research communications
Two cadmium coordination polymers with bridging acetate and phenylenediamine ligands that exhibit two-dimensional layered structures
aDepartment of Chemistry, SUNY-College at Geneseo, Geneseo, NY 14454, USA
*Correspondence e-mail: geiger@geneseo.edu
Poly[tetra-μ2-acetato-κ8O:O′-bis(μ2-benzene-1,2-diamine-κ2N:N′)dicadmium], [Cd2(CH3COO)4(C6H8N2)2]n, (I), and poly[[(μ2-acetato-κ2O:O′)(acetato-κ2O,O′)(μ2-benzene-1,3-diamine-κ2N:N′)cadmium] hemihydrate], {[Cd(CH3COO)2(C6H8N2)]·0.5H2O}n, (II), have two-dimensional polymeric structures in which monomeric units are joined by bridging acetate and benzenediamine ligands. Each of the CdII ions has an O4N2 coordination environment. The coordination geometries of the symmetry-independent CdII ions are distorted octahedral and distorted trigonal antiprismatic in (I) and distorted antiprismatic in (II). Both compounds exhibit an intralayer hydrogen-bonding network. In addition, the water of hydration in (II) is involved in interlayer hydrogen bonding.
1. Chemical context
CdII is able to substitute for ZnII in the active sites of zinc-containing enzymes and to interfere with the metabolism of CaII, which are the primary reasons for its toxicity (Borsari, 2014). In addition, the substitution of CdII for spectroscopically silent ZnII provides a means of exploring zinc-containing biomolecules using 111Cd and 113Cd NMR spectroscopies (Kimblin & Parkin, 1996; Henehan et al., 1993; Jalilehvand et al., 2009, 2012). Thus, the coordination chemistry of cadmium is of interest.
Metal–organic frameworks (MOFs) have received much attention because of their many potential applications including gas storage, catalysis, chemical sensors and molecular separation (Dey et al., 2014; Kreno et al., 2012; Farha & Hupp, 2010). Our previous efforts in the area of coordination polymers have focused on compounds based on phenylenediamine and acetate ligands incorporating ZnII (Geiger & Parsons, 2014) and PbII (Geiger et al., 2014). We have extended this work to include Cd and report the structural analyses of two Cd compounds herein. Although acetate ligands adopt a myriad of different metal-binding modes, only the μ2-acetato-κ2O:O′ mode is observed in (I). Both acetato-κ2O,O′ and μ2-acetato-κ2O:O′ modes are found in (II).
Numerous examples of structures with benzene-1,2-diamines exhibiting monodentate and/or bidentate coordination modes have been reported (Narayanan & Bhadbhade, 1996; Ovalle-Marroquín et al., 2002; Ariyananda & Norman, 2005; Chen et al., 2006; Maxcy et al., 2000; Qian et al., 2007; Dickman, 2000; Mei et al., 2009; Djebli et al., 2012; Zick & Geiger, 2016; Geiger et al., 2014; Geiger & Parsons, 2014; Geiger, 2012). Examples of benzene-1,4-diamine metal-complex structures have also been reported (Batten et al., 2001; Faizi & Prisyazhnaya, 2015). Few examples of bridging benzene-1,2-diamine-κ2N:N′ (Liang & Qu, 2008; Duff, 1968), 1,3-diamine-κ2N:N′ (Chemli et al., 2013), or benzene-1,4-diamine-κ2N:N′ (Liu et al., 2012) ligands have been reported. Compounds (I) and (II) are two new examples of coordination polymers in which benzenediamine ligands bridge two metal atoms.
2. Structural commentary
As shown in Fig. 1, (I) has two symmetry-independent CdII ions. Cd1 sits on a crystallographically imposed inversion center and Cd2 resides on a crystallographically imposed twofold rotation axis. Each of the CdII ions exhibits an O4N2 coordination sphere composed of four bridging κ2O:O′ acetate ligands and two bridging κ2N:N′ benzene-1,2-diamine ligands. For the coordination sphere of Cd1, the twist angles (Muetterties & Guggenberger, 1974; Dymock & Palenik, 1975) defined employing the triangular face centroids N1O1O3 and N1iiiO3iiiO1iii (see Fig. 2) are 52.26 (12), 66.27 (15) and 56.47 (9)°, giving an average value of 60 (5)°. Perfect Oh or D3d trigonal antiprismatic structures have a twist angle of 60°, whereas a D3h trigonal prismatic structure has a twist angle of 0°. The coordination sphere of Cd2 exhibits twist angles of 35.49 (8), 45.92 (17) and 45.92 (17)° [average 42 (6)°] using opposite triangular faces O2O4iN2iv and N2iiO4ivO2vii (see Fig. 2). The coordination geometry is best described as distorted octahedral with the two nitrogen donor atoms trans for Cd1 and distorted trigonal antiprismatic for Cd2 with O2N trigonal faces. Selected geometrical parameters are given in Table 1.
The N2O4 coordination geometry of (II) can be described as severely distorted trigonal antiprismatic with bidentate acetate oxygen atoms and a κ2N:N′ benzene-1,3-diamine nitrogen atom (O1O2N2i) forming one of the trigonal faces and two κ2O:O′ acetate ligand oxygen atoms and a nitrogen atom from a κ2N:N′ benzene-1,3-diamine (O3O4iiN1) forming the other trigonal face (see Fig. 2). The atom-labeling scheme is shown in Fig. 3. The twist angles are 53.71 (11), 22.56 (8) and 45.38 (13)° [average = 41 (16)°]. As seen in Table 2, the Cd—O bond lengths associated with the bidentate acetate ligand are shorter than those of the bridging, monodentate acetate ligands, as has been observed in other cadmium complexes (Wang et al., 2011, 2013).
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3. Supramolecular features
As seen in Fig. 4, the supramolecular architecture of (I) exhibits independent layers in the bc plane, which are repeated in the [100] direction. Extensive N—H⋯O hydrogen-bonding interactions exist (see Table 3), but none of them extend between the layers. Based on an analysis of the extended structure using the SOLV routine of PLATON (Spek, 2009), the contains no solvent-accessible voids.
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Compound (II) also exhibits a two-dimensional extended structure. Layers parallel to the bc plane and repeated in the [100] direction are observed as seen in Fig. 5. N—H⋯O(acetate) hydrogen bonds (Table 4) are present within the layers. The water of hydration sits on a crystallographically imposed twofold rotation axis and, as seen in Fig. 6, is involved in O—H⋯O and N—H⋯O hydrogen-bonding interactions (Table 4) that link adjacent layers.
4. Database survey
Examples of cadmium coordination polymers with carboxylate ligands and that exhibit two-dimensional sheet structures have been reported (Li et al., 2014; Gao et al., 2004; Chen & Zhang, 2014; Zhang et al., 2007; Liu & Xu, 2005; Song et al., 2006; Kong et al., 2008a,b; Xu et al., 2013; Zhuo et al., 2006). Cadmium is commonly observed with a trigonal–prismatic or trigonal–antiprismatic coordination geometry, often with one or two capping ligands (Bygott et al., 2007; Cherni et al., 2012; Uçar et al., 2004; Banerjee et al., 2005; Keypour et al., 2000). Coordination polymers with bridging benzene-1,2-diamine ligands (Liang & Qu, 2008; Duff, 1968), bridging benzene-1,3-diamine ligands (Chemli et al., 2013), and bridging benzene-1,4-diamine ligands (Liu et al., 2012) have been reported
5. Synthesis and crystallization
5.1. Preparation of (I)
213 mg (0.924 mmole) cadmium acetate hydrate were dissolved in 10 mL of ethanol. With stirring, 204 mg (1.89 mmol) of benzene-1,2-diamine were added and the resulting solution was refluxed for 2 h. A white precipitate formed, which was isolated by filtration and dried under vacuum. The yield was quantitative (310 mg). Selected IR bands (diamond anvil, cm−1): 3278 (w), 1532 (s), 1504 (s), 1405 (s). 1H NMR (400 MHz, dmso-d6, p.p.m.): 1.87 (s, 6H), 6.35 (m, 2H), 6.35 (m, 2H).
Single crystals were obtained by heating some of the product in N,N′-dimethylformamide and allowing the solution to slowly cool to room temperature. The crystal used for data collection was obtained by cutting a piece from a larger plate.
5.2. Preparation of (II)
230 mg (1.00 mmol) cadmium acetate hydrate were dissolved in 10 mL of ethanol. 217 mg (2.01 mmol) benzene-1,3-diamine were added with stirring. The solution was gently refluxed for 2 h. After chilling the reaction mixture in an ice bath, the precipitate was filtered and dried under vacuum. A yield of 248 mg (71%) was obtained. Selected IR bands (diamond anvil, cm−1): 3425 (b), 3329 (s) 3328 (b), 3137 (m), 1520 (s), 1505 (s), 1400 (s). 1H NMR (400 MHz, dmso-d6, p.p.m.): 1.83 (s, 6H), 5.78 (m, 3H), 6.64 (t, 1H). 13C NMR (dmso-d6, p.p.m.): 22.1, 100.5, 103.6, 129.6, 149.5, 178.0.
Clear, brown needles suitable for X-ray analysis were obtained upon slow evaporation of an ethanolic solution of the product. The crystals exhibit a melting range of 441–443 K with decomposition.
6. Refinement
Crystal data, data collection and structure . For both (I) and (II), all hydrogen atoms were located in difference Fourier maps. The hydrogen atoms were refined using a riding model with a C—H distance of 0.98 Å for the methyl groups and 0.95 Å for the phenyl carbon atoms. The methyl hydrogen atom isotropic displacement parameters were set using the approximation Uiso(H) = 1.5Ueq(C). All other C—H hydrogen atom isotropic displacement parameters were set using the approximation Uiso(H) = 1.2Ueq(C). The N—H bond lengths were restrained to 0.88 Å in (I) and (II). The O—H bond length of the water of hydration in (II) was restrained to 0.84 Å and the H—O—H angle was restrained to 105°. Uiso(H) was refined freely for the amine and water hydrogen atoms, except that for (II) the isotropic displacement parameters of the hydrogen atoms associated with N2 were restrained to be the same.
details are summarized in Table 5
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Supporting information
https://doi.org/10.1107/S2056989016017382/pj2037sup1.cif
contains datablocks global, I, II. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989016017382/pj2037Isup2.hkl
Structure factors: contains datablock II. DOI: https://doi.org/10.1107/S2056989016017382/pj2037IIsup3.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2056989016017382/pj2037Isup4.mol
Supporting information file. DOI: https://doi.org/10.1107/S2056989016017382/pj2037IIsup5.mol
For both compounds, data collection: APEX2 (Bruker, 2013); cell
APEX2 (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: PLATON (Spek, 2009) and Mercury (Macrae et al., 2006); software used to prepare material for publication: publCIF (Westrip, 2010).[Cd2(C2H3O2)4(C6H8N2)2] | F(000) = 1344 |
Mr = 338.63 | Dx = 1.883 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
a = 23.283 (3) Å | Cell parameters from 120 reflections |
b = 7.2399 (9) Å | θ = 3.5–24.0° |
c = 14.2744 (16) Å | µ = 1.83 mm−1 |
β = 96.887 (4)° | T = 200 K |
V = 2388.8 (5) Å3 | Plate, clear colourless |
Z = 8 | 0.40 × 0.40 × 0.05 mm |
Bruker SMART X2S benchtop diffractometer | 2263 independent reflections |
Radiation source: sealed microfocus tube | 1633 reflections with I > 2σ(I) |
Doubly curved silicon crystal monochromator | Rint = 0.089 |
Detector resolution: 8.3330 pixels mm-1 | θmax = 25.7°, θmin = 2.9° |
ω scans | h = −28→27 |
Absorption correction: multi-scan (SADABS; Bruker, 2013) | k = −8→8 |
Tmin = 0.53, Tmax = 0.91 | l = −17→16 |
14588 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.038 | Hydrogen site location: mixed |
wR(F2) = 0.109 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0496P)2 + 0.5909P] where P = (Fo2 + 2Fc2)/3 |
2263 reflections | (Δ/σ)max < 0.001 |
174 parameters | Δρmax = 1.14 e Å−3 |
4 restraints | Δρmin = −1.17 e Å−3 |
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. |
x | y | z | Uiso*/Ueq | ||
Cd1 | 0.5 | 1.0 | 1.0 | 0.02022 (18) | |
Cd2 | 0.5 | 1.48311 (6) | 0.75 | 0.02246 (18) | |
O1 | 0.53894 (13) | 1.2329 (4) | 0.91404 (19) | 0.0280 (7) | |
O2 | 0.57421 (14) | 1.2817 (4) | 0.7785 (2) | 0.0341 (8) | |
O3 | 0.43034 (13) | 1.2226 (4) | 1.01819 (19) | 0.0287 (8) | |
O4 | 0.44787 (12) | 1.2680 (4) | 1.17354 (18) | 0.0275 (7) | |
N1 | 0.44368 (16) | 0.9351 (5) | 0.8581 (2) | 0.0220 (8) | |
H1A | 0.4354 (19) | 1.040 (4) | 0.831 (3) | 0.033 (14)* | |
H1B | 0.4683 (16) | 0.875 (6) | 0.824 (3) | 0.045 (15)* | |
N2 | 0.44711 (17) | 0.5481 (6) | 0.8818 (2) | 0.0226 (8) | |
H2A | 0.438 (2) | 0.445 (4) | 0.905 (3) | 0.040 (15)* | |
H2B | 0.4719 (16) | 0.612 (6) | 0.917 (3) | 0.044 (15)* | |
C1 | 0.39101 (18) | 0.8316 (6) | 0.8544 (3) | 0.0232 (10) | |
C2 | 0.39284 (18) | 0.6415 (6) | 0.8678 (3) | 0.0213 (10) | |
C3 | 0.3425 (2) | 0.5424 (7) | 0.8632 (3) | 0.0315 (12) | |
H3 | 0.344 | 0.4118 | 0.8697 | 0.038* | |
C4 | 0.2890 (2) | 0.6318 (8) | 0.8489 (3) | 0.0409 (13) | |
H4 | 0.2541 | 0.5629 | 0.8467 | 0.049* | |
C5 | 0.2872 (2) | 0.8209 (8) | 0.8380 (3) | 0.0403 (13) | |
H5 | 0.251 | 0.8824 | 0.829 | 0.048* | |
C6 | 0.3376 (2) | 0.9219 (7) | 0.8400 (3) | 0.0326 (11) | |
H6 | 0.336 | 1.052 | 0.8316 | 0.039* | |
C7 | 0.57788 (19) | 1.2169 (6) | 0.8615 (3) | 0.0267 (11) | |
C8 | 0.6357 (3) | 1.1326 (10) | 0.8978 (4) | 0.0650 (18) | |
H8A | 0.6648 | 1.2304 | 0.9089 | 0.098* | |
H8B | 0.6473 | 1.0454 | 0.8511 | 0.098* | |
H8C | 0.6324 | 1.0673 | 0.9571 | 0.098* | |
C9 | 0.41522 (19) | 1.2753 (6) | 1.0965 (3) | 0.0248 (10) | |
C10 | 0.3540 (2) | 1.3437 (8) | 1.0964 (3) | 0.0450 (14) | |
H10A | 0.3441 | 1.3462 | 1.1612 | 0.067* | |
H10B | 0.3274 | 1.2609 | 1.0581 | 0.067* | |
H10C | 0.3507 | 1.4686 | 1.0697 | 0.067* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cd1 | 0.0250 (3) | 0.0215 (3) | 0.0140 (3) | −0.00045 (16) | 0.0019 (2) | −0.00028 (16) |
Cd2 | 0.0275 (3) | 0.0228 (3) | 0.0180 (3) | 0 | 0.0066 (2) | 0 |
O1 | 0.0330 (18) | 0.0259 (18) | 0.0270 (16) | 0.0015 (14) | 0.0107 (14) | 0.0053 (14) |
O2 | 0.047 (2) | 0.034 (2) | 0.0226 (18) | 0.0065 (16) | 0.0110 (14) | 0.0081 (15) |
O3 | 0.0396 (18) | 0.0311 (19) | 0.0166 (16) | 0.0122 (15) | 0.0083 (13) | 0.0014 (14) |
O4 | 0.0324 (18) | 0.0324 (19) | 0.0173 (16) | −0.0035 (15) | 0.0010 (14) | −0.0029 (14) |
N1 | 0.030 (2) | 0.018 (2) | 0.017 (2) | 0.0000 (18) | 0.0014 (16) | 0.0001 (17) |
N2 | 0.032 (2) | 0.021 (2) | 0.016 (2) | −0.0048 (19) | 0.0047 (17) | 0.0002 (18) |
C1 | 0.032 (3) | 0.028 (3) | 0.010 (2) | −0.001 (2) | 0.0050 (18) | −0.0021 (18) |
C2 | 0.028 (2) | 0.023 (2) | 0.012 (2) | 0.0015 (19) | 0.0038 (18) | −0.0012 (18) |
C3 | 0.039 (3) | 0.030 (3) | 0.026 (3) | −0.008 (2) | 0.007 (2) | −0.004 (2) |
C4 | 0.033 (3) | 0.051 (4) | 0.038 (3) | −0.006 (3) | 0.004 (2) | −0.001 (3) |
C5 | 0.030 (3) | 0.049 (4) | 0.041 (3) | 0.011 (3) | 0.004 (2) | 0.003 (3) |
C6 | 0.032 (3) | 0.035 (3) | 0.029 (3) | 0.006 (2) | 0.000 (2) | −0.002 (2) |
C7 | 0.029 (3) | 0.023 (3) | 0.028 (3) | 0.003 (2) | 0.004 (2) | 0.001 (2) |
C8 | 0.065 (4) | 0.066 (5) | 0.065 (4) | 0.004 (4) | 0.013 (3) | 0.002 (4) |
C9 | 0.030 (2) | 0.017 (2) | 0.028 (3) | −0.0014 (19) | 0.009 (2) | 0.000 (2) |
C10 | 0.036 (3) | 0.063 (4) | 0.036 (3) | 0.016 (3) | 0.006 (2) | −0.004 (3) |
C1—C6 | 1.398 (6) | Cd1—O1i | 2.332 (3) |
C1—C2 | 1.390 (6) | Cd1—N1 | 2.325 (4) |
C10—H10C | 0.98 | Cd1—N1i | 2.325 (4) |
C10—H10B | 0.98 | Cd2—O4ii | 2.365 (3) |
C10—H10A | 0.98 | Cd2—O4iii | 2.365 (3) |
C2—C3 | 1.369 (6) | Cd2—O2iv | 2.260 (3) |
C3—H3 | 0.95 | Cd2—O2 | 2.260 (3) |
C3—C4 | 1.398 (7) | Cd2—N2v | 2.416 (4) |
C4—H4 | 0.95 | Cd2—N2vi | 2.416 (4) |
C4—C5 | 1.378 (7) | N1—H1B | 0.907 (19) |
C5—H5 | 0.95 | N1—H1A | 0.864 (19) |
C5—C6 | 1.378 (7) | N1—C1 | 1.432 (5) |
C6—H6 | 0.95 | N2—H2B | 0.857 (19) |
C7—C8 | 1.512 (7) | N2—H2A | 0.86 (2) |
C8—H8C | 0.98 | N2—Cd2vii | 2.415 (4) |
C8—H8B | 0.98 | N2—C2 | 1.426 (6) |
C8—H8A | 0.98 | O1—C7 | 1.250 (5) |
C9—C10 | 1.509 (6) | O2—C7 | 1.267 (5) |
Cd1—O3i | 2.323 (3) | O3—C9 | 1.270 (5) |
Cd1—O3 | 2.323 (3) | O4—Cd2ii | 2.365 (3) |
Cd1—O1 | 2.332 (3) | O4—C9 | 1.261 (5) |
O3i—Cd1—O3 | 180.00 (13) | C2—N2—H2A | 102 (3) |
O3i—Cd1—N1 | 95.21 (12) | Cd2vii—N2—H2A | 108 (3) |
O3—Cd1—N1 | 84.79 (12) | C2—N2—H2B | 110 (4) |
O3i—Cd1—N1i | 84.79 (12) | Cd2vii—N2—H2B | 101 (3) |
O3—Cd1—N1i | 95.21 (12) | H2A—N2—H2B | 115 (4) |
N1—Cd1—N1i | 180.0 | C2—C1—C6 | 119.7 (4) |
O3i—Cd1—O1 | 97.02 (11) | C2—C1—N1 | 120.1 (4) |
O3—Cd1—O1 | 82.98 (11) | C6—C1—N1 | 120.2 (4) |
N1—Cd1—O1 | 84.38 (12) | C3—C2—C1 | 120.1 (4) |
N1i—Cd1—O1 | 95.62 (12) | C3—C2—N2 | 119.8 (4) |
O3i—Cd1—O1i | 82.98 (11) | C1—C2—N2 | 120.1 (4) |
O3—Cd1—O1i | 97.02 (11) | C2—C3—C4 | 120.5 (5) |
N1—Cd1—O1i | 95.62 (12) | C2—C3—H3 | 119.8 |
N1i—Cd1—O1i | 84.38 (12) | C4—C3—H3 | 119.8 |
O1—Cd1—O1i | 180.0 | C5—C4—C3 | 119.4 (5) |
O2iv—Cd2—O2 | 99.65 (17) | C5—C4—H4 | 120.3 |
O2iv—Cd2—O4ii | 156.01 (10) | C3—C4—H4 | 120.3 |
O2—Cd2—O4ii | 93.98 (12) | C4—C5—C6 | 120.7 (5) |
O2iv—Cd2—O4iii | 93.98 (11) | C4—C5—H5 | 119.6 |
O2—Cd2—O4iii | 156.01 (10) | C6—C5—H5 | 119.6 |
O4ii—Cd2—O4iii | 80.73 (15) | C5—C6—C1 | 119.6 (5) |
O2iv—Cd2—N2v | 79.40 (12) | C5—C6—H6 | 120.2 |
O2—Cd2—N2v | 115.81 (12) | C1—C6—H6 | 120.2 |
O4ii—Cd2—N2v | 76.91 (12) | O1—C7—O2 | 123.6 (4) |
O4iii—Cd2—N2v | 85.97 (11) | O1—C7—C8 | 120.8 (4) |
O2iv—Cd2—N2vi | 115.81 (12) | O2—C7—C8 | 115.3 (4) |
O2—Cd2—N2vi | 79.40 (12) | C7—C8—H8A | 109.5 |
O4ii—Cd2—N2vi | 85.97 (12) | C7—C8—H8B | 109.5 |
O4iii—Cd2—N2vi | 76.91 (12) | H8A—C8—H8B | 109.5 |
N2v—Cd2—N2vi | 157.5 (2) | C7—C8—H8C | 109.5 |
C7—O1—Cd1 | 127.2 (3) | H8A—C8—H8C | 109.5 |
C7—O2—Cd2 | 111.8 (3) | H8B—C8—H8C | 109.5 |
C9—O3—Cd1 | 125.3 (3) | O4—C9—O3 | 123.6 (4) |
C9—O4—Cd2ii | 126.4 (3) | O4—C9—C10 | 119.1 (4) |
C1—N1—Cd1 | 121.9 (2) | O3—C9—C10 | 117.3 (4) |
C1—N1—H1A | 107 (3) | C9—C10—H10A | 109.5 |
Cd1—N1—H1A | 107 (3) | C9—C10—H10B | 109.5 |
C1—N1—H1B | 109 (3) | H10A—C10—H10B | 109.5 |
Cd1—N1—H1B | 104 (3) | C9—C10—H10C | 109.5 |
H1A—N1—H1B | 107 (4) | H10A—C10—H10C | 109.5 |
C2—N2—Cd2vii | 120.6 (2) | H10B—C10—H10C | 109.5 |
Cd1—N1—C1—C2 | −75.0 (4) | C4—C5—C6—C1 | −0.8 (7) |
Cd1—N1—C1—C6 | 103.1 (4) | C2—C1—C6—C5 | −0.9 (6) |
C6—C1—C2—C3 | 2.6 (6) | N1—C1—C6—C5 | −179.0 (4) |
N1—C1—C2—C3 | −179.3 (4) | Cd1—O1—C7—O2 | 131.3 (4) |
C6—C1—C2—N2 | 179.5 (4) | Cd1—O1—C7—C8 | −54.7 (6) |
N1—C1—C2—N2 | −2.4 (6) | Cd2—O2—C7—O1 | 13.3 (6) |
Cd2vii—N2—C2—C3 | 99.3 (4) | Cd2—O2—C7—C8 | −160.9 (4) |
Cd2vii—N2—C2—C1 | −77.6 (5) | Cd2ii—O4—C9—O3 | 100.8 (5) |
C1—C2—C3—C4 | −2.7 (6) | Cd2ii—O4—C9—C10 | −81.4 (5) |
N2—C2—C3—C4 | −179.6 (4) | Cd1—O3—C9—O4 | 26.7 (6) |
C2—C3—C4—C5 | 1.0 (7) | Cd1—O3—C9—C10 | −151.1 (4) |
C3—C4—C5—C6 | 0.8 (7) |
Symmetry codes: (i) −x+1, −y+2, −z+2; (ii) −x+1, −y+3, −z+2; (iii) x, −y+3, z−1/2; (iv) −x+1, y, −z+3/2; (v) x, y+1, z; (vi) −x+1, y+1, −z+3/2; (vii) x, y−1, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O2iv | 0.86 (2) | 2.34 (2) | 3.175 (5) | 163 (4) |
N1—H1B···O4i | 0.91 (2) | 2.21 (3) | 3.003 (5) | 146 (4) |
N1—H1B···O4viii | 0.91 (2) | 2.38 (4) | 3.029 (5) | 128 (4) |
N2—H2A···O3vii | 0.86 (2) | 2.30 (2) | 3.111 (5) | 158 (4) |
N2—H2B···O3i | 0.86 (2) | 2.64 (2) | 3.458 (5) | 161 (4) |
N2—H2B···O4i | 0.86 (2) | 2.55 (4) | 2.973 (5) | 111 (3) |
C8—H8C···O3i | 0.98 | 2.61 | 3.295 (7) | 127 |
Symmetry codes: (i) −x+1, −y+2, −z+2; (iv) −x+1, y, −z+3/2; (vii) x, y−1, z; (viii) x, −y+2, z−1/2. |
[Cd(C2H3O2)2(C6H8N2)]·0.5H2O | F(000) = 1384 |
Mr = 695.28 | Dx = 1.843 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
a = 20.777 (6) Å | Cell parameters from 2588 reflections |
b = 8.2374 (18) Å | θ = 2.7–23.5° |
c = 15.002 (4) Å | µ = 1.75 mm−1 |
β = 102.583 (9)° | T = 200 K |
V = 2505.9 (11) Å3 | Needle, clear brown |
Z = 4 | 0.40 × 0.08 × 0.08 mm |
Bruker SMART X2S benchtop diffractometer | 2443 independent reflections |
Radiation source: sealed microfocus tube | 1859 reflections with I > 2σ(I) |
Doubly curved silicon crystal monochromator | Rint = 0.057 |
Detector resolution: 8.3330 pixels mm-1 | θmax = 26.0°, θmin = 2.7° |
ω scans | h = −25→25 |
Absorption correction: multi-scan (SADABS; Bruker, 2013) | k = −9→10 |
Tmin = 0.69, Tmax = 0.87 | l = −18→11 |
8942 measured reflections |
Refinement on F2 | 6 restraints |
Least-squares matrix: full | Hydrogen site location: mixed |
R[F2 > 2σ(F2)] = 0.037 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.095 | w = 1/[σ2(Fo2) + (0.0489P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.99 | (Δ/σ)max = 0.001 |
2443 reflections | Δρmax = 0.86 e Å−3 |
180 parameters | Δρmin = −1.02 e Å−3 |
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. |
x | y | z | Uiso*/Ueq | ||
Cd1 | 0.69991 (2) | 0.34064 (4) | 0.80989 (2) | 0.02831 (14) | |
O1 | 0.68026 (16) | 0.1764 (4) | 0.9313 (2) | 0.0381 (9) | |
O2 | 0.59435 (17) | 0.3087 (4) | 0.8546 (2) | 0.0436 (9) | |
O3 | 0.80578 (15) | 0.3370 (3) | 0.7917 (3) | 0.0357 (8) | |
O4 | 0.79978 (15) | 0.6013 (4) | 0.7691 (2) | 0.0375 (8) | |
O5 | 0.5 | 0.5121 (7) | 0.75 | 0.0581 (16) | |
H5 | 0.517 (3) | 0.455 (4) | 0.792 (2) | 0.09 (2)* | |
N1 | 0.63907 (19) | 0.5002 (5) | 0.6938 (3) | 0.0281 (9) | |
HN1A | 0.6021 (14) | 0.522 (5) | 0.708 (3) | 0.039 (15)* | |
HN1B | 0.649 (2) | 0.605 (3) | 0.701 (3) | 0.039 (14)* | |
N2 | 0.7361 (2) | 0.4639 (5) | 0.4277 (3) | 0.0328 (9) | |
HN2A | 0.750 (2) | 0.394 (5) | 0.393 (3) | 0.044 (11)* | |
HN2B | 0.7682 (17) | 0.526 (5) | 0.457 (3) | 0.044 (11)* | |
C1 | 0.6204 (2) | 0.2190 (6) | 0.9196 (3) | 0.0316 (11) | |
C2 | 0.5810 (3) | 0.1613 (6) | 0.9855 (4) | 0.0553 (16) | |
H2A | 0.5764 | 0.2496 | 1.0275 | 0.083* | |
H2B | 0.6034 | 0.0692 | 1.0204 | 0.083* | |
H2C | 0.5372 | 0.1272 | 0.952 | 0.083* | |
C3 | 0.8315 (2) | 0.4712 (5) | 0.7778 (3) | 0.0283 (10) | |
C4 | 0.9037 (2) | 0.4701 (6) | 0.7760 (4) | 0.0423 (13) | |
H4A | 0.9093 | 0.5044 | 0.7156 | 0.064* | |
H4B | 0.9213 | 0.3602 | 0.7888 | 0.064* | |
H4C | 0.9275 | 0.5451 | 0.8224 | 0.064* | |
C5 | 0.6364 (2) | 0.4410 (5) | 0.6031 (3) | 0.0276 (10) | |
C6 | 0.6875 (2) | 0.4739 (5) | 0.5613 (3) | 0.0292 (11) | |
H6 | 0.7238 | 0.5375 | 0.5921 | 0.035* | |
C7 | 0.6866 (2) | 0.4152 (5) | 0.4748 (3) | 0.0314 (11) | |
C8 | 0.6335 (3) | 0.3195 (6) | 0.4305 (4) | 0.0463 (14) | |
H8 | 0.6327 | 0.2769 | 0.3714 | 0.056* | |
C9 | 0.5833 (3) | 0.2881 (7) | 0.4720 (4) | 0.0573 (17) | |
H9 | 0.5473 | 0.2237 | 0.4413 | 0.069* | |
C10 | 0.5832 (3) | 0.3481 (5) | 0.5588 (4) | 0.0436 (14) | |
H10 | 0.5475 | 0.3258 | 0.5871 | 0.052* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cd1 | 0.0331 (2) | 0.0280 (2) | 0.0254 (2) | 0.00293 (14) | 0.00988 (14) | −0.00140 (14) |
O1 | 0.0347 (19) | 0.045 (2) | 0.036 (2) | 0.0083 (15) | 0.0105 (16) | 0.0041 (15) |
O2 | 0.043 (2) | 0.049 (2) | 0.038 (2) | 0.0063 (16) | 0.0066 (17) | 0.0087 (16) |
O3 | 0.0333 (17) | 0.0217 (17) | 0.056 (2) | −0.0019 (13) | 0.0175 (17) | 0.0015 (15) |
O4 | 0.0414 (19) | 0.0292 (17) | 0.047 (2) | 0.0059 (15) | 0.0204 (17) | 0.0114 (15) |
O5 | 0.044 (3) | 0.065 (4) | 0.058 (4) | 0 | −0.004 (3) | 0 |
N1 | 0.032 (2) | 0.029 (2) | 0.026 (2) | −0.0001 (19) | 0.0113 (17) | 0.0008 (17) |
N2 | 0.041 (2) | 0.036 (2) | 0.024 (2) | −0.0003 (19) | 0.0143 (18) | −0.0007 (18) |
C1 | 0.033 (3) | 0.035 (3) | 0.028 (3) | −0.006 (2) | 0.011 (2) | −0.005 (2) |
C2 | 0.041 (3) | 0.073 (4) | 0.054 (4) | 0.004 (3) | 0.014 (3) | 0.014 (3) |
C3 | 0.033 (2) | 0.033 (3) | 0.021 (2) | −0.001 (2) | 0.0095 (19) | −0.0018 (18) |
C4 | 0.036 (3) | 0.045 (3) | 0.045 (3) | −0.006 (2) | 0.007 (2) | 0.004 (2) |
C5 | 0.034 (2) | 0.025 (2) | 0.022 (2) | 0.0006 (19) | 0.002 (2) | 0.0044 (17) |
C6 | 0.029 (2) | 0.030 (2) | 0.027 (2) | −0.0059 (19) | 0.002 (2) | 0.0020 (19) |
C7 | 0.041 (3) | 0.025 (2) | 0.029 (3) | 0.004 (2) | 0.011 (2) | 0.0054 (19) |
C8 | 0.070 (4) | 0.043 (3) | 0.027 (3) | −0.020 (3) | 0.013 (3) | −0.008 (2) |
C9 | 0.070 (4) | 0.064 (4) | 0.037 (3) | −0.041 (3) | 0.009 (3) | −0.014 (3) |
C10 | 0.044 (3) | 0.052 (3) | 0.035 (3) | −0.025 (2) | 0.012 (2) | −0.001 (2) |
Cd1—O3 | 2.275 (3) | C1—C2 | 1.492 (8) |
Cd1—O4i | 2.301 (3) | C2—H2A | 0.98 |
Cd1—N1 | 2.324 (4) | C2—H2B | 0.98 |
Cd1—O1 | 2.374 (4) | C2—H2C | 0.98 |
Cd1—N2ii | 2.388 (4) | C3—C4 | 1.506 (6) |
Cd1—O2 | 2.443 (4) | C4—H4A | 0.98 |
O1—C1 | 1.268 (5) | C4—H4B | 0.98 |
O2—C1 | 1.249 (5) | C4—H4C | 0.98 |
O3—C3 | 1.265 (5) | C5—C6 | 1.374 (6) |
O4—C3 | 1.250 (5) | C5—C10 | 1.388 (6) |
O4—Cd1iii | 2.301 (3) | C6—C7 | 1.381 (6) |
O5—H5 | 0.808 (18) | C6—H6 | 0.95 |
N1—C5 | 1.435 (6) | C7—C8 | 1.401 (6) |
N1—HN1A | 0.859 (19) | C8—C9 | 1.350 (8) |
N1—HN1B | 0.886 (19) | C8—H8 | 0.95 |
N2—C7 | 1.425 (6) | C9—C10 | 1.394 (8) |
N2—Cd1iv | 2.388 (4) | C9—H9 | 0.95 |
N2—HN2A | 0.870 (19) | C10—H10 | 0.95 |
N2—HN2B | 0.877 (19) | ||
O3—Cd1—O4i | 79.37 (11) | C1—C2—H2A | 109.5 |
O3—Cd1—N1 | 107.45 (13) | C1—C2—H2B | 109.5 |
O4i—Cd1—N1 | 99.25 (13) | H2A—C2—H2B | 109.5 |
O3—Cd1—O1 | 114.63 (11) | C1—C2—H2C | 109.5 |
O4i—Cd1—O1 | 85.82 (12) | H2A—C2—H2C | 109.5 |
N1—Cd1—O1 | 137.80 (13) | H2B—C2—H2C | 109.5 |
O3—Cd1—N2ii | 86.63 (14) | O4—C3—O3 | 122.3 (4) |
O4i—Cd1—N2ii | 157.39 (13) | O4—C3—C4 | 120.5 (4) |
N1—Cd1—N2ii | 101.86 (14) | O3—C3—C4 | 117.1 (4) |
O1—Cd1—N2ii | 84.00 (13) | C3—C4—H4A | 109.5 |
O3—Cd1—O2 | 168.71 (11) | C3—C4—H4B | 109.5 |
O4i—Cd1—O2 | 98.78 (12) | H4A—C4—H4B | 109.5 |
N1—Cd1—O2 | 83.83 (13) | C3—C4—H4C | 109.5 |
O1—Cd1—O2 | 54.09 (11) | H4A—C4—H4C | 109.5 |
N2ii—Cd1—O2 | 91.49 (13) | H4B—C4—H4C | 109.5 |
C1—O1—Cd1 | 93.7 (3) | C6—C5—C10 | 120.3 (5) |
C1—O2—Cd1 | 91.0 (3) | C6—C5—N1 | 119.4 (4) |
C3—O3—Cd1 | 117.6 (3) | C10—C5—N1 | 120.3 (5) |
C3—O4—Cd1iii | 136.7 (3) | C5—C6—C7 | 120.4 (4) |
C5—N1—Cd1 | 114.9 (3) | C5—C6—H6 | 119.8 |
C5—N1—HN1A | 117 (3) | C7—C6—H6 | 119.8 |
Cd1—N1—HN1A | 108 (3) | C6—C7—C8 | 119.4 (5) |
C5—N1—HN1B | 114 (3) | C6—C7—N2 | 120.2 (4) |
Cd1—N1—HN1B | 113 (3) | C8—C7—N2 | 120.1 (5) |
HN1A—N1—HN1B | 88 (4) | C9—C8—C7 | 119.8 (5) |
C7—N2—Cd1iv | 114.3 (3) | C9—C8—H8 | 120.1 |
C7—N2—HN2A | 119 (3) | C7—C8—H8 | 120.1 |
Cd1iv—N2—HN2A | 96 (3) | C8—C9—C10 | 121.4 (5) |
C7—N2—HN2B | 118 (4) | C8—C9—H9 | 119.3 |
Cd1iv—N2—HN2B | 94 (3) | C10—C9—H9 | 119.3 |
HN2A—N2—HN2B | 111 (5) | C5—C10—C9 | 118.7 (5) |
O2—C1—O1 | 121.0 (5) | C5—C10—H10 | 120.6 |
O2—C1—C2 | 120.0 (4) | C9—C10—H10 | 120.6 |
O1—C1—C2 | 119.0 (4) | ||
Cd1—O2—C1—O1 | −4.6 (4) | N1—C5—C6—C7 | 178.6 (4) |
Cd1—O2—C1—C2 | 174.9 (4) | C5—C6—C7—C8 | −1.0 (7) |
Cd1—O1—C1—O2 | 4.8 (5) | C5—C6—C7—N2 | 173.2 (4) |
Cd1—O1—C1—C2 | −174.8 (4) | Cd1iv—N2—C7—C6 | −103.9 (4) |
Cd1iii—O4—C3—O3 | −148.4 (4) | Cd1iv—N2—C7—C8 | 70.2 (5) |
Cd1iii—O4—C3—C4 | 34.3 (6) | C6—C7—C8—C9 | 1.1 (8) |
Cd1—O3—C3—O4 | −3.8 (6) | N2—C7—C8—C9 | −173.1 (5) |
Cd1—O3—C3—C4 | 173.5 (3) | C7—C8—C9—C10 | −0.4 (9) |
Cd1—N1—C5—C6 | −82.6 (4) | C6—C5—C10—C9 | 0.6 (7) |
Cd1—N1—C5—C10 | 95.9 (4) | N1—C5—C10—C9 | −177.9 (5) |
C10—C5—C6—C7 | 0.1 (6) | C8—C9—C10—C5 | −0.5 (9) |
Symmetry codes: (i) −x+3/2, y−1/2, −z+3/2; (ii) x, −y+1, z+1/2; (iii) −x+3/2, y+1/2, −z+3/2; (iv) x, −y+1, z−1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H5···O2 | 0.81 (2) | 2.06 (4) | 2.788 (5) | 149 (7) |
N1—HN1A···O5 | 0.86 (2) | 2.34 (2) | 3.183 (4) | 166 (4) |
N1—HN1B···O3iii | 0.89 (2) | 2.12 (2) | 2.991 (5) | 166 (5) |
N2—HN2A···O4iv | 0.87 (2) | 2.32 (4) | 3.012 (6) | 137 (4) |
N2—HN2B···O1iii | 0.88 (2) | 2.17 (3) | 2.994 (5) | 156 (5) |
C6—H6···O1iii | 0.95 | 2.39 | 3.195 (5) | 142 |
Symmetry codes: (iii) −x+3/2, y+1/2, −z+3/2; (iv) x, −y+1, z−1/2. |
Acknowledgements
This work was supported by a Congressionally directed grant from the US Department of Education (grant No. P116Z100020) for the X-ray diffractometer and a grant from the Geneseo Foundation.
References
Ariyananda, W. G. P. & Norman, R. E. (2005). Acta Cryst. E61, m187–m189. Web of Science CSD CrossRef IUCr Journals Google Scholar
Banerjee, S., Ghosh, A., Wu, B., Lassahn, P.-G. & Janiak, C. (2005). Polyhedron, 24, 593–599. Web of Science CSD CrossRef CAS Google Scholar
Batten, S. R., McKenzie, C. J. & Nielsen, L. P. (2001). Acta Cryst. C57, 156–157. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Borsari, M. (2014). Cadmium: Coordination Chemistry in Encyclopedia of Inorganic and Bioinorganic Chemistry, pp. 1–16 New York: Wiley. Google Scholar
Bruker (2013). APEX2, SAINT, SADABS, and XSHELL. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bygott, A. M. T., Geue, R. J., Ralph, S. F., Sargeson, A. M. & Willis, A. C. (2007). Dalton Trans. pp. 4778–4748. Web of Science CSD CrossRef Google Scholar
Chemli, R., Kamoun, S. & Roisnel, T. (2013). Acta Cryst. E69, m670–m671. CSD CrossRef IUCr Journals Google Scholar
Chen, H.-R. & Zhang, W.-W. (2014). Acta Cryst. C70, 1079–1082. Web of Science CSD CrossRef IUCr Journals Google Scholar
Chen, Z.-L., Zhang, Y.-Z. & Liang, F.-P. (2006). Acta Cryst. E62, m1296–m1297. Web of Science CSD CrossRef IUCr Journals Google Scholar
Cherni, S. N., Cherni, A. & Driss, A. (2012). X-ray Struct. Anal. Online, 28, 13–14. CSD CrossRef CAS Google Scholar
Dey, C., Kundu, T., Biswal, B. P., Mallick, A. & Banerjee, R. (2014). Acta Cryst. B70, 3–10. Web of Science CrossRef CAS IUCr Journals Google Scholar
Dickman, M. H. (2000). Acta Cryst. C56, 58–60. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Djebli, Y., Boufas, S., Bencharif, L., Roisnel, T. & Bencharif, M. (2012). Acta Cryst. E68, m1411–m1412. CSD CrossRef IUCr Journals Google Scholar
Duff, E. J. (1968). J. Chem. Soc. A, pp. 434–437. CrossRef Web of Science Google Scholar
Dymock, K. R. & Palenik, G. J. (1975). Inorg. Chem. 14, 1220–1222. CrossRef CAS Web of Science Google Scholar
Faizi, M. S. H. & Prisyazhnaya, E. V. (2015). Acta Cryst. E71, m175–m176. Web of Science CSD CrossRef IUCr Journals Google Scholar
Farha, O. K. & Hupp, J. T. (2010). Acc. Chem. Res. 43, 1166–1175. Web of Science CrossRef CAS PubMed Google Scholar
Gao, S., Liu, J.-W., Huo, L.-H., Zhao, H. & Zhao, J.-G. (2004). Acta Cryst. E60, m1875–m1877. Web of Science CSD CrossRef IUCr Journals Google Scholar
Geiger, D. K. (2012). Acta Cryst. E68, m1040. CSD CrossRef IUCr Journals Google Scholar
Geiger, D. K. & Parsons, D. E. (2014). Acta Cryst. E70, m247–m248. CSD CrossRef IUCr Journals Google Scholar
Geiger, D. K., Parsons, D. E. & Zick, P. L. (2014). Acta Cryst. E70, 566–572. CSD CrossRef IUCr Journals Google Scholar
Henehan, C. J., Pountney, D. L., Vašák, M. & Zerbe, O. (1993). Protein Sci. 2, 1756–1764. CrossRef CAS PubMed Google Scholar
Jalilehvand, F., Amini, Z. & Parmar, K. (2012). Inorg. Chem. 51, 10619–10630. Web of Science CrossRef CAS PubMed Google Scholar
Jalilehvand, F., Leung, B. O. & Mah, V. (2009). Inorg. Chem. 48, 5758–5771. Web of Science CrossRef PubMed CAS Google Scholar
Keypour, H., Salehzadeh, S., Pritchard, R. G. & Parish, R. V. (2000). Polyhedron, 19, 1633–1637. Web of Science CSD CrossRef CAS Google Scholar
Kimblin, C. & Parkin, G. (1996). Inorg. Chem. 35, 6912–6913. CSD CrossRef PubMed CAS Web of Science Google Scholar
Kong, Z.-G., Wang, J.-J. & Wang, X.-Y. (2008a). Acta Cryst. C64, m333–m335. Web of Science CSD CrossRef IUCr Journals Google Scholar
Kong, Z.-G., Wang, J.-J. & Wang, X.-Y. (2008b). Acta Cryst. C64, m365–m368. Web of Science CSD CrossRef IUCr Journals Google Scholar
Kreno, L. E., Leong, K., Farha, O. K., Allendorf, M., Van Duyne, R. P. & Hupp, J. T. (2012). Chem. Rev. 112, 1105–1125. Web of Science CrossRef CAS PubMed Google Scholar
Li, Q., Wang, H.-T. & Ye, Q. (2014). Acta Cryst. C70, 992–997. Web of Science CSD CrossRef IUCr Journals Google Scholar
Liang, W.-X. & Qu, Z.-R. (2008). Acta Cryst. E64, m1254. Web of Science CSD CrossRef IUCr Journals Google Scholar
Liu, B.-X. & Xu, D.-J. (2005). Acta Cryst. E61, m1218–m1220. Web of Science CSD CrossRef IUCr Journals Google Scholar
Liu, J.-Q., Zhang, Y., Lü, Y.-J. & Jiang, Z.-J. (2012). Acta Cryst. E68, m430. CSD CrossRef IUCr Journals Google Scholar
Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Maxcy, K. R., Smith, R., Willett, R. D. & Vij, A. (2000). Acta Cryst. C56, e454. Web of Science CSD CrossRef IUCr Journals Google Scholar
Mei, L., Li, J., Ming, Z. S., Rong, L. Q. & Liang, L. X. (2009). Russ. J. Coord. Chem. 35, 871–873. Web of Science CrossRef CAS Google Scholar
Muetterties, E. L. & Guggenberger, L. J. (1974). J. Am. Chem. Soc. 96, 1748–1756. CrossRef CAS Web of Science Google Scholar
Narayanan, B. & Bhadbhade, M. M. (1996). Acta Cryst. C52, 3049–3051. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Ovalle-Marroquín, P., Gómez-Lara, J. & Hernández-Ortega, S. (2002). Acta Cryst. E58, m269–m271. Web of Science CSD CrossRef IUCr Journals Google Scholar
Qian, B., Ma, W.-X., Lu, L.-D., Yang, X.-J. & Wang, X. (2007). Acta Cryst. E63, m2930. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Song, W.-D., Gu, C.-S., Liu, J.-W. & Hao, X.-M. (2006). Acta Cryst. E62, m2397–m2399. Web of Science CSD CrossRef IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Uçar, İ., Yeşilel, O. Z., Bulut, A., İçbudak, H., Ölmez, H. & Kazak, C. (2004). Acta Cryst. C60, m392–m394. Web of Science CSD CrossRef IUCr Journals Google Scholar
Wang, J., Tao, J.-Q. & Xu, X.-J. (2011). Acta Cryst. C67, m173–m175. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Wang, P., Zhao, Y., Chen, Y. & Kou, X.-Y. (2013). Acta Cryst. C69, 1340–1343. Web of Science CSD CrossRef IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
Xu, X.-J., Miao, J.-Y. & Wang, J. (2013). Acta Cryst. C69, 620–623. Web of Science CSD CrossRef IUCr Journals Google Scholar
Zhang, X.-F., Gao, S., Huo, L.-H. & Zhao, H. (2007). Acta Cryst. E63, m1314–m1316. Web of Science CSD CrossRef IUCr Journals Google Scholar
Zhuo, X., Wang, Z.-W., Li, Y.-Z. & Zheng, H.-G. (2006). Acta Cryst. E62, m785–m787. Web of Science CSD CrossRef IUCr Journals Google Scholar
Zick, P. L. & Geiger, D. K. (2016). Acta Cryst. E72, 1037–1042. Web of Science CSD CrossRef IUCr Journals Google Scholar
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