(2E,4E)-1-(2-Hy­droxy­phen­yl)-5-phenyl­penta-2,4-dien-1-one

Silva, W.A.; Gatto, C.C.; Oliveira, G.R.

doi:10.1107/S160053681103025X

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 67| Part 9| September 2011| Page o2210

doi:10.1107/S160053681103025X

Open

access

(2E,4E)-1-(2-Hydroxyphenyl)-5-phenylpenta-2,4-dien-1-one

W. A. Silva,^a ^* C. C. Gatto ^a and G. R. Oliveira ^b

^aInstituto de Química – IQ, Universidade de Brasília – UnB, Campus Universitário Darcy Ribeiro, Caixa postal 04478, Asa Norte Brasília DF, CEP 70904-970, Brazil, and ^bInstituto de Química – IQ, Universidade Federal de Goiás, CP 131, Campus Samambaia, Goiânia GO, CEP 74001-970, Brazil
^*Correspondence e-mail: wender@unb.br

(Received 28 June 2011; accepted 26 July 2011; online 2 August 2011)

In the structure of the title chalcone, C₁₇H₁₄O₂, derived from cinnamaldehyde, the olefine group has a trans configuration. The molecular conformation is stabilized by an intramolecular O—H⋯O hydrogen-bond interaction with graph-set motif S(6).

Related literature

For the preparation, see: Lawrence et al. (2001 ). For related structures, see: Patil et al. (2007 ); Zhao et al. (2007 ). For standard bond lengths, see: Allen (2002 ). For hydrogen-bond motifs, see: Bernstein et al. (1995 ). For related activity and structures, see: Dyrager et al. (2011 ); Jasinski et al. (2009 ); Ruan et al. (2011 ); Vencato et al. (2006 ).

Experimental

Crystal data

C₁₇H₁₄O₂
M_r = 250.28
Orthorhombic, P b c a
a = 10.9068 (3) Å
b = 7.9851 (2) Å
c = 30.2131 (7) Å
V = 2631.32 (12) Å³
Z = 8
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 296 K
0.39 × 0.17 × 0.09 mm

Data collection

Bruker X8 SMART APEXII diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ) T_min = 0.92, T_max = 0.99
18214 measured reflections
2691 independent reflections
1479 reflections with I > 2σ(I)
R_int = 0.059

Refinement

R[F² > 2σ(F²)] = 0.050
wR(F²) = 0.134
S = 1.01
2691 reflections
174 parameters
H-atom parameters constrained
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O2	0.82	1.81	2.5317 (19)	146

Data collection: APEX2 (Bruker, 2009 ); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; 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: publCIF (Westrip, 2010).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681103025X/bx2361sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053681103025X/bx2361Isup2.hkl

Supporting information file. DOI: 10.1107/S160053681103025X/bx2361Isup3.cml

checkCIF report

Comment top

A large number of chalcones showed significant activity against many diseases. Some results from our laboratory showed that the synthesis of analogues of chalcones derived from cinnamaldehyde was often accompanied by increased in vitro bioactivity. However, the synthesis and analysis cytotoxic of these analogs of chalcones appears to be a largely unexplored field. With that, needs to make an accurate study of this new class of compounds in order to improve their structure-activity relationships.

The configuration of the olefinic group is trans, this was caractherized for 1HNMR where was showed the coupling J trans is around 15 Hz [C8—C9—C10—C11]. The presence of α-β-unsaturated ketone is indicated by the short O2–C11 and C9–C10 bond lengths of 1.245 (3) and 1.334 (3) Å, respectively, and the O2–C11–C10 and C9–C10–C11 bond angles of 118.8 (2)° and 121.8 (2)°, respectively. The bond distances are of normal values and are comparable with those found in related structures [Zhao et al. (2007); Patil et al. (2007)]. The molecular conformation is stabilized by one intramolecular O—H···O hydrogen-bond interaction with set graph motif S(6), (Bernstein et al., 1995) [O1···O2 2.5285 (19) Å, O1–H1···O2 146.4°] (Fig. 2).

Related literature top

For the preparation, see: Lawrence et al. (2001). For related structures, see: Patil et al. (2007); Zhao et al. (2007). For standard bond lengths, see: Allen (2002). For hydrogen-bond motifs, see: Bernstein et al. (1995). For related activity and structures, see: Dyrager et al. (2011); Jasinski et al. (2009); Ruan et al. (2011); Vencato et al. (2006).

Experimental top

Compound was obtained by the aldol condensation of cinnamaldehyde, and 2-hidroxyacetophenone, using a method described previously [Lawrence et al. 2001]. Crystals were obtained from an EtOH solution (m.p. 428 K). Yield = 80% 1H NMR: δ 6.92 (ddd, J = 7.8, 7.6 and 1.1 Hz, 1 H, 16-H), 7.01 (dd, J = 8.1 and 1.1 Hz, 1 H, 14- H), 7.05–7.07 (m, 2 H, 8, 7-H), 7.22 (d, J = 14.7 Hz, 1 H, 10-H), 7.34–7.42 (m, 3 H, 3,4,5-H), 7.49 (ddd, J = 8.1, 7.6 and 1.4 Hz, 1 H, 15-H), 7.52 (dd, J = 7.8 and 1.7 Hz, 2 H, 2,6-H), 7.67–7.76 (m, 1 H, 9-H), 7.85 (dd, J = 7.8 and 1.4 Hz, 1 H, 17-H), 12.88 (s, 1 H, OH). 13 C NMR: δ = 118.6 (C-14), 118.8 (C-16), 120.0 (C-12), 123.5 (C-10), 126.7 (C-8), 127.4 (C-2,6), 128.9 (C-3,5), 129.4 (C-4), 129.5 (C-17), 135.9 (C-1), 136.2 (C-15), 142.9 (C-7), 145.4 (C-9), 163.5 (C-13), 194.0 (C11).

Computing details top

Data collection: SAINT (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); 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: publCIF (Westrip, 2010).

Figures top

Fig. 1. The molecular structure of showing the atomic labelling scheme. The anisotropic displacement parameters are at the 50% level. The dashed line indicates an intramolecular hydrogen bond, O1—H1···O2.

(2E,4E)-1-(2-Hydroxyphenyl)-5-phenylpenta-2,4-dien-1-one top

Crystal data top

C₁₇H₁₄O₂	D_x = 1.264 Mg m⁻³
M_r = 250.28	Melting point: 428 K
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
a = 10.9068 (3) Å	Cell parameters from 1573 reflections
b = 7.9851 (2) Å	θ = 2.7–19.5°
c = 30.2131 (7) Å	µ = 0.08 mm⁻¹
V = 2631.32 (12) Å³	T = 296 K
Z = 8	Block, yellow
F(000) = 1056	0.39 × 0.17 × 0.09 mm

Data collection top

Bruker X8 SMART APEXII diffractometer	2691 independent reflections
Graphite monochromator	1479 reflections with I > 2σ(I)
Detector resolution: 8.3333 pixels mm^-1	R_int = 0.059
ϕ and ω scans	θ_max = 26.4°, θ_min = 1.4°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −13→11
T_min = 0.92, T_max = 0.99	k = −9→9
18214 measured reflections	l = −36→37

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)] = 0.050	H-atom parameters constrained
wR(F²) = 0.134	w = 1/[σ²(F_o²) + (0.0634P)²] where P = (F_o² + 2F_c²)/3
S = 1.01	(Δ/σ)_max = 0.001
2691 reflections	Δρ_max = 0.19 e Å⁻³
174 parameters	Δρ_min = −0.15 e Å⁻³
0 restraints	Extinction correction: SHELXL
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0109 (11)

Crystal data top

C₁₇H₁₄O₂	V = 2631.32 (12) Å³
M_r = 250.28	Z = 8
Orthorhombic, Pbca	Mo Kα radiation
a = 10.9068 (3) Å	µ = 0.08 mm⁻¹
b = 7.9851 (2) Å	T = 296 K
c = 30.2131 (7) Å	0.39 × 0.17 × 0.09 mm

Data collection top

Bruker X8 SMART APEXII diffractometer	2691 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2008)	1479 reflections with I > 2σ(I)
T_min = 0.92, T_max = 0.99	R_int = 0.059
18214 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.050	0 restraints
wR(F²) = 0.134	H-atom parameters constrained
S = 1.01	Δρ_max = 0.19 e Å⁻³
2691 reflections	Δρ_min = −0.15 e Å⁻³
174 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
O2	0.09900 (13)	0.62840 (18)	1.00369 (4)	0.0625 (4)
O1	0.07689 (13)	0.4619 (2)	1.07455 (5)	0.0652 (5)
H1	0.0543	0.5068	1.0515	0.098*
C12	0.27179 (18)	0.5570 (2)	1.04643 (6)	0.0443 (5)
C13	0.19982 (19)	0.4740 (2)	1.07803 (6)	0.0488 (5)
C11	0.21235 (18)	0.6346 (2)	1.00794 (6)	0.0472 (5)
C9	0.23958 (18)	0.7440 (2)	0.93309 (6)	0.0511 (5)
H9	0.1581	0.7152	0.9281	0.061*
C1	0.33154 (19)	0.8908 (3)	0.81740 (6)	0.0532 (5)
C10	0.28508 (18)	0.7155 (2)	0.97335 (6)	0.0515 (5)
H10	0.3651	0.748	0.9796	0.062*
C17	0.39835 (19)	0.5612 (3)	1.05313 (7)	0.0567 (6)
H17	0.4476	0.6164	1.0327	0.068*
C8	0.30670 (19)	0.8155 (2)	0.89703 (6)	0.0535 (5)
H8	0.3844	0.8579	0.903	0.064*
C7	0.26596 (19)	0.8255 (2)	0.85581 (7)	0.0554 (6)
H7	0.1868	0.7866	0.8508	0.066*
C6	0.4439 (2)	0.9703 (3)	0.82097 (7)	0.0620 (6)
H6	0.4796	0.9844	0.8487	0.074*
C5	0.5037 (2)	1.0290 (3)	0.78378 (8)	0.0762 (7)
H5	0.5794	1.0815	0.7866	0.091*
C15	0.3789 (2)	0.4036 (3)	1.11921 (7)	0.0686 (6)
H15	0.4151	0.3511	1.1434	0.082*
C16	0.4517 (2)	0.4863 (3)	1.08888 (7)	0.0671 (6)
H16	0.5362	0.491	1.0928	0.081*
C14	0.2542 (2)	0.3976 (3)	1.11417 (7)	0.0627 (6)
H14	0.2062	0.3423	1.135	0.075*
C2	0.2808 (2)	0.8734 (3)	0.77533 (7)	0.0663 (7)
H2	0.2052	0.8209	0.7721	0.08*
C3	0.3414 (3)	0.9331 (3)	0.73832 (7)	0.0791 (8)
H3	0.3065	0.9205	0.7104	0.095*
C4	0.4522 (3)	1.0105 (4)	0.74271 (8)	0.0822 (8)
H4	0.4929	1.0507	0.7178	0.099*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O2	0.0432 (9)	0.0774 (10)	0.0669 (10)	−0.0019 (7)	−0.0019 (7)	0.0144 (7)
O1	0.0552 (10)	0.0791 (11)	0.0615 (10)	−0.0017 (8)	0.0075 (7)	0.0119 (8)
C12	0.0438 (13)	0.0442 (11)	0.0450 (11)	0.0031 (9)	0.0010 (9)	−0.0063 (9)
C13	0.0491 (13)	0.0487 (11)	0.0485 (11)	0.0033 (10)	0.0014 (10)	−0.0078 (9)
C11	0.0418 (12)	0.0468 (11)	0.0529 (12)	−0.0010 (9)	0.0037 (10)	−0.0051 (9)
C9	0.0454 (13)	0.0494 (12)	0.0585 (13)	0.0008 (10)	0.0042 (10)	−0.0005 (10)
C1	0.0542 (15)	0.0540 (12)	0.0515 (13)	0.0060 (11)	0.0009 (10)	0.0018 (9)
C10	0.0447 (13)	0.0557 (12)	0.0540 (12)	−0.0048 (10)	−0.0008 (10)	−0.0004 (10)
C17	0.0505 (14)	0.0619 (14)	0.0577 (13)	0.0023 (10)	−0.0012 (11)	−0.0059 (10)
C8	0.0468 (12)	0.0561 (12)	0.0577 (13)	−0.0039 (10)	0.0033 (10)	0.0043 (10)
C7	0.0499 (13)	0.0580 (13)	0.0583 (13)	−0.0028 (10)	−0.0025 (11)	0.0024 (10)
C6	0.0575 (15)	0.0729 (15)	0.0555 (14)	−0.0001 (12)	0.0010 (11)	0.0080 (11)
C5	0.0616 (16)	0.0920 (18)	0.0748 (17)	0.0004 (13)	0.0064 (13)	0.0201 (14)
C15	0.0813 (19)	0.0689 (14)	0.0555 (14)	0.0150 (13)	−0.0163 (13)	−0.0059 (12)
C16	0.0564 (15)	0.0764 (16)	0.0684 (16)	0.0061 (12)	−0.0148 (12)	−0.0087 (13)
C14	0.0792 (17)	0.0614 (14)	0.0476 (12)	0.0033 (12)	0.0012 (12)	−0.0001 (10)
C2	0.0660 (16)	0.0763 (16)	0.0566 (14)	0.0051 (12)	−0.0074 (12)	0.0013 (11)
C3	0.086 (2)	0.101 (2)	0.0504 (14)	0.0173 (16)	−0.0046 (13)	0.0067 (13)
C4	0.0790 (19)	0.107 (2)	0.0610 (17)	0.0177 (16)	0.0127 (14)	0.0238 (14)

Geometric parameters (Å, º) top

O2—C11	1.244 (2)	C8—C7	1.324 (3)
O1—C13	1.348 (2)	C8—H8	0.93
O1—H1	0.82	C7—H7	0.93
C12—C17	1.395 (3)	C6—C5	1.381 (3)
C12—C13	1.402 (3)	C6—H6	0.93
C12—C11	1.469 (3)	C5—C4	1.370 (3)
C13—C14	1.384 (3)	C5—H5	0.93
C11—C10	1.463 (3)	C15—C14	1.369 (3)
C9—C10	1.333 (2)	C15—C16	1.381 (3)
C9—C8	1.431 (3)	C15—H15	0.93
C9—H9	0.93	C16—H16	0.93
C1—C6	1.385 (3)	C14—H14	0.93
C1—C2	1.393 (3)	C2—C3	1.383 (3)
C1—C7	1.460 (3)	C2—H2	0.93
C10—H10	0.93	C3—C4	1.364 (3)
C17—C16	1.365 (3)	C3—H3	0.93
C17—H17	0.93	C4—H4	0.93

C13—O1—H1	109.5	C8—C7—H7	116.4
C17—C12—C13	117.80 (18)	C1—C7—H7	116.4
C17—C12—C11	122.77 (18)	C5—C6—C1	120.6 (2)
C13—C12—C11	119.44 (18)	C5—C6—H6	119.7
O1—C13—C14	117.13 (19)	C1—C6—H6	119.7
O1—C13—C12	122.51 (18)	C4—C5—C6	120.5 (2)
C14—C13—C12	120.4 (2)	C4—C5—H5	119.7
O2—C11—C10	118.87 (17)	C6—C5—H5	119.7
O2—C11—C12	120.23 (17)	C14—C15—C16	120.9 (2)
C10—C11—C12	120.87 (17)	C14—C15—H15	119.5
C10—C9—C8	124.9 (2)	C16—C15—H15	119.5
C10—C9—H9	117.6	C17—C16—C15	119.3 (2)
C8—C9—H9	117.6	C17—C16—H16	120.3
C6—C1—C2	117.93 (19)	C15—C16—H16	120.3
C6—C1—C7	122.38 (18)	C15—C14—C13	119.9 (2)
C2—C1—C7	119.7 (2)	C15—C14—H14	120.1
C9—C10—C11	121.70 (19)	C13—C14—H14	120.1
C9—C10—H10	119.2	C3—C2—C1	120.9 (2)
C11—C10—H10	119.2	C3—C2—H2	119.5
C16—C17—C12	121.7 (2)	C1—C2—H2	119.5
C16—C17—H17	119.1	C4—C3—C2	120.0 (2)
C12—C17—H17	119.1	C4—C3—H3	120.0
C7—C8—C9	124.6 (2)	C2—C3—H3	120.0
C7—C8—H8	117.7	C3—C4—C5	120.0 (2)
C9—C8—H8	117.7	C3—C4—H4	120.0
C8—C7—C1	127.2 (2)	C5—C4—H4	120.0

C17—C12—C13—O1	−179.60 (17)	C6—C1—C7—C8	−7.7 (3)
C11—C12—C13—O1	0.2 (3)	C2—C1—C7—C8	172.1 (2)
C17—C12—C13—C14	−0.8 (3)	C2—C1—C6—C5	−0.5 (3)
C11—C12—C13—C14	178.95 (17)	C7—C1—C6—C5	179.4 (2)
C17—C12—C11—O2	−179.47 (18)	C1—C6—C5—C4	0.5 (4)
C13—C12—C11—O2	0.8 (3)	C12—C17—C16—C15	0.3 (3)
C17—C12—C11—C10	2.5 (3)	C14—C15—C16—C17	−0.9 (3)
C13—C12—C11—C10	−177.20 (17)	C16—C15—C14—C13	0.6 (3)
C8—C9—C10—C11	−177.06 (18)	O1—C13—C14—C15	179.10 (18)
O2—C11—C10—C9	−17.4 (3)	C12—C13—C14—C15	0.2 (3)
C12—C11—C10—C9	160.63 (18)	C6—C1—C2—C3	0.3 (3)
C13—C12—C17—C16	0.5 (3)	C7—C1—C2—C3	−179.6 (2)
C11—C12—C17—C16	−179.20 (18)	C1—C2—C3—C4	−0.1 (4)
C10—C9—C8—C7	171.7 (2)	C2—C3—C4—C5	0.0 (4)
C9—C8—C7—C1	−177.45 (19)	C6—C5—C4—C3	−0.2 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2	0.82	1.81	2.5317 (19)	146

Experimental details

Crystal data
Chemical formula	C₁₇H₁₄O₂
M_r	250.28
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	296
a, b, c (Å)	10.9068 (3), 7.9851 (2), 30.2131 (7)
V (Å³)	2631.32 (12)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.39 × 0.17 × 0.09

Data collection
Diffractometer	Bruker X8 SMART APEXII diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2008)
T_min, T_max	0.92, 0.99
No. of measured, independent and observed [I > 2σ(I)] reflections	18214, 2691, 1479
R_int	0.059
(sin θ/λ)_max (Å⁻¹)	0.626

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.050, 0.134, 1.01
No. of reflections	2691
No. of parameters	174
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.19, −0.15

Computer programs: SAINT (Bruker, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2	0.82	1.81	2.5317 (19)	146.3

Acknowledgements

The authors gratefully acknowledge support from the CNPq, FINEP-CT INFRA No. 0970/01 and the Instituto de Química - UnB.

References

Allen, F. H. (2002). Acta Cryst. B58, 380–388. Web of Science CrossRef CAS IUCr Journals 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
Bruker (2008). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Dyrager, C., Wickström, M., Fridén-Saxin, M., Friberg, A., Dahlén, K., Wallén, E. A. A., Gullbo, J., Grotli, M. & Luthman, K. (2011). Bioorg. Med. Chem. 19, 2659–2665. CrossRef CAS Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Jasinski, J. P., Butcher, R. J., Mayekar, A. N., Yathirajan, H. S. & Narayana, B. (2009). J. Chem. Crystallogr. 39, 157–162. Web of Science CSD CrossRef CAS Google Scholar
Lawrence, N. J., Rennison, D., McGown, A. T., Ducki, S., Gul, L. A., Hadfield, J. A. & Khan, N. (2001). J. Comb. Chem. 3, 421–426. Web of Science CrossRef PubMed CAS Google Scholar
Patil, P. S., Teh, J. B.-J., Fun, H.-K., Razak, I. A. & Dharmaprakash, S. M. (2007). Acta Cryst. E63, o2122–o2123. Web of Science CSD CrossRef IUCr Journals Google Scholar
Ruan, B., Lu, X., Tang, J., Wei, Y., Wang, X., Zhang, Y., Wang, L. & Zhu, H. (2011). Bioorg. Med. Chem. 19, 2688–2695. CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Vencato, I., Andrade, C. K. Z., Silva, W. A. & Lariucci, C. (2006). Acta Cryst. E62, o1033–o1035. CSD CrossRef IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
Zhao, B., Rong, Y.-Z. & Huang, W. (2007). Acta Cryst. E63, o2971. Web of Science CSD CrossRef IUCr Journals Google Scholar