supplementary materials


sj5337 scheme

Acta Cryst. (2013). E69, o1166    [ doi:10.1107/S1600536813017157 ]

4,4'-Di-tert-butyl-2,2'-[imidazolidine-1,3-diylbis(methylene)]diphenol

A. Rivera, L. S. Nerio and M. Bolte

Abstract top

In the title compound, C25H36N2O2, the two tert-butyl-substituted benzene rings are inclined at an angle of 53.5 (3)° to one another. The imidazolidine ring has an envelope conformation with with one of the C atoms of the ethylene fragment as the flap. The structure displays two intramolecular O-H...N hydrogen bonds that generate S(6) ring motifs. The crystal studied was a non-merohedral twin with a fractional contribution of 0.281(6) for the minor domain.

Comment top

2,2'-[imidazolidine-1,3-diylbis(methylene)]diphenol system has been used as ligand in the synthesis of a variety of coordination compounds, with potential applications in homogeneous catalysis (Kober et al., 2012, Xu et al., 2007, Zhang et al., 2009). The molecular structure and atom-numbering scheme for (I) are shown in Fig. 1. The imidazolidine ring adopts an envelope conformation, with C3 as the flap. The dihedral angle between aromatic rings is 53.5 (3)°. Its X-ray structure confirms the presence of two intramolecular hydrogen bonds between the phenolic hydroxyl groups and the imidazolidine nitrogen atoms with S(6) graph-set motifs (Bernstein et al., 1995) (Table 1).

Related literature top

For related structures, see: Rivera et al. (2011, 2012a, 2012b); Rivera, Nerio, Ríos-Motta, Fejfarová et al. (2012). For the use of the 2,2'-[imidazolidine-1,3-diylbis(methylene)]diphenol system as a ligand in the synthesis of a variety of coordination compounds, see: Kober et al. (2012); Xu et al. (2007); Zhang et al. (2009). For the original synthesis of the title compound, see: Rivera et al. (1993). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Experimental top

For the original synthesis of the title compound, see: Rivera et al. (1993). Single crystals suitable for X-ray diffraction were obtained from a mixture chloroform:methanol (1:1), by slow evaporation over 5 days at room temperature.

Refinement top

H atoms bonded to C were positioned geometrically, with C–H = 0.95–0.99 Å and constrained to ride on their parent atom, with Uiso(H) = 1.5Ueq(C) for methyl H atoms and 1.2Ueq(C) for other H atoms. The crystal was a non-merohedral twin with a fractional contribution of 0.281 (6) for the minor domain. The twin law is (1 0 0.773/0 - 1 0/0 0 - 1). As a result of this twinning, the figures of merit are rather high. Nevertheless, the H atoms bonded to O could be located in a difference map and they could be freely refined.

Computing details top

Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA (Stoe & Cie, 2001); data reduction: X-AREA (Stoe & Cie, 2001); 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: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, displacement ellipsoids are drawn at the 50% probability level. Intramolecular hydrogen bonds are drawn as dashed lines.
4,4'-Di-tert-butyl-2,2'-[imidazolidine-1,3-diylbis(methylene)]diphenol top
Crystal data top
C25H36N2O2F(000) = 864
Mr = 396.56Dx = 1.189 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 21.0879 (16) ÅCell parameters from 20905 reflections
b = 6.2110 (4) Åθ = 2.1–26.0°
c = 17.9086 (16) ŵ = 0.08 mm1
β = 109.168 (6)°T = 173 K
V = 2215.6 (3) Å3Block, colourless
Z = 40.24 × 0.22 × 0.19 mm
Data collection top
Stoe IPDS II two-circle
diffractometer
Rint = 0.101
Radiation source: Genix 3D IµS microfocus X-ray sourceθmax = 25.0°, θmin = 2.1°
ω scansh = 2524
22835 measured reflectionsk = 77
3909 independent reflectionsl = 1821
3131 reflections with I > 2σ(I)
Refinement top
Refinement on F2Hydrogen site location: mixed
Least-squares matrix: fullH atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.119 w = 1/[σ2(Fo2) + (0.0705P)2 + 10.9502P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.324(Δ/σ)max < 0.001
S = 1.13Δρmax = 0.42 e Å3
3909 reflectionsΔρmin = 0.39 e Å3
272 parametersExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.037 (4)
Crystal data top
C25H36N2O2V = 2215.6 (3) Å3
Mr = 396.56Z = 4
Monoclinic, P21/cMo Kα radiation
a = 21.0879 (16) ŵ = 0.08 mm1
b = 6.2110 (4) ÅT = 173 K
c = 17.9086 (16) Å0.24 × 0.22 × 0.19 mm
β = 109.168 (6)°
Data collection top
Stoe IPDS II two-circle
diffractometer
3131 reflections with I > 2σ(I)
22835 measured reflectionsRint = 0.101
3909 independent reflectionsθmax = 25.0°
Refinement top
R[F2 > 2σ(F2)] = 0.119 w = 1/[σ2(Fo2) + (0.0705P)2 + 10.9502P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.324Δρmax = 0.42 e Å3
S = 1.13Δρmin = 0.39 e Å3
3909 reflectionsAbsolute structure: ?
272 parametersAbsolute structure parameter: ?
0 restraintsRogers parameter: ?
H atoms treated by a mixture of independent and constrained refinement
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. Refined as a 2-component twin.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.4712 (2)0.0117 (8)0.5876 (3)0.0455 (12)
H10.500 (5)0.122 (16)0.624 (6)0.09 (3)*
O20.6663 (2)0.9590 (8)0.7246 (3)0.0455 (12)
H20.635 (4)0.845 (13)0.716 (5)0.06 (2)*
N10.5256 (3)0.3720 (9)0.6606 (3)0.0385 (13)
N20.6261 (3)0.5545 (8)0.7268 (3)0.0368 (13)
C10.5734 (3)0.4179 (13)0.7397 (4)0.0489 (18)
H1A0.59290.28270.76690.059*
H1B0.55080.49450.77240.059*
C20.5537 (3)0.4692 (12)0.6021 (4)0.0433 (16)
H2A0.53460.61390.58540.052*
H2B0.54530.37650.55490.052*
C30.6280 (3)0.4820 (11)0.6489 (4)0.0369 (14)
H3A0.65010.33980.65250.044*
H3B0.65130.58750.62560.044*
C40.4565 (3)0.4390 (11)0.6528 (4)0.0419 (16)
H4A0.45240.59640.64370.050*
H4B0.44830.40890.70310.050*
C50.6896 (3)0.5301 (11)0.7933 (4)0.0394 (15)
H5A0.70460.37850.79600.047*
H5B0.68130.56390.84340.047*
C110.4026 (3)0.3260 (10)0.5857 (4)0.0364 (14)
C120.4124 (3)0.1211 (11)0.5592 (4)0.0407 (15)
C130.3586 (4)0.0247 (11)0.5019 (4)0.0492 (18)
H130.36480.11130.48100.059*
C140.2970 (4)0.1210 (11)0.4750 (4)0.0449 (16)
H140.26170.05080.43540.054*
C150.2846 (3)0.3197 (10)0.5040 (4)0.0399 (15)
C160.3396 (3)0.4209 (11)0.5576 (4)0.0421 (16)
H160.33390.56080.57580.050*
C170.2157 (3)0.4268 (12)0.4738 (4)0.0420 (16)
C180.2078 (4)0.5451 (13)0.3962 (4)0.0518 (19)
H18A0.21410.44310.35740.078*
H18B0.24150.65960.40570.078*
H18C0.16280.60810.37580.078*
C190.2058 (4)0.5876 (14)0.5326 (4)0.055 (2)
H19A0.21040.51440.58250.082*
H19B0.16090.65100.51140.082*
H19C0.23960.70150.54170.082*
C200.1589 (4)0.2555 (15)0.4574 (6)0.066 (2)
H20A0.16290.17770.50630.099*
H20B0.16300.15370.41740.099*
H20C0.11520.32720.43810.099*
C210.7443 (3)0.6742 (10)0.7855 (4)0.0363 (14)
C220.7299 (3)0.8793 (10)0.7516 (4)0.0403 (15)
C230.7822 (3)1.0074 (11)0.7463 (4)0.0434 (16)
H230.77311.14530.72220.052*
C240.8475 (3)0.9344 (11)0.7760 (4)0.0434 (16)
H240.88251.02410.77150.052*
C250.8639 (3)0.7346 (11)0.8122 (4)0.0422 (16)
C260.8101 (3)0.6077 (10)0.8153 (4)0.0366 (14)
H260.81940.46930.83900.044*
C270.9369 (3)0.6602 (12)0.8458 (5)0.0506 (18)
C280.9627 (4)0.613 (2)0.7759 (6)0.090 (4)
H28A0.95880.74330.74380.135*
H28B0.93590.49750.74320.135*
H28C1.00990.56870.79640.135*
C290.9436 (4)0.4555 (14)0.8947 (6)0.069 (2)
H29A0.91590.34170.86190.103*
H29B0.92860.48360.94010.103*
H29C0.99070.40940.91340.103*
C300.9809 (4)0.8335 (14)0.8977 (6)0.071 (3)
H30A0.97680.96690.86720.106*
H30B1.02780.78580.91560.106*
H30C0.96650.85950.94360.106*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.044 (3)0.040 (3)0.055 (3)0.004 (2)0.020 (2)0.007 (2)
O20.039 (3)0.036 (3)0.055 (3)0.004 (2)0.007 (2)0.006 (2)
N10.034 (3)0.046 (3)0.039 (3)0.001 (2)0.017 (2)0.001 (2)
N20.033 (3)0.039 (3)0.037 (3)0.003 (2)0.011 (2)0.003 (2)
C10.039 (4)0.055 (4)0.053 (4)0.012 (3)0.014 (3)0.000 (4)
C20.039 (4)0.047 (4)0.041 (4)0.003 (3)0.010 (3)0.001 (3)
C30.039 (3)0.038 (3)0.033 (3)0.004 (3)0.011 (3)0.004 (3)
C40.036 (3)0.042 (4)0.051 (4)0.001 (3)0.020 (3)0.008 (3)
C50.036 (3)0.044 (4)0.036 (3)0.001 (3)0.009 (3)0.002 (3)
C110.037 (3)0.032 (3)0.041 (4)0.004 (3)0.015 (3)0.003 (3)
C120.047 (4)0.039 (4)0.039 (3)0.001 (3)0.017 (3)0.005 (3)
C130.060 (4)0.032 (3)0.052 (4)0.003 (3)0.013 (4)0.005 (3)
C140.051 (4)0.041 (4)0.042 (4)0.008 (3)0.014 (3)0.006 (3)
C150.040 (3)0.038 (3)0.042 (4)0.004 (3)0.013 (3)0.003 (3)
C160.038 (3)0.036 (3)0.050 (4)0.001 (3)0.012 (3)0.001 (3)
C170.035 (3)0.051 (4)0.041 (4)0.001 (3)0.014 (3)0.006 (3)
C180.048 (4)0.065 (5)0.039 (4)0.001 (4)0.010 (3)0.005 (3)
C190.048 (4)0.068 (5)0.046 (4)0.013 (4)0.012 (3)0.000 (4)
C200.040 (4)0.072 (5)0.081 (6)0.012 (4)0.011 (4)0.006 (5)
C210.041 (3)0.035 (3)0.030 (3)0.004 (3)0.009 (3)0.003 (3)
C220.042 (4)0.035 (3)0.044 (4)0.000 (3)0.013 (3)0.003 (3)
C230.055 (4)0.036 (3)0.037 (3)0.007 (3)0.013 (3)0.005 (3)
C240.042 (4)0.047 (4)0.043 (4)0.013 (3)0.016 (3)0.003 (3)
C250.042 (4)0.042 (4)0.040 (4)0.005 (3)0.010 (3)0.006 (3)
C260.036 (3)0.036 (3)0.035 (3)0.001 (3)0.008 (3)0.003 (3)
C270.040 (4)0.055 (4)0.052 (4)0.003 (3)0.010 (3)0.007 (4)
C280.049 (5)0.135 (10)0.089 (7)0.009 (6)0.027 (5)0.027 (7)
C290.045 (4)0.056 (5)0.094 (7)0.002 (4)0.007 (4)0.000 (5)
C300.055 (5)0.055 (5)0.085 (6)0.010 (4)0.001 (4)0.011 (5)
Geometric parameters (Å, º) top
O1—C121.357 (8)C17—C181.533 (10)
O1—H11.00 (10)C17—C201.556 (10)
O2—C221.360 (8)C18—H18A0.9800
O2—H20.95 (8)C18—H18B0.9800
N1—C11.473 (9)C18—H18C0.9800
N1—C41.478 (8)C19—H19A0.9800
N1—C21.490 (9)C19—H19B0.9800
N2—C11.476 (8)C19—H19C0.9800
N2—C51.479 (8)C20—H20A0.9800
N2—C31.479 (8)C20—H20B0.9800
C1—H1A0.9900C20—H20C0.9800
C1—H1B0.9900C21—C261.377 (9)
C2—C31.517 (9)C21—C221.401 (9)
C2—H2A0.9900C22—C231.389 (9)
C2—H2B0.9900C23—C241.378 (10)
C3—H3A0.9900C23—H230.9500
C3—H3B0.9900C24—C251.391 (10)
C4—C111.526 (9)C24—H240.9500
C4—H4A0.9900C25—C261.397 (9)
C4—H4B0.9900C25—C271.529 (9)
C5—C211.503 (9)C26—H260.9500
C5—H5A0.9900C27—C301.522 (10)
C5—H5B0.9900C27—C291.523 (12)
C11—C161.388 (9)C27—C281.549 (12)
C11—C121.397 (9)C28—H28A0.9800
C12—C131.392 (10)C28—H28B0.9800
C13—C141.365 (10)C28—H28C0.9800
C13—H130.9500C29—H29A0.9800
C14—C151.397 (9)C29—H29B0.9800
C14—H140.9500C29—H29C0.9800
C15—C161.390 (9)C30—H30A0.9800
C15—C171.526 (9)C30—H30B0.9800
C16—H160.9500C30—H30C0.9800
C17—C191.514 (10)
C12—O1—H1101 (5)C18—C17—C20108.0 (6)
C22—O2—H2110 (5)C17—C18—H18A109.5
C1—N1—C4112.3 (5)C17—C18—H18B109.5
C1—N1—C2107.0 (5)H18A—C18—H18B109.5
C4—N1—C2115.3 (5)C17—C18—H18C109.5
C1—N2—C5110.1 (5)H18A—C18—H18C109.5
C1—N2—C3103.2 (5)H18B—C18—H18C109.5
C5—N2—C3115.6 (5)C17—C19—H19A109.5
N1—C1—N2105.8 (5)C17—C19—H19B109.5
N1—C1—H1A110.6H19A—C19—H19B109.5
N2—C1—H1A110.6C17—C19—H19C109.5
N1—C1—H1B110.6H19A—C19—H19C109.5
N2—C1—H1B110.6H19B—C19—H19C109.5
H1A—C1—H1B108.7C17—C20—H20A109.5
N1—C2—C3102.2 (5)C17—C20—H20B109.5
N1—C2—H2A111.3H20A—C20—H20B109.5
C3—C2—H2A111.3C17—C20—H20C109.5
N1—C2—H2B111.3H20A—C20—H20C109.5
C3—C2—H2B111.3H20B—C20—H20C109.5
H2A—C2—H2B109.2C26—C21—C22119.3 (6)
N2—C3—C2101.1 (5)C26—C21—C5119.5 (6)
N2—C3—H3A111.5C22—C21—C5121.2 (6)
C2—C3—H3A111.5O2—C22—C23118.7 (6)
N2—C3—H3B111.5O2—C22—C21122.2 (6)
C2—C3—H3B111.5C23—C22—C21119.1 (6)
H3A—C3—H3B109.4C24—C23—C22120.0 (6)
N1—C4—C11113.6 (5)C24—C23—H23120.0
N1—C4—H4A108.8C22—C23—H23120.0
C11—C4—H4A108.8C23—C24—C25122.5 (6)
N1—C4—H4B108.8C23—C24—H24118.8
C11—C4—H4B108.8C25—C24—H24118.8
H4A—C4—H4B107.7C24—C25—C26116.2 (6)
N2—C5—C21112.5 (5)C24—C25—C27121.2 (6)
N2—C5—H5A109.1C26—C25—C27122.6 (6)
C21—C5—H5A109.1C21—C26—C25122.9 (6)
N2—C5—H5B109.1C21—C26—H26118.6
C21—C5—H5B109.1C25—C26—H26118.6
H5A—C5—H5B107.8C30—C27—C29108.5 (7)
C16—C11—C12119.6 (6)C30—C27—C25111.1 (6)
C16—C11—C4117.8 (6)C29—C27—C25111.7 (6)
C12—C11—C4122.1 (6)C30—C27—C28108.7 (7)
O1—C12—C13119.0 (6)C29—C27—C28108.4 (8)
O1—C12—C11123.2 (6)C25—C27—C28108.4 (6)
C13—C12—C11117.8 (6)C27—C28—H28A109.5
C14—C13—C12121.5 (7)C27—C28—H28B109.5
C14—C13—H13119.2H28A—C28—H28B109.5
C12—C13—H13119.2C27—C28—H28C109.5
C13—C14—C15121.9 (7)H28A—C28—H28C109.5
C13—C14—H14119.0H28B—C28—H28C109.5
C15—C14—H14119.0C27—C29—H29A109.5
C16—C15—C14116.1 (6)C27—C29—H29B109.5
C16—C15—C17121.9 (6)H29A—C29—H29B109.5
C14—C15—C17121.8 (6)C27—C29—H29C109.5
C11—C16—C15122.8 (6)H29A—C29—H29C109.5
C11—C16—H16118.6H29B—C29—H29C109.5
C15—C16—H16118.6C27—C30—H30A109.5
C19—C17—C15112.0 (6)C27—C30—H30B109.5
C19—C17—C18108.4 (6)H30A—C30—H30B109.5
C15—C17—C18109.7 (6)C27—C30—H30C109.5
C19—C17—C20108.0 (6)H30A—C30—H30C109.5
C15—C17—C20110.6 (6)H30B—C30—H30C109.5
C4—N1—C1—N2123.4 (6)C16—C15—C17—C1926.9 (9)
C2—N1—C1—N24.0 (7)C14—C15—C17—C19157.8 (7)
C5—N2—C1—N1154.4 (5)C16—C15—C17—C1893.5 (8)
C3—N2—C1—N130.5 (7)C14—C15—C17—C1881.8 (8)
C1—N1—C2—C323.1 (7)C16—C15—C17—C20147.5 (7)
C4—N1—C2—C3148.8 (5)C14—C15—C17—C2037.2 (9)
C1—N2—C3—C244.4 (6)N2—C5—C21—C26148.4 (6)
C5—N2—C3—C2164.6 (5)N2—C5—C21—C2234.6 (8)
N1—C2—C3—N241.3 (6)C26—C21—C22—O2176.7 (6)
C1—N1—C4—C11159.1 (6)C5—C21—C22—O20.3 (10)
C2—N1—C4—C1177.9 (7)C26—C21—C22—C232.4 (9)
C1—N2—C5—C21177.0 (6)C5—C21—C22—C23179.4 (6)
C3—N2—C5—C2166.5 (7)O2—C22—C23—C24177.5 (6)
N1—C4—C11—C16160.5 (6)C21—C22—C23—C241.6 (10)
N1—C4—C11—C1227.4 (9)C22—C23—C24—C250.4 (11)
C16—C11—C12—O1175.5 (6)C23—C24—C25—C261.6 (10)
C4—C11—C12—O13.6 (10)C23—C24—C25—C27178.9 (7)
C16—C11—C12—C133.2 (10)C22—C21—C26—C251.2 (10)
C4—C11—C12—C13175.2 (6)C5—C21—C26—C25178.2 (6)
O1—C12—C13—C14175.6 (7)C24—C25—C26—C210.8 (10)
C11—C12—C13—C143.2 (11)C27—C25—C26—C21179.7 (6)
C12—C13—C14—C150.7 (11)C24—C25—C27—C3048.9 (10)
C13—C14—C15—C164.5 (10)C26—C25—C27—C30131.5 (8)
C13—C14—C15—C17180.0 (7)C24—C25—C27—C29170.2 (7)
C12—C11—C16—C150.7 (10)C26—C25—C27—C2910.3 (10)
C4—C11—C16—C15171.6 (6)C24—C25—C27—C2870.4 (9)
C14—C15—C16—C114.4 (10)C26—C25—C27—C28109.1 (9)
C17—C15—C16—C11180.0 (6)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N11.00 (10)1.70 (10)2.655 (7)157 (8)
O2—H2···N20.95 (8)1.83 (8)2.656 (7)144 (7)

Experimental details

Crystal data
Chemical formulaC25H36N2O2
Mr396.56
Crystal system, space groupMonoclinic, P21/c
Temperature (K)173
a, b, c (Å)21.0879 (16), 6.2110 (4), 17.9086 (16)
β (°) 109.168 (6)
V3)2215.6 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.24 × 0.22 × 0.19
Data collection
DiffractometerStoe IPDS II two-circle
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
22835, 3909, 3131
Rint0.101
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.119, 0.324, 1.13
No. of reflections3909
No. of parameters272
No. of restraints0
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
w = 1/[σ2(Fo2) + (0.0705P)2 + 10.9502P]
where P = (Fo2 + 2Fc2)/3
Δρmax, Δρmin (e Å3)0.42, 0.39

Computer programs: X-AREA (Stoe & Cie, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2006).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N11.00 (10)1.70 (10)2.655 (7)157 (8)
O2—H2···N20.95 (8)1.83 (8)2.656 (7)144 (7)
Acknowledgements top

The authors acknowledge the Dirección de Investigaciones, Sede Bogotá (DIB) de la Universidad Nacional de Colombia, for financial support of this work. LSN thanks COLCIENCIAS for a fellowship.

references
References top

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Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.

Kober, E., Nerkowski, T., Janas, Z. & Jerzykiewicz, L. B. (2012). Dalton Trans. 41, 5188–5192.

Rivera, A., Gallo, G. I., Gayón, M. E. & Joseph-Nathan, P. (1993). Synth. Commun. 23, 2921–2929.

Rivera, A., Nerio, L. S., Ríos-Motta, J., Fejfarová, K. & Dušek, M. (2012). Acta Cryst. E68, o170–o171.

Rivera, A., Nerio, L. S., Ríos-Motta, J., Kučeráková, M. & Dušek, M. (2012a). Acta Cryst. E68, o3043–o3044.

Rivera, A., Nerio, L. S., Ríos-Motta, J., Kučeraková, M. & Dušek, M. (2012b). Acta Cryst. E68, o3172.

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Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Stoe & Cie (2001). X-AREA. Stoe & Cie, Darmstadt, Germany.

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Zhang, Z., Xu, X., Li, W., Yao, Y., Zhang, Y., Shen, Q. & Luo, Y. (2009). Inorg. Chem. 48, 5715–5724.