PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of actaeInternational Union of Crystallographysearchopen accessarticle submissionjournal home pagethis article
 
Acta Crystallogr Sect E Struct Rep Online. 2010 December 1; 66(Pt 12): m1661–m1662.
Published online 2010 November 27. doi:  10.1107/S1600536810048725
PMCID: PMC3011696

Bis(benzoato-κ2 O,O′)(1,10-phenanthroline-κ2 N,N′)lead(II) benzoic acid mono­solvate

Abstract

The reaction of lead acetate, benzoic acid and 1,10-phenanthroline (phen) in aqueous solution yielded the title complex, [Pb(C7H5O2)2(C12H8N2)]·C7H6O2. In the crystal, the PbII ion is hexa­coordinated by two N atoms from one 1,10-phenanthroline ligand and four O atoms from two chelate benzoate anions. If the second benzoate ligand is treated as one coordination site, the overall coordination may be represented as a distorted pseudo-square pyramid. An inter­molecular O—H(...)O hydrogen bond links the solvent benzoic acid mol­ecule with a metal-coordinated benzoate ligand. The shortest Pb(...)Pb distance is 3.864 (4) Å, indicating a weak metal–metal inter­action. Two complex mol­ecules related by an inversion centre form dimeric units via Pb(...)O inter­actions of 3.206 (4) Å.

Related literature

For general background to the applications of complexes containing Pb(II) ions, see: Fan & Zhu (2006 [triangle]); Hamilton et al. (2004 [triangle]); Alvarado et al. (2005 [triangle]). For the use of aromatic carboxyl­ates and the phenanthroline ligand in the preparation of metal complexes, see: Wang et al. (2006 [triangle]); Yang et al. (2010 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-m1661-scheme1.jpg

Experimental

Crystal data

  • [Pb(C7H5O2)2(C12H8N2)]·C7H6O2
  • M r = 751.73
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-m1661-efi1.jpg
  • a = 10.0725 (8) Å
  • b = 10.5697 (8) Å
  • c = 15.5477 (17) Å
  • α = 93.414 (2)°
  • β = 102.836 (2)°
  • γ = 117.972 (1)°
  • V = 1399.3 (2) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 6.08 mm−1
  • T = 296 K
  • 0.26 × 0.18 × 0.15 mm

Data collection

  • Bruker APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2007 [triangle]) T min = 0.263, T max = 0.582
  • 8277 measured reflections
  • 5710 independent reflections
  • 4950 reflections with I > 2σ(I)
  • R int = 0.020

Refinement

  • R[F 2 > 2σ(F 2)] = 0.029
  • wR(F 2) = 0.074
  • S = 1.02
  • 5710 reflections
  • 379 parameters
  • H-atom parameters constrained
  • Δρmax = 0.73 e Å−3
  • Δρmin = −0.73 e Å−3

Data collection: APEX2 (Bruker, 2007 [triangle]); cell refinement: SAINT (Bruker, 2007 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL (Sheldrick, 2008 [triangle]); software used to prepare material for publication: SHELXTL.

Table 1
Selected bond lengths (Å)
Table 2
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810048725/bt5413sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810048725/bt5413Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors acknowledge financial support by the Doctoral Foundation of Henan Polytechnic University (B2008–58 648265).

supplementary crystallographic information

Comment

Complexes containing Pb(II) ions have recently attracted considerable interest not only because of the variety of their architectures, but also because of their potential applications, especially in environmental protection and in systems with different biological properties (Fan & Zhu, 2006; Hamilton et al., 2004; Alvarado et al., 2005). As an important family of bidentate O-donor ligands, aromatic carboxylates have been extensively employed in the preparation of metal complexes of various structural topologies (Wang et al., 2006; Yang et al., 2010).

The asymmetric unit of the title complex, [Pb(C7H5O2)2(C12H8N2)] •(C7H6O2), contains a PbII cation, two benzoate ligands, one 1,10-phenanthroline (phen) ligand and one free benzoic acid molecule, as illustrated in Fig.1. In the crystal, the PbII ion is hexacoordinated by two N atoms from one phen ligand and four O atoms from two chelate benzoate anions.The O atoms from one of carboxylate ligands (O3 and O4) are almost coplanar with the N atoms of the phen-ligand (N1 and N2)[dihedral angle of 10.49 (12)°]. Therefore, if we consider that the second carboxylate ligand occupies just one coordination site, the coordination environment of PbII ion may be described as pseudo-square-pyramidal. The intermolecular hydrogen bond exist between the carboxyl H atom of solvent benzoic acid and metal-coordinated carboxylate O atom. The inter-distance of Pb···Pbi [i 1 - x, 1 - y, 1 - z] is 3.864 (4) Å, indicating the weak metal-metal interaction. The complex molecules related by inversion center are organized into dimeric units via a pair of Pb···O interactions of 3.206 (4) Å (Fig.2) and stacking inteactions between phen and benzoate ligands, with the shortest centroid–centroid distance between their planes of 3.521 (5) Å.

Experimental

A mixture of Pb(CH3COO)2. 3H2O (0.05 g, 0.13 mmol), benzoic acid (0.102 g, 0.84 mmol), 1,10-phenanthroline (0.083 g, 0.41 mmol) and distilled water (10 ml) was sealed in a 25 ml Teflon-lined stainless autoclave. The mixture was heated at 403 K for 6 days to give the colorless crystals suitable for X-ray diffraction analysis.

Refinement

All H atoms bound to C atoms were placed in calculated positions and treated in a riding-model approximation, with C—H = 0.93 Å and Uiso (H) = 1.2 Ueq(C). The carboxylic H atom was located in a difference Fourier map. Nevertheless, it was treated as riding with an idealized distance of O—H = 0.82 Å and Uiso (H) = 1.2 Ueq(O).

Figures

Fig. 1.
The asymmetric unit of the title complex, showing displacement ellipsoids at the 30% probability level and the atom-labeling scheme. The H-bond is shown as dashed lines in blue.
Fig. 2.
The dimer structure of complexes, formed by the weak intermolecular Pb···O interactions (dashed lines in violet).

Crystal data

[Pb(C7H5O2)2(C12H8N2)]·C7H6O2Z = 2
Mr = 751.73F(000) = 732
Triclinic, P1Dx = 1.784 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 10.0725 (8) ÅCell parameters from 3689 reflections
b = 10.5697 (8) Åθ = 1.4–26.5°
c = 15.5477 (17) ŵ = 6.08 mm1
α = 93.414 (2)°T = 296 K
β = 102.836 (2)°Prism, colorless
γ = 117.972 (1)°0.26 × 0.18 × 0.15 mm
V = 1399.3 (2) Å3

Data collection

Bruker APEXII CCD area-detector diffractometer5710 independent reflections
Radiation source: fine-focus sealed tube4950 reflections with I > 2σ(I)
graphiteRint = 0.020
ω scansθmax = 26.5°, θmin = 1.4°
Absorption correction: multi-scan (SADABS; Bruker, 2007)h = −12→12
Tmin = 0.263, Tmax = 0.582k = −10→13
8277 measured reflectionsl = −15→19

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.029Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.074H-atom parameters constrained
S = 1.02w = 1/[σ2(Fo2) + (0.038P)2] where P = (Fo2 + 2Fc2)/3
5710 reflections(Δ/σ)max = 0.001
379 parametersΔρmax = 0.73 e Å3
0 restraintsΔρmin = −0.73 e Å3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

xyzUiso*/Ueq
Pb10.595637 (19)0.391099 (18)0.465657 (12)0.04103 (7)
O10.7152 (4)0.4830 (4)0.3537 (2)0.0547 (9)
O20.4876 (4)0.4755 (4)0.3081 (3)0.0577 (9)
O30.8489 (4)0.5402 (4)0.5653 (3)0.0659 (11)
O40.7626 (4)0.6979 (4)0.5547 (3)0.0567 (9)
O50.2159 (4)0.3215 (4)0.1819 (3)0.0696 (11)
H50.31180.36650.20140.084*
O60.1681 (6)0.5034 (5)0.1686 (4)0.0944 (15)
N10.4405 (4)0.1384 (4)0.3537 (3)0.0416 (9)
N20.7216 (4)0.2286 (4)0.4793 (3)0.0393 (8)
C10.6176 (6)0.5023 (5)0.2969 (3)0.0452 (11)
C20.6615 (5)0.5607 (5)0.2168 (3)0.0424 (11)
C30.5676 (6)0.5993 (5)0.1582 (3)0.0488 (12)
H3A0.47710.59080.16950.059*
C40.6080 (7)0.6507 (6)0.0828 (4)0.0582 (13)
H4A0.54460.67650.04350.070*
C50.7400 (7)0.6634 (6)0.0660 (4)0.0632 (15)
H5A0.76540.69650.01470.076*
C60.8358 (7)0.6282 (6)0.1236 (4)0.0607 (14)
H6A0.92750.64020.11230.073*
C70.7965 (6)0.5747 (6)0.1985 (4)0.0563 (13)
H7A0.86020.54810.23670.068*
C80.8635 (6)0.6642 (5)0.5888 (3)0.0444 (11)
C91.0096 (5)0.7720 (5)0.6587 (3)0.0385 (10)
C101.0375 (6)0.9115 (6)0.6866 (3)0.0482 (12)
H10A0.96290.93740.66200.058*
C111.1724 (6)1.0110 (6)0.7493 (4)0.0569 (13)
H11A1.18851.10380.76750.068*
C121.2841 (6)0.9756 (7)0.7857 (4)0.0644 (15)
H12A1.37641.04420.82820.077*
C131.2596 (6)0.8381 (7)0.7592 (4)0.0623 (15)
H13A1.33510.81340.78420.075*
C141.1226 (6)0.7364 (6)0.6955 (3)0.0484 (12)
H14A1.10670.64370.67730.058*
C150.3050 (6)0.0935 (6)0.2932 (4)0.0534 (13)
H15A0.27210.16120.28190.064*
C160.2095 (6)−0.0469 (6)0.2458 (4)0.0574 (14)
H16A0.1150−0.07300.20370.069*
C170.2566 (6)−0.1472 (5)0.2620 (3)0.0504 (12)
H17A0.1938−0.24290.23060.060*
C180.3980 (5)−0.1070 (5)0.3252 (3)0.0421 (10)
C190.4560 (6)−0.2050 (5)0.3430 (3)0.0457 (11)
H19A0.3956−0.30190.31350.055*
C200.5954 (6)−0.1606 (5)0.4015 (3)0.0452 (11)
H20A0.6318−0.22620.41110.054*
C210.6893 (5)−0.0133 (5)0.4495 (3)0.0376 (10)
C220.8359 (6)0.0362 (5)0.5108 (3)0.0451 (11)
H22A0.8740−0.02780.52240.054*
C230.9227 (6)0.1780 (6)0.5534 (4)0.0524 (12)
H23A1.02100.21230.59360.063*
C240.8615 (5)0.2722 (5)0.5357 (3)0.0442 (11)
H24A0.92180.36930.56490.053*
C250.6365 (5)0.0866 (5)0.4351 (3)0.0355 (9)
C260.4878 (5)0.0390 (5)0.3695 (3)0.0371 (10)
C270.1292 (6)0.3771 (7)0.1484 (4)0.0581 (14)
C28−0.0215 (6)0.2676 (6)0.0814 (4)0.0506 (12)
C29−0.1214 (8)0.3134 (8)0.0389 (5)0.083 (2)
H29A−0.09360.41120.05150.100*
C30−0.2625 (9)0.2159 (10)−0.0223 (5)0.102 (3)
H30A−0.32990.2480−0.04990.122*
C31−0.3037 (8)0.0742 (9)−0.0426 (5)0.089 (2)
H31A−0.39900.0085−0.08390.107*
C32−0.2035 (9)0.0287 (7)−0.0015 (5)0.084 (2)
H32A−0.2310−0.0688−0.01550.100*
C33−0.0624 (7)0.1247 (6)0.0603 (4)0.0641 (15)
H33A0.00480.09200.08750.077*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Pb10.03974 (10)0.03631 (11)0.05214 (12)0.02321 (8)0.01173 (8)0.01013 (8)
O10.0413 (19)0.064 (2)0.061 (2)0.0280 (17)0.0112 (17)0.0219 (18)
O20.045 (2)0.068 (2)0.066 (2)0.0305 (18)0.0171 (17)0.0281 (19)
O30.058 (2)0.042 (2)0.085 (3)0.0297 (18)−0.011 (2)−0.0138 (19)
O40.0458 (19)0.050 (2)0.068 (2)0.0275 (17)−0.0041 (17)0.0032 (18)
O50.049 (2)0.064 (2)0.088 (3)0.0263 (19)0.005 (2)0.028 (2)
O60.086 (3)0.062 (3)0.118 (4)0.040 (3)−0.007 (3)−0.003 (3)
N10.038 (2)0.040 (2)0.046 (2)0.0210 (18)0.0070 (17)0.0083 (18)
N20.041 (2)0.040 (2)0.045 (2)0.0264 (18)0.0130 (18)0.0077 (17)
C10.041 (3)0.032 (2)0.053 (3)0.015 (2)0.006 (2)0.004 (2)
C20.040 (2)0.032 (2)0.044 (3)0.013 (2)0.006 (2)0.002 (2)
C30.045 (3)0.041 (3)0.053 (3)0.018 (2)0.010 (2)0.008 (2)
C40.062 (3)0.054 (3)0.049 (3)0.025 (3)0.006 (3)0.011 (3)
C50.074 (4)0.047 (3)0.056 (3)0.018 (3)0.024 (3)0.006 (3)
C60.057 (3)0.057 (3)0.068 (4)0.024 (3)0.025 (3)0.008 (3)
C70.050 (3)0.049 (3)0.070 (4)0.024 (3)0.017 (3)0.010 (3)
C80.046 (3)0.046 (3)0.043 (3)0.026 (2)0.008 (2)0.009 (2)
C90.035 (2)0.035 (2)0.041 (3)0.0148 (19)0.0085 (19)0.006 (2)
C100.055 (3)0.053 (3)0.042 (3)0.033 (3)0.011 (2)0.005 (2)
C110.058 (3)0.045 (3)0.052 (3)0.017 (3)0.011 (3)−0.002 (2)
C120.046 (3)0.067 (4)0.051 (3)0.010 (3)0.007 (3)−0.005 (3)
C130.046 (3)0.089 (5)0.053 (3)0.037 (3)0.008 (3)0.015 (3)
C140.045 (3)0.052 (3)0.049 (3)0.027 (2)0.009 (2)0.008 (2)
C150.047 (3)0.050 (3)0.067 (4)0.029 (3)0.009 (3)0.021 (3)
C160.048 (3)0.056 (3)0.059 (3)0.025 (3)−0.001 (3)0.007 (3)
C170.048 (3)0.039 (3)0.054 (3)0.016 (2)0.009 (2)0.004 (2)
C180.039 (2)0.040 (3)0.048 (3)0.019 (2)0.015 (2)0.010 (2)
C190.054 (3)0.033 (2)0.055 (3)0.022 (2)0.022 (2)0.012 (2)
C200.055 (3)0.041 (3)0.056 (3)0.031 (2)0.027 (2)0.016 (2)
C210.042 (2)0.038 (2)0.040 (2)0.023 (2)0.017 (2)0.013 (2)
C220.046 (3)0.049 (3)0.053 (3)0.033 (2)0.016 (2)0.016 (2)
C230.045 (3)0.062 (3)0.055 (3)0.034 (3)0.003 (2)0.012 (3)
C240.043 (3)0.046 (3)0.044 (3)0.024 (2)0.009 (2)0.009 (2)
C250.038 (2)0.037 (2)0.038 (2)0.021 (2)0.0147 (19)0.0129 (19)
C260.037 (2)0.038 (2)0.039 (2)0.020 (2)0.0110 (19)0.0096 (19)
C270.052 (3)0.064 (4)0.068 (4)0.033 (3)0.021 (3)0.028 (3)
C280.051 (3)0.060 (3)0.053 (3)0.035 (3)0.019 (2)0.014 (3)
C290.082 (5)0.087 (5)0.092 (5)0.062 (4)0.003 (4)0.000 (4)
C300.083 (5)0.118 (7)0.108 (6)0.071 (5)−0.009 (5)0.004 (5)
C310.061 (4)0.100 (6)0.076 (5)0.029 (4)−0.006 (3)0.006 (4)
C320.087 (5)0.059 (4)0.084 (5)0.025 (4)0.012 (4)0.011 (4)
C330.055 (3)0.058 (4)0.074 (4)0.026 (3)0.010 (3)0.019 (3)

Geometric parameters (Å, °)

Pb1—O12.337 (3)C12—H12A0.9300
Pb1—O32.361 (4)C13—C141.384 (7)
Pb1—N22.564 (3)C13—H13A0.9300
Pb1—N12.632 (4)C14—H14A0.9300
Pb1—O22.822 (3)C15—C161.373 (7)
Pb1—O42.928 (4)C15—H15A0.9300
O1—C11.269 (6)C16—C171.365 (7)
O2—C11.259 (6)C16—H16A0.9300
O3—C81.269 (5)C17—C181.391 (7)
O4—C81.250 (5)C17—H17A0.9300
O5—C271.303 (6)C18—C261.401 (6)
O5—H50.8200C18—C191.422 (6)
O6—C271.199 (6)C19—C201.335 (7)
N1—C151.320 (6)C19—H19A0.9300
N1—C261.356 (6)C20—C211.429 (6)
N2—C241.327 (6)C20—H20A0.9300
N2—C251.367 (5)C21—C221.397 (6)
C1—C21.485 (7)C21—C251.397 (6)
C2—C31.384 (7)C22—C231.359 (8)
C2—C71.393 (7)C22—H22A0.9300
C3—C41.384 (7)C23—C241.407 (7)
C3—H3A0.9300C23—H23A0.9300
C4—C51.358 (8)C24—H24A0.9300
C4—H4A0.9300C25—C261.445 (6)
C5—C61.365 (8)C27—C281.495 (8)
C5—H5A0.9300C28—C331.363 (7)
C6—C71.381 (8)C28—C291.372 (8)
C6—H6A0.9300C29—C301.377 (10)
C7—H7A0.9300C29—H29A0.9300
C8—C91.488 (7)C30—C311.348 (10)
C9—C141.380 (6)C30—H30A0.9300
C9—C101.385 (6)C31—C321.365 (10)
C10—C111.361 (7)C31—H31A0.9300
C10—H10A0.9300C32—C331.377 (9)
C11—C121.366 (8)C32—H32A0.9300
C11—H11A0.9300C33—H33A0.9300
C12—C131.374 (8)
O1—Pb1—O384.82 (14)C9—C14—H14A119.9
O1—Pb1—N288.82 (12)C13—C14—H14A119.9
O3—Pb1—N275.08 (11)N1—C15—C16124.2 (5)
O1—Pb1—N185.71 (12)N1—C15—H15A117.9
O3—Pb1—N1137.85 (11)C16—C15—H15A117.9
N2—Pb1—N163.74 (12)C17—C16—C15118.4 (5)
O1—Pb1—O249.51 (10)C17—C16—H16A120.8
O3—Pb1—O2121.87 (13)C15—C16—H16A120.8
N2—Pb1—O2127.06 (11)C16—C17—C18120.3 (5)
N1—Pb1—O279.89 (11)C16—C17—H17A119.8
C1—O1—Pb1105.9 (3)C18—C17—H17A119.8
C1—O2—Pb183.1 (3)C17—C18—C26117.1 (4)
C8—O3—Pb1107.8 (3)C17—C18—C19123.0 (4)
C27—O5—H5125.4C26—C18—C19119.8 (4)
C15—N1—C26117.5 (4)C20—C19—C18121.2 (4)
C15—N1—Pb1123.7 (3)C20—C19—H19A119.4
C26—N1—Pb1117.7 (3)C18—C19—H19A119.4
C24—N2—C25117.8 (4)C19—C20—C21120.7 (4)
C24—N2—Pb1122.2 (3)C19—C20—H20A119.6
C25—N2—Pb1119.5 (3)C21—C20—H20A119.6
O2—C1—O1121.4 (5)C22—C21—C25117.9 (4)
O2—C1—C2120.2 (4)C22—C21—C20121.9 (4)
O1—C1—C2118.4 (4)C25—C21—C20120.2 (4)
C3—C2—C7118.8 (5)C23—C22—C21119.9 (4)
C3—C2—C1120.7 (4)C23—C22—H22A120.1
C7—C2—C1120.4 (4)C21—C22—H22A120.1
C2—C3—C4120.1 (5)C22—C23—C24119.0 (5)
C2—C3—H3A119.9C22—C23—H23A120.5
C4—C3—H3A119.9C24—C23—H23A120.5
C5—C4—C3120.2 (5)N2—C24—C23122.9 (5)
C5—C4—H4A119.9N2—C24—H24A118.6
C3—C4—H4A119.9C23—C24—H24A118.6
C4—C5—C6120.8 (5)N2—C25—C21122.5 (4)
C4—C5—H5A119.6N2—C25—C26118.7 (4)
C6—C5—H5A119.6C21—C25—C26118.8 (4)
C5—C6—C7120.0 (5)N1—C26—C18122.5 (4)
C5—C6—H6A120.0N1—C26—C25118.2 (4)
C7—C6—H6A120.0C18—C26—C25119.2 (4)
C6—C7—C2120.0 (5)O6—C27—O5123.2 (6)
C6—C7—H7A120.0O6—C27—C28124.0 (5)
C2—C7—H7A120.0O5—C27—C28112.8 (5)
O4—C8—O3122.7 (5)C33—C28—C29118.9 (6)
O4—C8—C9120.2 (4)C33—C28—C27122.5 (5)
O3—C8—C9117.0 (4)C29—C28—C27118.6 (5)
C14—C9—C10118.4 (4)C28—C29—C30120.6 (6)
C14—C9—C8120.5 (4)C28—C29—H29A119.7
C10—C9—C8121.0 (4)C30—C29—H29A119.7
C11—C10—C9121.1 (5)C31—C30—C29120.5 (7)
C11—C10—H10A119.5C31—C30—H30A119.7
C9—C10—H10A119.5C29—C30—H30A119.7
C10—C11—C12120.4 (5)C30—C31—C32119.0 (7)
C10—C11—H11A119.8C30—C31—H31A120.5
C12—C11—H11A119.8C32—C31—H31A120.5
C11—C12—C13119.7 (5)C31—C32—C33121.2 (7)
C11—C12—H12A120.1C31—C32—H32A119.4
C13—C12—H12A120.1C33—C32—H32A119.4
C12—C13—C14120.1 (5)C28—C33—C32119.8 (6)
C12—C13—H13A120.0C28—C33—H33A120.1
C14—C13—H13A120.0C32—C33—H33A120.1
C9—C14—C13120.2 (5)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O5—H5···O20.821.942.654 (5)145

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BT5413).

References

  • Alvarado, R. J., Rosenberg, J. M., Andreu, A., Bryan, J. C., Chen, W.-Z., Ren, T. & Kavallieratos, K. (2005). Inorg. Chem.44, 7951–7959. [PubMed]
  • Bruker (2007). APEX2, SAINT and SADABS Bruker AXS Inc., Madison, Wisconsin, USA.
  • Fan, S. R. & Zhu, L. G. (2006). Inorg. Chem.45, 7935–7942. [PubMed]
  • Hamilton, B. H., Kelley, K. A., Wagler, T. A., Espe, M. P. & Ziegler, C. J. (2004). Inorg. Chem.43, 50–56. [PubMed]
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Wang, X. L., Qin, C. & Wang, E. B. (2006). Cryst. Growth Des.6, 439–443.
  • Yang, L., Li, B., Xue, Q., Huo, Y. & Wang, G. (2010). Acta Cryst. E66, m987. [PMC free article] [PubMed]

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography