Methyl 4-(5-meth­oxy-1H-indol-3-yl)benzoate

Wang, C.-P.; Yu, J.-L.; Zhang, Z.-Q.; Yan, J.-B.

doi:10.1107/S1600536811052135

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 68| Part 1| January 2012| Page o133

doi:10.1107/S1600536811052135

Open

access

Methyl 4-(5-methoxy-1H-indol-3-yl)benzoate

Cui-Ping Wang,^a Jiang-Long Yu,^a Zhi-Qiang Zhang ^a ^* and Jing-Bo Yan ^a

^aSchool of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051, People's Republic of China
^*Correspondence e-mail: zhangzhiqiang@ustl.edu.cn

(Received 19 November 2011; accepted 3 December 2011; online 17 December 2011)

In the title compound, C₁₇H₁₅NO₃, the dihedral angle between the benzene ring and the indole ring system is 22.5 (3)°. In the crystal, molecules are linked by N—H⋯π and C—H⋯O interactions.

Related literature

For background to the catalysed arylation of indoles, see: Zhang et al. (2007 ). For reference bond-length data, see: Allen et al. (1987 ).

Experimental

Crystal data

C₁₇H₁₅NO₃
M_r = 281.30
Monoclinic, P 2₁ /c
a = 15.023 (8) Å
b = 5.871 (3) Å
c = 16.867 (9) Å
β = 113.721 (6)°
V = 1361.9 (12) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 113 K
0.20 × 0.16 × 0.14 mm

Data collection

Rigaku Saturn724 CCD diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2007 ) T_min = 0.981, T_max = 0.987
13161 measured reflections
3241 independent reflections
2460 reflections with I > 2σ(I)
R_int = 0.038

Refinement

R[F² > 2σ(F²)] = 0.037
wR(F²) = 0.110
S = 1.06
3241 reflections
196 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

Cg2 is the centroid ofthe C2–C5/C8/C9 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯Cg2ⁱ	0.90 (1)	2.54 (2)	3.295 (2)	142 (1)
C6—H6⋯O1ⁱⁱ	0.95	2.43	3.369 (2)	172
C17—H17B⋯O2ⁱⁱⁱ	0.98	2.60	3.484 (2)	150
Symmetry codes: (i) $[-x+1, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (ii) $[x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]$ ; (iii) x, y+1, z.

Data collection: CrystalClear (Rigaku, 2007); cell refinement: CrystalClear; data reduction: CrystalClear; 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/S1600536811052135/hb6526sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811052135/hb6526Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811052135/hb6526Isup3.cml

checkCIF report

Comment top

In 2007, our group reported direct palladium-catalyzed C-3 arylation of indoles (Zhang et al., 2007). As an extension of this work, we now report the synthesis and crystal structure of the title compound, (I), (Fig. 1).

The dihedral angle between the benzene ring and the indole ring is 22.5 (3)°. All the bond values are within normal ranges (Allen et al., 1987). In the crystal, N—H···π and C—H···O interactions occur (Table 1).

Related literature top

For background to the catalysed arylation of indoles, see: Zhang et al. (2007). For reference bond-length data, see: Allen et al. (1987).

Experimental top

A mixture of 5-methoxy-1H-indole (0.5 mmol), 1-(4-bromophenyl)ethanone (0.6 mmol), potassium carbonate (1.5 mmol) and (^tBu)₂P(OH)]₂PdCl₂ (abbreviated as POPd, 0.025 mmol) was stirred and refluxed in 2 ml of dioxane under nitrogen atmosphere for 24 h. The reaction mixture was allowed to cool to room temperature, quenched with water and extracted with EtOAc. The combined organic layers were washed with brine and dried over MgSO₄, and the solvent was removed under vacuum. The residue was purified by chromatography on silica gel eluting with hexane/EtOAc (5/1 by vol.) to give light yellow power in 54.0%, m.p.123.0–124.8 °C. Colourless prisms of (I) were grown by slow evaporation of a solution in chloroform/ethanol (1:1).

Computing details top

Data collection: CrystalClear (Rigaku, 2007); cell refinement: CrystalClear (Rigaku, 2007); data reduction: CrystalClear (Rigaku, 2007); 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 molecular structure of the title compound, showing 30% probability displacement ellipsoids for the non-hydrogen atoms.

Methyl 4-(5-methoxy-1H-indol-3-yl)benzoate top

Crystal data top

C₁₇H₁₅NO₃	F(000) = 592
M_r = 281.30	D_x = 1.372 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 15.023 (8) Å	Cell parameters from 4649 reflections
b = 5.871 (3) Å	θ = 1.5–27.9°
c = 16.867 (9) Å	µ = 0.10 mm⁻¹
β = 113.721 (6)°	T = 113 K
V = 1361.9 (12) Å³	Prism, colorless
Z = 4	0.20 × 0.16 × 0.14 mm

Data collection top

Rigaku Saturn724 CCD diffractometer	3241 independent reflections
Radiation source: rotating anode	2460 reflections with I > 2σ(I)
Multilayer monochromator	R_int = 0.038
Detector resolution: 14.22 pixels mm^-1	θ_max = 27.9°, θ_min = 1.5°
ω and ϕ scans	h = −19→19
Absorption correction: multi-scan (CrystalClear; Rigaku, 2007)	k = −7→7
T_min = 0.981, T_max = 0.987	l = −22→22
13161 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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.110	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ²(F_o²) + (0.0702P)²] where P = (F_o² + 2F_c²)/3
3241 reflections	(Δ/σ)_max = 0.001
196 parameters	Δρ_max = 0.24 e Å⁻³
1 restraint	Δρ_min = −0.25 e Å⁻³

Crystal data top

C₁₇H₁₅NO₃	V = 1361.9 (12) Å³
M_r = 281.30	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 15.023 (8) Å	µ = 0.10 mm⁻¹
b = 5.871 (3) Å	T = 113 K
c = 16.867 (9) Å	0.20 × 0.16 × 0.14 mm
β = 113.721 (6)°

Data collection top

Rigaku Saturn724 CCD diffractometer	3241 independent reflections
Absorption correction: multi-scan (CrystalClear; Rigaku, 2007)	2460 reflections with I > 2σ(I)
T_min = 0.981, T_max = 0.987	R_int = 0.038
13161 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.037	1 restraint
wR(F²) = 0.110	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	Δρ_max = 0.24 e Å⁻³
3241 reflections	Δρ_min = −0.25 e Å⁻³
196 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
O1	0.65330 (5)	1.06706 (14)	0.57107 (5)	0.0256 (2)
O2	1.06010 (5)	1.07061 (13)	1.21305 (5)	0.0268 (2)
O3	1.03480 (5)	1.38309 (12)	1.12988 (5)	0.0231 (2)
N1	0.57543 (7)	0.50593 (17)	0.79506 (6)	0.0252 (2)
C1	0.72517 (8)	1.2391 (2)	0.60676 (7)	0.0266 (3)
H1A	0.7069	1.3383	0.6445	0.040*
H1B	0.7300	1.3297	0.5598	0.040*
H1C	0.7881	1.1678	0.6405	0.040*
C2	0.63635 (7)	0.92664 (19)	0.62868 (7)	0.0201 (2)
C3	0.56197 (8)	0.76524 (19)	0.59007 (7)	0.0233 (3)
H3	0.5285	0.7610	0.5288	0.028*
C4	0.53738 (7)	0.61387 (19)	0.64008 (7)	0.0232 (3)
H4	0.4883	0.5024	0.6144	0.028*
C5	0.58711 (7)	0.62954 (18)	0.73024 (7)	0.0206 (2)
C6	0.63929 (8)	0.58338 (19)	0.87366 (7)	0.0230 (2)
H6	0.6447	0.5255	0.9280	0.028*
C7	0.69470 (7)	0.75701 (17)	0.86292 (7)	0.0188 (2)
C8	0.66109 (7)	0.79141 (17)	0.77034 (7)	0.0177 (2)
C9	0.68678 (7)	0.94025 (18)	0.71752 (6)	0.0191 (2)
H9	0.7377	1.0478	0.7424	0.023*
C10	0.77498 (7)	0.86947 (18)	0.93408 (7)	0.0182 (2)
C11	0.82087 (7)	0.75877 (18)	1.01399 (7)	0.0204 (2)
H11	0.7983	0.6129	1.0219	0.024*
C12	0.89807 (7)	0.85678 (18)	1.08147 (7)	0.0202 (2)
H12	0.9277	0.7784	1.1350	0.024*
C13	0.93258 (7)	1.06998 (18)	1.07123 (7)	0.0186 (2)
C14	0.88750 (7)	1.18392 (18)	0.99234 (7)	0.0197 (2)
H14	0.9106	1.3292	0.9845	0.024*
C15	0.80911 (7)	1.08586 (18)	0.92535 (7)	0.0199 (2)
H15	0.7780	1.1670	0.8726	0.024*
C16	1.01559 (7)	1.16901 (18)	1.14560 (7)	0.0194 (2)
C17	1.11194 (8)	1.4968 (2)	1.20010 (7)	0.0237 (3)
H17A	1.1040	1.4704	1.2543	0.036*
H17B	1.1092	1.6607	1.1883	0.036*
H17C	1.1749	1.4365	1.2053	0.036*
H1	0.5318 (9)	0.3932 (19)	0.7867 (10)	0.047 (4)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0261 (4)	0.0340 (5)	0.0151 (4)	−0.0048 (3)	0.0069 (3)	0.0006 (3)
O2	0.0269 (4)	0.0248 (4)	0.0210 (4)	0.0003 (3)	0.0017 (3)	0.0020 (3)
O3	0.0247 (4)	0.0209 (4)	0.0202 (4)	−0.0035 (3)	0.0056 (3)	−0.0013 (3)
N1	0.0233 (5)	0.0248 (5)	0.0264 (5)	−0.0070 (4)	0.0090 (4)	−0.0006 (4)
C1	0.0273 (6)	0.0322 (7)	0.0208 (6)	−0.0051 (5)	0.0102 (5)	0.0010 (5)
C2	0.0189 (5)	0.0235 (6)	0.0182 (5)	0.0021 (4)	0.0076 (4)	0.0000 (4)
C3	0.0198 (5)	0.0285 (6)	0.0181 (5)	0.0015 (4)	0.0041 (4)	−0.0046 (4)
C4	0.0188 (5)	0.0235 (6)	0.0247 (6)	−0.0020 (4)	0.0058 (4)	−0.0060 (4)
C5	0.0181 (5)	0.0201 (5)	0.0231 (6)	0.0004 (4)	0.0078 (4)	−0.0013 (4)
C6	0.0227 (5)	0.0248 (6)	0.0215 (5)	−0.0009 (4)	0.0090 (4)	0.0018 (4)
C7	0.0188 (5)	0.0190 (5)	0.0190 (5)	0.0011 (4)	0.0081 (4)	−0.0002 (4)
C8	0.0147 (5)	0.0187 (5)	0.0190 (5)	0.0019 (4)	0.0062 (4)	−0.0012 (4)
C9	0.0162 (5)	0.0220 (5)	0.0176 (5)	−0.0008 (4)	0.0052 (4)	−0.0012 (4)
C10	0.0181 (5)	0.0205 (5)	0.0180 (5)	0.0015 (4)	0.0092 (4)	−0.0014 (4)
C11	0.0227 (5)	0.0174 (5)	0.0216 (5)	−0.0001 (4)	0.0095 (4)	0.0007 (4)
C12	0.0222 (5)	0.0201 (6)	0.0179 (5)	0.0041 (4)	0.0075 (4)	0.0023 (4)
C13	0.0194 (5)	0.0202 (6)	0.0175 (5)	0.0025 (4)	0.0087 (4)	−0.0013 (4)
C14	0.0233 (5)	0.0188 (5)	0.0188 (5)	−0.0007 (4)	0.0102 (4)	−0.0006 (4)
C15	0.0239 (5)	0.0208 (6)	0.0158 (5)	0.0010 (4)	0.0089 (4)	0.0015 (4)
C16	0.0196 (5)	0.0198 (5)	0.0204 (5)	0.0018 (4)	0.0097 (4)	−0.0011 (4)
C17	0.0234 (5)	0.0235 (6)	0.0221 (6)	−0.0035 (4)	0.0069 (4)	−0.0031 (4)

Geometric parameters (Å, º) top

O1—C2	1.3739 (14)	C6—H6	0.9500
O1—C1	1.4232 (14)	C7—C8	1.4491 (16)
O2—C16	1.2095 (13)	C7—C10	1.4718 (15)
O3—C16	1.3397 (14)	C8—C9	1.4082 (15)
O3—C17	1.4449 (13)	C9—H9	0.9500
N1—C6	1.3643 (15)	C10—C15	1.3997 (16)
N1—C5	1.3811 (15)	C10—C11	1.4025 (15)
N1—H1	0.902 (8)	C11—C12	1.3818 (15)
C1—H1A	0.9800	C11—H11	0.9500
C1—H1B	0.9800	C12—C13	1.3919 (16)
C1—H1C	0.9800	C12—H12	0.9500
C2—C9	1.3828 (15)	C13—C14	1.3970 (15)
C2—C3	1.4089 (16)	C13—C16	1.4859 (15)
C3—C4	1.3742 (16)	C14—C15	1.3872 (15)
C3—H3	0.9500	C14—H14	0.9500
C4—C5	1.4020 (17)	C15—H15	0.9500
C4—H4	0.9500	C17—H17A	0.9800
C5—C8	1.4110 (15)	C17—H17B	0.9800
C6—C7	1.3733 (15)	C17—H17C	0.9800

C2—O1—C1	116.85 (9)	C5—C8—C7	106.77 (9)
C16—O3—C17	115.91 (9)	C2—C9—C8	118.67 (10)
C6—N1—C5	109.30 (10)	C2—C9—H9	120.7
C6—N1—H1	125.4 (10)	C8—C9—H9	120.7
C5—N1—H1	125.3 (10)	C15—C10—C11	117.54 (10)
O1—C1—H1A	109.5	C15—C10—C7	122.41 (10)
O1—C1—H1B	109.5	C11—C10—C7	120.04 (10)
H1A—C1—H1B	109.5	C12—C11—C10	121.59 (10)
O1—C1—H1C	109.5	C12—C11—H11	119.2
H1A—C1—H1C	109.5	C10—C11—H11	119.2
H1B—C1—H1C	109.5	C11—C12—C13	120.22 (10)
O1—C2—C9	123.72 (10)	C11—C12—H12	119.9
O1—C2—C3	114.50 (10)	C13—C12—H12	119.9
C9—C2—C3	121.78 (10)	C12—C13—C14	119.12 (10)
C4—C3—C2	120.68 (10)	C12—C13—C16	118.36 (10)
C4—C3—H3	119.7	C14—C13—C16	122.51 (10)
C2—C3—H3	119.7	C15—C14—C13	120.30 (10)
C3—C4—C5	117.76 (10)	C15—C14—H14	119.8
C3—C4—H4	121.1	C13—C14—H14	119.8
C5—C4—H4	121.1	C14—C15—C10	121.18 (10)
N1—C5—C4	129.97 (11)	C14—C15—H15	119.4
N1—C5—C8	107.51 (10)	C10—C15—H15	119.4
C4—C5—C8	122.51 (10)	O2—C16—O3	123.55 (10)
N1—C6—C7	110.23 (10)	O2—C16—C13	124.46 (10)
N1—C6—H6	124.9	O3—C16—C13	111.99 (9)
C7—C6—H6	124.9	O3—C17—H17A	109.5
C6—C7—C8	106.17 (9)	O3—C17—H17B	109.5
C6—C7—C10	124.52 (10)	H17A—C17—H17B	109.5
C8—C7—C10	129.22 (9)	O3—C17—H17C	109.5
C9—C8—C5	118.56 (10)	H17A—C17—H17C	109.5
C9—C8—C7	134.66 (10)	H17B—C17—H17C	109.5

C1—O1—C2—C9	−1.96 (15)	C5—C8—C9—C2	2.07 (14)
C1—O1—C2—C3	177.66 (9)	C7—C8—C9—C2	−178.95 (11)
O1—C2—C3—C4	179.99 (9)	C6—C7—C10—C15	−159.36 (10)
C9—C2—C3—C4	−0.38 (16)	C8—C7—C10—C15	24.50 (16)
C2—C3—C4—C5	1.45 (16)	C6—C7—C10—C11	21.27 (15)
C6—N1—C5—C4	−179.04 (11)	C8—C7—C10—C11	−154.88 (10)
C6—N1—C5—C8	−0.29 (12)	C15—C10—C11—C12	−1.09 (15)
C3—C4—C5—N1	177.83 (10)	C7—C10—C11—C12	178.32 (9)
C3—C4—C5—C8	−0.75 (16)	C10—C11—C12—C13	−0.27 (15)
C5—N1—C6—C7	−0.45 (13)	C11—C12—C13—C14	0.69 (15)
N1—C6—C7—C8	0.98 (12)	C11—C12—C13—C16	179.85 (9)
N1—C6—C7—C10	−175.91 (9)	C12—C13—C14—C15	0.28 (15)
N1—C5—C8—C9	−179.88 (9)	C16—C13—C14—C15	−178.85 (9)
C4—C5—C8—C9	−1.02 (15)	C13—C14—C15—C10	−1.69 (15)
N1—C5—C8—C7	0.87 (11)	C11—C10—C15—C14	2.06 (15)
C4—C5—C8—C7	179.74 (10)	C7—C10—C15—C14	−177.33 (9)
C6—C7—C8—C9	179.80 (11)	C17—O3—C16—O2	−1.53 (14)
C10—C7—C8—C9	−3.51 (19)	C17—O3—C16—C13	177.50 (8)
C6—C7—C8—C5	−1.13 (11)	C12—C13—C16—O2	5.35 (15)
C10—C7—C8—C5	175.56 (10)	C14—C13—C16—O2	−175.51 (10)
O1—C2—C9—C8	178.17 (9)	C12—C13—C16—O3	−173.67 (8)
C3—C2—C9—C8	−1.43 (15)	C14—C13—C16—O3	5.47 (13)

Hydrogen-bond geometry (Å, º) top

Cg2 is the centroid ofthe C2–C5/C8/C9 ring.

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cg2ⁱ	0.90 (1)	2.54 (2)	3.295 (2)	142 (1)
C6—H6···O1ⁱⁱ	0.95	2.43	3.369 (2)	172
C17—H17B···O2ⁱⁱⁱ	0.98	2.60	3.484 (2)	150

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

Experimental details

Crystal data
Chemical formula	C₁₇H₁₅NO₃
M_r	281.30
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	113
a, b, c (Å)	15.023 (8), 5.871 (3), 16.867 (9)
β (°)	113.721 (6)
V (Å³)	1361.9 (12)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.20 × 0.16 × 0.14

Data collection
Diffractometer	Rigaku Saturn724 CCD diffractometer
Absorption correction	Multi-scan (CrystalClear; Rigaku, 2007)
T_min, T_max	0.981, 0.987
No. of measured, independent and observed [I > 2σ(I)] reflections	13161, 3241, 2460
R_int	0.038
(sin θ/λ)_max (Å⁻¹)	0.658

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.037, 0.110, 1.06
No. of reflections	3241
No. of parameters	196
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.24, −0.25

Computer programs: CrystalClear (Rigaku, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

Cg2 is the centroid ofthe C2–C5/C8/C9 ring.

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cg2ⁱ	0.902 (8)	2.535 (15)	3.295 (2)	142.3 (11)
C6—H6···O1ⁱⁱ	0.95	2.43	3.369 (2)	172
C17—H17B···O2ⁱⁱⁱ	0.98	2.60	3.484 (2)	150

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

Acknowledgements

This work was supported by the Natural Science Foundation of Liaoning Education Department (No. 2008 T094). We would like to thank Dr George Li, at CombiPhos Catalysts, Inc., Princeton, NJ, for helpful discussions regarding the use of POPd catalysts.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
Rigaku (2007). CrystalClear. Rigaku Corp., Tokyo, Japan. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Zhang, Z., Hu, Z., Yu, Z., Lei, P., Chi, H., Wang, Y. & He, R. (2007). Tetrahedron Lett. 48, 2415–2419. Web of Science CrossRef CAS Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 68| Part 1| January 2012| Page o133

doi:10.1107/S1600536811052135

Open

access