Diisopropyl­ammonium hydrogen phenyl­phospho­nate

Sarr, M.; Boye, M.S.; Diasse-Sarr, A.; Grosjean, A.; Guionneau, P.

doi:10.1107/S1600536812041086

organic compounds

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ISSN: 2056-9890

Volume 68| Part 11| November 2012| Page o3078

doi:10.1107/S1600536812041086

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Diisopropylammonium hydrogen phenylphosphonate

Modou Sarr,^a Mouhamadou Sembene Boye,^a ^* Aminata Diasse-Sarr,^a Arnaud Grosjean ^b and Philippe Guionneau ^b

^aLaboratoire de Chimie Minerale et Analytique, Département de Chimie, Faculté des Sciences et Techniques, Université Cheikh Anta Diop, Dakar, Senegal, and ^bCNRS, Universite de Bordeaux, ICMCB, 87 Avenue du Dr A. Schweitzer, Pessac F-33608, France
^*Correspondence e-mail: mouhasboye@hotmail.com

(Received 17 September 2012; accepted 30 September 2012; online 6 October 2012)

In the title salt, [(CH₃)₂CH]₂NH₂]⁺·[C₆H₅PO₂(OH)]⁻, the anions are linked by pairs of O—H⋯O hydrogen bonds, forming inversion dimers. These dimers are bridged by the cations via N—H⋯O hydrogen bonds, leading to a three-dimensional structure.

Related literature

For crystal structures of closely related compounds, see: Diop et al. (2012 ); Beckmann et al. (2003 ).

Experimental

Crystal data

C₆H₁₆N⁺·C₆H₆O₃P⁻
M_r = 259.28
Monoclinic, P 2₁ /n
a = 11.9166 (2) Å
b = 9.0982 (1) Å
c = 12.8539 (1) Å
β = 101.013 (1)°
V = 1367.95 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.20 mm⁻¹
T = 293 K
0.88 × 0.63 × 0.25 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997 ) T_min = 0.845, T_max = 0.952
7738 measured reflections
3990 independent reflections
3626 reflections with I > 2σ(I)
R_int = 0.013

Refinement

R[F² > 2σ(F²)] = 0.029
wR(F²) = 0.080
S = 1.03
3990 reflections
243 parameters
All H atoms refined
Δρ_max = 0.38 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H17⋯O3	0.900 (14)	1.960 (14)	2.8510 (10)	170.3 (12)
O2—H6⋯O3ⁱ	0.847 (19)	1.744 (19)	2.5895 (10)	177.4 (19)
N1—H16⋯O1ⁱⁱ	0.916 (15)	1.764 (15)	2.6782 (10)	176.7 (13)
Symmetry codes: (i) -x+2, -y+1, -z+2; (ii) $[-x+{\script{3\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Data collection: COLLECT (Hooft, 1998 ); cell refinement: HKL DENZO (Otwinowski & Minor, 1997); data reduction: SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997 ); software used to prepare material for publication: publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812041086/pv2589sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812041086/pv2589Isup2.hkl

checkCIF report

Comment top

In the assymmetric unit of the title salt (Fig. 1), the anion, hydrogen phenylphosphonate (PhPO₃H^-), adopts a tetrahedral geometry, with three oxygen atoms and a benzene group with O—P—O and O—P—C angles in the ranges 109.58 (4) - 115.20 (4) and 105.24 (4) - 108.51 (4)°, respectively. Two P—O distances in the anion are close, (P1—O1 = 1.4932 (7) and P1—O3 = 1.5191 (7) Å) indicating the presence of extensive π-delocalization of the P═O double bonds. The bond distance P1—O2 (1.5809 (7) Å for P—OH bond) is significantly longer than the other two P—O bonds. The P—O bond distances in the title salt agree very well with the corresponding bond distances reported in closely related compounds (Diop et al., 2012; Beckmann et al., 2003).

In the crystal, the anions are connected by O2—H6···O3 hydrogen bonds forming dimers about inversion centers. These pairs are then bridged through cations via N—H···O hydrogen bonds leading to a three-dimensional structure (Tab. 1 & Fig. 2).

Related literature top

For crystal structures of closely related compounds, see: Diop et al. (2012); Beckmann et al. (2003).

Experimental top

The title compound was synthesized by mixing [(CH₃)₂CH]₂NH and PhPO₃H₂ in water (1/1 ratio). The precipitate obtained was filtered. The crystals suitable for X-ray crystallographic analysis were grown from a solution of water by slow evaporation at room temperature.

Computing details top

Data collection: COLLECT (Hooft, 1998); cell refinement: HKL DENZO (Otwinowski & Minor, 1997); data reduction: SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top

	Fig. 1. The assymmetric unit of the title salt. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A view of the O—-H···O and N—H···O hydrogen bonds (light-blue colored lines) in the crystal structure of the title compound. H atoms non-participating in hydrogen-bonding were omitted for clarity.

Diisopropylammonium hydrogen phenylphosphonate top

Crystal data top

C₆H₁₆N⁺·C₆H₆O₃P⁻	F(000) = 560
M_r = 259.28	D_x = 1.259 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 4223 reflections
a = 11.9166 (2) Å	θ = 0.4–30.0°
b = 9.0982 (1) Å	µ = 0.20 mm⁻¹
c = 12.8539 (1) Å	T = 293 K
β = 101.013 (1)°	Prism, colourless
V = 1367.95 (3) Å³	0.88 × 0.63 × 0.25 mm
Z = 4

Data collection top

Nonius KappaCCD diffractometer	3990 independent reflections
Radiation source: fine-focus sealed tube	3626 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.013
ϕ scans, and ω scans with κ	θ_max = 30.1°, θ_min = 3.2°
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997)	h = −16→16
T_min = 0.845, T_max = 0.952	k = −12→12
7738 measured reflections	l = −18→18

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)] = 0.029	All H-atom parameters refined
wR(F²) = 0.080	w = 1/[σ²(F_o²) + (0.0397P)² + 0.4747P] where P = (F_o² + 2F_c²)/3
S = 1.03	(Δ/σ)_max = 0.001
3990 reflections	Δρ_max = 0.38 e Å⁻³
243 parameters	Δρ_min = −0.33 e Å⁻³
0 restraints	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.013 (2)

Crystal data top

C₆H₁₆N⁺·C₆H₆O₃P⁻	V = 1367.95 (3) Å³
M_r = 259.28	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 11.9166 (2) Å	µ = 0.20 mm⁻¹
b = 9.0982 (1) Å	T = 293 K
c = 12.8539 (1) Å	0.88 × 0.63 × 0.25 mm
β = 101.013 (1)°

Data collection top

Nonius KappaCCD diffractometer	3990 independent reflections
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997)	3626 reflections with I > 2σ(I)
T_min = 0.845, T_max = 0.952	R_int = 0.013
7738 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.029	0 restraints
wR(F²) = 0.080	All H-atom parameters refined
S = 1.03	Δρ_max = 0.38 e Å⁻³
3990 reflections	Δρ_min = −0.33 e Å⁻³
243 parameters

Special details top

Experimental. The analytical data - % calculated (% found): C: 55.59 (55.64); H: 8.55 (8.91); N: 5.40 (5.58).

Infrared data (cm^-1) [br= broad; s= strong; m=medium]

2694br νNH; 1148m, 1129 s, 1059, 1027m νPO₃; 898 s δPO₃; 752 m νPC; 708 s, 696 s νPh.

Melting point = 437–438 K

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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	0.966159 (19)	0.40247 (2)	0.846319 (17)	0.01271 (8)
O2	1.04330 (6)	0.32302 (7)	0.94386 (5)	0.01729 (14)
N1	0.66048 (7)	0.51553 (9)	0.78554 (6)	0.01430 (15)
C1	1.06532 (7)	0.49048 (10)	0.77593 (7)	0.01453 (17)
C6	1.14485 (9)	0.59178 (11)	0.82778 (8)	0.0222 (2)
C12	0.62928 (8)	0.41946 (10)	0.68876 (8)	0.01742 (18)
C13	0.69808 (9)	0.47210 (12)	0.60787 (8)	0.0225 (2)
C2	1.06337 (9)	0.46114 (11)	0.66912 (8)	0.01979 (19)
C4	1.21864 (9)	0.63037 (13)	0.66783 (9)	0.0270 (2)
C3	1.13968 (9)	0.53095 (13)	0.61530 (9)	0.0256 (2)
C5	1.22118 (10)	0.66111 (13)	0.77426 (10)	0.0287 (2)
O1	0.89926 (6)	0.29081 (8)	0.77497 (5)	0.02025 (15)
C8	0.60257 (8)	0.48352 (11)	0.87717 (8)	0.01757 (18)
C9	0.64492 (9)	0.59615 (12)	0.96314 (8)	0.0215 (2)
C11	0.50164 (9)	0.42810 (13)	0.64537 (9)	0.0245 (2)
C10	0.62574 (10)	0.32619 (12)	0.91508 (9)	0.0257 (2)
O3	0.89542 (5)	0.52144 (7)	0.88605 (5)	0.01657 (14)
H6	1.0624 (16)	0.376 (2)	0.9984 (15)	0.054 (5)*
H17	0.7362 (12)	0.5109 (14)	0.8110 (11)	0.022 (3)*
H16	0.6429 (12)	0.6104 (16)	0.7649 (11)	0.028 (3)*
H21	0.5218 (11)	0.4980 (14)	0.8513 (10)	0.018 (3)*
H18	0.6510 (11)	0.3197 (15)	0.7094 (10)	0.020 (3)*
H10	0.6767 (12)	0.5719 (16)	0.5864 (11)	0.029 (4)*
H7	0.7279 (12)	0.5857 (15)	0.9907 (11)	0.027 (3)*
H12	0.6818 (13)	0.4116 (16)	0.5460 (12)	0.034 (4)*
H9	0.6088 (13)	0.5821 (17)	1.0245 (12)	0.036 (4)*
H11	0.7788 (13)	0.4705 (16)	0.6362 (12)	0.032 (4)*
H8	0.6298 (13)	0.6961 (18)	0.9372 (12)	0.035 (4)*
H13	0.4820 (12)	0.3727 (17)	0.5783 (12)	0.034 (4)*
H20	0.7076 (13)	0.3059 (16)	0.9306 (11)	0.029 (3)*
H19	0.5963 (13)	0.3128 (18)	0.9806 (13)	0.041 (4)*
H15	0.4790 (13)	0.5297 (17)	0.6277 (12)	0.034 (4)*
H14	0.4571 (13)	0.3869 (16)	0.6953 (12)	0.034 (4)*
H22	0.5884 (13)	0.2571 (18)	0.8637 (13)	0.038 (4)*
H5	1.1462 (12)	0.6131 (15)	0.9024 (11)	0.028 (3)*
H3	1.2709 (13)	0.6789 (17)	0.6323 (12)	0.037 (4)*
H4	1.2746 (13)	0.7291 (18)	0.8131 (12)	0.040 (4)*
H2	1.1388 (13)	0.5080 (17)	0.5413 (12)	0.034 (4)*
H1	1.0101 (12)	0.3924 (16)	0.6328 (11)	0.027 (3)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
P1	0.01307 (12)	0.01214 (12)	0.01264 (12)	−0.00065 (7)	0.00175 (8)	−0.00020 (7)
O2	0.0219 (3)	0.0150 (3)	0.0141 (3)	0.0025 (2)	0.0012 (2)	0.0012 (2)
N1	0.0134 (3)	0.0143 (3)	0.0154 (3)	0.0003 (3)	0.0031 (3)	0.0005 (3)
C1	0.0141 (4)	0.0135 (4)	0.0161 (4)	0.0019 (3)	0.0032 (3)	0.0015 (3)
C6	0.0229 (5)	0.0226 (5)	0.0214 (5)	−0.0063 (4)	0.0051 (4)	−0.0012 (4)
C12	0.0184 (4)	0.0157 (4)	0.0179 (4)	0.0004 (3)	0.0027 (3)	−0.0029 (3)
C13	0.0214 (5)	0.0297 (5)	0.0171 (4)	0.0020 (4)	0.0049 (4)	−0.0015 (4)
C2	0.0207 (4)	0.0222 (5)	0.0171 (4)	0.0005 (4)	0.0052 (3)	−0.0001 (3)
C4	0.0241 (5)	0.0279 (5)	0.0321 (6)	0.0004 (4)	0.0129 (4)	0.0102 (4)
C3	0.0275 (5)	0.0309 (6)	0.0209 (5)	0.0033 (4)	0.0110 (4)	0.0049 (4)
C5	0.0262 (5)	0.0280 (5)	0.0326 (6)	−0.0105 (4)	0.0077 (4)	0.0014 (4)
O1	0.0231 (3)	0.0169 (3)	0.0193 (3)	−0.0056 (3)	0.0003 (3)	−0.0021 (3)
C8	0.0148 (4)	0.0209 (4)	0.0182 (4)	0.0006 (3)	0.0064 (3)	0.0026 (3)
C9	0.0228 (5)	0.0247 (5)	0.0179 (4)	0.0034 (4)	0.0065 (4)	−0.0007 (4)
C11	0.0190 (4)	0.0267 (5)	0.0263 (5)	−0.0035 (4)	0.0005 (4)	−0.0067 (4)
C10	0.0306 (5)	0.0215 (5)	0.0264 (5)	−0.0017 (4)	0.0089 (4)	0.0066 (4)
O3	0.0137 (3)	0.0197 (3)	0.0161 (3)	0.0026 (2)	0.0023 (2)	−0.0017 (2)

Geometric parameters (Å, º) top

P1—O1	1.4932 (7)	C2—C3	1.3962 (14)
P1—O3	1.5191 (7)	C2—H1	0.948 (14)
P1—O2	1.5809 (7)	C4—C3	1.3845 (17)
P1—C1	1.8068 (9)	C4—C5	1.3910 (16)
O2—H6	0.847 (19)	C4—H3	0.949 (15)
N1—C8	1.5030 (12)	C3—H2	0.972 (15)
N1—C12	1.5077 (12)	C5—H4	0.957 (16)
N1—H17	0.900 (14)	C8—C10	1.5202 (14)
N1—H16	0.916 (15)	C8—C9	1.5208 (14)
C1—C2	1.3945 (13)	C8—H21	0.965 (13)
C1—C6	1.3966 (13)	C9—H7	0.989 (15)
C6—C5	1.3920 (14)	C9—H9	0.976 (15)
C6—H5	0.976 (14)	C9—H8	0.973 (16)
C12—C11	1.5188 (14)	C11—H13	0.987 (15)
C12—C13	1.5193 (14)	C11—H15	0.977 (16)
C12—H18	0.967 (13)	C11—H14	0.982 (15)
C13—H10	0.969 (15)	C10—H20	0.976 (15)
C13—H12	0.957 (15)	C10—H19	0.980 (16)
C13—H11	0.961 (15)	C10—H22	0.957 (16)

O1—P1—O3	115.20 (4)	C3—C4—C5	119.74 (9)
O1—P1—O2	109.72 (4)	C3—C4—H3	121.1 (9)
O3—P1—O2	109.58 (4)	C5—C4—H3	119.1 (9)
O1—P1—C1	108.51 (4)	C4—C3—C2	120.12 (10)
O3—P1—C1	108.10 (4)	C4—C3—H2	119.8 (9)
O2—P1—C1	105.24 (4)	C2—C3—H2	120.1 (9)
P1—O2—H6	114.8 (12)	C4—C5—C6	120.10 (10)
C8—N1—C12	117.16 (7)	C4—C5—H4	122.1 (10)
C8—N1—H17	106.5 (8)	C6—C5—H4	117.8 (10)
C12—N1—H17	110.1 (8)	N1—C8—C10	110.56 (8)
C8—N1—H16	107.3 (9)	N1—C8—C9	107.49 (8)
C12—N1—H16	107.5 (9)	C10—C8—C9	112.76 (9)
H17—N1—H16	107.9 (12)	N1—C8—H21	106.3 (7)
C2—C1—C6	118.58 (9)	C10—C8—H21	110.3 (8)
C2—C1—P1	121.24 (7)	C9—C8—H21	109.2 (7)
C6—C1—P1	120.17 (7)	C8—C9—H7	111.5 (8)
C5—C6—C1	120.74 (10)	C8—C9—H9	111.2 (9)
C5—C6—H5	120.4 (8)	H7—C9—H9	105.2 (12)
C1—C6—H5	118.8 (8)	C8—C9—H8	111.5 (9)
N1—C12—C11	110.17 (8)	H7—C9—H8	108.6 (12)
N1—C12—C13	107.55 (8)	H9—C9—H8	108.5 (12)
C11—C12—C13	111.46 (9)	C12—C11—H13	110.3 (8)
N1—C12—H18	107.9 (8)	C12—C11—H15	110.3 (9)
C11—C12—H18	110.2 (8)	H13—C11—H15	105.8 (12)
C13—C12—H18	109.5 (7)	C12—C11—H14	111.6 (9)
C12—C13—H10	110.1 (8)	H13—C11—H14	108.0 (12)
C12—C13—H12	109.8 (9)	H15—C11—H14	110.7 (12)
H10—C13—H12	107.5 (12)	C8—C10—H20	110.9 (8)
C12—C13—H11	111.6 (9)	C8—C10—H19	108.6 (9)
H10—C13—H11	108.2 (12)	H20—C10—H19	108.0 (12)
H12—C13—H11	109.6 (12)	C8—C10—H22	111.4 (9)
C1—C2—C3	120.72 (10)	H20—C10—H22	109.3 (12)
C1—C2—H1	119.7 (8)	H19—C10—H22	108.3 (13)
C3—C2—H1	119.6 (8)

O1—P1—C1—C2	6.07 (9)	C8—N1—C12—C13	−179.89 (8)
O3—P1—C1—C2	−119.51 (8)	C6—C1—C2—C3	0.34 (14)
O2—P1—C1—C2	123.46 (8)	P1—C1—C2—C3	179.35 (8)
O1—P1—C1—C6	−174.93 (8)	C5—C4—C3—C2	−0.39 (17)
O3—P1—C1—C6	59.48 (8)	C1—C2—C3—C4	0.11 (16)
O2—P1—C1—C6	−57.55 (8)	C3—C4—C5—C6	0.21 (18)
C2—C1—C6—C5	−0.53 (15)	C1—C6—C5—C4	0.26 (17)
P1—C1—C6—C5	−179.55 (8)	C12—N1—C8—C10	58.07 (11)
C8—N1—C12—C11	58.44 (11)	C12—N1—C8—C9	−178.48 (8)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H17···O3	0.900 (14)	1.960 (14)	2.8510 (10)	170.3 (12)
O2—H6···O3ⁱ	0.847 (19)	1.744 (19)	2.5895 (10)	177.4 (19)
N1—H16···O1ⁱⁱ	0.916 (15)	1.764 (15)	2.6782 (10)	176.7 (13)

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

Experimental details

Crystal data
Chemical formula	C₆H₁₆N⁺·C₆H₆O₃P⁻
M_r	259.28
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	293
a, b, c (Å)	11.9166 (2), 9.0982 (1), 12.8539 (1)
β (°)	101.013 (1)
V (Å³)	1367.95 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.20
Crystal size (mm)	0.88 × 0.63 × 0.25

Data collection
Diffractometer	Nonius KappaCCD diffractometer
Absorption correction	Multi-scan (SCALEPACK; Otwinowski & Minor, 1997)
T_min, T_max	0.845, 0.952
No. of measured, independent and observed [I > 2σ(I)] reflections	7738, 3990, 3626
R_int	0.013
(sin θ/λ)_max (Å⁻¹)	0.705

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.029, 0.080, 1.03
No. of reflections	3990
No. of parameters	243
H-atom treatment	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.38, −0.33

Computer programs: COLLECT (Hooft, 1998), HKL DENZO (Otwinowski & Minor, 1997), SCALEPACK (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H17···O3	0.900 (14)	1.960 (14)	2.8510 (10)	170.3 (12)
O2—H6···O3ⁱ	0.847 (19)	1.744 (19)	2.5895 (10)	177.4 (19)
N1—H16···O1ⁱⁱ	0.916 (15)	1.764 (15)	2.6782 (10)	176.7 (13)

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

References

Beckmann, J., Dakternieks, D. & Duthie, A. (2003). Appl. Organomet. Chem. 17, 817–818. Web of Science CSD CrossRef CAS Google Scholar
Diop, T., Diop, L., Maris, T. & Stoeckli-Evans, H. (2012). Acta Cryst. E68, o1432. CSD CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Hooft, R. (1998). COLLECT. Nonius BV, Delft, The Netherlands. Google Scholar
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar

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Volume 68| Part 11| November 2012| Page o3078

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