Dimorpholinium penta­chloridoanti­monate(III)

Chen, L.Z.

doi:10.1107/S1600536809019345

metal-organic compounds

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ISSN: 2056-9890

Volume 65| Part 6| June 2009| Page m689

doi:10.1107/S1600536809019345

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Dimorpholinium pentachloridoantimonate(III)

Li Zhuang Chen ^a ^*

^aOrdered Matter Science Research Center, College of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096, People's Republic of China
^*Correspondence e-mail: clz1977@sina.com

(Received 7 May 2009; accepted 21 May 2009; online 29 May 2009)

The asymmetric unit of the title compound, (C₄H₁₀NO)₂[SbCl₅], consists of two morpholinium cations in chair conformations, and a pentachloridoantimonate dianion with the Sb^III ion in a slightly distorted square-pyramidal coordination environment. The morpholinium cations are connected to each other by N—H⋯O hydrogen bonds, and they link the chloride anions and the antimonate SbCl₃ group via N—H⋯Cl contacts.

Related literature

For a phase transition in bis(ethyldimethylammonium) pentachloridoantimonate(III), see: Bujak & Zaleski (1999 ); for the structure of N-methylpiperazinediium pentachloridoantimonate(III), see: Shen-Tu et al. (2008 ); for the low-temperature phase of morpholinium tetrafluoridoborate, see: Owczarek et al. (2008 ).

Experimental

Crystal data

(C₄H₁₀NO)₂[SbCl₅]
M_r = 475.26
Orthorhombic, P 2₁ 2₁ 2₁
a = 9.0562 (18) Å
b = 10.273 (2) Å
c = 18.032 (4) Å
V = 1677.6 (6) Å³
Z = 4
Mo Kα radiation
μ = 2.44 mm⁻¹
T = 298 K
0.25 × 0.20 × 0.20 mm

Data collection

Rigaku Mercury2 (2× 2 bin mode) diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ) T_min = 0.567, T_max = 0.616
17552 measured reflections
3845 independent reflections
3759 reflections with I > 2σ(I)
R_int = 0.026

Refinement

R[F² > 2σ(F²)] = 0.021
wR(F²) = 0.046
S = 1.24
3845 reflections
163 parameters
H-atom parameters constrained
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.66 e Å⁻³
Absolute structure: Flack (1983 )
Flack parameter: −0.005 (15)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1D⋯Cl5ⁱ	0.90	2.35	3.180 (2)	154
C1—H1B⋯Cl3ⁱⁱ	0.97	2.82	3.548 (3)	132
N2—H2D⋯Cl5ⁱⁱⁱ	0.90	2.73	3.394 (2)	131
N2—H2C⋯Cl1^iv	0.90	2.45	3.306 (3)	159
N2—H2D⋯O1^v	0.90	2.44	2.848 (3)	108
N1—H1C⋯Cl3	0.90	2.75	3.463 (3)	137
N1—H1C⋯Cl5	0.90	2.72	3.448 (3)	138
Symmetry codes: (i) $[x-{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+2]$ ; (ii) $[x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+2]$ ; (iii) $[-x+{\script{3\over 2}}, -y+2, z-{\script{1\over 2}}]$ ; (iv) $[-x+2, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (v) $[-x+2, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Data collection: CrystalClear (Rigaku, 2005); 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: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809019345/si2174sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809019345/si2174Isup2.hkl

checkCIF report

Comment top

Structural investigation of crystalline solids undergoing phase transformation has been one of the classical areas of research among both chemists and physicists. The morpholinium tetrafluoroborate undergoes two reversible phase transitions (Owczarek et al. 2008). In our laboratory, a compound containing two morpholinium cations and a pentachloridoantimonate dianion in the asymmetric unit has been synthesized (Fig. 1), with the Sb^III ion in a slightly distorted square-pyramidal coordination environment.

The Sb atom is coordinated by five Cl atoms, with Sb—Cl distances ranging from 2.4045 (8) to 2.9230 (9) Å. The Sb—Cl distances are similar to the values of 2.4110 (10) to 2.9112 (11) Å reported by Shen-Tu et al. (2008) and slightly different to the values of 2.499 (4)–2.768 (4) Å reported by Bujak & Zaleski (1999). In the title compound the difference between the longest bond (Sb1—Cl5) and shortest bond (Sb1—Cl4) is ca 0.50 Å. The six-membered ring morpholinium cations have chair conformation. The morpholinium cations are connected to each other by N—H···O hydrogen bonds, and they link the Cl^- anions and the antimonate group SbCl₃ via N–H···Cl contacts (Table 1, Fig. 2).

Related literature top

For a phase transition in bis(ethyldimethylammonium) pentachloroantimonate(III), see: Bujak & Zaleski (1999); for the structure of N-methylpiperazinediium pentachloroantimonate(III), see: Shen-Tu et al. (2008); for the low-temperature phase of morpholinium tetrafluoroborate, see: Owczarek et al. (2008).

Experimental top

SbCl₃, morpholine and 20% aqueous HCl in a molar ratio of 1:1:1 were mixed and dissolved in sufficient ethanol by heating to 353 K forming a clear solution. The reaction mixture was cooled slowly to room temperature, crystals of the title compound were formed, collected and washed with dilute aqueous HCl.

Computing details top

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); 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: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. A view of the title compound with the atomic numbering scheme. Displacement ellipsoids were drawn at the 30% probability level.
	Fig. 2. The packing viewed approximately along the b axis. Hydrogen bonds are drawn as dashed lines.

Dimorpholinium pentachloridoantimonate(III) top

Crystal data top

(C₄H₁₀NO)₂[SbCl₅]	F(000) = 936
M_r = 475.26	D_x = 1.882 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 3845 reflections
a = 9.0562 (18) Å	θ = 3–27.5°
b = 10.273 (2) Å	µ = 2.44 mm⁻¹
c = 18.032 (4) Å	T = 298 K
V = 1677.6 (6) Å³	Block, colourless
Z = 4	0.25 × 0.20 × 0.20 mm

Data collection top

Rigaku Mercury2 (2× 2 bin mode) diffractometer	3845 independent reflections
Radiation source: fine-focus sealed tube	3759 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.026
Detector resolution: 13.6612 pixels mm^-1	θ_max = 27.5°, θ_min = 3.0°
ω scans	h = −11→11
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −13→13
T_min = 0.567, T_max = 0.616	l = −23→23
17552 measured reflections

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)] = 0.021	H-atom parameters constrained
wR(F²) = 0.046	w = 1/[σ²(F_o²) + (0.0201P)²] where P = (F_o² + 2F_c²)/3
S = 1.24	(Δ/σ)_max = 0.003
3845 reflections	Δρ_max = 0.32 e Å⁻³
163 parameters	Δρ_min = −0.66 e Å⁻³
0 restraints	Absolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.005 (15)

Crystal data top

(C₄H₁₀NO)₂[SbCl₅]	V = 1677.6 (6) Å³
M_r = 475.26	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 9.0562 (18) Å	µ = 2.44 mm⁻¹
b = 10.273 (2) Å	T = 298 K
c = 18.032 (4) Å	0.25 × 0.20 × 0.20 mm

Data collection top

Rigaku Mercury2 (2× 2 bin mode) diffractometer	3845 independent reflections
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	3759 reflections with I > 2σ(I)
T_min = 0.567, T_max = 0.616	R_int = 0.026
17552 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.021	H-atom parameters constrained
wR(F²) = 0.046	Δρ_max = 0.32 e Å⁻³
S = 1.24	Δρ_min = −0.66 e Å⁻³
3845 reflections	Absolute structure: Flack (1983)
163 parameters	Absolute structure parameter: −0.005 (15)
0 restraints

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ 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
C1	0.7135 (3)	0.5818 (4)	0.95313 (17)	0.0425 (8)
H1A	0.7413	0.6730	0.9546	0.051*
H1B	0.7866	0.5329	0.9808	0.051*
C2	0.5653 (4)	0.5651 (3)	0.98887 (17)	0.0431 (7)
H2A	0.5395	0.4735	0.9906	0.052*
H2B	0.5680	0.5980	1.0393	0.052*
C3	0.4560 (3)	0.5973 (4)	0.86593 (18)	0.0459 (8)
H3A	0.3890	0.6514	0.8374	0.055*
H3B	0.4236	0.5076	0.8616	0.055*
C4	0.6092 (3)	0.6104 (3)	0.83609 (17)	0.0440 (8)
H4A	0.6114	0.5797	0.7852	0.053*
H4B	0.6372	0.7016	0.8361	0.053*
C5	0.8890 (4)	0.6967 (3)	0.68509 (19)	0.0461 (8)
H5A	0.7903	0.6605	0.6819	0.055*
H5B	0.9521	0.6478	0.6516	0.055*
C6	0.8854 (3)	0.8366 (3)	0.66122 (19)	0.0442 (8)
H6A	0.8495	0.8431	0.6107	0.053*
H6B	0.8196	0.8858	0.6931	0.053*
C7	1.0960 (3)	0.8730 (3)	0.74228 (15)	0.0376 (6)
H7A	1.0382	0.9243	0.7769	0.045*
H7B	1.1976	0.9028	0.7446	0.045*
C8	1.0880 (4)	0.7312 (3)	0.76295 (16)	0.0411 (7)
H8A	1.1510	0.6814	0.7299	0.049*
H8B	1.1247	0.7199	0.8131	0.049*
Cl1	0.82449 (9)	1.24256 (9)	0.98134 (4)	0.0472 (2)
Cl2	0.55039 (9)	1.24280 (7)	0.82480 (4)	0.04292 (19)
Cl3	0.39146 (8)	0.94495 (7)	0.87224 (4)	0.03967 (18)
Cl4	0.76734 (9)	0.96688 (8)	0.86621 (5)	0.04330 (19)
Cl5	0.60479 (7)	0.89292 (7)	1.04341 (4)	0.03298 (15)
N1	0.4534 (2)	0.6378 (2)	0.94513 (14)	0.0407 (6)
H1C	0.4718	0.7238	0.9483	0.049*
H1D	0.3631	0.6231	0.9641	0.049*
N2	1.0376 (3)	0.8903 (2)	0.66613 (14)	0.0365 (6)
H2C	1.0966	0.8490	0.6336	0.044*
H2D	1.0366	0.9754	0.6544	0.044*
O1	0.7123 (2)	0.5387 (2)	0.87871 (12)	0.0377 (5)
O2	0.9422 (2)	0.6830 (2)	0.75855 (11)	0.0430 (5)
Sb1	0.580748 (19)	1.092473 (15)	0.928491 (9)	0.02418 (5)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0334 (15)	0.054 (2)	0.0404 (17)	0.0040 (17)	−0.0037 (13)	−0.0141 (16)
C2	0.0470 (18)	0.0450 (18)	0.0374 (16)	−0.0036 (16)	0.0051 (15)	−0.0036 (13)
C3	0.0338 (16)	0.053 (2)	0.0507 (19)	0.0112 (17)	−0.0098 (13)	−0.0112 (17)
C4	0.0459 (18)	0.0497 (19)	0.0364 (16)	0.0138 (17)	0.0012 (13)	0.0029 (14)
C5	0.0397 (18)	0.0457 (18)	0.0531 (19)	−0.0173 (15)	−0.0041 (15)	0.0022 (15)
C6	0.0322 (16)	0.0501 (19)	0.0502 (19)	−0.0012 (15)	−0.0070 (14)	0.0157 (15)
C7	0.0376 (15)	0.0393 (15)	0.0360 (15)	−0.0078 (14)	0.0006 (13)	−0.0015 (12)
C8	0.0445 (17)	0.0466 (17)	0.0322 (15)	0.0030 (17)	−0.0056 (15)	0.0060 (12)
Cl1	0.0464 (4)	0.0481 (5)	0.0472 (5)	−0.0051 (4)	0.0000 (4)	−0.0024 (4)
Cl2	0.0547 (5)	0.0364 (4)	0.0377 (4)	−0.0036 (4)	−0.0052 (3)	0.0098 (3)
Cl3	0.0387 (4)	0.0398 (4)	0.0405 (4)	−0.0074 (3)	−0.0098 (3)	0.0001 (3)
Cl4	0.0394 (4)	0.0377 (4)	0.0529 (5)	0.0030 (4)	0.0191 (4)	−0.0080 (3)
Cl5	0.0284 (3)	0.0367 (4)	0.0338 (3)	0.0025 (3)	0.0000 (3)	0.0024 (3)
N1	0.0215 (11)	0.0392 (14)	0.0613 (18)	−0.0020 (10)	0.0108 (11)	−0.0130 (12)
N2	0.0381 (13)	0.0300 (13)	0.0413 (14)	−0.0037 (11)	0.0054 (10)	0.0085 (11)
O1	0.0298 (11)	0.0443 (13)	0.0389 (12)	0.0123 (9)	0.0013 (9)	−0.0074 (10)
O2	0.0443 (12)	0.0420 (11)	0.0427 (12)	−0.0127 (11)	0.0039 (10)	0.0146 (9)
Sb1	0.02303 (8)	0.02452 (8)	0.02498 (8)	−0.00036 (8)	0.00101 (7)	−0.00180 (7)

Geometric parameters (Å, º) top

C1—O1	1.413 (4)	C6—N2	1.487 (4)
C1—C2	1.499 (4)	C6—H6A	0.9700
C1—H1A	0.9700	C6—H6B	0.9700
C1—H1B	0.9700	C7—N2	1.482 (4)
C2—N1	1.485 (4)	C7—C8	1.506 (4)
C2—H2A	0.9700	C7—H7A	0.9700
C2—H2B	0.9700	C7—H7B	0.9700
C3—N1	1.488 (4)	C8—O2	1.412 (4)
C3—C4	1.494 (4)	C8—H8A	0.9700
C3—H3A	0.9700	C8—H8B	0.9700
C3—H3B	0.9700	Cl1—Sb1	2.8562 (9)
C4—O1	1.416 (4)	Cl2—Sb1	2.4405 (8)
C4—H4A	0.9700	Cl3—Sb1	2.5028 (8)
C4—H4B	0.9700	Cl4—Sb1	2.4045 (8)
C5—O2	1.417 (4)	N1—H1C	0.9000
C5—C6	1.501 (4)	N1—H1D	0.9000
C5—H5A	0.9700	N2—H2C	0.9000
C5—H5B	0.9700	N2—H2D	0.9000

O1—C1—C2	111.4 (2)	C5—C6—H6B	110.0
O1—C1—H1A	109.3	H6A—C6—H6B	108.4
C2—C1—H1A	109.3	N2—C7—C8	109.1 (2)
O1—C1—H1B	109.3	N2—C7—H7A	109.9
C2—C1—H1B	109.3	C8—C7—H7A	109.9
H1A—C1—H1B	108.0	N2—C7—H7B	109.9
N1—C2—C1	109.0 (3)	C8—C7—H7B	109.9
N1—C2—H2A	109.9	H7A—C7—H7B	108.3
C1—C2—H2A	109.9	O2—C8—C7	111.7 (3)
N1—C2—H2B	109.9	O2—C8—H8A	109.3
C1—C2—H2B	109.9	C7—C8—H8A	109.3
H2A—C2—H2B	108.3	O2—C8—H8B	109.3
N1—C3—C4	109.6 (2)	C7—C8—H8B	109.3
N1—C3—H3A	109.8	H8A—C8—H8B	107.9
C4—C3—H3A	109.8	C2—N1—C3	111.0 (2)
N1—C3—H3B	109.8	C2—N1—H1C	109.4
C4—C3—H3B	109.8	C3—N1—H1C	109.4
H3A—C3—H3B	108.2	C2—N1—H1D	109.4
O1—C4—C3	111.7 (3)	C3—N1—H1D	109.4
O1—C4—H4A	109.3	H1C—N1—H1D	108.0
C3—C4—H4A	109.3	C7—N2—C6	110.0 (2)
O1—C4—H4B	109.3	C7—N2—H2C	109.7
C3—C4—H4B	109.3	C6—N2—H2C	109.7
H4A—C4—H4B	107.9	C7—N2—H2D	109.7
O2—C5—C6	111.7 (3)	C6—N2—H2D	109.7
O2—C5—H5A	109.3	H2C—N2—H2D	108.2
C6—C5—H5A	109.3	C1—O1—C4	111.0 (2)
O2—C5—H5B	109.3	C8—O2—C5	109.6 (2)
C6—C5—H5B	109.3	Cl4—Sb1—Cl2	93.49 (3)
H5A—C5—H5B	107.9	Cl4—Sb1—Cl3	88.12 (3)
N2—C6—C5	108.5 (2)	Cl2—Sb1—Cl3	89.74 (3)
N2—C6—H6A	110.0	Cl4—Sb1—Cl1	84.40 (3)
C5—C6—H6A	110.0	Cl2—Sb1—Cl1	90.06 (3)
N2—C6—H6B	110.0	Cl3—Sb1—Cl1	172.49 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1D···Cl5ⁱ	0.90	2.35	3.180 (2)	154
C1—H1B···Cl3ⁱⁱ	0.97	2.82	3.548 (3)	132
N2—H2D···Cl5ⁱⁱⁱ	0.90	2.73	3.394 (2)	131
N2—H2C···Cl1^iv	0.90	2.45	3.306 (3)	159
N2—H2D···O1^v	0.90	2.44	2.848 (3)	108
N1—H1C···Cl3	0.90	2.75	3.463 (3)	137
N1—H1C···Cl5	0.90	2.72	3.448 (3)	138

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

Experimental details

Crystal data
Chemical formula	(C₄H₁₀NO)₂[SbCl₅]
M_r	475.26
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	298
a, b, c (Å)	9.0562 (18), 10.273 (2), 18.032 (4)
V (Å³)	1677.6 (6)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	2.44
Crystal size (mm)	0.25 × 0.20 × 0.20

Data collection
Diffractometer	Rigaku Mercury2 (2× 2 bin mode) diffractometer
Absorption correction	Multi-scan (CrystalClear; Rigaku, 2005)
T_min, T_max	0.567, 0.616
No. of measured, independent and observed [I > 2σ(I)] reflections	17552, 3845, 3759
R_int	0.026
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.021, 0.046, 1.24
No. of reflections	3845
No. of parameters	163
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.32, −0.66
Absolute structure	Flack (1983)
Absolute structure parameter	−0.005 (15)

Computer programs: CrystalClear (Rigaku, 2005), 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
N1—H1D···Cl5ⁱ	0.90	2.35	3.180 (2)	153.5
C1—H1B···Cl3ⁱⁱ	0.97	2.82	3.548 (3)	132.1
N2—H2D···Cl5ⁱⁱⁱ	0.90	2.73	3.394 (2)	131.1
N2—H2C···Cl1^iv	0.90	2.45	3.306 (3)	159.3
N2—H2D···O1^v	0.90	2.44	2.848 (3)	107.9
N1—H1C···Cl3	0.90	2.75	3.463 (3)	136.8
N1—H1C···Cl5	0.90	2.72	3.448 (3)	138.4

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

References

Bujak, M. & Zaleski, J. (1999). Acta Cryst. C55, 1775–1778. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Owczarek, M., Szklarz, P., Jakubas, R. & Lis, T. (2008). Acta Cryst. E64, o667. Web of Science CrossRef IUCr Journals Google Scholar
Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Shen-Tu, C., Li, H. Y., Ma, X. J., Huang, W. & Jin, Z. M. (2008). Acta Cryst. E64, m146. Web of Science CSD CrossRef IUCr Journals Google Scholar

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ISSN: 2056-9890

Volume 65| Part 6| June 2009| Page m689

doi:10.1107/S1600536809019345

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