supplementary materials


bt6846 scheme

Acta Cryst. (2012). E68, m1392    [ doi:10.1107/S1600536812042638 ]

(Acetylacetonato-[kappa]2O,O')dichloridobis(methanolato-[kappa]O)niobium(V)

L. Herbst, H. G. Visser, A. Roodt and C. Pretorius

Abstract top

In the title compound, [Nb(CH3O)2(C5H7O2)Cl2], a slightly distorted octahedral coordination geometry is observed around the NbV atom with Nb-O distances in the range of 1.8254 (16)-2.0892 (16) Å and Nb-Cl distances of 2.3997 (14) and 2.4023 (12) Å. The O-Nb-O angles vary between 81.36 (7) and 172.65 (7) °, while the trans Cl-Nb-Cl angle is 167.34 (2)°. There are no hydrogen bonds observed.

Comment top

Acetylacetone and other β-diketones are strong chelating agents that find applications in homogenous catalysis and the separations industry (Steyn et al., 1992; 1997; Otto et al., 1998; Roodt & Steyn, 2000; Brink et al., 2010). This study forms part of ongoing research to investigate the interaction of transition metals used in the nuclear industry, specifically zirconium, hafnium, niobium and tantalum, with O,O'- and N,O-bidentate ligands. (Steyn et al., 2008; Viljoen et al., 2008; 2009a,b; 2010; Herbst et al., 2010; 2011).

The title complex crystallizes in the monoclinic space group P21/c with Z = 4. The assymetric unit consists of a niobium(V) atom surrounded by two methanolate groups, two chlorido ligands and an O,O'-bonded acetylacetonato ligand (Figure 1). The octahedral environment around the niobium metal centre is slightly disordered with Nb—O distances varying between 1.8254 (16) and 2.0892 (16) Å, while the Nb—Cl distances are 2.3997 (14) and 2.4023 (12) Å respectively. The O—Nb—O angles vary between and 81.36 (7) and 172.65 (7) °, while the trans Cl—Nb—Cl angle is 167.34 (2) °. All the bond distances and angles are similar to other relevant niobium(V) structures (Herbst et al., 2010; 2011; Sokolov et al., 1999; 2005; Antinolo et al., 2000 and Dahan et al., 1976).

Related literature top

For synthetic background, see: Herbst et al. (2010; 2011); Davies et al. (1999). For applications of acetylacetone-type ligands in industry, see: Steyn et al. (1992, 1997, 2008); Otto et al. (1998); Roodt & Steyn (2000); Brink et al. (2010); Viljoen et al. (2008, 2009a,b, 2010). For related niobium complexes, see: Sokolov et al. (1999, 2005); Antinolo et al. (2000); Dahan et al. (1976).

Experimental top

NbCl5 (0.3134 g; 1.16 mmol) was carefully dissolved in absolute methanol (5 ml) (Care: exothermic reaction). Acetylacetone (0.119 ml; 1.16 mmol) was added to the solution. The colourless solution was stirred for 1 h at room temperature and the solution was left to stand at 252 K for 24 h after which pale-yellow crystals, suitable for X-ray diffraction were obtained.

Refinement top

The methyl and aromatic H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C—H = 0.95 and 0.98 Å and Uiso(H) = 1.5Ueq(C) and 1.2Ueq(C), respectively. The highest peak is located 0.74 Å from Nb1 and the deepest hole is situated 0.65 Å from Nb1.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004); program(s) used to solve structure: SIR92 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2004); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability displacement level.
(Acetylacetonato-κ2O,O')dichloridobis(methanolato- κO)niobium(V) top
Crystal data top
[Nb(CH3O)2(C5H7O2)Cl2]F(000) = 648
Mr = 324.98Dx = 1.744 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71069 Å
Hall symbol: -P 2ybcCell parameters from 9867 reflections
a = 7.7985 (2) Åθ = 2.3–32.9°
b = 11.6028 (3) ŵ = 1.39 mm1
c = 14.6819 (2) ÅT = 100 K
β = 111.279 (1)°Cubiod, yellow
V = 1237.91 (5) Å30.38 × 0.13 × 0.08 mm
Z = 4
Data collection top
Bruker APEXII CCD
diffractometer
2873 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.024
φ and ω scansθmax = 28°, θmin = 2.3°
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
h = 109
Tmin = 0.810, Tmax = 0.895k = 1415
25521 measured reflectionsl = 1919
2995 independent reflections
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)] = 0.026Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.060H-atom parameters constrained
S = 1.04 w = 1/[σ2(Fo2) + (0.0177P)2 + 2.6018P]
where P = (Fo2 + 2Fc2)/3
2995 reflections(Δ/σ)max = 0.001
131 parametersΔρmax = 1.90 e Å3
0 restraintsΔρmin = 1.14 e Å3
Crystal data top
[Nb(CH3O)2(C5H7O2)Cl2]V = 1237.91 (5) Å3
Mr = 324.98Z = 4
Monoclinic, P21/cMo Kα radiation
a = 7.7985 (2) ŵ = 1.39 mm1
b = 11.6028 (3) ÅT = 100 K
c = 14.6819 (2) Å0.38 × 0.13 × 0.08 mm
β = 111.279 (1)°
Data collection top
Bruker APEXII CCD
diffractometer
2995 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
2873 reflections with I > 2σ(I)
Tmin = 0.810, Tmax = 0.895Rint = 0.024
25521 measured reflectionsθmax = 28°
Refinement top
R[F2 > 2σ(F2)] = 0.026H-atom parameters constrained
wR(F2) = 0.060Δρmax = 1.90 e Å3
S = 1.04Δρmin = 1.14 e Å3
2995 reflectionsAbsolute structure: ?
131 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

Experimental. The intensity data was collected on a Bruker X8 ApexII 4 K Kappa CCD diffractometer using an exposure time of 60 s/frame. A total of 1033 frames were collected with a frame width of 0.5° covering up to θ = 28.32° with 99.8% 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.5973 (4)0.0556 (2)0.41589 (19)0.0291 (5)
H1A0.50410.00910.36980.044*
H1B0.54610.09490.45770.044*
H1C0.6970.00730.45470.044*
C20.6671 (3)0.14217 (19)0.36226 (16)0.0209 (4)
C30.6842 (3)0.25776 (19)0.38971 (15)0.0217 (4)
H30.64280.28010.4390.026*
C40.7590 (3)0.34165 (18)0.34795 (15)0.0189 (4)
C50.7749 (3)0.4644 (2)0.38144 (17)0.0256 (5)
H5A0.89620.49250.39150.038*
H5B0.75310.46890.44160.038*
H5C0.68560.51040.33260.038*
C61.0638 (4)0.3334 (2)0.1093 (2)0.0351 (6)
H6A1.04170.41040.12630.053*
H6B1.04410.33020.04090.053*
H6C1.18840.31190.14670.053*
C70.7155 (4)0.0737 (2)0.12959 (19)0.0315 (5)
H7A0.66270.08360.17880.047*
H7B0.80870.1310.13790.047*
H7C0.62130.08170.06610.047*
O10.7114 (2)0.10264 (14)0.29243 (12)0.0260 (3)
O20.8199 (2)0.32042 (13)0.27942 (12)0.0236 (3)
O30.9420 (2)0.25678 (14)0.12973 (12)0.0249 (3)
O40.7944 (2)0.03654 (13)0.13835 (12)0.0235 (3)
Cl11.11377 (9)0.13058 (6)0.32569 (5)0.03473 (14)
Cl20.51757 (8)0.23365 (5)0.10144 (4)0.02774 (12)
Nb10.82643 (3)0.178209 (17)0.198700 (15)0.02255 (7)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0387 (13)0.0244 (11)0.0336 (12)0.0020 (10)0.0241 (11)0.0074 (9)
C20.0234 (10)0.0220 (10)0.0208 (10)0.0033 (8)0.0122 (8)0.0047 (8)
C30.0271 (11)0.0233 (10)0.0194 (10)0.0032 (8)0.0142 (9)0.0006 (8)
C40.0204 (10)0.0202 (10)0.0166 (9)0.0022 (8)0.0074 (8)0.0015 (7)
C50.0325 (12)0.0212 (10)0.0277 (11)0.0021 (9)0.0162 (10)0.0065 (9)
C60.0348 (13)0.0404 (14)0.0344 (13)0.0160 (11)0.0177 (11)0.0021 (11)
C70.0391 (14)0.0204 (11)0.0358 (13)0.0076 (10)0.0145 (11)0.0050 (10)
O10.0399 (9)0.0187 (7)0.0296 (8)0.0034 (7)0.0247 (8)0.0019 (6)
O20.0349 (9)0.0186 (7)0.0246 (8)0.0050 (6)0.0194 (7)0.0042 (6)
O30.0307 (8)0.0245 (8)0.0274 (8)0.0071 (7)0.0199 (7)0.0046 (6)
O40.0291 (8)0.0184 (7)0.0279 (8)0.0037 (6)0.0161 (7)0.0059 (6)
Cl10.0379 (3)0.0295 (3)0.0374 (3)0.0022 (2)0.0144 (3)0.0032 (2)
Cl20.0297 (3)0.0293 (3)0.0283 (3)0.0040 (2)0.0154 (2)0.0029 (2)
Nb10.03316 (12)0.01790 (10)0.02524 (11)0.00586 (8)0.02096 (9)0.00534 (7)
Geometric parameters (Å, º) top
C1—C21.495 (3)C6—H6A0.96
C1—H1A0.96C6—H6B0.96
C1—H1B0.96C6—H6C0.96
C1—H1C0.96C7—O41.405 (3)
C2—O11.280 (3)C7—H7A0.96
C2—C31.393 (3)C7—H7B0.96
C3—C41.387 (3)C7—H7C0.96
C3—H30.93O1—Nb12.0892 (16)
C4—O21.283 (3)O2—Nb12.0429 (16)
C4—C51.497 (3)O3—Nb11.8254 (16)
C5—H5A0.96O4—Nb11.8410 (17)
C5—H5B0.96Cl1—Nb12.4023 (12)
C5—H5C0.96Cl2—Nb12.3997 (14)
C6—O31.411 (3)
C2—C1—H1A109.5H6B—C6—H6C109.5
C2—C1—H1B109.5O4—C7—H7A109.5
H1A—C1—H1B109.5O4—C7—H7B109.5
C2—C1—H1C109.5H7A—C7—H7B109.5
H1A—C1—H1C109.5O4—C7—H7C109.5
H1B—C1—H1C109.5H7A—C7—H7C109.5
O1—C2—C3123.49 (19)H7B—C7—H7C109.5
O1—C2—C1115.9 (2)C2—O1—Nb1133.05 (15)
C3—C2—C1120.6 (2)C4—O2—Nb1134.78 (14)
C4—C3—C2124.00 (19)C6—O3—Nb1159.91 (16)
C4—C3—H3118C7—O4—Nb1146.66 (15)
C2—C3—H3118O3—Nb1—O4100.77 (7)
O2—C4—C3123.2 (2)O3—Nb1—O292.28 (7)
O2—C4—C5115.49 (19)O4—Nb1—O2166.62 (7)
C3—C4—C5121.35 (19)O3—Nb1—O1172.65 (7)
C4—C5—H5A109.5O4—Nb1—O185.79 (7)
C4—C5—H5B109.5O2—Nb1—O181.36 (7)
H5A—C5—H5B109.5O3—Nb1—Cl297.31 (7)
C4—C5—H5C109.5O4—Nb1—Cl291.23 (6)
H5A—C5—H5C109.5O2—Nb1—Cl284.13 (5)
H5B—C5—H5C109.5O1—Nb1—Cl285.76 (6)
O3—C6—H6A109.5O3—Nb1—Cl192.06 (7)
O3—C6—H6B109.5O4—Nb1—Cl195.37 (6)
H6A—C6—H6B109.5O2—Nb1—Cl187.03 (5)
O3—C6—H6C109.5O1—Nb1—Cl183.97 (7)
H6A—C6—H6C109.5Cl2—Nb1—Cl1167.34 (2)
Acknowledgements top

Financial assistance from the Advanced Metals Initiative (AMI) of the Department of Science and Technology (DST) of South Africa, through the New Metals Development Network (NMDN) coordinated by the South African Nuclear Energy Corporation Limited (Necsa) and the University of the Free State is gratefully acknowledged.

references
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