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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

{4,4′-Di­methyl-2,2′-[2,2-di­methyl­propane-1,3-diylbis(nitrilo­methanylyl­­idene)]diphenolato}copper(II) monohydrate

aDepartment of Chemistry, Payame Noor University, PO Box 19395-3697 Tehran, I. R. of IRAN, bDepartment of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran, and cDepartment of Chemistry, University of Isfahan, 81746-73441 Isfahan, Iran
*Correspondence e-mail: h.kargar@pnu.ac.ir

(Received 23 July 2012; accepted 2 August 2012; online 11 August 2012)

The asymmetric unit of the title compound, [Cu(C21H24N2O2)]·H2O, comprises half of a Schiff base complex and half of a water mol­ecule. The whole compound is generated by crystallographic twofold rotation symmetry. The geometry around the CuII atom, located on a twofold axis, is distorted square-planar, which is supported by the N2O2 donor atoms of the coordinating Schiff base ligand. The dihedral angle between the symmetry-related benzene rings is 47.5 (4)°. In the crystal, the water mol­ecule that is hydrogen bonded to the coordinated O atoms links the mol­ecules via O—H⋯O inter­actions into chains parallel to [001]. The crystal structure is further stabilized by C—H⋯π inter­actions, and by ππ inter­actions involving inversion-related chelate rings [centroid–centroid distance = 3.480 (4) Å].

Related literature

For applications of Schiff bases in coordination chemistry, see: Granovski et al. (1993[Granovski, A. D., Nivorozhkin, A. L. & Minkin, V. I. (1993). Coord. Chem. Rev. 126, 1-69.]); Blower (1998[Blower, P. J. (1998). Transition Met. Chem. 23, 109-112.]). For related structures, see: Ghaemi et al. (2011[Ghaemi, A., Rayati, S., Elahi, E., Ng, S. W. & Tiekink, E. R. T. (2011). Acta Cryst. E67, m1445-m1446.]); Kargar et al. (2011[Kargar, H., Kia, R., Pahlavani, E. & Tahir, M. N. (2011). Acta Cryst. E67, m941.], 2012[Kargar, H., Kia, R., Sharafi, Z. & Tahir, M. N. (2012). Acta Cryst. E68, m82.]). For standard bond lengths, see: Allen et al. (1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]).

[Scheme 1]

Experimental

Crystal data
  • [Cu(C21H24N2O2)]·H2O

  • Mr = 417.98

  • Monoclinic, C 2/c

  • a = 13.353 (5) Å

  • b = 15.986 (5) Å

  • c = 10.023 (5) Å

  • β = 104.696 (5)°

  • V = 2069.5 (14) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 1.08 mm−1

  • T = 296 K

  • 0.11 × 0.08 × 0.05 mm

Data collection
  • Bruker SMART APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.891, Tmax = 0.948

  • 4967 measured reflections

  • 1779 independent reflections

  • 1053 reflections with I > 2σ(I)

  • Rint = 0.101

Refinement
  • R[F2 > 2σ(F2)] = 0.084

  • wR(F2) = 0.209

  • S = 0.95

  • 1779 reflections

  • 125 parameters

  • H-atom parameters constrained

  • Δρmax = 1.03 e Å−3

  • Δρmin = −0.96 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the C1–C6 ring.

D—H⋯A D—H H⋯A DA D—H⋯A
O1W—H1W1⋯O1 0.85 2.46 2.783 (7) 103
O1W—H1W1⋯O1i 0.85 2.44 2.783 (7) 105
C3—H3⋯O1Wii 0.93 2.55 3.48 (1) 173
C8—H8BCg1iii 0.97 2.83 3.693 (9) 148
C11—H11BCg1iv 0.96 2.98 3.850 (12) 151
Symmetry codes: (i) [-x+1, y, -z-{\script{1\over 2}}]; (ii) [-x+{\script{1\over 2}}, -y-{\script{1\over 2}}, -z-1]; (iii) [x+{\script{3\over 2}}, y+{\script{1\over 2}}, z-1]; (iv) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z-{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; 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: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

Schiff base complexes are one of the most important stereochemical models in transition metal coordination chemistry, with the ease of preparation and structural variations (Granovski et al., 1993; Blower, 1998). In continuation of our work on the structural analysis of Schiff base metal complexes (Kargar et al., 2012; Kargar et al., 2011; Ghaemi, et al., (2011), we synthesized the title compound and report herein on its crystal structure.

The asymmetric unit of the title compound, Fig. 1, comprises half of a Schiff base complex and half a water molecule. The Cu1 and C9 atoms of the complex and the O atom of the water molecule lie on a two-fold rotation axis which generates the whole complex. The bond lengths (Allen et al., 1987) and angles are within the normal ranges and are comparable to those reported for related structures (Kargar et al., 2012; Kargar et al., 2011; Ghaemi et al., (2011). The geometry around the CuII atom is distorted square-planar which is supported by the N2O2 donor atoms of the coordinated Schiff base ligand. The dihedral angle between the substituted benzene rings is 47.5 (4)°.

In the crystal, the water molecule that is hydrogen bonded to the coordinated O atoms, O1, mediates linking of molecules by C—H···O interactions (Table 1 and Fig. 2). The crystal structure is further stabilized by C-H···π interactions (Table 1), and by π-π interactions involving inversion related chelate rings [Cg···Cgi = 3.480 (4) Å; Cg is the centroid of the Cu1/O1/C1/C6/C7/N1 ring; symmetry code: (i) 1 - x, -y, -1 - z].

Related literature top

For applications of Schiff bases in coordination chemistry, see: Granovski et al. (1993); Blower (1998). For related structures, see: Ghaemi et al. (2011); Kargar et al. (2011, 2012). For standard bond lengths, see: Allen et al. (1987).

Experimental top

The title compound was synthesized by adding 5-methyl-salicylaldehyde-2,2-dimethyl-1,3-propanediamine (2 mmol) to a solution of CuCl2. 4H2O (2.1 mmol) in ethanol (30 ml). The mixture was refluxed with stirring for 30 min. The resultant solution was filtered. Dark-green single crystals of the title compound suitable for X-ray structure determination were recrystallized from ethanol by slow evaporation of the solvents at room temperature over several days.

Refinement top

The water H atom was located in a difference Fourier map and refined as a riding atom with Uiso(H) = 1.5Ueq(O). The C-bound H-atoms were included in calculated positions and treated as riding atoms: C—H = 0.93, 0.96 and 0.97 Å for CH, CH3 and CH2 H-atoms, respectively, with Uiso (H) = k x Ueq(C), where k = 1.5 for CH3 H-atoms, and = 1.2 for other H-atoms.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 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: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. A view of the molecular structure of the title compound, with the atom numbering. The displacement ellipsoids are drawn at the 40% probability level. The O-H···O hydrogen bonds are shown as dashed lines (see Table 1 for details; symmetry code for suffix A = -x+1, y, -z-1/2).
[Figure 2] Fig. 2. A view along the b axis of the crystal packing of the title compound showing the C—H···O interactions as dashed lines [see Table 1 for details; only the H atoms involved in these interactions are shown].
{4,4'-Dimethyl-2,2'-[2,2-dimethylpropane-1,3- diylbis(nitrilomethanylylidene)]diphenolato}copper(II) monohydrate top
Crystal data top
[Cu(C21H24N2O2)]·H2OF(000) = 876
Mr = 417.98Dx = 1.342 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 512 reflections
a = 13.353 (5) Åθ = 2.5–27.4°
b = 15.986 (5) ŵ = 1.08 mm1
c = 10.023 (5) ÅT = 296 K
β = 104.696 (5)°Block, dark-green
V = 2069.5 (14) Å30.11 × 0.08 × 0.05 mm
Z = 4
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
1779 independent reflections
Radiation source: fine-focus sealed tube1053 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.101
ϕ and ω scansθmax = 25.0°, θmin = 2.0°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
h = 1511
Tmin = 0.891, Tmax = 0.948k = 1818
4967 measured reflectionsl = 1011
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)] = 0.084Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.209H-atom parameters constrained
S = 0.95 w = 1/[σ2(Fo2) + (0.0775P)2]
where P = (Fo2 + 2Fc2)/3
1779 reflections(Δ/σ)max < 0.001
125 parametersΔρmax = 1.03 e Å3
0 restraintsΔρmin = 0.96 e Å3
Crystal data top
[Cu(C21H24N2O2)]·H2OV = 2069.5 (14) Å3
Mr = 417.98Z = 4
Monoclinic, C2/cMo Kα radiation
a = 13.353 (5) ŵ = 1.08 mm1
b = 15.986 (5) ÅT = 296 K
c = 10.023 (5) Å0.11 × 0.08 × 0.05 mm
β = 104.696 (5)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
1779 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
1053 reflections with I > 2σ(I)
Tmin = 0.891, Tmax = 0.948Rint = 0.101
4967 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0840 restraints
wR(F2) = 0.209H-atom parameters constrained
S = 0.95Δρmax = 1.03 e Å3
1779 reflectionsΔρmin = 0.96 e Å3
125 parameters
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 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 > 2sigma(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
Cu10.50000.01026 (6)0.25000.0266 (5)
O10.4089 (4)0.0737 (2)0.3499 (6)0.0312 (14)
N10.4554 (5)0.0944 (3)0.3912 (7)0.0305 (16)
C10.3331 (6)0.0612 (4)0.4620 (9)0.0293 (19)
C20.2617 (6)0.1276 (4)0.5073 (10)0.042 (3)
H20.26620.17580.45410.050*
C30.1860 (7)0.1214 (5)0.6291 (11)0.046 (3)
H30.13750.16420.65300.055*
C40.1790 (6)0.0526 (5)0.7191 (10)0.045 (2)
C60.3222 (6)0.0109 (4)0.5441 (9)0.0311 (19)
C70.3854 (6)0.0845 (4)0.5067 (10)0.032 (2)
H70.37530.12820.56990.038*
C80.5166 (6)0.1727 (4)0.3691 (9)0.036 (2)
H8A0.49840.20560.45310.043*
H8B0.58940.15870.35120.043*
C90.50000.2260 (6)0.25000.048 (4)
C50.2449 (6)0.0134 (5)0.6699 (10)0.042 (2)
H50.23800.06210.72240.051*
C110.1004 (8)0.0471 (7)0.8564 (12)0.069 (3)
H11B0.12060.00420.91130.104*
H11A0.03380.03380.84210.104*
H11C0.09680.09990.90320.104*
C100.4033 (10)0.2806 (6)0.2988 (13)0.087 (5)
H10B0.39470.31490.22380.130*
H10A0.34360.24550.32990.130*
H10C0.41100.31570.37330.130*
O1W0.50000.2254 (4)0.25000.091 (5)
H1W10.52810.19360.29810.137*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.0194 (7)0.0263 (6)0.0300 (9)0.0000.0015 (6)0.000
O10.026 (3)0.026 (2)0.031 (4)0.0008 (18)0.012 (3)0.005 (2)
N10.033 (4)0.032 (3)0.030 (5)0.005 (2)0.016 (4)0.003 (3)
C10.018 (4)0.038 (4)0.030 (5)0.001 (3)0.003 (4)0.005 (3)
C20.031 (5)0.037 (4)0.049 (7)0.000 (3)0.007 (5)0.000 (4)
C30.020 (5)0.060 (5)0.052 (7)0.007 (3)0.001 (5)0.014 (5)
C40.017 (4)0.068 (5)0.046 (7)0.005 (4)0.003 (5)0.003 (5)
C60.022 (4)0.036 (3)0.032 (5)0.007 (3)0.001 (4)0.001 (3)
C70.030 (5)0.029 (3)0.036 (6)0.007 (3)0.006 (5)0.011 (3)
C80.026 (5)0.032 (4)0.044 (6)0.007 (3)0.002 (5)0.004 (3)
C90.046 (9)0.025 (5)0.073 (12)0.0000.018 (8)0.000
C50.026 (5)0.052 (4)0.043 (6)0.005 (3)0.002 (4)0.007 (4)
C110.036 (6)0.113 (8)0.049 (8)0.013 (5)0.007 (6)0.000 (6)
C100.123 (12)0.058 (6)0.089 (11)0.050 (6)0.045 (9)0.034 (6)
O1W0.106 (10)0.033 (5)0.106 (11)0.0000.026 (8)0.000
Geometric parameters (Å, º) top
Cu1—O1i1.914 (4)C6—C71.441 (10)
Cu1—O11.914 (4)C7—H70.9300
Cu1—N1i1.934 (6)C8—C91.527 (10)
Cu1—N11.934 (6)C8—H8A0.9700
O1—C11.322 (9)C8—H8B0.9700
N1—C71.300 (10)C9—C8i1.527 (10)
N1—C81.480 (8)C9—C101.533 (10)
C1—C61.403 (10)C9—C10i1.533 (10)
C1—C21.423 (10)C5—H50.9300
C2—C31.377 (12)C11—H11B0.9600
C2—H20.9300C11—H11A0.9600
C3—C41.411 (13)C11—H11C0.9600
C3—H30.9300C10—H10B0.9600
C4—C51.382 (11)C10—H10A0.9600
C4—C111.507 (12)C10—H10C0.9600
C6—C51.413 (11)O1W—H1W10.8513
O1i—Cu1—O191.0 (3)N1—C8—C9113.9 (7)
O1i—Cu1—N1i93.9 (2)N1—C8—H8A108.8
O1—Cu1—N1i155.2 (3)C9—C8—H8A108.8
O1i—Cu1—N1155.1 (3)N1—C8—H8B108.8
O1—Cu1—N193.9 (2)C9—C8—H8B108.8
N1i—Cu1—N191.9 (4)H8A—C8—H8B107.7
C1—O1—Cu1125.9 (4)C8—C9—C8i112.2 (8)
C7—N1—C8118.8 (6)C8—C9—C10110.2 (6)
C7—N1—Cu1125.8 (4)C8i—C9—C10106.9 (6)
C8—N1—Cu1115.0 (5)C8—C9—C10i106.9 (6)
O1—C1—C6124.5 (6)C8i—C9—C10i110.2 (6)
O1—C1—C2117.8 (7)C10—C9—C10i110.5 (11)
C6—C1—C2117.6 (8)C4—C5—C6123.4 (8)
C3—C2—C1120.8 (8)C4—C5—H5118.3
C3—C2—H2119.6C6—C5—H5118.3
C1—C2—H2119.6C4—C11—H11B109.5
C2—C3—C4122.5 (7)C4—C11—H11A109.5
C2—C3—H3118.8H11B—C11—H11A109.5
C4—C3—H3118.8C4—C11—H11C109.5
C5—C4—C3115.8 (8)H11B—C11—H11C109.5
C5—C4—C11121.0 (9)H11A—C11—H11C109.5
C3—C4—C11123.1 (8)C9—C10—H10B109.5
C1—C6—C5119.4 (7)C9—C10—H10A109.5
C1—C6—C7123.4 (7)H10B—C10—H10A109.5
C5—C6—C7117.1 (7)C9—C10—H10C109.5
N1—C7—C6124.9 (7)H10B—C10—H10C109.5
N1—C7—H7117.5H10A—C10—H10C109.5
C6—C7—H7117.5
O1i—Cu1—O1—C1166.5 (8)C2—C1—C6—C52.8 (12)
N1i—Cu1—O1—C192.1 (9)O1—C1—C6—C77.9 (13)
N1—Cu1—O1—C110.9 (7)C2—C1—C6—C7176.4 (8)
O1i—Cu1—N1—C7101.3 (8)C8—N1—C7—C6178.2 (8)
O1—Cu1—N1—C70.5 (8)Cu1—N1—C7—C65.8 (13)
N1i—Cu1—N1—C7155.3 (9)C1—C6—C7—N13.6 (14)
O1i—Cu1—N1—C871.3 (8)C5—C6—C7—N1175.7 (8)
O1—Cu1—N1—C8172.1 (6)C7—N1—C8—C9116.3 (8)
N1i—Cu1—N1—C832.1 (4)Cu1—N1—C8—C970.5 (7)
Cu1—O1—C1—C615.7 (11)N1—C8—C9—C8i35.3 (4)
Cu1—O1—C1—C2168.6 (6)N1—C8—C9—C1083.7 (9)
O1—C1—C2—C3174.8 (8)N1—C8—C9—C10i156.2 (8)
C6—C1—C2—C31.2 (14)C3—C4—C5—C66.1 (15)
C1—C2—C3—C44.2 (15)C11—C4—C5—C6177.9 (9)
C2—C3—C4—C57.7 (15)C1—C6—C5—C41.0 (14)
C2—C3—C4—C11176.4 (10)C7—C6—C5—C4179.7 (9)
O1—C1—C6—C5172.9 (8)
Symmetry code: (i) x+1, y, z1/2.
Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the C1–C6 ring.
D—H···AD—HH···AD···AD—H···A
O1W—H1W1···O10.852.462.783 (7)103
O1W—H1W1···O1i0.852.442.783 (7)105
C3—H3···O1Wii0.932.553.48 (1)173
C8—H8B···Cg1iii0.972.833.693 (9)148
C11—H11B···Cg1iv0.962.983.850 (12)151
Symmetry codes: (i) x+1, y, z1/2; (ii) x+1/2, y1/2, z1; (iii) x+3/2, y+1/2, z1; (iv) x+1/2, y+1/2, z1/2.

Experimental details

Crystal data
Chemical formula[Cu(C21H24N2O2)]·H2O
Mr417.98
Crystal system, space groupMonoclinic, C2/c
Temperature (K)296
a, b, c (Å)13.353 (5), 15.986 (5), 10.023 (5)
β (°) 104.696 (5)
V3)2069.5 (14)
Z4
Radiation typeMo Kα
µ (mm1)1.08
Crystal size (mm)0.11 × 0.08 × 0.05
Data collection
DiffractometerBruker SMART APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.891, 0.948
No. of measured, independent and
observed [I > 2σ(I)] reflections
4967, 1779, 1053
Rint0.101
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.084, 0.209, 0.95
No. of reflections1779
No. of parameters125
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)1.03, 0.96

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
Cg1 is the centroid of the C1–C6 ring.
D—H···AD—HH···AD···AD—H···A
O1W—H1W1···O10.852.462.783 (7)103
O1W—H1W1···O1i0.852.442.783 (7)105
C3—H3···O1Wii0.932.553.48 (1)173
C8—H8B···Cg1iii0.972.833.693 (9)148
C11—H11B···Cg1iv0.962.983.850 (12)151
Symmetry codes: (i) x+1, y, z1/2; (ii) x+1/2, y1/2, z1; (iii) x+3/2, y+1/2, z1; (iv) x+1/2, y+1/2, z1/2.
 

Acknowledgements

HK and FG thank PNU for financial support.

References

First citationAllen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.  CrossRef Web of Science Google Scholar
First citationBlower, P. J. (1998). Transition Met. Chem. 23, 109–112.  CrossRef CAS Google Scholar
First citationBruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationGhaemi, A., Rayati, S., Elahi, E., Ng, S. W. & Tiekink, E. R. T. (2011). Acta Cryst. E67, m1445–m1446.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationGranovski, A. D., Nivorozhkin, A. L. & Minkin, V. I. (1993). Coord. Chem. Rev. 126, 1–69.  Google Scholar
First citationKargar, H., Kia, R., Pahlavani, E. & Tahir, M. N. (2011). Acta Cryst. E67, m941.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationKargar, H., Kia, R., Sharafi, Z. & Tahir, M. N. (2012). Acta Cryst. E68, m82.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds