Structural and Electronic Properties of Polyoxovanadoborates Containing the [V12B18O60] Core in Different Mixed Valence States

Abstract

Abstract:This review summarizes all published data until April 2015 related to crystalline lattices formed by the [V12B18O60] core, which generates polyanionic clusters with different degrees of protonation and mixed-valence ratios. The negative charge of this cluster is counterbalanced by different cations such as protonated amines, hydronium, and alkaline, and transition metal ions. The cluster is shown to form extended 1D, 2D, or 3D frameworks by forming covalent bonds or presenting hydrogen bond interactions with the present secondary cations. These cations have little influence on the solid state reflectance UV-visible spectra of the polyanionic cluster, but are shown to modify the FT-IR spectra and the magnetic behavior of the different reported species. OPEN ACCESSInorganics 2015, 3 310

A New 3-D Open-Framework Zinc Borovanadate with Catalytic Potentials in α-Phenethyl Alcohol Oxidation

“…The absorption band centered at 550 nm presumably arises from an intervalence charge transfer transition (IVCT) between the V IV /V V centers of the mixed valence vanadoborate unit. The absorptions in the high-energy UV region at 224 and 350 nm can be assigned to the O→V and O→B charge transfers of the [V 12 B 18 O 54 (OH) 6 (H 2 O)] 10− cluster [26,37].…”

“…As is well known, borovanadate anions are a class of discrete transition metal oxide clusters with high negative charges and oxygen-rich surfaces. These anions are one of the most ideal multi-dentate nucleophilic candidates for the construction of extended open frameworks [26]. Therefore, an approach that is widely used for designing such open frameworks is to link borovanadate polyanion clusters with different types of linkers of transition metal (TM) ions [21] or TM complex moieties [27].…”

Non-covalent interactions in hexanuclear polyoxidometalates [VIV6B20O50H8]8−. An experimental and theoretical approach

“…Among the polyoxidometalate family, polyoxidovanadoborates (VBO) display an exceptionally rich structural chemistry. Although vanadium atoms included in these systems always adopt a base square pyramid (SP) coordination geometry, borate units enrich the structural diversity since boron can adopt both tetrahedral [BO 4 ] and trigonal [BO 3 ] geometries [1,2]. Additionally, the VBO family has attracted considerable interest because of their magnetic, electronic and catalytic properties [3,4] associated with the presence of vanadium(IV) atoms (d 1 configuration).…”

“…Recent studies of vanadoborates related to the conductivity of these materials show the importance of the nature of the crystalline packing and all interactions present in it [5][6][7]. The reported VBO structures are mainly composed by six, ten and twelve vanadium centres [2,6], namely the {V 6 -type} clusters: {V 6 B 20 O 50 H n } (n=0, 6,8,12) [8][9][10][11] and {V 6 B 22 O 54 H 10 } [12]; the {V 10 -type} clusters: {V 10 B 28 O 74 H n } [13] and {V 10 B 28 O 74 H n } (n=4, 8) [14,15]; the {V 12 i -type} clusters: {V 12 [11,20,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36], and the {V 12 iii -type} clusters: {V 12 B 32 O 84 H 8 } [38,39]. The most interesting feature of the boron rich structures {V 6 -type}, {V 10 -type} and {V 12 iii -type} is their central oxo-vanadium ring formed by penta-coordinated vanadium units [VO 5 ].…”

The Fascination of Polyoxometalate Chemistry

“…The present special issue also contains selected contributions focused on polyoxometalates with group 4 (Zr) and 5 (V, Nb, Ta) metal ions: two review articles by Pavel A. Abramov and co-workers on polyoxonobiates and polyoxotantalates [7], and by Diego Venegas-Yazigi and co-workers on polyoxovanadates [8]. Pavel A. Abramov et al summarize their contributions to the coordination chemistry of noble metals (Rh, Ir, Ru, Pt(IV)) and polyoxometalates of Nb(V) and Ta(V).…”