Hydrothermal synthesis and structure of molybdoarsenate [H4AsIII2AsVMoV8MoVI4O40]-, a bicapped, reduced Keggin species

Synthesis of Metforminium(2+) Decavanadates – Crystal Structures and Solid‐State Characterization

“…Although 2 and 3 crystallize in the same centrosymmetric space group as 1, a remarkable difference for 2 and 3 is that the [V 10 O 28 ] 6-anion is placed on an inversion center, which is not the case for 1. modulation of the structures and properties of the new hybrid materials on the basis of electrostatic and hydrogenbond interactions. [9] Interestingly, inorganic and organic decavanadates have been used as building blocks [21] to generate supramolecular frameworks that exhibit wide structural diversity in one, two, or three dimensions (e.g., chains, [13,20,22] layers, [14,16,23] channels, [24] or 3D networks). [10,14,17,18] The formation of the supramolecular structure is strongly dependent on the solvent, [25] pH value, ionic strength, temperature, and nature of the counterions [13][14][15][16][17][18][19][20][21]26] used in the synthesis.…”

Highly Reduced, Polyoxo(alkoxo)vanadium(III/IV) Clusters

“…[2,3] The latter species have found much interest for their redox, electrical and magnetic properties, recent examples including Daniel and Hartls [V 6 O 7 (OR) 12 ] n + ion, which displays five discrete oxidation states ranging from {V IV 2 V V 4 } to {V IV 6 }, [4] and hybrid conducting materials, such as Coronados [BEDT-TTF] 5 -A C H T U N G T R E N N U N G [H 3 V 10 O 28 ] (BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene). [5] So-called "fully reduced" examples, [6] defined as those that contain only vanadium(IV) ions, have been of particular interest for their magnetic properties, [7] with notable examples including a rare ferromagnetically coupled, large-spin ground-state vanadyl {V IV 8 } cluster, [8] and Müllers layered {V IV 15 } species, [9] which has been important in studies of spin frustration and phonon bottleneck phenomena. Given these exciting properties it seems a logical step to extend this chemistry to vanadiumA C H T U N G T R E N N U N G (III), particularly given the potentially useful properties of this ion [10] for materials such as single-molecule magnets.…”

“…[17] In contrast to the dearth of discrete molecular species, a number of V III and V III/IV extended lattice oxide, phosphate and organophosphate materials are known. [18] Zubieta has suggested that the preference of the V III ion for extended lattices is partly explained by its regular octahedral geometry favouring more extensive connectivity between metal (or heteroatom) centres, in contrast to the highly distorted {VO 6 } or {VO 4/5 } geometries characteristic of V IV/V due to multiply bonded oxo groups. [19] Nevertheless, the existence of these extended lattices suggests that more molecular clusAbstract: A family of high nuclearity oxoA C H T U N G T R E N N U N G (alkoxo)vanadium clusters in unprecedentedly low oxidation states is reported, synthesised from simple A C H T U N G T R E N N U N G vanadium diketonate precursors in alcohols under solvothermal conditions.…”

“…[19] Nevertheless, the existence of these extended lattices suggests that more molecular clusAbstract: A family of high nuclearity oxoA C H T U N G T R E N N U N G (alkoxo)vanadium clusters in unprecedentedly low oxidation states is reported, synthesised from simple A C H T U N G T R E N N U N G vanadium diketonate precursors in alcohols under solvothermal conditions. Crystal structures of [V 18 (O) 12 (OH) 2 4 A C H T U N G T R E N N U N G (EtO) 22 A C H T U N G T R E N N U N G (O 2 CPh) 6 A C H T U N G T R E N N U N G (acac) 2 ] (1), [V 16 Na 2 (O) 18 A C H T U N G T R E N N U N G (EtO) 16 …”

Hydrothermal Synthesis and Crystal Structure of an Unusual Compound: [Cu(en)2]4[SiMo8VV4O40(VIVO)2][MoO4]2·5H2O

“…During these years, however, owing to the limitation of synthesis methods, POMs with the capped Keggin structure feature have rarely been reported in comparison with numerous Keggin and transition-metal-substituted Keggin species (4,11,13). More recently, the introduction of hydrothermal techniques and the use of suitable templates have led to the appearance of various capped Keggin derivatives (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) pertaining to several systems. Among these systems, the V/ As/O system has been extensively studied, such as [AsV 14 O 42 ]…”