(Acetyl­acetonato-κ2 O,O′)chlorido­trimethano­latoniobium(V)

Leandra Herbst; Renier Koen; Andreas Roodt; Hendrik G Visser

doi:10.1107/S1600536810021719

. 2010 Jun 16;66(Pt 7):m801–m802. doi: 10.1107/S1600536810021719

(Acetylacetonato-κ² O,O′)chloridotrimethanolatoniobium(V)

Leandra Herbst ^a,^*, Renier Koen ^a, Andreas Roodt ^a, Hendrik G Visser ^a

PMCID: PMC3006950 PMID: 21587722

Abstract

In the title compound, [Nb(CH₃O)₃(C₅H₇O₂)Cl], the Nb^V atom is coordinated by two O atoms from the chelating acetylacetonate ligand, three O atoms from the methanolate groups and one chloride ligand. The octahedral environment around niobium is slightly distorted with Nb—O distances in the range 1.8603 (15)–2.1083 (15) Å and an Nb—Cl distance of 2.4693 (9) Å. The O—Nb—O angles vary between 80.74 (6) and 100.82 (7)°, while the trans Cl—Nb—O angle is 167.60 (5)°. There are no hydrogen bonds observed, only an intermolecular C—H⋯O interaction.

Related literature

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

Experimental

Crystal data

[Nb(CH₃O)₃(C₅H₇O₂)Cl]
M _r = 320.57
Orthorhombic,
a = 12.296 (5) Å
b = 12.915 (4) Å
c = 15.470 (5) Å
V = 2456.7 (16) Å³
Z = 8
Mo Kα radiation
μ = 1.20 mm⁻¹
T = 100 K
0.36 × 0.30 × 0.19 mm

Data collection

Bruker X8 APEXII 4K Kappa CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.673, T _max = 0.805
28601 measured reflections
3083 independent reflections
2757 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.023
wR(F ²) = 0.068
S = 1.16
3083 reflections
141 parameters
H-atom parameters constrained
Δρ_max = 1.06 e Å⁻³
Δρ_min = −0.87 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT-Plus (Bruker, 2004 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810021719/pv2289sup1.cif

e-66-0m801-sup1.cif^{(17KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810021719/pv2289Isup2.hkl

e-66-0m801-Isup2.hkl^{(148.3KB, hkl)}

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

Table 1. Selected geometric parameters (Å, °).

O1—Nb1	1.8640 (15)
O2—Nb1	1.8811 (16)
O3—Nb1	1.8603 (15)
O4—Nb1	2.1083 (15)
O5—Nb1	2.0842 (15)
Cl1—Nb1	2.4693 (9)

Open in a new tab

O3—Nb1—O1	100.82 (7)
O3—Nb1—O2	99.96 (7)
O1—Nb1—O2	99.45 (7)
O3—Nb1—O5	163.63 (6)
O1—Nb1—O5	91.53 (7)
O2—Nb1—O5	88.43 (7)
O3—Nb1—O4	85.71 (7)
O2—Nb1—Cl1	167.60 (5)

Open in a new tab

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8C⋯O4ⁱ	0.98	2.46	3.442 (3)	176

Open in a new tab

Symmetry code: (i) Inline graphic .

Acknowledgments

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

supplementary crystallographic information

Comment

Acetylacetone and its analogues 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 intimate mechanism of the reactions of O,O'- and N,O -bidentate ligands with transition metals used in the nuclear industry, specifically hafnium, zirconium, niobium and tantalum (Viljoen et al., 2008; 2009a,b; 2010; Steyn et al., 2008).

Pale-yellow cubic crystals of the title complex crystallize from a methanol reaction solution containing niobium(V) chloride and acetylacetone after several days (Davies et al., 1999). The asymmetric unit consists of a niobium(V) atom surrounded by three methanolate groups, a chloride ligand and a O,O'- bonded acetylacetonato ligand (Figure 1). The octahedral environment around niobium is slightly distorted with Nb–O distances varying between 1.8603 (15) and 2.1083 (15) Å, while the Nb–Cl distance is 2.4693 (9) Å. The O–Nb–O angles vary between 80.74 (6) and 100.82 (7) ° while the trans Cl–Nb–O angle is 167.60 (5) °. All the bond distances and angles are similar to other relevant niobium(V) structures (Sokolov et al., 1999; 2005; Antinolo et al., 2000 and Dahan et al., 1976). The niobium compounds pack in a head-to-tail fashion along the bc plain.

There are no classical hydrogen bonds observed in this structure. However, the structure is stabilized by C8–H8C..O4* (* = -1/2+x,1/2-y,1-z) intermolecular interactions with C—H = 0.98, H···O = 2.46 and C···O = 3.442 (3) Å and C—H···O angle = 176°.

Experimental

The reaction was performed under modified Schlenk conditions under an argon atmosphere. 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 a few days after which pale-yellow crystals, suitable for X-ray diffraction were obtained.