Controlling transformations in the assembly of polyoxometalate clusters: {Mo11V7}, {Mo17V8} and {Mo72V30}

Abstract

The reaction of molybdate with vanadium(V) in the presence of sulfite anions is explored showing how, via cation control, stepwise assembly through the {Mo(11)V(7)} cluster yields a {M(25)} cluster-based compound, [Mo(VI)(11)V(V)(5)V(IV)(2)O(52)(μ(9)-SO(3))(Mo(VI)(6)V(V)O(22))](10-) (1a), which was first discovered using cryospray mass spectrometry, whereas switching the cation away from ammonium allows the direct formation of the spherical 'Keplerate' {Mo(72)V(30)} cluster.

Directed Self‐Assembly, Symmetry Breaking, and Electronic Modulation of Metal Oxide Clusters by Pyramidal Heteroanions

“…The overlapped distribution envelopes observed in the range of m / z 964.2 and 1640.4 can be assigned to the general formula {[Mo 11 V 7 O 52 (TeO 3 )](MeOH)H n Na p (Me 2 NH 2 ) q (OH 2 ) r } z − with n= 0–5, p= 1–7, q =3–10, r =7–22, z= 2 and 3 (Table S5). The change of the oxidation state of the metal centers is due to the ionization and consecutive ion‐transfer process of the charged species and has been observed previously on numerous occasions …”

“…As has been described in previous reports, tungstate‐based POM clusters incorporating non‐classical heteroanions are less common because of the stability of their lacunary species . On the other hand, more common mixed valence molybdenum/vanadium‐based POMs templated by non‐traditional heteroanions have been reported . Thus, the rich redox chemistry of Mo and V based species coupled with the redox behavior of the EO 3 2− anions offer a unique opportunity for the design of highly modular molecular species with desirable functionality.…”

“…More specifically, the first examples of clusters incorporating pyramidal heteroanions are Mo V ‐ and V IV ‐based sulfite species, such as (NH 4 ) 20 [Mo 12 O 24 (SO 3 ) 16 ] ⋅ 4 H 2 O and (NH 4 ) 15 {Na[Mo 6 O 15 (SO 3 ) 4 ] 2 } ⋅ 15 H 2 O, the two‐electron reduced Dawson anion (HOCH 2 CH 2 ) 6 [Mo 18 O 54 (SO 3 ) 2 ] ⋅ 4 H 2 O with two templating sulfite (SO 3 2− ) ions, and the [(V IV O) 6 ( μ 4 ‐O) 2 ( μ 3 ‐OH) 2 ( μ 3 ‐SO 3 ) 4 (H 2 O) 2 ] 2− family . The molybdenum‐based moieties combined with the ability of the vanadium metal centers to adopt various oxidation states (V III , V IV , V V ) and coordination modes led to a remarkable structural diversity …”

“…[12] The molybdenum-based moieties combinedw ith the abilityo ft he vanadium metal centers to adopt various oxidation states (V III ,V IV ,V V )and coordination modes led to aremarkable structural diversity. [13][14][15][16] The development of molecular metal oxide clusterso ffers a unique opportunity to generate complex buildingb lock libraries because of the stabilization of wider ange of configurable subunits with different properties and organize them further into highly modular architectures.F or example, the ability to construct core-shell molecular clusters allowed the controlo f compartmentalized reactions, [17] exploration of electron coupled structural reorganizations, [18] new type of oscillatory phenomena [19] as well as the development of nanocluster-based information storage devices. [20] As has been described in previousr eports, tungstate-based POM clusters incorporatingn on-classical heteroanions are less common because of the stability of their lacunary species.…”

“…[9,17,21] On the other hand, more common mixed valence molybdenum/vanadium-based POMs templated by non-traditional heteroanions have been reported. [13][14][15][16] Thus, the rich redox chemistry of Mo and Vb ased speciesc oupled with the redox behavioro ft he EO 3 2À anions offer au nique opportunity for the design of highly modular molecular species with desirable functionality.…”