0.0392 (13)	0.0343 (17)	0.0363 (14)	−0.0022 (12)	0.0019 (11)	0.0010 (12)
C4	0.0453 (14)	0.0431 (18)	0.0346 (13)	−0.0041 (13)	−0.0005 (12)	−0.0007 (12)
C5	0.0395 (14)	0.0344 (16)	0.0465 (16)	−0.0016 (12)	0.0023 (12)	0.0040 (13)
C6	0.0591 (16)	0.050 (2)	0.0437 (16)	0.0102 (14)	0.0013 (13)	0.0107 (13)
C7	0.0703 (18)	0.060 (2)	0.0348 (15)	0.0112 (16)	0.0026 (14)	0.0027 (14)
C8	0.0553 (15)	0.0440 (18)	0.0404 (15)	0.0106 (13)	0.0060 (13)	0.0005 (13)
C9	0.0453 (15)	0.0417 (18)	0.0503 (15)	−0.0006 (14)	0.0000 (13)	−0.0003 (13)
C10	0.0378 (13)	0.0352 (16)	0.0495 (16)	−0.0004 (12)	0.0019 (12)	−0.0013 (13)
C11	0.0448 (15)	0.054 (2)	0.0474 (17)	0.0058 (14)	−0.0004 (13)	0.0054 (14)
C12	0.0594 (17)	0.068 (2)	0.0447 (16)	0.0077 (16)	0.0070 (14)	−0.0040 (15)
C13	0.0473 (15)	0.053 (2)	0.0645 (19)	0.0076 (14)	0.0098 (15)	−0.0063 (15)
C14	0.0397 (14)	0.0403 (18)	0.0567 (17)	0.0044 (13)	0.0009 (13)	0.0048 (14)
C15	0.0425 (14)	0.0480 (19)	0.0465 (15)	−0.0007 (13)	−0.0016 (12)	0.0002 (13)

Geometric parameters (Å, º) top

Cl1—C14	1.739 (2)	C5—C6	1.384 (3)
N1—C2	1.269 (3)	C6—C7	1.373 (3)
N1—O1	1.403 (2)	C6—H6	0.9300
N2—C9	1.279 (3)	C7—C8	1.379 (3)
N2—C5	1.419 (3)	C7—H7	0.9300
O1—H1	0.8200	C8—H8	0.9300
O2—C11	1.351 (3)	C9—C10	1.439 (3)
O2—H2	0.8200	C9—H9	0.9300
C1—C2	1.495 (3)	C10—C15	1.393 (3)
C1—H1A	0.9600	C10—C11	1.402 (3)
C1—H1B	0.9600	C11—C12	1.372 (3)
C1—H1C	0.9600	C12—C13	1.375 (3)
C2—C3	1.482 (3)	C12—H12	0.9300
C3—C4	1.382 (3)	C13—C14	1.381 (3)
C3—C8	1.386 (3)	C13—H13	0.9300
C4—C5	1.385 (3)	C14—C15	1.361 (3)
C4—H4	0.9300	C15—H15	0.9300

C2—N1—O1	112.91 (19)	C6—C7—H7	119.4
C9—N2—C5	122.4 (2)	C8—C7—H7	119.4
N1—O1—H1	109.5	C7—C8—C3	120.3 (2)
C11—O2—H2	109.5	C7—C8—H8	119.8
C2—C1—H1A	109.5	C3—C8—H8	119.8
C2—C1—H1B	109.5	N2—C9—C10	122.2 (2)
H1A—C1—H1B	109.5	N2—C9—H9	118.9
C2—C1—H1C	109.5	C10—C9—H9	118.9
H1A—C1—H1C	109.5	C15—C10—C11	118.5 (2)
H1B—C1—H1C	109.5	C15—C10—C9	119.8 (2)
N1—C2—C3	116.7 (2)	C11—C10—C9	121.7 (2)
N1—C2—C1	123.0 (2)	O2—C11—C12	118.8 (2)
C3—C2—C1	120.3 (2)	O2—C11—C10	121.4 (2)
C4—C3—C8	117.8 (2)	C12—C11—C10	119.8 (2)
C4—C3—C2	120.8 (2)	C11—C12—C13	120.8 (2)
C8—C3—C2	121.4 (2)	C11—C12—H12	119.6
C3—C4—C5	122.4 (2)	C13—C12—H12	119.6
C3—C4—H4	118.8	C12—C13—C14	119.5 (3)
C5—C4—H4	118.8	C12—C13—H13	120.3
C6—C5—C4	118.8 (2)	C14—C13—H13	120.3
C6—C5—N2	125.2 (2)	C15—C14—C13	120.6 (2)
C4—C5—N2	116.0 (2)	C15—C14—Cl1	120.0 (2)
C7—C6—C5	119.5 (2)	C13—C14—Cl1	119.5 (2)
C7—C6—H6	120.3	C14—C15—C10	120.7 (2)
C5—C6—H6	120.3	C14—C15—H15	119.6
C6—C7—C8	121.3 (2)	C10—C15—H15	119.6

O1—N1—C2—C3	178.37 (18)	C2—C3—C8—C7	−179.7 (2)
O1—N1—C2—C1	−0.7 (3)	C5—N2—C9—C10	−178.9 (2)
N1—C2—C3—C4	−177.5 (2)	N2—C9—C10—C15	−179.8 (2)
C1—C2—C3—C4	1.6 (3)	N2—C9—C10—C11	−1.0 (4)
N1—C2—C3—C8	2.1 (3)	C15—C10—C11—O2	179.4 (2)
C1—C2—C3—C8	−178.8 (2)	C9—C10—C11—O2	0.6 (4)
C8—C3—C4—C5	−0.5 (3)	C15—C10—C11—C12	0.1 (4)
C2—C3—C4—C5	179.1 (2)	C9—C10—C11—C12	−178.8 (2)
C3—C4—C5—C6	1.0 (3)	O2—C11—C12—C13	−179.3 (2)
C3—C4—C5—N2	−178.2 (2)	C10—C11—C12—C13	0.1 (4)
C9—N2—C5—C6	3.5 (4)	C11—C12—C13—C14	0.1 (4)
C9—N2—C5—C4	−177.4 (2)	C12—C13—C14—C15	−0.5 (4)
C4—C5—C6—C7	−0.9 (4)	C12—C13—C14—Cl1	179.35 (19)
N2—C5—C6—C7	178.2 (2)	C13—C14—C15—C10	0.6 (4)
C5—C6—C7—C8	0.3 (4)	Cl1—C14—C15—C10	−179.18 (17)
C6—C7—C8—C3	0.2 (4)	C11—C10—C15—C14	−0.4 (4)
C4—C3—C8—C7	−0.1 (3)	C9—C10—C15—C14	178.4 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···N2	0.82	1.87	2.601 (3)	147
O1—H1···N1ⁱ	0.82	2.06	2.789 (3)	149

Symmetry code: (i) −x, −y+3, −z.

Experimental details

Crystal data
Chemical formula	C₁₅H₁₃ClN₂O₂
M_r	288.72
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	298
a, b, c (Å)	16.7139 (16), 5.9983 (6), 13.3902 (11)
β (°)	96.328 (2)
V (Å³)	1334.3 (2)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.29
Crystal size (mm)	0.40 × 0.12 × 0.07

Data collection
Diffractometer	Siemens SMART 1000 CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.893, 0.980
No. of measured, independent and observed [I > 2σ(I)] reflections	6410, 2349, 1398
R_int	0.053
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.044, 0.092, 1.04
No. of reflections	2349
No. of parameters	182
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.17, −0.18

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···N2	0.82	1.87	2.601 (3)	147
O1—H1···N1ⁱ	0.82	2.06	2.789 (3)	149

Symmetry code: (i) −x, −y+3, −z.

Acknowledgements

This work was supported by the Foundation of the Education Department of Gansu Province (No. 0904–11) and the `Jing Lan' Talent Engineering Funds of Lanzhou Jiaotong University, which are gratefully acknowledged.

References

Butcher, R. J., Bendre, R. S. & Kuwar, A. S. (2005). Acta Cryst. E61, o3511–o3513. Web of Science CSD CrossRef IUCr Journals Google Scholar
Dong, W.-K. & Duan, J.-G. (2008). J. Coord. Chem. 61, 781–788. Web of Science CSD CrossRef CAS Google Scholar
Dong, W.-K., Duan, J.-G. & Liu, G.-L. (2007). Transition Met. Chem. 32, 702–705. Web of Science CSD CrossRef CAS Google Scholar
Dong, W.-K., He, X.-N., Yan, H.-B., Lv, Z.-W., Chen, X., Zhao, C.-Y. & Tang, X.-L. (2009). Polyhedron, 28, 1419–1428. Web of Science CSD CrossRef CAS Google Scholar
Eltayeb, N. E., Teoh, S. G., Chantrapromma, S., Fun, H.-K. & Adnan, R. (2008). Acta Cryst. E64, m570–m571. Web of Science CSD CrossRef IUCr Journals Google Scholar
Golovnia, E., Prisyazhnaya, E. V., Iskenderov, T. S., Haukka, M. & Fritsky, I. O. (2009). Acta Cryst. E65, o2018–o2019. Web of Science CSD CrossRef IUCr Journals Google Scholar
Rafiq, M., Hanif, M., Qadeer, G., Vuoti, S. & Autio, J. (2008). Acta Cryst. E64, o2173. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA. Google Scholar
Xu, S.-Q. & Li, J.-M. (2008). Acta Cryst. E64, o1469. Web of Science CSD CrossRef IUCr Journals Google Scholar
Zhao, L., Dong, W.-K., Wu, J.-C., Sun, Y.-X. & Xu, L. (2009). Acta Cryst. E65, o2462. Web of Science CSD CrossRef IUCr Journals Google Scholar