Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536811031710/zq2119sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536811031710/zq2119Isup2.hkl |
CCDC reference: 845236
Key indicators
- Single-crystal X-ray study
- T = 100 K
- Mean (C-C) = 0.003 Å
- R factor = 0.037
- wR factor = 0.100
- Data-to-parameter ratio = 17.0
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT230_ALERT_2_C Hirshfeld Test Diff for O1 -- C1 .. 6.4 su PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L= 0.600 4 PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L= 0.600 5
Alert level G PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite 2 PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF .... ? PLAT152_ALERT_1_G The Supplied and Calc. Volume s.u. Differ by ... 2 Units PLAT720_ALERT_4_G Number of Unusual/Non-Standard Labels .......... 2 PLAT794_ALERT_5_G Note: Tentative Bond Valency for Zr1 (IV) 4.24 PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints ....... 1
0 ALERT level A = Most likely a serious problem - resolve or explain 0 ALERT level B = A potentially serious problem, consider carefully 3 ALERT level C = Check. Ensure it is not caused by an omission or oversight 6 ALERT level G = General information/check it is not something unexpected 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 2 ALERT type 2 Indicator that the structure model may be wrong or deficient 2 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion 2 ALERT type 5 Informative message, check
Chemicals were purchased from Sigma-Aldrich and used as received. ZrCl4 (103.3 mg, 0.463 mmol) and picolinic acid (PicA) (175.2 mg, 1.423 mmol) was separately dissolved in DMF (2.5 ml ea) and heated to 60 °C. The PicA solution was added drop-wise to the zirconium solution and stirred at 60 °C for 30 minutes. The reaction solution was removed from heating, covered and left to stand for crystallization. White cubic crystals, suitable for single-crystal X-ray diffraction, formed after 30 days (yield: 178 mg, 86%).
The aromatic H atoms were placed in geometrically idealized positions (C–H = 0.95 Å) and constrained to ride on their parent atoms with Uiso(H) = 1.2Ueq(C). The hydrogen atoms of the solvent water molecule were located on the Fourier difference map and refined isotropically. The highest residual electron density was located 0.74 Å from O1.
Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004); 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: WinGX (Farrugia, 1999).
[Zr(C6H4NO2)4]·2H2O | Dx = 1.743 Mg m−3 |
Mr = 615.66 | Mo Kα radiation, λ = 0.71073 Å |
Tetragonal, P42/n | Cell parameters from 9933 reflections |
Hall symbol: -P 4bc | θ = 2.6–28.4° |
a = 11.083 (5) Å | µ = 0.54 mm−1 |
c = 9.548 (5) Å | T = 100 K |
V = 1172.8 (10) Å3 | Cuboid, colourless |
Z = 2 | 0.12 × 0.09 × 0.04 mm |
F(000) = 624 |
Bruker X8 APEXII 4K Kappa CCD diffractometer | 1477 independent reflections |
Radiation source: fine-focus sealed tube | 1271 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.074 |
ω and ϕ scans | θmax = 28.5°, θmin = 2.6° |
Absorption correction: multi-scan (SADABS; Bruker, 2004) | h = −14→13 |
Tmin = 0.942, Tmax = 0.977 | k = −14→14 |
27234 measured reflections | l = −12→12 |
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)] = 0.037 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.100 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0415P)2 + 2.5407P] where P = (Fo2 + 2Fc2)/3 |
1477 reflections | (Δ/σ)max < 0.001 |
87 parameters | Δρmax = 0.64 e Å−3 |
1 restraint | Δρmin = −0.92 e Å−3 |
[Zr(C6H4NO2)4]·2H2O | Z = 2 |
Mr = 615.66 | Mo Kα radiation |
Tetragonal, P42/n | µ = 0.54 mm−1 |
a = 11.083 (5) Å | T = 100 K |
c = 9.548 (5) Å | 0.12 × 0.09 × 0.04 mm |
V = 1172.8 (10) Å3 |
Bruker X8 APEXII 4K Kappa CCD diffractometer | 1477 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2004) | 1271 reflections with I > 2σ(I) |
Tmin = 0.942, Tmax = 0.977 | Rint = 0.074 |
27234 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | 1 restraint |
wR(F2) = 0.100 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | Δρmax = 0.64 e Å−3 |
1477 reflections | Δρmin = −0.92 e Å−3 |
87 parameters |
Experimental. The intensity data were collected on a Bruker X8 ApexII 4 K Kappa CCD diffractometer using an exposure time of 40 s/frame. A total of 1709 frames were collected with a frame width of 0.5° covering up to θ = 28.40° with 99.5% completeness accomplished. |
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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. |
x | y | z | Uiso*/Ueq | ||
Zr1 | 0.25 | 0.25 | 0.75 | 0.01305 (15) | |
O1 | 0.41797 (14) | 0.31522 (14) | 0.82454 (18) | 0.01305 (15) | |
O2 | 0.56146 (18) | 0.33223 (18) | 0.9859 (2) | 0.0263 (4) | |
C3 | 0.4700 (2) | 0.1154 (2) | 1.1212 (3) | 0.0195 (5) | |
H3 | 0.5415 | 0.144 | 1.1601 | 0.023* | |
N1 | 0.31289 (18) | 0.13671 (18) | 0.9505 (2) | 0.0157 (4) | |
C2 | 0.4174 (2) | 0.1737 (2) | 1.0089 (3) | 0.0169 (5) | |
C5 | 0.3088 (2) | −0.0267 (2) | 1.1131 (3) | 0.0206 (5) | |
H5 | 0.2707 | −0.0959 | 1.1461 | 0.025* | |
C6 | 0.2603 (2) | 0.0372 (2) | 1.0016 (3) | 0.0178 (5) | |
H6 | 0.1891 | 0.01 | 0.961 | 0.021* | |
C4 | 0.4143 (2) | 0.0137 (2) | 1.1748 (3) | 0.0222 (5) | |
H4 | 0.4473 | −0.0269 | 1.251 | 0.027* | |
C1 | 0.4728 (2) | 0.2822 (2) | 0.9379 (3) | 0.0183 (5) | |
O03 | 0.25 | 0.75 | 0.3385 (4) | 0.0472 (9) | |
H03A | 0.274 (4) | 0.815 (3) | 0.396 (4) | 0.068 (15)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Zr1 | 0.01054 (17) | 0.01054 (17) | 0.0181 (2) | 0 | 0 | 0 |
O1 | 0.01054 (17) | 0.01054 (17) | 0.0181 (2) | 0 | 0 | 0 |
O2 | 0.0201 (9) | 0.0257 (10) | 0.0332 (11) | −0.0070 (8) | −0.0066 (8) | 0.0008 (8) |
C3 | 0.0170 (11) | 0.0211 (12) | 0.0205 (12) | 0.0015 (9) | −0.0014 (9) | −0.0035 (10) |
N1 | 0.0141 (9) | 0.0136 (9) | 0.0194 (10) | −0.0005 (8) | 0.0000 (8) | −0.0002 (8) |
C2 | 0.0145 (11) | 0.0160 (11) | 0.0203 (12) | 0.0000 (9) | 0.0007 (9) | −0.0030 (9) |
C5 | 0.0221 (12) | 0.0178 (12) | 0.0220 (13) | 0.0026 (9) | 0.0043 (10) | 0.0027 (10) |
C6 | 0.0158 (11) | 0.0154 (11) | 0.0223 (12) | −0.0003 (9) | 0.0005 (9) | 0.0003 (9) |
C4 | 0.0236 (13) | 0.0240 (13) | 0.0191 (13) | 0.0056 (10) | 0.0003 (10) | 0.0020 (10) |
C1 | 0.0148 (11) | 0.0171 (11) | 0.0231 (12) | −0.0001 (9) | 0.0006 (9) | −0.0032 (9) |
O03 | 0.059 (2) | 0.038 (2) | 0.045 (2) | −0.0011 (18) | 0 | 0 |
Zr1—O1i | 2.1200 (18) | C3—C4 | 1.384 (4) |
Zr1—O1 | 2.1200 (18) | C3—H3 | 0.93 |
Zr1—O1ii | 2.1200 (18) | N1—C6 | 1.340 (3) |
Zr1—O1iii | 2.1200 (18) | N1—C2 | 1.349 (3) |
Zr1—N1i | 2.393 (2) | C2—C1 | 1.511 (4) |
Zr1—N1ii | 2.393 (2) | C5—C4 | 1.384 (4) |
Zr1—N1iii | 2.393 (2) | C5—C6 | 1.386 (4) |
Zr1—N1 | 2.393 (2) | C5—H5 | 0.93 |
O1—C1 | 1.294 (3) | C6—H6 | 0.93 |
O2—C1 | 1.218 (3) | C4—H4 | 0.93 |
C3—C2 | 1.381 (4) | O03—H03A | 0.941 (19) |
O1i—Zr1—O1 | 96.47 (3) | N1i—Zr1—N1 | 129.78 (7) |
O1i—Zr1—O1ii | 96.47 (3) | N1ii—Zr1—N1 | 73.76 (11) |
O1—Zr1—O1ii | 140.77 (10) | N1iii—Zr1—N1 | 129.78 (7) |
O1i—Zr1—O1iii | 140.77 (10) | C1—O1—Zr1 | 126.61 (15) |
O1—Zr1—O1iii | 96.47 (3) | C2—C3—C4 | 118.7 (2) |
O1ii—Zr1—O1iii | 96.47 (3) | C2—C3—H3 | 120.7 |
O1i—Zr1—N1i | 69.79 (7) | C4—C3—H3 | 120.7 |
O1—Zr1—N1i | 145.95 (7) | C6—N1—C2 | 118.2 (2) |
O1ii—Zr1—N1i | 73.05 (7) | C6—N1—Zr1 | 126.65 (17) |
O1iii—Zr1—N1i | 78.95 (7) | C2—N1—Zr1 | 114.94 (16) |
O1i—Zr1—N1ii | 145.95 (7) | N1—C2—C3 | 122.8 (2) |
O1—Zr1—N1ii | 78.95 (7) | N1—C2—C1 | 113.9 (2) |
O1ii—Zr1—N1ii | 69.79 (7) | C3—C2—C1 | 123.3 (2) |
O1iii—Zr1—N1ii | 73.05 (7) | C4—C5—C6 | 119.3 (2) |
N1i—Zr1—N1ii | 129.78 (7) | C4—C5—H5 | 120.4 |
O1i—Zr1—N1iii | 78.95 (7) | C6—C5—H5 | 120.4 |
O1—Zr1—N1iii | 73.05 (7) | N1—C6—C5 | 122.1 (2) |
O1ii—Zr1—N1iii | 145.95 (7) | N1—C6—H6 | 118.9 |
O1iii—Zr1—N1iii | 69.79 (7) | C5—C6—H6 | 118.9 |
N1i—Zr1—N1iii | 73.76 (11) | C3—C4—C5 | 118.9 (2) |
N1ii—Zr1—N1iii | 129.78 (7) | C3—C4—H4 | 120.6 |
O1i—Zr1—N1 | 73.05 (7) | C5—C4—H4 | 120.6 |
O1—Zr1—N1 | 69.79 (7) | O2—C1—O1 | 124.4 (2) |
O1ii—Zr1—N1 | 78.95 (7) | O2—C1—C2 | 121.4 (2) |
O1iii—Zr1—N1 | 145.95 (7) | O1—C1—C2 | 114.2 (2) |
Symmetry codes: (i) y, −x+1/2, −z+3/2; (ii) −x+1/2, −y+1/2, z; (iii) −y+1/2, x, −z+3/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O03—H03A···O2iv | 0.94 (2) | 1.89 (2) | 2.829 (3) | 175 (5) |
Symmetry code: (iv) y, −x+3/2, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | [Zr(C6H4NO2)4]·2H2O |
Mr | 615.66 |
Crystal system, space group | Tetragonal, P42/n |
Temperature (K) | 100 |
a, c (Å) | 11.083 (5), 9.548 (5) |
V (Å3) | 1172.8 (10) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.54 |
Crystal size (mm) | 0.12 × 0.09 × 0.04 |
Data collection | |
Diffractometer | Bruker X8 APEXII 4K Kappa CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2004) |
Tmin, Tmax | 0.942, 0.977 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 27234, 1477, 1271 |
Rint | 0.074 |
(sin θ/λ)max (Å−1) | 0.671 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.100, 1.10 |
No. of reflections | 1477 |
No. of parameters | 87 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.64, −0.92 |
Computer programs: APEX2 (Bruker, 2010), SAINT-Plus (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2006), WinGX (Farrugia, 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
O03—H03A···O2i | 0.941 (19) | 1.89 (2) | 2.829 (3) | 175 (5) |
Symmetry code: (i) y, −x+3/2, −z+3/2. |
The introduction of N,O-bidentate ligands with the oxine or aminovinylketone backbones significantly influences both steric and electronic properties of transition metal centres as illustrated by literature examples (Graham et al., 1991; Mtshali et al., 2006; Roodt et al., 2011; Schutte et al., 2008; Steyn et al., 1997; Van Aswegen et al., 1991; Van der Westhuizen et al., 2010). This study is part of ongoing research initiatives investigating coordination behaviour of O,O'- and N, O,-bidentate ligands with zirconium(IV) and hafnium(IV) for possible separation of these two metals from base ore sources (Steyn et al., 2008; Viljoen et al., 2010a,b).
The title compound, [Zr(C6H4NO2)4].2H2O, with C6H4NO2 as picolinic acid, crystallizes in the form of colourless cubic crystals in the tetragonal P42/n space group. The ZrIV atom, located on a crystallographic fourfold rotoinversion axis (4), is coordinated to four picolinic acid ligands (Fig. 1). The assymetric unit contains half a solvent molecule located on a twofold axis. The Zr—O and Zr—N bond lengths are 2.120 (2) Å and 2.393 (2) Å, respectively, with a N—Zr—O bite angle of 69.79 (7) °. The coordination polyhedron around the metal centre is an approximate square antiprism of the N,O-coordination ligand atoms, with a distortion towards dodecahedral geometry. The crystal packing is stabilized by intermolecular π-π interactions (Fig. 2), between adjacent picolinato rings, with interplanar and centroid-to-centroid distances of 3.271 (1) Å and 3.640 (2) Å, respectively. Further stabilization of the crystal structure is afforded by O—H···O hydrogen bonding (Fig. 3) between the carbonyl group of the picolinato ligands and the solvent water molecules. All of these interactions serve to link the molecules into a supramolecular three-dimensional network.