Di-μ-oxido-bis­{[(R,R)-(+)-1-amino-2-(3-methoxy-2-oxidobenzyl­ideneamino-κ2 O 2,N)-1,2-diphenyl­ethane-κN]oxidovanadium(V)} dihydrate

Grzegorz Romanowski; Tadeusz Lis

doi:10.1107/S1600536808014396

. 2008 Jun 7;64(Pt 7):m886–m887. doi: 10.1107/S1600536808014396

Di-μ-oxido-bis{[(R,R)-(+)-1-amino-2-(3-methoxy-2-oxidobenzylideneamino-κ² O ²,N)-1,2-diphenylethane-κN]oxidovanadium(V)} dihydrate

Grzegorz Romanowski ^a,^*, Tadeusz Lis ^b

PMCID: PMC2961776 PMID: 21202755

Abstract

In the crystal structure of the title compound, [V₂(C₂₂H₂₁N₂O₂)₂O₄]·2H₂O, oxide-bridged dimers of the complex are linked to water molecules by hydrogen-bonding interactions. The two five-membered chelate rings in the dimeric molecule both adopt twist conformations. Each V^V atom is six-coordinated by one oxide group and by two N and one O atom of the tridentate Schiff base ligand, and is bridged by two additional oxide atoms. The metal centre has a distorted octahedral coordination. The monoanionic ligands occupy one equatorial and two axial positions.

Related literature

For general background, see: Robinson et al. (1986 ▶); Vilter (1984 ▶); Gruning & Rehder (2000 ▶); Casny & Rehder (2001 ▶); Kimblin et al. (2002 ▶); Kwiatkowski et al. (2003 ▶, 2007 ▶); Romanowski et al. (2008 ▶); Wever & Hemrika (1997 ▶); Butler & Carter-Franklin (2004 ▶). For related structures, see: Root et al. (1993 ▶); Romanowski et al. (2008 ▶); Colpas et al. (1994 ▶); Li et al. (1988 ▶). For the synthesis, see: Kwiatkowski et al. (2003 ▶).

Experimental

Crystal data

[V₂(C₂₂H₂₁N₂O₂)₂O₄]·2H₂O
M _r = 892.73
Orthorhombic,
a = 9.328 (4) Å
b = 16.950 (7) Å
c = 25.490 (10) Å
V = 4030 (3) Å³
Z = 4
Cu Kα radiation
μ = 4.44 mm⁻¹
T = 100 (2) K
0.14 × 0.12 × 0.09 mm

Data collection

Oxford Xcalibur PX diffractometer with CCD area-detector
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2006 ▶) T _min = 0.627, T _max = 0.768
27320 measured reflections
7083 independent reflections
3677 reflections with I > 2σ(I)
R _int = 0.066

Refinement

R[F ² > 2σ(F ²)] = 0.048
wR(F ²) = 0.069
S = 1.01
7083 reflections
541 parameters
H-atom parameters constrained
Δρ_max = 0.64 e Å⁻³
Δρ_min = −0.39 e Å⁻³
Absolute structure: Flack (1983 ▶), 2905 Friedel pairs
Flack parameter: −0.007 (9)

Data collection: CrysAlis CCD (Oxford Diffraction, 2006 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2006 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPII (Johnson, 1976 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808014396/xu2414sup1.cif

e-64-0m886-sup1.cif^{(34.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808014396/xu2414Isup2.hkl

e-64-0m886-Isup2.hkl^{(346.6KB, hkl)}

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

Table 1. Selected bond lengths (Å).

V27A—O7A	1.908 (4)
V27A—O28A	1.607 (4)
V27A—O29A	1.703 (4)
V27A—O29	2.263 (4)
V27A—N11A	2.163 (5)
V27A—N14A	2.147 (5)
V27—O7	1.904 (4)
V27—O28	1.610 (4)
V27—O29	1.694 (3)
V27—O29A	2.247 (4)
V27—N11	2.179 (5)
V27—N14	2.135 (5)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N14—H14A⋯O7A	0.92	2.20	2.946 (6)	138
N14A—H14D⋯O7	0.92	2.02	2.855 (6)	151
O1W—H1W1⋯O29A	0.84	2.14	2.795 (6)	134
O2W—H1W2⋯O29	0.84	2.04	2.834 (7)	158
C3—H3⋯O1Wⁱ	0.95	2.52	3.431 (8)	160
C3A—H3A⋯O2Wⁱⁱ	0.95	2.52	3.424 (9)	159
C10A—H10A⋯O28ⁱⁱⁱ	0.95	2.48	3.075 (7)	120
C13A—H13A⋯O29	1.00	2.53	3.057 (7)	113

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

This scientific work has been supported from funds for science in years 2007–2009 as a research project (Nos. N204 0355 33 and DS/8210–4-0086–8).

supplementary crystallographic information

Comment

The discovery of vanadium in active sites of biological systems of nitrogenase (Robinson et al., 1986) and bromoperoxidase (Vilter, 1984) and recognition of its environment increased the interest in the vanadium complexes with ligands bearing oxygen and nitrogen atoms for mimicking the biological activity in natural systems. Structural models for the active site in haloperoxidases have already been reported (Gruning & Rehder, 2000; Casny & Rehder, 2001; Kimblin et al., 2002). Recently, it has been established that vanadium(V) complexes with Schiff bases, which are excellent models for active sites of vanadium containing haloperoxidases, are able to catalyze the oxidation of organic sulfides to the corresponding sulfoxides (Kwiatkowski et al., 2003, 2007; Romanowski et al., 2008). Vanadium haloperoxidases catalyze the oxidation of halides in the presence of hydrogen peroxide to highly reactive intermediate, a hypohalous acid, which may react either with suitable nucleophilic acceptor, if present, forming a halogenated compound or with hydrogen peroxide yielding ¹O₂ (Wever & Hemrika, 1997). Lately, it has been shown that vanadium bromoperoxidase from marine red algae can catalyze the bromination and cyclization of terpene substrates or the selective sulfoxidation of sulfides to the sulfoxides (Butler & Carter-Franklin, 2004).

The structure of (I) indicates that each vanadium atom is six-coordinated. The vanadium atoms V27 and V27A are joined together through two oxygen bridges, O29 and O29A being the bridging atoms coordinated to vanadium atoms at short and long distances (Table 1 and Fig. 1). The coordination sphere around each vanadium atom is composed of phenolate oxygen atoms (O7 or O7A) and of primary amine nitrogen atom (N14 or N14A) occupying axial positions and of imine nitrogen atom (N11 or N11A), two strongly coordinated terminal oxo (O28, O29 or O28A, O29A) and one weakly associated oxo group (O29A or O29) derived from the neighbouring VO₂ unit defining the equatorial plane. The polyhedron that describes the quadrilateral core consisting of the V₂O₂ unit and the spatial arrangement of remaining coordinated atoms resembles two edge shared octahedrons that are significantly distorted. The V27=O28 and V27A=O28A bond lengths of 1.616 (4) and 1.612 (4) Å respectively compare well with the distances between vanadium and the doubly bonded oxygen atoms (Root et al., 1993; Romanowski et al., 2008). The V27—O29 and V27A—O29A bonds (average 1.696 (4) Å) are longer than V27—O28 and V27A—O28A bonds (average 1.614 (4) Å) due to involvement of O29 and O29A atoms in V27—V27A bridging and hydrogen bonding interactions with water molecules. The V27—V27A distance of 3.057 (2) Å is much shorter than the V(V)—V(V) distance of 3.204 Å found in similar complex (Romanowski et al., 2008). The O28—V27—O29 and O28A—V27A—O29A angles of 105.6 (2)° and 104.6 (2)° respectively indicate significant double bond character of these bonds (Colpas et al., 1994) and are close to other cis-VO₂ units (Li et al., 1988). The two five-membered chelate rings adopt twisted conformations, while in similar dimeric vanadium(V) complex adopt differently puckered envelope conformations (Romanowski et al., 2008). The rings defined by V27, N11, C12, C13, N14 and V27A, N11A, C12A, C13A, N14A choose twisted conformation on C12, C13 and C12A, C13A, respectively.

The crystal structure of (I) is stabilized by intermolecular hydrogen bonds linking dimeric molecules both directly by N—H···O interactions and indirectly through water molecules by O···H—O—H interactions (Fig. 2, Table 2).

Experimental

The complex (I) were obtained in a template/complexation reactions analogous to those described for preparation of dioxovanadium(V) complexes with Schiff base ligands (Kwiatkowski et al., 2003). A solution of 1 mmol of (R,R)-(+)-1,2-diphenyl-1,2-diaminoethane in 10 ml of absolute ethanol was added under stirring to a freshly filtered solution of vanadium(V) oxytriethoxide (1 mmol) in 50 ml of absolute EtOH producing a yellow suspension of the intermediate. 3-Methoxysalicylaldehyde (1 mmol) dissolved in absolute EtOH was added to the aforementioned suspension. After refluxing (70 ml) of the resulting mixture for 2 h and its cooling to room temperature the separated solids were filtered off, washed several times with EtOH, recrystallized from DMSO-EtOH mixture and dried over molecular sieves.