organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 1| January 2010| Pages o45-o46

1-[2-(Carb­oxy­meth­­oxy)phen­yl]-N-(4-chloro­phen­yl)methanimine oxide

aDepartment of Chemistry, University of Aberdeen, Old Aberdeen AB15 5NY, Scotland, bDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia, cCentro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz (FIOCRUZ), Casa Amarela, Campus de Manguinhos, Av. Brasil 4365, 21040-900, Rio de Janeiro, RJ, Brazil, and dCHEMSOL, 1 Harcourt Road, Aberdeen AB15 5NY, Scotland
*Correspondence e-mail: edward.tiekink@gmail.com

(Received 10 November 2009; accepted 28 November 2009; online 4 December 2009)

In the title resonance conformer, C15H12ClNO4, the central C–N bond [1.297 (2) Å] has considerable double-bond character and the N–O bond [1.3215 (18) Å] indicates formal negative charge on the oxygen atom. Considerable deviations from co-planarity are evident in the mol­ecule, with both benzene rings twisted out of the central C–C–N–C plane [the dihedral angle formed between the rings = 81.99 (8)°]. Similarly, the carboxylic acid residue occupies a position almost normal to the plane of the benzene ring to which it is connected [C—C—O—C torsion angle = −78.42 (17)°]. The most prominent inter­molecular inter­actions involve the carboxylic acid the N+–O residues with the O—H⋯O hydrogen bonds leading to helical supra­molecular chains along the b axis. These chains are connected into layers via C–H⋯Ocarbon­yl inter­actions and the layers are consolidated into the crystal structure by C–H⋯Cl contacts.

Related literature

For the synthesis, see: Forrester et al. (1974[Forrester, A. R., Skilling, J. & Thomson, R. H. (1974). J. Chem. Soc. Perkin Trans. 1, pp. 2162-2166.]).

[Scheme 1]

Experimental

Crystal data
  • C15H12ClNO4

  • Mr = 305.72

  • Monoclinic, P 21 /c

  • a = 7.6631 (2) Å

  • b = 19.3034 (5) Å

  • c = 9.6305 (3) Å

  • β = 107.083 (1)°

  • V = 1361.73 (7) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.30 mm−1

  • T = 120 K

  • 0.26 × 0.14 × 0.12 mm

Data collection
  • Bruker–Nonius 95mm CCD camera on κ-goniostat diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2003[Sheldrick, G. M. (2003). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.760, Tmax = 1.000

  • 15210 measured reflections

  • 3113 independent reflections

  • 2589 reflections with I > 2σ(I)

  • Rint = 0.043

Refinement
  • R[F2 > 2σ(F2)] = 0.038

  • wR(F2) = 0.109

  • S = 1.10

  • 3113 reflections

  • 191 parameters

  • H-atom parameters constrained

  • Δρmax = 0.40 e Å−3

  • Δρmin = −0.46 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O2—H2⋯O4i 0.84 1.76 2.5834 (17) 167
C2—H2a⋯O1ii 0.99 2.29 3.205 (2) 154
C9—H9⋯Cl1iii 0.95 2.71 3.5538 (16) 148
Symmetry codes: (i) [-x+2, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) [x, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]; (iii) -x+1, -y+1, -z.

Data collection: COLLECT (Hooft, 1998[Hooft, R. W. W. (1998). COLLECT. Nonius BV, Delft, The Netherlands.]); cell refinement: DENZO (Otwinowski & Minor, 1997[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.]) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg, 2006[Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: publCIF (Westrip, 2009[Westrip, S. P. (2009). publCIF. In preparation.]).

Supporting information


Comment top

The title compound (I) and other N-(2-carboxymethoxybenzylidene)aniline N-oxides are useful precursors of 4-aryl-2H-1,4-benzoxazin-3(4H)-ones on photolysis in the presence of persulfate.

The C9–N1 bond distance of 1.297 (2) Å in (I), Fig. 1, indicates significant double bond character is this bond, and the N1–O4 distance of 1.3215 (18) Å is indicative of significant negative charge on the O4 centre, indicating that (I) exists primarily as a zwitterion. The molecular structure of (I) displays considerable deviations from co-planarity of the various residues. Thus, while the central moiety is planar as seen in the C4/C9/N1/C10 torsion angle of 176.07 (14) °, both phenyl substituents are twisted out of this plane as seen in the N1/C9/C4/C3 and C9/N1/C10/C11 torsion angles of 161.63 (15) and -60.8 (2) °, respectively. The carboxylic acid residue occupies a position approximately normal to the plane of the C3—C8 phenyl ring as seen in the C1/C2/O3/C3 torsion angle of -78.42 (17) °. The most prominent hydrogen bonding interactions are of the type O–H···O and occur between the carboxylic acid-O2–H and N–O- atoms. These lead to supramolecular helical chains aligned along the b axis, Table 1 and Fig. 2. Connections between chains are afforded by C–H···O2 interactions leading to undulating supramolecular arrays in the bc plane, Table 1 and Fig. 3, with the chloride atoms lying to either side. Layers stack along the a direction being held in place by C–H···Cl contacts, Table 1 and Fig. 4.

Related literature top

For the synthesis, see: Forrester et al. (1974).

Experimental top

The compound was prepared according to a published procedure (Forrester et al., 1974) from 2-H(O)CC6H4OCH2CO2H and 4-ClC6H4NHOH, m. pt. 484–485 K, lit. value 480–482 K. The sample used in the structure determination was grown from EtOH solution.

Refinement top

All H atoms were located from a difference map but, were geometrically placed (O–H = 0.84 Å and C–H = 0.95–0.99 Å) and refined as riding with Uiso(H) = 1.2–1.5Ueq(C, O).

Computing details top

Data collection: COLLECT (Hooft, 1998); cell refinement: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); data reduction: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2009).

Figures top
[Figure 1] Fig. 1. Molecular structure of (I) showing atom-labelling scheme and displacement ellipsoids at the 70% probability level.
[Figure 2] Fig. 2. Supramolecular helical chain in (I) aligned along the b axis and mediated by O–H···O hydrogen bonds (orange dashed lines). Colour code: Cl, cyan; O, red; N, blue; C, grey; and H, green.
[Figure 3] Fig. 3. Supramolecular array in (I) in the bc plane whereby the chains illustrated in Fig. 2 are connected by C–H···O contacts (blue dashed lines). Colour code as for Fig. 2.
[Figure 4] Fig. 4. Unit-cell contents for (I) viewed in projection down the c axis showing the stacking of the layers, illustrated in Fig. 3, along the a direction with the C–H···Cl contacts shown as pink dashed lines. Colour code as for Fig. 2.
1-[2-(Carboxymethoxy)phenyl]-N-(4-chlorophenyl)methanimine oxide top
Crystal data top
C15H12ClNO4F(000) = 632
Mr = 305.72Dx = 1.491 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71069 Å
Hall symbol: -P 2ybcCell parameters from 3158 reflections
a = 7.6631 (2) Åθ = 2.9–27.5°
b = 19.3034 (5) ŵ = 0.30 mm1
c = 9.6305 (3) ÅT = 120 K
β = 107.083 (1)°Block, colourless
V = 1361.73 (7) Å30.26 × 0.14 × 0.12 mm
Z = 4
Data collection top
Bruker–Nonius 95mm CCD camera on κ-goniostat
diffractometer
3113 independent reflections
Radiation source: Bruker-Nonius FR591 rotating anode2589 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.043
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 3.1°
ϕ & ω scansh = 99
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
k = 2424
Tmin = 0.760, Tmax = 1.000l = 1212
15210 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.038Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.109H-atom parameters constrained
S = 1.10 w = 1/[σ2(Fo2) + (0.0552P)2 + 0.4283P]
where P = (Fo2 + 2Fc2)/3
3113 reflections(Δ/σ)max < 0.001
191 parametersΔρmax = 0.40 e Å3
0 restraintsΔρmin = 0.46 e Å3
Crystal data top
C15H12ClNO4V = 1361.73 (7) Å3
Mr = 305.72Z = 4
Monoclinic, P21/cMo Kα radiation
a = 7.6631 (2) ŵ = 0.30 mm1
b = 19.3034 (5) ÅT = 120 K
c = 9.6305 (3) Å0.26 × 0.14 × 0.12 mm
β = 107.083 (1)°
Data collection top
Bruker–Nonius 95mm CCD camera on κ-goniostat
diffractometer
3113 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
2589 reflections with I > 2σ(I)
Tmin = 0.760, Tmax = 1.000Rint = 0.043
15210 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0380 restraints
wR(F2) = 0.109H-atom parameters constrained
S = 1.10Δρmax = 0.40 e Å3
3113 reflectionsΔρmin = 0.46 e Å3
191 parameters
Special details top

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
xyzUiso*/Ueq
Cl10.29830 (5)0.38201 (2)0.07891 (5)0.02112 (14)
O10.93820 (17)0.79845 (6)0.20859 (13)0.0221 (3)
O20.98035 (17)0.87208 (6)0.03948 (13)0.0188 (3)
H20.93830.90170.08510.028*
O31.10293 (16)0.69282 (6)0.10258 (12)0.0173 (3)
O41.14983 (15)0.47536 (6)0.35203 (13)0.0215 (3)
N11.02235 (18)0.51788 (7)0.27572 (14)0.0153 (3)
C10.9942 (2)0.81150 (8)0.10650 (17)0.0158 (3)
C21.0864 (2)0.75905 (8)0.03432 (17)0.0170 (3)
H2A1.01480.75430.06910.020*
H2B1.20940.77620.03790.020*
C31.2385 (2)0.68188 (8)0.23022 (17)0.0145 (3)
C41.2202 (2)0.62054 (8)0.30478 (17)0.0137 (3)
C51.3572 (2)0.60303 (9)0.43187 (18)0.0165 (3)
H51.34710.56140.48160.020*
C61.5076 (2)0.64566 (9)0.48609 (19)0.0195 (4)
H61.59950.63370.57290.023*
C71.5222 (2)0.70602 (9)0.41192 (19)0.0209 (4)
H71.62500.73530.44910.025*
C81.3896 (2)0.72460 (9)0.28434 (19)0.0191 (4)
H81.40210.76600.23470.023*
C91.0503 (2)0.58210 (9)0.24893 (17)0.0158 (3)
H90.94990.60650.18670.019*
C100.8406 (2)0.48799 (8)0.21883 (17)0.0153 (3)
C110.6971 (2)0.51583 (9)0.25987 (18)0.0180 (3)
H110.71400.55630.31830.022*
C120.5272 (2)0.48347 (9)0.21402 (18)0.0185 (4)
H120.42650.50140.24120.022*
C130.5076 (2)0.42485 (8)0.12845 (17)0.0155 (3)
C140.6508 (2)0.39793 (9)0.08408 (18)0.0179 (3)
H140.63280.35850.02250.022*
C150.8205 (2)0.42961 (9)0.13122 (18)0.0178 (3)
H150.92120.41170.10400.021*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0142 (2)0.0219 (3)0.0254 (2)0.00393 (15)0.00286 (17)0.00054 (16)
O10.0261 (7)0.0237 (7)0.0188 (6)0.0052 (5)0.0103 (5)0.0049 (5)
O20.0244 (6)0.0137 (6)0.0191 (6)0.0040 (5)0.0076 (5)0.0017 (5)
O30.0220 (6)0.0128 (6)0.0153 (6)0.0007 (5)0.0024 (5)0.0011 (4)
O40.0154 (6)0.0150 (6)0.0306 (7)0.0007 (5)0.0015 (5)0.0064 (5)
N10.0153 (6)0.0149 (7)0.0151 (7)0.0001 (5)0.0037 (5)0.0002 (5)
C10.0129 (8)0.0178 (9)0.0141 (8)0.0003 (6)0.0000 (6)0.0007 (6)
C20.0227 (8)0.0133 (8)0.0145 (8)0.0019 (7)0.0047 (7)0.0029 (6)
C30.0153 (8)0.0147 (8)0.0142 (7)0.0033 (6)0.0053 (6)0.0014 (6)
C40.0150 (8)0.0118 (8)0.0147 (8)0.0007 (6)0.0052 (6)0.0024 (6)
C50.0185 (8)0.0146 (8)0.0168 (8)0.0014 (6)0.0057 (7)0.0004 (6)
C60.0164 (8)0.0192 (9)0.0208 (8)0.0020 (7)0.0021 (7)0.0014 (7)
C70.0155 (8)0.0176 (9)0.0277 (9)0.0030 (7)0.0035 (7)0.0015 (7)
C80.0204 (8)0.0143 (8)0.0232 (9)0.0025 (7)0.0073 (7)0.0003 (7)
C90.0168 (8)0.0153 (8)0.0142 (8)0.0001 (6)0.0029 (6)0.0003 (6)
C100.0143 (8)0.0148 (8)0.0157 (8)0.0029 (6)0.0028 (6)0.0021 (6)
C110.0214 (8)0.0146 (8)0.0179 (8)0.0010 (7)0.0060 (7)0.0026 (6)
C120.0163 (8)0.0195 (9)0.0207 (8)0.0023 (7)0.0068 (7)0.0004 (7)
C130.0137 (7)0.0158 (8)0.0153 (8)0.0017 (6)0.0015 (6)0.0033 (6)
C140.0187 (8)0.0171 (8)0.0174 (8)0.0005 (7)0.0043 (7)0.0022 (6)
C150.0169 (8)0.0174 (9)0.0195 (8)0.0005 (7)0.0060 (6)0.0008 (6)
Geometric parameters (Å, º) top
Cl1—C131.7419 (16)C5—H50.9500
O1—C11.2095 (19)C6—C71.388 (2)
O2—C11.3248 (19)C6—H60.9500
O2—H20.8400C7—C81.392 (2)
O3—C31.3729 (19)C7—H70.9500
O3—C21.4260 (19)C8—H80.9500
O4—N11.3215 (18)C9—H90.9500
N1—C91.297 (2)C10—C111.382 (2)
N1—C101.458 (2)C10—C151.389 (2)
C1—C21.515 (2)C11—C121.394 (2)
C2—H2A0.9900C11—H110.9500
C2—H2B0.9900C12—C131.382 (2)
C3—C81.392 (2)C12—H120.9500
C3—C41.413 (2)C13—C141.390 (2)
C4—C51.400 (2)C14—C151.387 (2)
C4—C91.458 (2)C14—H140.9500
C5—C61.387 (2)C15—H150.9500
C1—O2—H2109.5C6—C7—H7119.3
C3—O3—C2119.48 (13)C8—C7—H7119.3
C9—N1—O4124.48 (14)C7—C8—C3119.28 (16)
C9—N1—C10119.93 (14)C7—C8—H8120.4
O4—N1—C10115.58 (13)C3—C8—H8120.4
O1—C1—O2125.67 (15)N1—C9—C4126.52 (15)
O1—C1—C2123.94 (15)N1—C9—H9116.7
O2—C1—C2110.37 (13)C4—C9—H9116.7
O3—C2—C1112.21 (13)C11—C10—C15122.26 (15)
O3—C2—H2A109.2C11—C10—N1119.43 (14)
C1—C2—H2A109.2C15—C10—N1118.20 (14)
O3—C2—H2B109.2C10—C11—C12118.87 (15)
C1—C2—H2B109.2C10—C11—H11120.6
H2A—C2—H2B107.9C12—C11—H11120.6
O3—C3—C8124.86 (15)C13—C12—C11118.92 (15)
O3—C3—C4114.96 (14)C13—C12—H12120.5
C8—C3—C4120.13 (15)C11—C12—H12120.5
C5—C4—C3119.07 (15)C12—C13—C14122.15 (15)
C5—C4—C9123.98 (14)C12—C13—Cl1118.82 (12)
C3—C4—C9116.77 (14)C14—C13—Cl1119.01 (13)
C6—C5—C4120.83 (15)C15—C14—C13118.91 (15)
C6—C5—H5119.6C15—C14—H14120.5
C4—C5—H5119.6C13—C14—H14120.5
C5—C6—C7119.21 (16)C14—C15—C10118.85 (15)
C5—C6—H6120.4C14—C15—H15120.6
C7—C6—H6120.4C10—C15—H15120.6
C6—C7—C8121.47 (16)
C3—O3—C2—C178.42 (17)C10—N1—C9—C4176.07 (14)
O1—C1—C2—O31.2 (2)C5—C4—C9—N123.3 (3)
O2—C1—C2—O3179.58 (13)C3—C4—C9—N1161.63 (15)
C2—O3—C3—C815.5 (2)C9—N1—C10—C1160.8 (2)
C2—O3—C3—C4167.06 (13)O4—N1—C10—C11119.82 (16)
O3—C3—C4—C5176.51 (14)C9—N1—C10—C15122.85 (17)
C8—C3—C4—C51.0 (2)O4—N1—C10—C1556.54 (19)
O3—C3—C4—C98.1 (2)C15—C10—C11—C121.2 (3)
C8—C3—C4—C9174.34 (14)N1—C10—C11—C12174.98 (14)
C3—C4—C5—C61.2 (2)C10—C11—C12—C130.3 (2)
C9—C4—C5—C6173.80 (15)C11—C12—C13—C141.4 (3)
C4—C5—C6—C70.6 (2)C11—C12—C13—Cl1176.80 (12)
C5—C6—C7—C80.1 (3)C12—C13—C14—C152.2 (3)
C6—C7—C8—C30.3 (3)Cl1—C13—C14—C15175.99 (12)
O3—C3—C8—C7176.99 (15)C13—C14—C15—C101.3 (2)
C4—C3—C8—C70.3 (2)C11—C10—C15—C140.4 (3)
O4—N1—C9—C44.6 (2)N1—C10—C15—C14175.84 (14)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2···O4i0.841.762.5834 (17)167
C2—H2a···O1ii0.992.293.205 (2)154
C9—H9···Cl1iii0.952.713.5538 (16)148
Symmetry codes: (i) x+2, y+1/2, z+1/2; (ii) x, y+3/2, z1/2; (iii) x+1, y+1, z.

Experimental details

Crystal data
Chemical formulaC15H12ClNO4
Mr305.72
Crystal system, space groupMonoclinic, P21/c
Temperature (K)120
a, b, c (Å)7.6631 (2), 19.3034 (5), 9.6305 (3)
β (°) 107.083 (1)
V3)1361.73 (7)
Z4
Radiation typeMo Kα
µ (mm1)0.30
Crystal size (mm)0.26 × 0.14 × 0.12
Data collection
DiffractometerBruker–Nonius 95mm CCD camera on κ-goniostat
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2003)
Tmin, Tmax0.760, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
15210, 3113, 2589
Rint0.043
(sin θ/λ)max1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.109, 1.10
No. of reflections3113
No. of parameters191
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.40, 0.46

Computer programs: , DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2006), publCIF (Westrip, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2···O4i0.841.762.5834 (17)167
C2—H2a···O1ii0.992.293.205 (2)154
C9—H9···Cl1iii0.952.713.5538 (16)148
Symmetry codes: (i) x+2, y+1/2, z+1/2; (ii) x, y+3/2, z1/2; (iii) x+1, y+1, z.
 

Footnotes

Additional correspondence author, e-mail: j.wardell@abdn.ac.uk.

Acknowledgements

The use of the EPSRC X-ray crystallographic service at the University of Southampton, England and the valuable assistance of the staff there is gratefully acknowledged. JLW acknowledges support from CAPES (Brazil).

References

First citationBrandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationForrester, A. R., Skilling, J. & Thomson, R. H. (1974). J. Chem. Soc. Perkin Trans. 1, pp. 2162–2166.  Google Scholar
First citationHooft, R. W. W. (1998). COLLECT. Nonius BV, Delft, The Netherlands.  Google Scholar
First citationOtwinowski, 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
First citationSheldrick, G. M. (2003). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationWestrip, S. P. (2009). publCIF. In preparation.  Google Scholar

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Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 1| January 2010| Pages o45-o46
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