New pronounced progress in the synthesis of group 5 polyoxometalates

Abstract

This highlight summarizes new developments made in group 5 polyoxometalate science of high nuclearity clusters with focus on synthetic approaches.

Room Temperature Synthesis of [Pd(cyclam)]5{H3Nb6O19}2 ⋅ 26H2O: a Suitable Precursor for the in‐situ Generation of a Highly Active Catalyst for Light‐Driven Hydrogen Evolution

“…The group 5 and 6 polyoxometalates (POMs) build cage like cluster anions composed of {MO 6 } octahedra (M=V, Nb, Ta, Mo and W), while V is often observed in a rectangular‐pyramidal VO 5 coordination [1–17] . Polyoxoniobates (PONbs) as a subgroup of POMs exhibit an impressive structural diversity, represented by e. g. the Lindqvist {Nb 6 O 19 } 8− , [18–21] the decaniobate {Nb 10 O 28 } 6− , [22–24] the Keggin {XNb 12 O 40 } n− (X=P, Si, Ge, V) clusters, [25–27] and giant cluster shells like {Nb 114 } [28] or {Nb 288 } [29] .…”

Vanadium O-Centered Selenoiodide Complex: Synthesis and Structure of V4O(Se2)4I6·I2

“…For instance, infinite chains present in the structures of VF 5 and MX 4 (M = Nb, Ta; X = Cl, Br, I); VS 4 , V 2 Se 9 , Nb 2 Se 9 ; infinite layers in NbF 4 , MQ 2 (M = V, Nb, − Ta − Q = S, Se, Te), MQ 3 (M = Nb, Ta, Q = S, Se); NbTe 4 , and TaTe 4 . V, Nb, and Ta are known to form polyoxometallate compounds; − a large class of cluster compounds is also developed …”

“…Polynuclear vanadium compounds are mainly represented by polyoxovanadates of different nuclearities and structures. ,, Polynuclear niobium and tantalum compounds are presented as polyoxometallates and also cluster complexes with bridging halogen atoms . Besides V 4 S 9 Br 4 , a few examples of polynuclear Group 5 TMCHs are compounds Ta 4 S 9 Br 8 and Ta 4 Se 9 I 8 as well as O-centered complexes Nb 4 OTe 9 I 4 and Ta 4 OTe 9 I 4 .…”

“…Polynuclear vanadium compounds are mainly represented by polyoxovanadates of different nuclearities and structures. 33,16,17 Polynuclear niobium and tantalum compounds are presented as polyoxometallates 34 and also cluster complexes with bridging halogen atoms. 35 atoms in the tetranuclear fragments are linked together also by dichalcogenide, chalcogenide, and halogenide bridging ligands.…”

Lacunary {Se4V10} Heteropolyoxovanadate Precursor with Monometal, Metal-Richer-Sandwiched Derivatives {Se8V20M} and {Se8V20M3}: Correlations between the Synthesis, Structure, and Catalytic Property

“…For instance, the research groups of Wang, Yang, Niu, Zheng, Zhao, etc., have constructed a series of high-nuclear transition-metal (TM)-substituted POTs by using {XW 9 } as precursors since 2006. − In the last year, Suzuki et al reported a couple of organic–inorganic POMo-based monomer, dimer, and tetramer architectures by reacting {PMo 9 } building units with pyridyl, 4,4′-bipyridyl, and porphyrin ligands, respectively . Polyoxovanadate (POV) has also been an intriguing subfamily in the POM field for the benefit of vanadium itself, carrying versatile valent states (+V, +IV, +III, or mixed oxidation states) and coordination geometries (VO n , n = 4–6) . However, the structural diversity of POVs is significantly lower compared to its peers, like POTs and POMos, which might be largely due to the lack of lacunary POV precursors.…”