Jozef Tatiersky

Oxo Peroxo Glycolato Complexesof Vanadium (V). Crystal Structureof (NBu4)2[V2O2(O2)2(C2H2O3)2]ċH2O

Summary. Oxo peroxo glycolato complexes of vanadium(V) (M2[V2O2(O2)2(C2H2O3)2]ċnH2O (n=0, 1; M=NBu4+ (1), K+ (2), NH4+ (3), Cs+ (4), NPr4+ (5)) as well as (NBu4)2[V2O4(C2H2O3)2]ċ H2O (6) have been prepared and characterized by spectroscopic methods. X-Ray structure analysis of 1 revealed the presence of dinuclear [V2O2(O2)2(C2H2O3)2]2− anions with a (chemical structure) bridging core and six coordinated vanadium(V) atoms in a distorted pentagonal pyramidal array.

Experimental and computational evidence of solid-state anion–π and π–π interactions in [VO(O2)(L)(pa)]·xH2O complexes (L = picolinate, pyrazinate or quinolinate; pa = picolinamide)

Two new neutral monoperoxidovanadium(V) complexes [VO(O2)(L)(pa)]·xH2O have been synthesized: [VO(O2)(pic)(pa)]·H2O (1) and [VO(O2)(Hquin)(pa)]·2H2O (2) [pic: pyridine-2-carboxylato(1–) or picolinato(1–), Hquin: pyridine-2,3-dicarboxylato(1–) or quinolinato(1–), and pa: picolinamide]. The solid state structures of 1 and 2 feature a typical distorted pentagonal bipyramid coordination polyhedron around the central vanadium atoms. The bidentate anionic ligands are coordinated in two equatorial positions, while the bidentate picolinamide molecule is bound via the aromatic nitrogen and the carboxamide oxygen in one equatorial and one apical position. The experimental geometric parameters were used for a detailed study of intermolecular interactions between the pic–pic and pa–pa aromatic rings in 1. Interestingly, no π–π interactions were observed between the pyridine rings of Hquin or pa in 2, however, the less common anion–π solid-state interactions were found between the pic ligands in 1 and pca [pca = pyrazinecarboxylato(1–)] ligands in the already published structure of the related complex [VO(O2)(pca)(pa)]·H2O (3). The presence of anion–π and π–π interactions in 1 and 3 was confirmed by DFT computations performed on their solid-state structures. Computational results suggested a direct analogy between anion–π and π–π interactions, both being of predominantly electrostatic character.

Preparation, chemical characterization and thermal behaviour of some alkyldiammonium polyoxovanadates(V)

Abstract The thermal behavior of 1,3-propanediammonium ( Pda ) polyvanadates: [ Pda H 2 ](VO 3 ) 2 ( 1 ), [ Pda H 2 ] 3 V 10 O 28 ·5H 2 O ( 2 ), [ Pda H 2 ] 2 H 2 V 10 O 28 ( 3 ), and 1,6-hexanediammonium ( Hda ) polyvanadates: [ Hda H 2 ](VO 3 ) 2 ( 4 ), [ Hda H 2 ] 3 V 10 O 28 ·2H 2 O ( 5 ), [ Hda H 2 ] 2 H 2 V 10 O 28 ·2H 2 O ( 6 ) was studied in air atmosphere. The thermal decomposition of polyvanadates is a more-steps process consisting of simultaneous processes involving also vanadium. V 2 O 5 is the final decomposition product formed from all polyvanadates studied. The new compounds, hexanediammonium decavanadates 5 and 6 were prepared by the reaction V 2 O 5 with 1,6-hexanediammine in aqueous solution. The IR spectra confirmed the presence of the decavanadate anion in these compounds.

Stereospecific Formation of Dinuclear Vanadium(V) Tartrato Complexes

The first dinuclear nonperoxido tartrato complexes of vanadium(V), (NMe(4))(2)[V(2)O(4)((2R,3R)-H(2)tart)(2)] x 6 H(2)O (1), (NMe(4))(2)[V(2)O(2)((2R,3R)-tart)((2S,3S)-tart)] (2), (NEt(4))(2)[V(2)O(2)((2R,3R)-tart)((2S,3S)-tart)] (3) (tart = tartrato(4-) = C(4)H(2)O(6)(4-)) have been prepared from water-ethanol medium and characterized by X-ray structure analysis and spectral methods. The formation of the complexes has been found to be stereospecific; the composition and structure of anions containing one or both enantiomers of the ligand are profoundly different. The structure of anions in 1-3 also differs significantly from the structure of other dinuclear vanadium(V) alpha-hydroxycarboxylato complexes, but, interestingly, the geometry of the [V(2)O(2)((2R,3R)-tart)((2S,3S)-tart)](2-) ion resembles the structure of the [(VO)(2)((2R,3R)-tart)((2S,3S)-tart)](4-) ion which has a vanadium(IV) center. Using Raman and (51)V NMR spectroscopy the solvent dependent mutual transformations of [V(4)O(8)((2R,3R)-tart)(2)](4-) (V(4)L(2)-RR), [V(4)O(8)((2S,3S)-tart)(2)](4-) (V(4)L(2)-SS), [V(2)O(4)((2R,3R)-H(2)tart)(2)](2-) (V(2)L(2)-RR), [V(2)O(4)((2S,3S)-H(2)tart)(2)](2-) (V(2)L(2)-SS), and [V(2)O(2)((2R,3R)-tart)((2S,3S)-tart)](2-) (V(2)L(2)-rac) have been established. In aqueous solution the following reactions take place; 2 V(2)L(2)-rac --> V(2)L(2)-RR + V(2)L(2)-SS followed by partial decomposition, V(2)L(2)-RR --> V(4)L(2)-RR + 2 L (V(2)L(2)-SS --> V(4)L(2)-SS + 2 L). On the other hand V(2)L(2)-rac is stable in CH(3)CN solution while V(2)L(2)-RR (V(2)L(2)-SS) decomposes into several species.

Interaction between chiral ions: synthesis and characterization of tartratovanadates(V) with tris(2,2′-bipyridine) complexes of iron(II) and nickel(II) as cations

Four new compounds composed of chiral complex cations and anions: Δ-[Fe(bpy)3] Λ-[Fe(bpy)3][V4O8((2R,3R)-tart)2]·12H2O (1), Δ-[Fe(bpy)3]2Λ-[Fe(bpy)3]2[V4O8((2R,3R)-tart)2][V4O8((2S,3S)-tart)2]·24H2O (2), Δ-[Ni(bpy)3]Λ-[Ni(bpy)3][V4O8((2R,3R)-tart)2]·12H2O (3) and Δ-[Ni(bpy)3]2Λ-[Ni(bpy)3]2[V4O8((2R,3R)-tart)2][V4O8((2S,3S)-tart)2]·24H2O (4) have been prepared. The compounds have been characterized by spectral methods, and their thermal decomposition was studied by simultaneous DTA, TG measurements. The final products after dynamic decomposition and additional heating were Fe2V4O13 for 1 and 2 and Ni(VO3)2 for 3 and 4. The crystal structures determined for 1, 2 and 4 have evidenced that 1 is “hemiracemic” and 2 and 4 are “fully racemic” compounds.

Peroxido Complexes of Vanadium(V) as Ligands. Crystal Structures of [Cd(NH3)6][{VO(O2)2(OH)}2{μ-Cd(NH3)4}] and [{VO(O2)2(Im)}2{μ-Cu(Im)4}] (Im = Imidazole)

Two novel heterometallic complexes [Cd(NH3)6][{VO(O2)2(OH)}2{μ-Cd(NH3)4}] (2) and [{VO(O2)2(Im)}2{μ-Cu(Im)4}] (3) (Im = imidazole) containing peroxidovanadium complexes as metalloligands were prepared and characterized by spectral methods. X-ray single-crystal analysis revealed the presence of unique trinuclear complexes in the crystal structures of 2 and 3. The structure of 2 contains an anionic complex, whose two {VO(O2)2(OH)}(2-) ions are interconnected by a {μ-Cd(NH3)4}(2+) group. Compound 3 is a trinuclear neutral complex comprising two {VO(O2)2(Im)}(-) ions and a single bridging {μ-Cu(Im)4}(2+) group. The bonding via an equatorial OH(-) ligand in 2 and via a doubly bonded apical oxygen atom in 3 represents coordination modes previously unobserved for diperoxidovanadium complexes. Compared with complex 2, density functional theory studies reported decreased Cu-μ-O bond orders and increased μ-O-V bond orders in 3, in accordance with the expected Jahn-Teller distortion of the latter complex.

Synthesis and Properties of Dipropylammonium and 1,3-Propanediammonium Polyvanadates

Summary. Dipropylammonium (DPAH) decavanadates and 1,3-propanediammonium (PDAH2) meta- and decavanadates of the composition [PDAH2](VO3)2 (1), [PDAH2]3V10O28ċ5H2O (2), [PDAH2]2H2V10O28 (3), [DPAH]5HV10O28ċ2H2O (4), [DPAH]4H2V10O28ċ2H2O (5), and [DPAH]3H3V10O28 (6) were prepared from the reaction system PDA/DPA-V2O5-H2O-HCl and characterized by X-ray powder diffraction and IR spectroscopy. The morphological and optical properties of 3 and 5 were studied.Zusammenfassung. Dipropylammonium-(DPAH)-decavanadate und 1,3-Propandiammonium-(PDAH2)-meta- und-decavanadate der Zusammensetzung [PDAH2](VO3)2 (1), [PDAH2]3V10O28ċ 5H2O (2), [PDAH2]2H2V10O28 (3), [DPAH]5HV10O28ċ2H2O (4), [DPAH]4H2V10O28ċ2H2O (5) und [DPAH]3H3V10O28 (6) wurden aus dem Reaktionssystem PDA/DPA–V2O5-H2O-HCl gewonnen und mittels Pulverdiffraktometrie und Infrarotspektroskopie charakterisiert. 3 und 5 wurden auch bezüglich ihrer morphologischen und optischen Eigenshaften untersucht.