Cyclo-thiazenokomplexe von Vanadium(V) Die Kristallstruktur von (AsPh₄)₂[V(N₃)₃(N₃S₂)]₂ · CH₂Cl₂ / Cyclo-thiazeno Complexes of Vanadium(V) The Crystal Structure of (AsPh₄)₂[V(N₃)₃(N₃S₂)]₂ · CH₂Cl₂

Abstract

<jats:p>An improved synthesis for [VCl<jats:sub>2</jats:sub>(N<jats:sub>3</jats:sub>S<jats:sub>2</jats:sub>)]<jats:sub>∞</jats:sub>, was found in the reaction of VOCl<jats:sub>3</jats:sub> with (NSCl)<jats:sub>3</jats:sub>; when the reaction is performed in H<jats:sub>2</jats:sub>CCl<jats:sub>2</jats:sub> and (NSCl)<jats:sub>3</jats:sub> is used in excess, the thiazyl-solvate [VCl<jats:sub>2</jats:sub>(N<jats:sub>3</jats:sub>S<jats:sub>2</jats:sub>) · NSCl]<jats:sub>2</jats:sub> is obtained. [VCl<jats:sub>2</jats:sub>(N<jats:sub>3</jats:sub>S<jats:sub>2</jats:sub>)] reacts with AsPh<jats:sub>4</jats:sub>Cl to form (AsPh<jats:sub>4</jats:sub>)<jats:sub>2</jats:sub>[VCl<jats:sub>3</jats:sub>(N <jats:sub>3</jats:sub>S<jats:sub>2</jats:sub>)]<jats:sub>2</jats:sub>; this reacts with AgN<jats:sub>3</jats:sub> in CH<jats:sub>2</jats:sub>Cl<jats:sub>2</jats:sub> suspension to yield (AsPh<jats:sub>4</jats:sub>)<jats:sub>2</jats:sub>[V (N<jats:sub>3</jats:sub>)<jats:sub>3</jats:sub>(N<jats:sub>3</jats:sub>S<jats:sub>2</jats:sub>)]<jats:sub>2 </jats:sub>· CH<jats:sub>2</jats:sub>Cl<jats:sub>2</jats:sub>. The compounds were characterized by their IR and <jats:sup>51</jats:sup>V NMR spectra. The latter are compared with new <jats:sup>51</jats:sup>V NMR data for [VO<jats:sub>2</jats:sub>Cl<jats:sub>2</jats:sub>]<jats:sup>⊖</jats:sup> and [VOCl<jats:sub>4</jats:sub>]<jats:sup>⊖</jats:sup> ; a decrease of <jats:sup>51</jats:sup>V shielding in the order [VO<jats:sub>2</jats:sub>Cl<jats:sub>2</jats:sub>]<jats:sup>⊖</jats:sup> &gt; [VOCl<jats:sub>4</jats:sub>]<jats:sup>⊖</jats:sup> &gt; [VX<jats:sub>3</jats:sub>(N<jats:sub>3</jats:sub>S<jats:sub>2</jats:sub>)]<jats:sub>2</jats:sub><jats:sup>2⊖</jats:sup> (X - N<jats:sub>3</jats:sub> &gt; Cl) is found, which is interpreted in terms of increasing polarizability of the ligands and of ring contributions to the extreme deshielding observed with the thiazenovanadates.</jats:p><jats:p>The crystal structure of (AsPh<jats:sub>4</jats:sub>)<jats:sub>2</jats:sub>[V(N<jats:sub>3</jats:sub>)<jats:sub>3</jats:sub>(N<jats:sub>3</jats:sub>S<jats:sub>2</jats:sub>)]<jats:sub>2</jats:sub> · CH<jats:sub>2</jats:sub>Cl<jats:sub>2</jats:sub> was determined from X-ray diffraction data (1496 observed reflexions, R = 0.058). It crystallizes in the triclinic space group P 1̄ with one formula unit per unit cell and with the lattice constants a - 1087, b = 1317, c = 1350 pm, α = 58.8, β = 85.9, γ = 68.0°. The structure consists of AsPh<jats:sub>4</jats:sub><jats:sup>⊕</jats:sup> ions, CH<jats:sub>2</jats:sub>Cl<jats:sub>2</jats:sub> molecules and centrosymmetric [V(N<jats:sub>3</jats:sub>)<jats:sub>3</jats:sub>(N<jats:sub>3</jats:sub>S<jats:sub>2</jats:sub>)]<jats:sub>2</jats:sub><jats:sup>2⊖</jats:sup> anions. In the latter. N<jats:sub>3</jats:sub>S<jats:sub>2</jats:sub> ligands are bonded to the V atoms in a chelate manner with short V = N bonds (189 and 172 pm) forming planar VN<jats:sub>3</jats:sub>S<jats:sub>2</jats:sub> rings. The dimerization is accomplished by V -N donor-acceptor interactions (224 pm) involving one N atom of each VN<jats:sub>3</jats:sub>S<jats:sub>2</jats:sub> ring. The vanadium coordination number of 6 is com pleted by three azido groups with V -N bond distances of 200 to 204 pm.</jats:p>

X-ray structure of a vanadium-containing enzyme: chloroperoxidase from the fungus Curvularia inaequalis.

“…The model was refined by energy-restrained crystallographic refinement with XPLOR (22), and the parameters were derived by Engh and Huber (23). Equilibrium bond distances and bond angles for the vanadium site were taken from hydrogen vanadate (24) and from a vanadium(V) complex containing bound azide (25 (Fig. 1A).…”

The Vanadium(V) Oxoazides [VO(N3)3], [(bipy)VO(N3)3], and [VO(N3)5]2−

“…The third N 3 ligand is oriented only slightly towards the O atom with an O1‐V1‐N1‐N2 dihedral angle of 65.0(1)°. The average VN azido distance of 1.970(2) Å is significantly shorter than the one found for [V(N 3 ) 6 ] 2− (1.994(3) Å) in [PPN] 2 [V(N 3 ) 6 ) 8a. The NN distances in the azido ligands are found to 1.219(2) Å for the internal NN bond and 1.142(2) Å for the external azide bond, and are typical for covalent azides.…”

Model Studies of the Interaction of Vanadium(III) and Oxovanadium(IV/V) with the Carbonyl Amide Oxygen

“…The peak at +19 ppm is assigned to [VOCl 4 ] -species, 23,24,25b while the peak at -366 ppm is probably a hydrolysis product [VO 2 Cl 2 ] -. 24 The 51 V NMR spectra of the alcoxy complexes 4-6 in CD 3 CN and CD 3 NO 2 are considerably different from the spectra of 1 despite of the similarity between the amide ligands Hpheca and Hpycan (Chart 1). These spectra gave two major resonances at -365 (4a) and -397 ppm (4b) for 4, at -365 (5a) and -381 ppm (5b) for 5, and at -365 (6a) and -412 ppm (6b) for 6 ( Figure 5).…”