2-Methyl­anilinium dihydrogen phosphate–phospho­ric acid (1/1)

Khemiri, H.; Akriche, S.; Rzaigui, M.

doi:10.1107/S1600536809014536

organic compounds

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ISSN: 2056-9890

Volume 65| Part 5| May 2009| Page o1152

doi:10.1107/S1600536809014536

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2-Methylanilinium dihydrogen phosphate–phosphoric acid (1/1)

Hamed Khemiri,^a ^* Samah Akriche ^a and Mohamed Rzaigui ^a

^aLaboratoire de Chimie des Matériaux, Faculté des Sciences de Bizerte, 7021 Zarzouna Bizerte, Tunisia
^*Correspondence e-mail: hamedkhemiri@voila.fr

(Received 16 April 2009; accepted 18 April 2009; online 30 April 2009)

In the title compound, C₇H₁₀N⁺·H₂PO₄⁻·H₃PO₄, there is a clear distinction between the P—O/P=O and P—OH bond lengths. In the crystal, the H₂PO₄⁻ anions and H₃PO₄ molecules are linked by O—H⋯O hydrogen bonds, leading to layers propagating in the bc plane. The organic cations are located between these layers and interact with them by way of N—H⋯O hydrogen bonds.

Related literature

For related structures, see: Akriche & Rzaigui (2000 ); Zaccaro et al. (1996 ). For background, see: Desiraju (1995 ).

Experimental

Crystal data

C₇H₁₀N⁺·H₂PO₄⁻·H₃PO₄
M_r = 303.14
Monoclinic, P 2₁ /c
a = 10.8769 (10) Å
b = 7.938 (4) Å
c = 15.302 (3) Å
β = 91.57 (2)°
V = 1320.7 (7) Å³
Z = 4
Ag Kα radiation
μ = 0.19 mm⁻¹
T = 298 K
0.37 × 0.31 × 0.25 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: none
5416 measured reflections
5250 independent reflections
4134 reflections with I > 2σ(I)
R_int = 0.013
2 standard reflections frequency: 120 min intensity decay: 18%

Refinement

R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.092
S = 1.08
5250 reflections
170 parameters
H-atom parameters constrained
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.41 e Å⁻³

Table 1
Selected bond lengths (Å)

P1—O3	1.4964 (9)
P1—O4	1.5092 (10)
P1—O2	1.5571 (9)
P1—O1	1.5707 (9)
P2—O8	1.4942 (9)
P2—O5	1.5422 (10)
P2—O7	1.5445 (10)
P2—O6	1.5493 (10)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O4ⁱ	0.82	1.83	2.6483 (16)	178
O2—H2⋯O8ⁱ	0.82	1.80	2.6132 (13)	170
O5—H5⋯O3	0.82	1.72	2.5351 (15)	176
O6—H6⋯O8ⁱⁱ	0.82	1.81	2.6223 (16)	170
O7—H7⋯O4ⁱⁱⁱ	0.82	1.69	2.5109 (13)	177
N1—H1A⋯O1ⁱ	0.89	2.08	2.9627 (16)	172
N1—H1B⋯O3	0.89	1.91	2.7808 (19)	164
N1—H1C⋯O7^iv	0.89	2.18	3.0086 (15)	154
Symmetry codes: (i) $[-x, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (ii) -x, -y+1, -z+2; (iii) $[x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]$ ; (iv) x, y-1, z.

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ); 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 (2005); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809014536/hb2955sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809014536/hb2955Isup2.hkl

checkCIF report

Comment top

Organic cation phosphates have been intensively studied due to their many uses in various fields such as biomolecular sciences, catalysts and nonlinear optics (e.g. Desiraju, 1995). Nevertheless, a bibliographical study on the organic monophosphates, and especially on the adduct monophosphate reveals that this kind of compounds are relatively very rare if compared with another types of phosphates (Zaccaro et al., 1996).

In the atomic arrangement of the title compound (I), the asymmetric unit consists of three fundamentals entities, the H₂PO_4- anion, the H₃PO₄ molecule and the organic cation C₇H₁₀N₊ (Fig. 1). A view of the structure projected along the b direction (Fig. 2) shows that the inorganic entities are organized in layers developed around the bc plane. The organic cations are arranged in opposite direction along the a axis in the interlayer spacing to neutralize the negative charge of the inorganic layers. Inside each layer the H₂PO_4- anions form an inorganic chains parallel to b direction and situated at Z = 1/4 and Z = 3/4. The H₃PO₄ molecules are associated by strong hydrogen bonds to form a dimmer of formula [H₆P₂O₈] centred at (0 1/2 0) and (0 0 1/2). The both entities are interconnected together via hydrogen bonds to form inorganic layer parallel to the bc plane (Fig. 2). In the two crystallographically independent phosphate groups, the P—O bonds are shorter than P—OH bonds (Table 1). The average values of P—O distances and O—P—O angles are 1,533 Å, 109,44° and 1,533 Å, 109,38°, respectively for P(1)O₄ and P(2)O₄ tetrahedra. These configurations are comparable to that observed elsewhere (Zaccaro et al., 1996). The organic and inorganic species establish between them two types of hydrogen bonds. The first one is O—H···O, involving short contacts with H···O lengths ranging between 1,69 - 1,83 Å, connects the H₂PO_4- and H₃PO₄ entities to develop the inorganic layer parallel to bc plane. The second type is N—H···O, with H···O distances ranging from 1,91 Å to 2,18 Å, links the organic cations to the phosphoric layer. The pattern of hydrogen bonds participate with the electrostatic and van Der Waals interactions to the cohesion of the network. The atoms C1, C2, C3, C4, C5 and C6 of the anilinium ring of the title compound are coplanar and they form a conjugated plane with average deviation of 0.0013 Å. The C—C distances ranging from 1.374 (2) to 1.496 (3) Å agree with those observed in literature (Akriche & Rzaigui 2000).

Related literature top

For related structures, see: Akriche & Rzaigui (2000); Zaccaro et al. (1996). For background, see: Desiraju (1995).

Experimental top

A solution of orthophosphoric acid (0.50 mmol in 30 ml of water) was added drop by drop to an ethanolic solution of 2-methylaniline (2.336 mmol in 5 ml). The so-obtained solution was slowly evaporated at room temperature, until colourless prisms of (I) formed.

Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); 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 (2005); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. The molecular structure of (I) with displacement ellipsoids drawn at the 30% probability level. H atoms are represented as small spheres of arbitrary radius. Hydrogen bonds are represented as dashed lines.
	Fig. 2. DIAMOND (Brandenburg, 2005) Projection of (I) along the b axis.

2-Methylanilinium dihydrogen phosphate–phosphoric acid (1/1) top

Crystal data top

C₇H₁₀N⁺·H₂PO₄⁻·H₃PO₄	F(000) = 632
M_r = 303.14	D_x = 1.525 Mg m⁻³
Monoclinic, P2₁/c	Ag Kα radiation, λ = 0.56085 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 10.8769 (10) Å	θ = 8–12°
b = 7.938 (4) Å	µ = 0.19 mm⁻¹
c = 15.302 (3) Å	T = 298 K
β = 91.57 (2)°	Prism, colorless
V = 1320.7 (7) Å³	0.37 × 0.31 × 0.25 mm
Z = 4

Data collection top

Enraf–Nonius CAD-4 diffractometer	θ_max = 26.0°, θ_min = 2.1°
Radiation source: fine-focus sealed tube	h = −16→16
Nonprofiled ω scans	k = 0→12
5416 measured reflections	l = 0→23
5250 independent reflections	2 standard reflections every 120 min
4134 reflections with I > 2σ(I)	intensity decay: 18%
R_int = 0.013

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)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.092	H-atom parameters constrained
S = 1.08	w = 1/[σ²(F_o²) + (0.0493P)² + 0.181P] where P = (F_o² + 2F_c²)/3
5250 reflections	(Δ/σ)_max = 0.001
170 parameters	Δρ_max = 0.30 e Å⁻³
0 restraints	Δρ_min = −0.41 e Å⁻³

Crystal data top

C₇H₁₀N⁺·H₂PO₄⁻·H₃PO₄	V = 1320.7 (7) Å³
M_r = 303.14	Z = 4
Monoclinic, P2₁/c	Ag Kα radiation, λ = 0.56085 Å
a = 10.8769 (10) Å	µ = 0.19 mm⁻¹
b = 7.938 (4) Å	T = 298 K
c = 15.302 (3) Å	0.37 × 0.31 × 0.25 mm
β = 91.57 (2)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	R_int = 0.013
5416 measured reflections	2 standard reflections every 120 min
5250 independent reflections	intensity decay: 18%
4134 reflections with I > 2σ(I)

Refinement top

R[F² > 2σ(F²)] = 0.033	0 restraints
wR(F²) = 0.092	H-atom parameters constrained
S = 1.08	Δρ_max = 0.30 e Å⁻³
5250 reflections	Δρ_min = −0.41 e Å⁻³
170 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
P1	0.08064 (3)	0.43847 (3)	0.736601 (16)	0.02322 (6)
P2	0.10749 (3)	0.71819 (3)	0.986049 (17)	0.02487 (7)
O1	−0.06037 (8)	0.40074 (11)	0.74454 (6)	0.03314 (17)
H1	−0.0695	0.3079	0.7670	0.050*
O2	0.13778 (8)	0.28822 (10)	0.68641 (6)	0.03396 (18)
H2	0.0974	0.2708	0.6413	0.051*
O3	0.14542 (9)	0.44285 (11)	0.82411 (5)	0.03420 (18)
O4	0.08566 (9)	0.59919 (10)	0.68413 (6)	0.03335 (18)
O5	0.19612 (9)	0.70906 (12)	0.90923 (6)	0.0394 (2)
H5	0.1806	0.6250	0.8798	0.059*
O6	0.14555 (9)	0.58760 (11)	1.05701 (6)	0.0372 (2)
H6	0.1003	0.5052	1.0530	0.056*
O7	0.13831 (9)	0.89278 (10)	1.02544 (5)	0.03362 (18)
H7	0.1232	0.8928	1.0776	0.050*
O8	−0.02457 (8)	0.69700 (11)	0.95881 (6)	0.03445 (18)
N1	0.20745 (9)	0.11752 (14)	0.87628 (7)	0.0355 (2)
H1A	0.1698	0.0513	0.8370	0.053*
H1B	0.1808	0.2228	0.8695	0.053*
H1C	0.1910	0.0818	0.9298	0.053*
C1	0.34057 (12)	0.11198 (18)	0.86394 (10)	0.0400 (3)
C2	0.41777 (14)	0.1876 (2)	0.92552 (12)	0.0517 (4)
C3	0.54313 (16)	0.1826 (3)	0.90905 (19)	0.0797 (7)
H3C	0.5986	0.2305	0.9492	0.096*
C4	0.58628 (19)	0.1090 (4)	0.8354 (2)	0.0930 (8)
H4C	0.6702	0.1099	0.8252	0.112*
C5	0.5070 (2)	0.0340 (4)	0.7763 (2)	0.0930 (8)
H5C	0.5374	−0.0182	0.7269	0.112*
C6	0.38195 (18)	0.0357 (3)	0.78970 (14)	0.0643 (5)
H6C	0.3272	−0.0136	0.7496	0.077*
C7	0.3703 (2)	0.2703 (4)	1.00570 (16)	0.0795 (7)
H7A	0.3238	0.1902	1.0382	0.119*
H7B	0.3185	0.3634	0.9890	0.119*
H7C	0.4382	0.3104	1.0413	0.119*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
P1	0.03254 (13)	0.01806 (11)	0.01906 (11)	0.00111 (9)	0.00062 (9)	−0.00078 (8)
P2	0.03360 (14)	0.02046 (11)	0.02043 (11)	−0.00449 (9)	−0.00143 (9)	0.00068 (9)
O1	0.0333 (4)	0.0282 (4)	0.0379 (4)	−0.0007 (3)	0.0019 (3)	0.0069 (3)
O2	0.0416 (5)	0.0282 (4)	0.0317 (4)	0.0095 (3)	−0.0053 (3)	−0.0105 (3)
O3	0.0498 (5)	0.0286 (4)	0.0238 (4)	−0.0003 (3)	−0.0071 (3)	−0.0040 (3)
O4	0.0491 (5)	0.0222 (3)	0.0292 (4)	0.0023 (3)	0.0101 (3)	0.0047 (3)
O5	0.0494 (5)	0.0385 (5)	0.0309 (4)	−0.0126 (4)	0.0104 (4)	−0.0106 (4)
O6	0.0437 (5)	0.0286 (4)	0.0387 (5)	−0.0069 (3)	−0.0126 (4)	0.0104 (3)
O7	0.0533 (5)	0.0225 (3)	0.0252 (4)	−0.0075 (3)	0.0034 (3)	−0.0037 (3)
O8	0.0366 (4)	0.0299 (4)	0.0363 (4)	−0.0056 (3)	−0.0082 (3)	0.0101 (3)
N1	0.0315 (5)	0.0339 (5)	0.0409 (5)	−0.0036 (4)	−0.0042 (4)	0.0062 (4)
C1	0.0318 (5)	0.0355 (6)	0.0526 (8)	0.0023 (5)	−0.0013 (5)	0.0065 (6)
C2	0.0360 (6)	0.0522 (9)	0.0662 (10)	0.0007 (6)	−0.0108 (6)	−0.0003 (8)
C3	0.0317 (7)	0.0912 (16)	0.1154 (19)	0.0004 (9)	−0.0107 (10)	−0.0069 (14)
C4	0.0366 (8)	0.123 (2)	0.120 (2)	0.0120 (11)	0.0082 (11)	−0.0074 (19)
C5	0.0630 (13)	0.113 (2)	0.105 (2)	0.0177 (13)	0.0272 (13)	−0.0215 (17)
C6	0.0528 (9)	0.0726 (12)	0.0677 (11)	0.0044 (9)	0.0066 (8)	−0.0128 (10)
C7	0.0610 (12)	0.1016 (18)	0.0752 (14)	−0.0020 (11)	−0.0123 (10)	−0.0313 (13)

Geometric parameters (Å, º) top

P1—O3	1.4964 (9)	N1—H1C	0.8900
P1—O4	1.5092 (10)	C1—C6	1.374 (2)
P1—O2	1.5571 (9)	C1—C2	1.382 (2)
P1—O1	1.5707 (9)	C2—C3	1.394 (2)
P2—O8	1.4942 (9)	C2—C7	1.496 (3)
P2—O5	1.5422 (10)	C3—C4	1.365 (4)
P2—O7	1.5445 (10)	C3—H3C	0.9300
P2—O6	1.5493 (10)	C4—C5	1.368 (4)
O1—H1	0.8200	C4—H4C	0.9300
O2—H2	0.8200	C5—C6	1.381 (3)
O5—H5	0.8200	C5—H5C	0.9300
O6—H6	0.8200	C6—H6C	0.9300
O7—H7	0.8200	C7—H7A	0.9600
N1—C1	1.4659 (16)	C7—H7B	0.9600
N1—H1A	0.8900	C7—H7C	0.9600
N1—H1B	0.8900

O3—P1—O4	115.69 (5)	C6—C1—N1	117.83 (14)
O3—P1—O2	105.94 (5)	C2—C1—N1	118.88 (14)
O4—P1—O2	111.37 (6)	C1—C2—C3	116.33 (18)
O3—P1—O1	111.84 (6)	C1—C2—C7	122.21 (15)
O4—P1—O1	104.60 (5)	C3—C2—C7	121.46 (18)
O2—P1—O1	107.21 (5)	C4—C3—C2	121.5 (2)
O8—P2—O5	113.47 (6)	C4—C3—H3C	119.3
O8—P2—O7	113.99 (6)	C2—C3—H3C	119.3
O5—P2—O7	101.89 (5)	C3—C4—C5	120.51 (19)
O8—P2—O6	110.89 (5)	C3—C4—H4C	119.7
O5—P2—O6	110.01 (6)	C5—C4—H4C	119.7
O7—P2—O6	106.02 (6)	C4—C5—C6	120.2 (2)
P1—O1—H1	109.5	C4—C5—H5C	119.9
P1—O2—H2	109.5	C6—C5—H5C	119.9
P2—O5—H5	109.5	C1—C6—C5	118.3 (2)
P2—O6—H6	109.5	C1—C6—H6C	120.9
P2—O7—H7	109.5	C5—C6—H6C	120.9
C1—N1—H1A	109.5	C2—C7—H7A	109.5
C1—N1—H1B	109.5	C2—C7—H7B	109.5
H1A—N1—H1B	109.5	H7A—C7—H7B	109.5
C1—N1—H1C	109.5	C2—C7—H7C	109.5
H1A—N1—H1C	109.5	H7A—C7—H7C	109.5
H1B—N1—H1C	109.5	H7B—C7—H7C	109.5
C6—C1—C2	123.26 (15)

C6—C1—C2—C3	−0.3 (3)	C2—C3—C4—C5	−1.6 (5)
N1—C1—C2—C3	−178.19 (16)	C3—C4—C5—C6	1.6 (5)
C6—C1—C2—C7	179.8 (2)	C2—C1—C6—C5	0.3 (3)
N1—C1—C2—C7	1.9 (3)	N1—C1—C6—C5	178.2 (2)
C1—C2—C3—C4	0.9 (3)	C4—C5—C6—C1	−0.9 (4)
C7—C2—C3—C4	−179.1 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O4ⁱ	0.82	1.83	2.6483 (16)	178
O2—H2···O8ⁱ	0.82	1.80	2.6132 (13)	170
O5—H5···O3	0.82	1.72	2.5351 (15)	176
O6—H6···O8ⁱⁱ	0.82	1.81	2.6223 (16)	170
O7—H7···O4ⁱⁱⁱ	0.82	1.69	2.5109 (13)	177
N1—H1A···O1ⁱ	0.89	2.08	2.9627 (16)	172
N1—H1B···O3	0.89	1.91	2.7808 (19)	164
N1—H1C···O7^iv	0.89	2.18	3.0086 (15)	154

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

Experimental details

Crystal data
Chemical formula	C₇H₁₀N⁺·H₂PO₄⁻·H₃PO₄
M_r	303.14
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	298
a, b, c (Å)	10.8769 (10), 7.938 (4), 15.302 (3)
β (°)	91.57 (2)
V (Å³)	1320.7 (7)
Z	4
Radiation type	Ag Kα, λ = 0.56085 Å
µ (mm⁻¹)	0.19
Crystal size (mm)	0.37 × 0.31 × 0.25

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	5416, 5250, 4134
R_int	0.013
(sin θ/λ)_max (Å⁻¹)	0.781

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.092, 1.08
No. of reflections	5250
No. of parameters	170
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.30, −0.41

Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND Brandenburg (2005), WinGX (Farrugia, 1999).

Selected bond lengths (Å) top

P1—O3	1.4964 (9)	P2—O8	1.4942 (9)
P1—O4	1.5092 (10)	P2—O5	1.5422 (10)
P1—O2	1.5571 (9)	P2—O7	1.5445 (10)
P1—O1	1.5707 (9)	P2—O6	1.5493 (10)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O4ⁱ	0.82	1.83	2.6483 (16)	178
O2—H2···O8ⁱ	0.82	1.80	2.6132 (13)	170
O5—H5···O3	0.82	1.72	2.5351 (15)	176
O6—H6···O8ⁱⁱ	0.82	1.81	2.6223 (16)	170
O7—H7···O4ⁱⁱⁱ	0.82	1.69	2.5109 (13)	177
N1—H1A···O1ⁱ	0.89	2.08	2.9627 (16)	172
N1—H1B···O3	0.89	1.91	2.7808 (19)	164
N1—H1C···O7^iv	0.89	2.18	3.0086 (15)	154

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

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Volume 65| Part 5| May 2009| Page o1152

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