Racemic monoperoxovanadium(v) complexes with achiral OO and ON donor set heteroligands: synthesis, crystal structure and stereochemistry of [NH3(CH2)2NH3][VO(O2)(ox)(pic)]·2H2O and [NH3(CH2)2NH3][VO(O2)(ox)(pca)]

Abstract

Monoperoxovanadium(V) complexes, [NH3(CH2)2NH3][VO(O2)(ox)(pic)].2H2O (1) and [NH3(CH2)2NH3][VO(O2)(ox)(pca)] (2) [NH3(CH2)2NH3 = ethane-1,2-diammonium(2+), ox=oxalate(2-), pic=pyridine-2-carboxylate(1-), pca=pyrazine-2-carboxylate(1-)], were synthesized and characterized by X-ray analysis, IR and Raman spectroscopies. The five equatorial positions of the pentagonal bipyramid around the vanadium atoms are occupied by the eta2-peroxo ligand, two oxygen atoms of the ox, and the nitrogen atom of the pic or pca ligands, respectively. The oxo ligand and the oxygen atom of pic or pca are in the axial positions. Networks of X-HO (X=C, N or O) hydrogen bonds, and pi-pi interactions between aromatic rings in and anion-pi interactions in , determine the molecular packings and build up the supramolecular architecture. Three stereochemical rules for occupation of the donor sites in two-heteroligand [VO(O2)(L1)(L2)] complexes (L1, L2 are bidentate neutral or differently charged anionic heteroligands providing an OO, NN or ON donor set) are discussed. and crystallize as racemic compounds. The 51V NMR spectra proved that the parent complex anions of and partially decompose on dissolution in water to the monoperoxo-ox, -pic or -pca complexes.

(EnH2)2[V2O2(O2)4(μ-C2O4)] — The vanadium(V) oxalato oxido peroxido complex with a bridging oxalato group

“…All bond lengths (Fig. 3) are within the expected intervals as were found in corresponding mononuclear complexes [9,12] In accord with the structurally characterised vanadium(V) mono-and diperoxido complexes [9,12,18] strong trans influence of the oxido ligand can be observed. Thus, the oxalato ligand is asymmetrically coordinated: the V\O 5 distance is longer than d(V\O 6 ) by 0.345 Å (this value can be compared with 0.191 Å in K 3 …”

“…A series of oxido oxalato peroxido complexes of vanadium(V) has been prepared and characterised [11]: [9,[12][13][14], NH 4 [12], N(CH 3 ) 4 [15] [13,16], N(CH 3 ) 4 [15], N(C 2 H 5 ) 4 [15], Hampic [17] [18]. The anions in all structures contain seven coordinated vanadium centres and the geometry is distorted pentagonal bipyramid.…”

Two new scorpionates vanadium haloperoxidases model complexes: Synthesis and structure of VO(O2)(pzH)(HB(pz)3) and VO(O2)(pzH)(B(pz)4) (pzH=pyrazole(C3H4N2))

“…Base on the starting materials, the previous reaction routes of synthesizing the peroxovanadium complexes can be classified as two types: (1) using vanadate(V) as starting materials [29][30][31][32][33][34][35][36][37]; (2) using vanadium(IV) as starting materials [38]. In this paper complexes 1 and 2 were synthesized by the reaction of VOSO 4 , H 2 O 2 , potassium tris(1H-pyrazol-yl)borate(or potassium tetra(1H-pyrazol-yl) borate) and pyrazole in methanol/water solution.…”

Probing for missing links in the binary and ternary V(V)–citrate–(H2O2) systems: Synthetic efforts and in vitro insulin mimetic activity studies

“…Typical bands assigned to V@O, V-O p (peroxo) and O-O vibrations in V(V)-peroxo complexes are observed [64][65][66] in the spectral windows 920-1000, 660-440, and 800-950 cm À1 , respectively. More precisely, the vibrational features of the [VO(O 2 )] group are expected in the respective spectral ranges of typical monoperoxo complexes of vanadium [66][67][68][69]; 945-980 cm À1 for the V@O stretches, 920-950 cm À1 for O-O vibrations, and 540-595 cm À1 for the V-O p stretches. In this work, a near-infrared laser excitation line (1064 nm) was employed to avoid pre-resonance phenomena.…”