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(E,E)-3,3′-Di­methyl-1,1′-di­phenyl-4,4′-{[3-aza­pentane-1,5-diylbis(aza­nedi­yl)]bis­­(phenyl­methyl­­idyne)}di-1H-pyrazol-5(4H)-one

aDepartment of Physics and Chemistry, Henan Polytechnic University, Jiaozuo 454000, People's Republic of China, and bInstitute of Functional Materials, Jiangxi University of Finance & Economics, Nanchang 330013, People's Republic of China
*Correspondence e-mail: wangyuan08@hpu.edu.cn

(Received 21 November 2010; accepted 23 November 2010; online 27 November 2010)

The asymmetric unit of the title compound, C38H37N7O2, contains one half-mol­ecule, situated on a twofold rotational axis, in which one amino group is involved in intra­molecular N—H⋯O hydrogen bond and the two phenyl rings are twisted from the plane of pyrazolone ring by 26.69 (10) and 79.64 (8)°. The crystal packing exhibits no classical inter­molecular contacts.

Related literature

For the synthesis of the title compound and the DNA binding properties of its transition metal complexes, see: Yang et al. (2000[Yang, Z.-Y., Yang, R.-D., Li, F.-S. & Yu, K.-B. (2000). Polyhedron, 19, 2599-2604.]); Wang & Yang (2005[Wang, Y. & Yang, Z.-Y. (2005). Transition Met. Chem. 30, 902-906.]). For the similar structure of (E,E)-3,3′-dimethyl-1,1′-diphenyl-4,4′-{(ethane-1,2-diyldiimino)­bis­[(2-fur­yl)-methyl­idyne]}di-1H-pyrazol-5(4H)-one, see: Wang (2010[Wang, H.-W. (2010). Acta Cryst. E66, o1534.]).

[Scheme 1]

Experimental

Crystal data
  • C38H37N7O2

  • Mr = 623.75

  • Monoclinic, C 2/c

  • a = 20.3219 (8) Å

  • b = 8.1990 (2) Å

  • c = 20.5468 (6) Å

  • β = 106.748 (2)°

  • V = 3278.27 (18) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.08 mm−1

  • T = 296 K

  • 0.23 × 0.21 × 0.15 mm

Data collection
  • Bruker SMART APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2007[Bruker (2007). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.982, Tmax = 0.988

  • 8269 measured reflections

  • 3765 independent reflections

  • 1886 reflections with I > 2σ(I)

  • Rint = 0.021

Refinement
  • R[F2 > 2σ(F2)] = 0.054

  • wR(F2) = 0.179

  • S = 1.01

  • 3765 reflections

  • 214 parameters

  • H-atom parameters constrained

  • Δρmax = 0.34 e Å−3

  • Δρmin = −0.29 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N3—H3A⋯O1 0.86 2.00 2.722 (2) 140

Data collection: APEX2 (Bruker, 2007[Bruker (2007). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2007[Bruker (2007). 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.

Supporting information


Comment top

The Schiff bases derivatives of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) and their metal complexes have been widely studied because of their high biological and pharmaceutical activities (Yang et al., 2000; Wang et al., 2005). For our interest in coordination chemistry, the crystal structure of the title compound was determined by X-ray diffraction analysis.

The asymmetric unit of the title compound contains a half of the molecule situated on a twofold rotational axis. In the independent part of the molecule, one amino group is invloved in intramolecular N—H···O hydrogen bond (Table 1), and two phenyl rings are twisted from the plane of pyrazolone ring at 26.69 (10)° and 79.64 (8)°, respectively. The crystal packing exhibits no classical intermolecular contacts.

Related literature top

For the synthesis of the title compound and the DNA binding properties of its transition metal complexes, see: Yang et al. (2000); Wang et al. (2005). For the similar structure of (E,E)-3,3'-dimethyl-1,1'-diphenyl-4,4'-{(ethane-1,2-diyldiimino)bis[(2-furyl)-methylidyne]}di-1H-pyrazol-5(4H)-one, see: Wang et al. (2010).

Experimental top

The title compound was prepared according to the literature (Wang et al., 2005). 1.1 g (4 mmol) of PMBP were dissolved in EtOH (50 ml), and the EtOH solution containing diethylenetriamine (0.2 g, 2 mmol) was added dropwise. The mixture refluxed on a water bath for 4 h, then part of the solvent was removed on a rotary evaporator. After cooling to 273 K, a large amount of yellow precipitate separated out. Yellow block crystals were obtained by slow evaporation of an ethanol /chloroform (1:1) solution.

Refinement top

All H atoms were placed in calculated positions, with C—H = 0.93–0.97 Å and N—H = 0.86 Å, and were treated as riding, with Uiso(H) = 1.2-1.5 Ueq of the parent atom.

Structure description top

The Schiff bases derivatives of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) and their metal complexes have been widely studied because of their high biological and pharmaceutical activities (Yang et al., 2000; Wang et al., 2005). For our interest in coordination chemistry, the crystal structure of the title compound was determined by X-ray diffraction analysis.

The asymmetric unit of the title compound contains a half of the molecule situated on a twofold rotational axis. In the independent part of the molecule, one amino group is invloved in intramolecular N—H···O hydrogen bond (Table 1), and two phenyl rings are twisted from the plane of pyrazolone ring at 26.69 (10)° and 79.64 (8)°, respectively. The crystal packing exhibits no classical intermolecular contacts.

For the synthesis of the title compound and the DNA binding properties of its transition metal complexes, see: Yang et al. (2000); Wang et al. (2005). For the similar structure of (E,E)-3,3'-dimethyl-1,1'-diphenyl-4,4'-{(ethane-1,2-diyldiimino)bis[(2-furyl)-methylidyne]}di-1H-pyrazol-5(4H)-one, see: Wang et al. (2010).

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); 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).

Figures top
[Figure 1] Fig. 1. The molecular structure shown with 30% probability displacement ellipsoids. Unlabelled atoms are related with the labelled ones by symmetry operation (-x, y, -z+1/2).
(E,E)-3,3'-Dimethyl-1,1'-diphenyl-4,4'-{[3-azapentane- 1,5-diylbis(azanediyl)]bis(phenylmethylidyne)}di-1H-pyrazol- 5(4H)-one top
Crystal data top
C38H37N7O2F(000) = 1320
Mr = 623.75Dx = 1.264 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
a = 20.3219 (8) ÅCell parameters from 1721 reflections
b = 8.1990 (2) Åθ = 2.5–22.0°
c = 20.5468 (6) ŵ = 0.08 mm1
β = 106.748 (2)°T = 296 K
V = 3278.27 (18) Å3Block, yellow
Z = 40.23 × 0.21 × 0.15 mm
Data collection top
Bruker SMART APEXII CCD
diffractometer
3765 independent reflections
Radiation source: fine-focus sealed tube1886 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.021
phi and ω scansθmax = 27.7°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Bruker, 2007)
h = 2620
Tmin = 0.982, Tmax = 0.988k = 810
8269 measured reflectionsl = 2625
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)] = 0.054Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.179H-atom parameters constrained
S = 1.01 w = 1/[σ2(Fo2) + (0.0884P)2 + 0.1149P]
where P = (Fo2 + 2Fc2)/3
3765 reflections(Δ/σ)max < 0.001
214 parametersΔρmax = 0.34 e Å3
0 restraintsΔρmin = 0.29 e Å3
Crystal data top
C38H37N7O2V = 3278.27 (18) Å3
Mr = 623.75Z = 4
Monoclinic, C2/cMo Kα radiation
a = 20.3219 (8) ŵ = 0.08 mm1
b = 8.1990 (2) ÅT = 296 K
c = 20.5468 (6) Å0.23 × 0.21 × 0.15 mm
β = 106.748 (2)°
Data collection top
Bruker SMART APEXII CCD
diffractometer
3765 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2007)
1886 reflections with I > 2σ(I)
Tmin = 0.982, Tmax = 0.988Rint = 0.021
8269 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0540 restraints
wR(F2) = 0.179H-atom parameters constrained
S = 1.01Δρmax = 0.34 e Å3
3765 reflectionsΔρmin = 0.29 e Å3
214 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
xyzUiso*/Ueq
O10.06573 (8)0.23883 (18)0.35444 (8)0.0809 (5)
N10.14838 (9)0.0606 (2)0.41990 (8)0.0707 (5)
C70.12657 (11)0.1980 (3)0.38051 (10)0.0645 (6)
C120.25215 (10)0.4844 (3)0.32781 (11)0.0661 (6)
N20.21985 (10)0.0439 (3)0.43823 (10)0.0819 (6)
N30.12874 (9)0.4629 (2)0.29494 (10)0.0833 (6)
H3A0.09270.41450.29920.100*
C110.18821 (10)0.4066 (3)0.33364 (11)0.0657 (6)
N40.00000.6106 (3)0.25000.0898 (9)
H40.00000.50570.25000.108*
C80.18835 (10)0.2749 (3)0.37639 (10)0.0635 (6)
C60.10856 (13)0.0732 (3)0.42954 (10)0.0719 (6)
C170.27276 (12)0.4657 (3)0.27000 (11)0.0738 (6)
H170.24560.40700.23330.089*
C90.24330 (11)0.1713 (3)0.41344 (10)0.0715 (6)
C190.06028 (11)0.7026 (3)0.25289 (12)0.0802 (7)
H19A0.07490.76080.29580.096*
H19B0.05000.78250.21650.096*
C150.37336 (13)0.6229 (3)0.32006 (17)0.0930 (8)
H150.41440.66850.31740.112*
C130.29269 (12)0.5747 (3)0.38196 (12)0.0822 (7)
H130.27910.58760.42120.099*
C160.33348 (14)0.5339 (3)0.26650 (14)0.0840 (7)
H160.34760.51960.22770.101*
C50.04144 (14)0.0517 (3)0.42877 (12)0.0830 (7)
H50.02240.05240.42390.100*
C180.11649 (12)0.5955 (3)0.24635 (13)0.0913 (8)
H18A0.10480.55110.20070.110*
H18B0.15820.65920.25350.110*
C140.35261 (13)0.6447 (3)0.37766 (15)0.0951 (8)
H140.37920.70680.41360.114*
C100.31871 (12)0.1867 (4)0.42487 (13)0.0961 (8)
H10A0.34120.09050.44720.144*
H10B0.33540.28030.45280.144*
H10C0.32810.19910.38200.144*
C10.13730 (17)0.2275 (3)0.43868 (12)0.0930 (8)
H10.18320.24280.44090.112*
C20.0968 (2)0.3578 (4)0.44439 (14)0.1196 (12)
H20.11560.46210.44960.144*
C40.00213 (17)0.1842 (4)0.43516 (14)0.1080 (9)
H4A0.04350.16920.43440.130*
C30.0297 (3)0.3380 (5)0.44262 (15)0.1220 (12)
H30.00300.42760.44640.146*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0582 (10)0.0849 (11)0.0935 (11)0.0105 (8)0.0123 (8)0.0203 (9)
N10.0691 (12)0.0775 (12)0.0639 (11)0.0186 (10)0.0165 (9)0.0105 (10)
C70.0633 (14)0.0714 (13)0.0550 (11)0.0118 (11)0.0113 (10)0.0031 (11)
C120.0527 (12)0.0789 (14)0.0630 (13)0.0104 (10)0.0106 (10)0.0064 (11)
N20.0710 (13)0.1030 (15)0.0698 (12)0.0299 (11)0.0171 (9)0.0151 (11)
N30.0534 (11)0.0994 (14)0.0904 (14)0.0020 (10)0.0098 (9)0.0312 (12)
C110.0534 (12)0.0782 (14)0.0613 (12)0.0071 (11)0.0099 (9)0.0004 (11)
N40.0586 (17)0.0646 (15)0.141 (3)0.0000.0209 (16)0.000
C80.0578 (13)0.0768 (14)0.0529 (11)0.0114 (11)0.0109 (9)0.0040 (11)
C60.0888 (17)0.0736 (15)0.0502 (11)0.0087 (13)0.0153 (11)0.0050 (11)
C170.0676 (15)0.0905 (16)0.0623 (13)0.0129 (12)0.0171 (11)0.0103 (12)
C90.0635 (14)0.0937 (16)0.0556 (12)0.0222 (13)0.0144 (10)0.0047 (12)
C190.0640 (15)0.0849 (15)0.0790 (15)0.0046 (13)0.0001 (11)0.0105 (13)
C150.0587 (15)0.0976 (19)0.118 (2)0.0060 (14)0.0185 (15)0.0314 (18)
C130.0626 (14)0.1095 (18)0.0691 (14)0.0038 (14)0.0101 (11)0.0065 (14)
C160.0793 (18)0.0950 (17)0.0848 (17)0.0241 (14)0.0348 (14)0.0294 (15)
C50.0876 (18)0.0819 (16)0.0771 (15)0.0009 (14)0.0201 (13)0.0111 (13)
C180.0667 (15)0.1080 (18)0.0938 (17)0.0109 (14)0.0146 (12)0.0381 (15)
C140.0646 (17)0.110 (2)0.101 (2)0.0025 (14)0.0075 (14)0.0023 (16)
C100.0650 (16)0.134 (2)0.0863 (16)0.0318 (15)0.0163 (12)0.0204 (16)
C10.136 (2)0.0787 (17)0.0666 (14)0.0274 (17)0.0325 (15)0.0120 (13)
C20.205 (4)0.074 (2)0.0774 (19)0.014 (2)0.037 (2)0.0158 (15)
C40.119 (2)0.105 (2)0.0920 (19)0.020 (2)0.0188 (16)0.0229 (17)
C30.182 (4)0.100 (3)0.0778 (18)0.037 (3)0.026 (2)0.0155 (17)
Geometric parameters (Å, º) top
O1—C71.243 (2)C19—H19A0.9700
N1—C71.383 (3)C19—H19B0.9700
N1—N21.398 (2)C15—C161.374 (4)
N1—C61.411 (3)C15—C141.378 (4)
C7—C81.429 (3)C15—H150.9300
C12—C171.377 (3)C13—C141.372 (3)
C12—C131.391 (3)C13—H130.9300
C12—C111.483 (3)C16—H160.9300
N2—C91.310 (3)C5—C41.377 (4)
N3—C111.324 (3)C5—H50.9300
N3—C181.448 (3)C18—H18A0.9700
N3—H3A0.8600C18—H18B0.9700
C11—C81.392 (3)C14—H140.9300
N4—C191.425 (3)C10—H10A0.9600
N4—C19i1.425 (3)C10—H10B0.9600
N4—H40.8600C10—H10C0.9600
C8—C91.435 (3)C1—C21.375 (4)
C6—C51.371 (3)C1—H10.9300
C6—C11.384 (3)C2—C31.362 (5)
C17—C161.375 (3)C2—H20.9300
C17—H170.9300C4—C31.370 (5)
C9—C101.487 (3)C4—H4A0.9300
C19—C181.477 (3)C3—H30.9300
C7—N1—N2111.73 (18)C16—C15—H15120.0
C7—N1—C6127.98 (19)C14—C15—H15120.0
N2—N1—C6118.64 (18)C14—C13—C12120.2 (2)
O1—C7—N1125.6 (2)C14—C13—H13119.9
O1—C7—C8129.6 (2)C12—C13—H13119.9
N1—C7—C8104.77 (18)C15—C16—C17120.3 (2)
C17—C12—C13119.5 (2)C15—C16—H16119.8
C17—C12—C11120.9 (2)C17—C16—H16119.8
C13—C12—C11119.66 (19)C6—C5—C4120.0 (3)
C9—N2—N1106.44 (17)C6—C5—H5120.0
C11—N3—C18128.4 (2)C4—C5—H5120.0
C11—N3—H3A115.8N3—C18—C19111.5 (2)
C18—N3—H3A115.8N3—C18—H18A109.3
N3—C11—C8119.03 (19)C19—C18—H18A109.3
N3—C11—C12118.1 (2)N3—C18—H18B109.3
C8—C11—C12122.84 (18)C19—C18—H18B109.3
C19—N4—C19i116.1 (3)H18A—C18—H18B108.0
C19—N4—H4122.0C13—C14—C15119.9 (3)
C19i—N4—H4122.0C13—C14—H14120.1
C11—C8—C7122.52 (18)C15—C14—H14120.1
C11—C8—C9130.9 (2)C9—C10—H10A109.5
C7—C8—C9105.7 (2)C9—C10—H10B109.5
C5—C6—C1119.9 (2)H10A—C10—H10B109.5
C5—C6—N1120.5 (2)C9—C10—H10C109.5
C1—C6—N1119.6 (2)H10A—C10—H10C109.5
C16—C17—C12120.0 (2)H10B—C10—H10C109.5
C16—C17—H17120.0C2—C1—C6118.8 (3)
C12—C17—H17120.0C2—C1—H1120.6
N2—C9—C8111.3 (2)C6—C1—H1120.6
N2—C9—C10118.7 (2)C3—C2—C1121.6 (3)
C8—C9—C10130.0 (2)C3—C2—H2119.2
N4—C19—C18111.1 (2)C1—C2—H2119.2
N4—C19—H19A109.4C3—C4—C5120.4 (3)
C18—C19—H19A109.4C3—C4—H4A119.8
N4—C19—H19B109.4C5—C4—H4A119.8
C18—C19—H19B109.4C2—C3—C4119.1 (3)
H19A—C19—H19B108.0C2—C3—H3120.4
C16—C15—C14120.1 (2)C4—C3—H3120.4
N2—N1—C7—O1176.4 (2)C11—C12—C17—C16177.64 (19)
C6—N1—C7—O111.4 (3)N1—N2—C9—C81.4 (2)
N2—N1—C7—C82.4 (2)N1—N2—C9—C10179.79 (19)
C6—N1—C7—C8167.39 (18)C11—C8—C9—N2168.8 (2)
C7—N1—N2—C92.5 (2)C7—C8—C9—N20.0 (2)
C6—N1—N2—C9169.01 (18)C11—C8—C9—C109.3 (4)
C18—N3—C11—C8178.9 (2)C7—C8—C9—C10178.1 (2)
C18—N3—C11—C120.7 (3)C19i—N4—C19—C18172.3 (2)
C17—C12—C11—N369.2 (3)C17—C12—C13—C140.1 (4)
C13—C12—C11—N3112.2 (2)C11—C12—C13—C14178.8 (2)
C17—C12—C11—C8108.9 (2)C14—C15—C16—C170.1 (4)
C13—C12—C11—C869.7 (3)C12—C17—C16—C151.0 (3)
N3—C11—C8—C70.3 (3)C1—C6—C5—C41.8 (3)
C12—C11—C8—C7178.43 (19)N1—C6—C5—C4177.1 (2)
N3—C11—C8—C9166.9 (2)C11—N3—C18—C19135.6 (3)
C12—C11—C8—C911.2 (3)N4—C19—C18—N352.7 (3)
O1—C7—C8—C117.3 (4)C12—C13—C14—C151.3 (4)
N1—C7—C8—C11171.45 (18)C16—C15—C14—C131.3 (4)
O1—C7—C8—C9177.3 (2)C5—C6—C1—C22.3 (3)
N1—C7—C8—C91.4 (2)N1—C6—C1—C2176.6 (2)
C7—N1—C6—C532.3 (3)C6—C1—C2—C31.3 (4)
N2—N1—C6—C5163.56 (19)C6—C5—C4—C30.3 (4)
C7—N1—C6—C1146.5 (2)C1—C2—C3—C40.2 (5)
N2—N1—C6—C117.5 (3)C5—C4—C3—C20.7 (5)
C13—C12—C17—C161.0 (3)
Symmetry code: (i) x, y, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H3A···O10.862.002.722 (2)140

Experimental details

Crystal data
Chemical formulaC38H37N7O2
Mr623.75
Crystal system, space groupMonoclinic, C2/c
Temperature (K)296
a, b, c (Å)20.3219 (8), 8.1990 (2), 20.5468 (6)
β (°) 106.748 (2)
V3)3278.27 (18)
Z4
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.23 × 0.21 × 0.15
Data collection
DiffractometerBruker SMART APEXII CCD
Absorption correctionMulti-scan
(SADABS; Bruker, 2007)
Tmin, Tmax0.982, 0.988
No. of measured, independent and
observed [I > 2σ(I)] reflections
8269, 3765, 1886
Rint0.021
(sin θ/λ)max1)0.655
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.054, 0.179, 1.01
No. of reflections3765
No. of parameters214
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.34, 0.29

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H3A···O10.862.002.722 (2)140.3
 

Acknowledgements

The authors are grateful to the National Natural Science Foundation of China for financial support (grant No. 21001040).

References

First citationBruker (2007). APEX2, SAINT and 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 citationWang, H.-W. (2010). Acta Cryst. E66, o1534.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationWang, Y. & Yang, Z.-Y. (2005). Transition Met. Chem. 30, 902–906.  Web of Science CrossRef CAS Google Scholar
First citationYang, Z.-Y., Yang, R.-D., Li, F.-S. & Yu, K.-B. (2000). Polyhedron, 19, 2599–2604.  Web of Science CSD CrossRef CAS Google Scholar

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