Methyl 2-(5-chloro-3-methyl­sulfinyl-1-benzofuran-2-yl)acetate

Choi, H.D.; Seo, P.J.; Son, B.W.; Lee, U.

doi:10.1107/S1600536808033503

organic compounds

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ISSN: 2056-9890

Volume 64| Part 11| November 2008| Page o2139

doi:10.1107/S1600536808033503

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Methyl 2-(5-chloro-3-methylsulfinyl-1-benzofuran-2-yl)acetate

Hong Dae Choi,^a Pil Ja Seo,^a Byeng Wha Son ^b and Uk Lee ^b ^*

^aDepartment of Chemistry, Dongeui University, San 24 Kaya-dong, Busanjin-gu, Busan 614-714, Republic of Korea, and ^bDepartment of Chemistry, Pukyong National University, 599-1 Daeyeon 3-dong, Nam-gu, Busan 608-737, Republic of Korea
^*Correspondence e-mail: uklee@pknu.ac.kr

(Received 13 October 2008; accepted 15 October 2008; online 18 October 2008)

The title compound, C₁₂H₁₁ClO₄S, was prepared by the oxidation of methyl 2-(5-chloro-3-methylsulfanyl-1-benzofuran-2-yl)acetate with 3-chloroperoxybenzoic acid. The O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. The crystal structure is stabilized by aromatic π–π interactions between the benzene rings of neighbouring molecules [centroid-to-centroid distance = 3.809 (2) Å], and by C—H⋯π interactions between a methyl H atom and the furan ring of an adjacent molecule. In addition, the crystal structure exhibits intermolecular C—H⋯O hydrogen bonds.

Related literature

For details of the pharmacological activities of benzofuran compounds, see: Ward (1999 ). For the crystal structures of similar 2-(3-methylsulfinyl-1-benzofuran-2-yl)acetic acid derivatives, see: Choi et al. (2007 , 2008 ).

Experimental

Crystal data

C₁₂H₁₁ClO₄S
M_r = 286.72
Triclinic, $[P \overline 1]$
a = 7.8910 (5) Å
b = 8.9416 (6) Å
c = 10.4048 (7) Å
α = 73.774 (1)°
β = 78.743 (1)°
γ = 68.559 (1)°
V = 652.55 (7) Å³
Z = 2
Mo Kα radiation
μ = 0.46 mm⁻¹
T = 298 (2) K
0.40 × 0.40 × 0.20 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1999 ) T_min = 0.827, T_max = 0.907
3753 measured reflections
2525 independent reflections
2123 reflections with I > 2σ(I)
R_int = 0.012

Refinement

R[F² > 2σ(F²)] = 0.035
wR(F²) = 0.101
S = 1.06
2525 reflections
169 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the C1/C2/C7/O1/C8 furan ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C11—H11C⋯Cg1ⁱ	0.96	2.92	3.858 (2)	165
C3—H3⋯O4ⁱⁱ	0.94 (2)	2.41 (2)	3.320 (3)	162.7 (17)
C9—H9B⋯O1ⁱⁱⁱ	0.97	2.59	3.550 (2)	172
C9—H9A⋯O4^iv	0.97	2.23	3.183 (3)	169
Symmetry codes: (i) x, y+1, z; (ii) -x, -y+1, -z+1; (iii) -x+1, -y+1, -z+2; (iv) -x+1, -y+1, -z+1.

Data collection: SMART (Bruker, 2001 ); cell refinement: SAINT (Bruker, 2001); 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 (Farrugia, 1997 ) and DIAMOND (Brandenburg, 1998 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808033503/zl2153sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808033503/zl2153Isup2.hkl

checkCIF report

Comment top

Benzofuran derivatives occur widely in natural products and show a variety of interesting pharmacological activities such as antimicrobial, fungicidal, insecticidal and antioxidant properties (Ward, 1999). As a part of our ongoing studies on the synthesis and structure of 2-(3-methylsulfinyl-1-benzofuran-2-yl)acetic acid analogues, the crystal structure of ethyl 2-(5-chloro-3-methylsulfinyl-1-benzofuran-2-yl)acetate (Choi et al., 2007) and methyl 2-(5-methyl-3-methylsulfinyl-1-benzofuran-2-yl)acetate (Choi et al., 2008) have been described in the literature. Here we report the crystal structure of the title compound, methyl 2-(5-chloro-3-methylsulfinyl-1-benzofuran-2-yl)acetate (Fig. 1).

The benzofuran unit is essentially planar, with a mean deviation of 0.011 (2) Å from the least-squares plane defined by the nine constituent atoms. The molecular packing (Fig. 2) is stabilized by aromatic π–π stacking interactions between the benzene rings of adjacent molecules. The Cg2···Cg2ⁱⁱ distance is 3.809 (2) Å (Cg2 is the centroid of the C2–C7 benzene ring; symmetry code as in Fig. 2). The molecular packing is further stabilized by C—H···π interactions between a methyl H atom and the furan ring of the benzofuran uint, with a C11—H11C···Cg1ⁱ separation of 2.92 Å (Fig. 2 and Table 1; Cg1 is the centroid of the C1/C2/C7/O1/C8 furan ring). Additionally, intermolecular C—H···O hydrogen bonds in the structure were observed (Table 1).

Related literature top

For details of the pharmacological activities of benzofuran compounds, see: Ward (1999). For the crystal structures of similar 2-(3-methylsulfinyl-1-benzofuran-2-yl)acetic acid derivatives, see: Choi et al. (2007, 2008).

Experimental top

77% 3-Chloroperoxybenzoic acid (292 mg, 1.3 mmol) was added in small portions to a stirred solution of methyl 2-(5-chloro-3-methylsulfanyl-1-benzofuran-2-yl)acetate (325 mg, 1.2 mmol) in dichloromethane (40 ml) at 273 K. After being stirred for 3 h at room temperature, the mixture was washed with saturated sodium bicarbonate solution and the organic layer was separated, dried over magnesium sulfate, filtered and concentrated in vacuum. The residue was purified by column chromatography (ethyl acetate) to afford the title compound as a colorless solid [yield 77%, m.p. 415–416 K; R_f = 0.72 (ethyl acetate)]. Single crystals suitable for X-ray diffraction were prepared by evaporation of a solution of the title compound in benzene at room temperature. Spectroscopic analysis: ¹H NMR (CDCl₃, 400 MHz) δ 3.07 (s, 3H), 3.75 (s, 3H), 4.05 (s, 2H), 7.34 (dd, J = 8.76 Hz and J = 1.80 Hz, 1H), 7.44 (d, J = 8.80 Hz, 1H), 7.90 (d, J = 1.80 Hz, 1H); EI–MS 288 [M+2], 286[M⁺].

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of the title compound, showing displacement ellipsoids drawn at the 30% probability level.
	Fig. 2. π–π and C—H···π interactions (dotted lines) in the title compound. Cg denotes the ring centroid. [Symmetry code: (i) x, y + 1, z; (ii) -x, -y + 1, -z + 2; (iii) x, y - 1, z.]

Methyl 2-(5-chloro-3-methylsulfinyl-1-benzofuran-2-yl)acetate top

Crystal data top

C₁₂H₁₁ClO₄S	Z = 2
M_r = 286.72	F(000) = 296
Triclinic, P1	D_x = 1.459 Mg m⁻³
Hall symbol: -P_1	Melting point = 415–416 K
a = 7.8910 (5) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.9416 (6) Å	Cell parameters from 2313 reflections
c = 10.4048 (7) Å	θ = 2.8–28.2°
α = 73.774 (1)°	µ = 0.46 mm⁻¹
β = 78.743 (1)°	T = 298 K
γ = 68.559 (1)°	Block, colourless
V = 652.55 (7) Å³	0.40 × 0.40 × 0.20 mm

Data collection top

Bruker SMART CCD diffractometer	2525 independent reflections
Radiation source: fine-focus sealed tube	2123 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.012
Detector resolution: 10.0 pixels mm^-1	θ_max = 26.0°, θ_min = 2.5°
ϕ and ω scans	h = −9→9
Absorption correction: multi-scan (SADABS; Sheldrick, 1999)	k = −11→7
T_min = 0.827, T_max = 0.907	l = −12→12
3753 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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.101	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ²(F_o²) + (0.0497P)² + 0.2053P] where P = (F_o² + 2F_c²)/3
2525 reflections	(Δ/σ)_max < 0.001
169 parameters	Δρ_max = 0.23 e Å⁻³
0 restraints	Δρ_min = −0.25 e Å⁻³

Crystal data top

C₁₂H₁₁ClO₄S	γ = 68.559 (1)°
M_r = 286.72	V = 652.55 (7) Å³
Triclinic, P1	Z = 2
a = 7.8910 (5) Å	Mo Kα radiation
b = 8.9416 (6) Å	µ = 0.46 mm⁻¹
c = 10.4048 (7) Å	T = 298 K
α = 73.774 (1)°	0.40 × 0.40 × 0.20 mm
β = 78.743 (1)°

Data collection top

Bruker SMART CCD diffractometer	2525 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1999)	2123 reflections with I > 2σ(I)
T_min = 0.827, T_max = 0.907	R_int = 0.012
3753 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.035	0 restraints
wR(F²) = 0.101	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	Δρ_max = 0.23 e Å⁻³
2525 reflections	Δρ_min = −0.25 e Å⁻³
169 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
Cl	−0.22541 (8)	0.20560 (7)	0.87139 (8)	0.0834 (2)
S	0.23616 (7)	0.63233 (7)	0.54121 (5)	0.05176 (17)
O1	0.33659 (17)	0.45642 (16)	0.92043 (12)	0.0468 (3)
O2	0.5278 (2)	0.89402 (19)	0.72451 (19)	0.0728 (5)
O3	0.2521 (2)	0.9006 (2)	0.69823 (19)	0.0748 (5)
O4	0.2462 (2)	0.4995 (2)	0.47609 (15)	0.0688 (4)
C1	0.2400 (2)	0.5423 (2)	0.71481 (17)	0.0429 (4)
C2	0.1418 (2)	0.4347 (2)	0.79676 (17)	0.0424 (4)
C3	0.0067 (3)	0.3789 (2)	0.7780 (2)	0.0489 (4)
H3	−0.040 (3)	0.409 (3)	0.694 (2)	0.053 (6)*
C4	−0.0519 (3)	0.2747 (2)	0.8878 (2)	0.0555 (5)
C5	0.0180 (3)	0.2229 (3)	1.0116 (2)	0.0596 (5)
H5	−0.0254	0.1511	1.0818	0.072*
C6	0.1517 (3)	0.2778 (2)	1.0307 (2)	0.0556 (5)
H6	0.2007	0.2447	1.1124	0.067*
C7	0.2087 (2)	0.3845 (2)	0.92181 (19)	0.0450 (4)
C8	0.3537 (2)	0.5507 (2)	0.79220 (18)	0.0433 (4)
C9	0.4870 (3)	0.6396 (2)	0.7667 (2)	0.0494 (4)
H9A	0.5801	0.6024	0.6959	0.059*
H9B	0.5470	0.6105	0.8475	0.059*
C10	0.4045 (3)	0.8245 (3)	0.72678 (19)	0.0489 (4)
C11	0.4682 (5)	1.0733 (3)	0.6855 (4)	0.1092 (12)
H11A	0.4158	1.1104	0.6016	0.164*
H11B	0.5713	1.1098	0.6754	0.164*
H11C	0.3782	1.1180	0.7537	0.164*
C12	0.0024 (3)	0.7661 (3)	0.5437 (2)	0.0661 (6)
H12A	−0.0223	0.8297	0.4543	0.099*
H12B	−0.0183	0.8390	0.6018	0.099*
H12C	−0.0772	0.7011	0.5764	0.099*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl	0.0594 (4)	0.0550 (3)	0.1360 (6)	−0.0274 (3)	−0.0214 (4)	−0.0029 (4)
S	0.0541 (3)	0.0652 (3)	0.0390 (3)	−0.0251 (2)	−0.0121 (2)	−0.0044 (2)
O1	0.0496 (7)	0.0499 (7)	0.0406 (7)	−0.0133 (6)	−0.0141 (5)	−0.0075 (5)
O2	0.0579 (9)	0.0575 (9)	0.1130 (14)	−0.0244 (7)	−0.0186 (9)	−0.0208 (9)
O3	0.0557 (9)	0.0564 (9)	0.1072 (13)	−0.0179 (7)	−0.0286 (9)	0.0023 (9)
O4	0.0751 (10)	0.0872 (11)	0.0505 (8)	−0.0219 (9)	−0.0140 (7)	−0.0269 (8)
C1	0.0460 (9)	0.0439 (10)	0.0394 (9)	−0.0139 (8)	−0.0101 (7)	−0.0081 (7)
C2	0.0436 (9)	0.0383 (9)	0.0431 (9)	−0.0087 (7)	−0.0086 (7)	−0.0096 (7)
C3	0.0465 (10)	0.0432 (10)	0.0584 (12)	−0.0125 (8)	−0.0119 (9)	−0.0123 (9)
C4	0.0449 (10)	0.0376 (10)	0.0800 (14)	−0.0101 (8)	−0.0095 (10)	−0.0100 (9)
C5	0.0537 (12)	0.0419 (10)	0.0671 (13)	−0.0109 (9)	0.0000 (10)	0.0018 (9)
C6	0.0564 (12)	0.0489 (11)	0.0489 (11)	−0.0091 (9)	−0.0087 (9)	−0.0009 (9)
C7	0.0437 (9)	0.0416 (10)	0.0455 (10)	−0.0078 (8)	−0.0086 (7)	−0.0093 (8)
C8	0.0428 (9)	0.0448 (10)	0.0417 (9)	−0.0107 (8)	−0.0107 (7)	−0.0093 (7)
C9	0.0449 (10)	0.0534 (11)	0.0534 (11)	−0.0163 (8)	−0.0143 (8)	−0.0115 (9)
C10	0.0472 (10)	0.0557 (11)	0.0468 (10)	−0.0193 (9)	−0.0064 (8)	−0.0124 (8)
C11	0.095 (2)	0.0580 (16)	0.186 (4)	−0.0338 (16)	−0.030 (2)	−0.0244 (19)
C12	0.0659 (13)	0.0603 (13)	0.0673 (14)	−0.0152 (11)	−0.0275 (11)	−0.0009 (11)

Geometric parameters (Å, º) top

Cl—C4	1.748 (2)	C4—C5	1.391 (3)
S—O4	1.4950 (17)	C5—C6	1.381 (3)
S—C1	1.7613 (18)	C5—H5	0.9300
S—C12	1.794 (2)	C6—C7	1.380 (3)
O1—C8	1.376 (2)	C6—H6	0.9300
O1—C7	1.377 (2)	C8—C9	1.482 (3)
O2—C10	1.327 (2)	C9—C10	1.504 (3)
O2—C11	1.454 (3)	C9—H9A	0.9700
O3—C10	1.194 (2)	C9—H9B	0.9700
C1—C8	1.350 (2)	C11—H11A	0.9600
C1—C2	1.443 (3)	C11—H11B	0.9600
C2—C7	1.394 (3)	C11—H11C	0.9600
C2—C3	1.396 (3)	C12—H12A	0.9600
C3—C4	1.378 (3)	C12—H12B	0.9600
C3—H3	0.94 (2)	C12—H12C	0.9600

O4—S—C1	105.98 (9)	C6—C7—C2	123.72 (18)
O4—S—C12	106.01 (11)	C1—C8—O1	110.86 (16)
C1—S—C12	98.50 (10)	C1—C8—C9	133.29 (17)
C8—O1—C7	106.35 (13)	O1—C8—C9	115.85 (15)
C10—O2—C11	116.4 (2)	C8—C9—C10	114.36 (15)
C8—C1—C2	107.57 (15)	C8—C9—H9A	108.7
C8—C1—S	124.18 (15)	C10—C9—H9A	108.7
C2—C1—S	127.95 (14)	C8—C9—H9B	108.7
C7—C2—C3	119.64 (17)	C10—C9—H9B	108.7
C7—C2—C1	104.63 (16)	H9A—C9—H9B	107.6
C3—C2—C1	135.72 (17)	O3—C10—O2	123.6 (2)
C4—C3—C2	116.31 (19)	O3—C10—C9	126.28 (19)
C4—C3—H3	121.9 (13)	O2—C10—C9	110.06 (16)
C2—C3—H3	121.8 (13)	O2—C11—H11A	109.5
C3—C4—C5	123.7 (2)	O2—C11—H11B	109.5
C3—C4—Cl	118.25 (17)	H11A—C11—H11B	109.5
C5—C4—Cl	118.09 (16)	O2—C11—H11C	109.5
C6—C5—C4	120.25 (19)	H11A—C11—H11C	109.5
C6—C5—H5	119.9	H11B—C11—H11C	109.5
C4—C5—H5	119.9	S—C12—H12A	109.5
C7—C6—C5	116.40 (19)	S—C12—H12B	109.5
C7—C6—H6	121.8	H12A—C12—H12B	109.5
C5—C6—H6	121.8	S—C12—H12C	109.5
O1—C7—C6	125.70 (17)	H12A—C12—H12C	109.5
O1—C7—C2	110.58 (15)	H12B—C12—H12C	109.5

O4—S—C1—C8	129.68 (17)	C5—C6—C7—C2	−1.4 (3)
C12—S—C1—C8	−120.88 (18)	C3—C2—C7—O1	−178.32 (15)
O4—S—C1—C2	−43.19 (19)	C1—C2—C7—O1	1.0 (2)
C12—S—C1—C2	66.26 (19)	C3—C2—C7—C6	1.4 (3)
C8—C1—C2—C7	−0.4 (2)	C1—C2—C7—C6	−179.31 (18)
S—C1—C2—C7	173.45 (14)	C2—C1—C8—O1	−0.4 (2)
C8—C1—C2—C3	178.8 (2)	S—C1—C8—O1	−174.49 (13)
S—C1—C2—C3	−7.4 (3)	C2—C1—C8—C9	−179.77 (19)
C7—C2—C3—C4	−0.2 (3)	S—C1—C8—C9	6.1 (3)
C1—C2—C3—C4	−179.2 (2)	C7—O1—C8—C1	1.0 (2)
C2—C3—C4—C5	−1.0 (3)	C7—O1—C8—C9	−179.52 (15)
C2—C3—C4—Cl	178.26 (14)	C1—C8—C9—C10	60.7 (3)
C3—C4—C5—C6	1.0 (3)	O1—C8—C9—C10	−118.61 (18)
Cl—C4—C5—C6	−178.22 (16)	C11—O2—C10—O3	0.5 (4)
C4—C5—C6—C7	0.2 (3)	C11—O2—C10—C9	179.1 (2)
C8—O1—C7—C6	179.08 (18)	C8—C9—C10—O3	−10.1 (3)
C8—O1—C7—C2	−1.22 (19)	C8—C9—C10—O2	171.31 (17)
C5—C6—C7—O1	178.32 (18)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C11—H11C···Cg1ⁱ	0.96	2.92	3.858 (2)	165
C3—H3···O4ⁱⁱ	0.94 (2)	2.41 (2)	3.320 (3)	162.7 (17)
C9—H9B···O1ⁱⁱⁱ	0.97	2.59	3.550 (2)	172
C9—H9A···O4^iv	0.97	2.23	3.183 (3)	169

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

Experimental details

Crystal data
Chemical formula	C₁₂H₁₁ClO₄S
M_r	286.72
Crystal system, space group	Triclinic, P1
Temperature (K)	298
a, b, c (Å)	7.8910 (5), 8.9416 (6), 10.4048 (7)
α, β, γ (°)	73.774 (1), 78.743 (1), 68.559 (1)
V (Å³)	652.55 (7)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.46
Crystal size (mm)	0.40 × 0.40 × 0.20

Data collection
Diffractometer	Bruker SMART CCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1999)
T_min, T_max	0.827, 0.907
No. of measured, independent and observed [I > 2σ(I)] reflections	3753, 2525, 2123
R_int	0.012
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.035, 0.101, 1.06
No. of reflections	2525
No. of parameters	169
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.23, −0.25

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1998).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C11—H11C···Cg1ⁱ	0.96	2.92	3.858 (2)	165.2
C3—H3···O4ⁱⁱ	0.94 (2)	2.41 (2)	3.320 (3)	162.7 (17)
C9—H9B···O1ⁱⁱⁱ	0.97	2.59	3.550 (2)	172.3
C9—H9A···O4^iv	0.97	2.23	3.183 (3)	168.9

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

References

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Volume 64| Part 11| November 2008| Page o2139

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