Electronic and Magnetic Properties of α-Keggin Anions:  A DFT Study of [XM12O40]n-, (M = W, Mo; X = AlIII, SiIV, PV, FeIII, CoII, CoIII ) and [SiM11VO40]m- (M = Mo and W)

Maestre, Joan Miquel; López, Xavier; Bo, Carles; Poblet, Josep M.

doi:10.1021/ja003563j

Cited by 223 publications

(152 citation statements)

References 52 publications

Supporting

Mentioning

143

Contrasting

Order By: Relevance

“…It is known that the redox properties depend on the energy and composition of the LUMO, as the LUMO formally delocalizes over the metal atoms, which determine the redox properties of POMs. [21] The LUMO of PW 11 Re is composed of 39.76 % Re and 16.46 %W contributions. It is more likely that Re will prefer to accept extra electrons when the cluster is reduced.…”

Section: Resultsmentioning

confidence: 99%

A DFT Study on the Electronic and Redox Properties of [PW₁₁O₃₉(ReN)]^n–(n = 3, 4, 5) and [PW₁₁O₃₉(OsN)]^2–

et al. 2006

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

A DFT Study on the Electronic and Redox Properties of [PW₁₁O₃₉(ReN)]^n–(n = 3, 4, 5) and [PW₁₁O₃₉(OsN)]^2–

et al. 2006

View full text Add to dashboard Cite

“…22 The POM clusters presented here contain metal atoms free of valence electrons (d 0 electronic configuration), so the molecular orbitals sequence consists of two well-separated sets of energy levels: the occupied oxo orbitals and the virtual metal orbitals. 23 Parameters related to the geometry and electronic structure of the molecules are listed in Table 1. In this series, the results for isolated anions are compared with those for anions in solution, where the solvent is modeled by a dielectric material simulating water.…”

Section: Resultsmentioning

confidence: 99%

Are the solvent effects critical in the modeling of polyoxoanions?

et al. 2004

View full text Add to dashboard Cite

DFT calculations were driven for a set of differently charged polyoxoanions in the gas phase and in solution. We have calculated and analyzed their geometries and orbital energies to trace simple rules of behavior regarding the modeling of anions in isolated form. We discuss the quality of the results depending on the molecular charge, q, and the size of the cluster in terms of the number of metal centers, m. When the q/m ratio reaches a value of approximately 0.8, DFT calculations for the isolated anion fail to describe the gap between the band of occupied oxo orbitals and the set of unoccupied orbitals delocalized among the metal atoms. In these cases the incorporation of the stabilizing external fields generated by the solvent through continuum models improves the geometries and orbital energies.

show abstract

“…In general terms, the electronic structure of a fully oxidized POM is quite simple: doubly occupied orbitals (HOMO) are formally delocalized over the oxo ligands and are perfectly separated from the unoccupied set of d-metal orbitals (LUMO) [23] (see the Experimental Section and Supporting Information for more details mÀ (X = W, Te, and I) are compared in Figure 3. When the central heteroatom is tungsten, the LUMO and LUMO + 1 are mainly delocalized over the belt metals, as occurs in the classic a-P 2 W 18 structure.…”

mentioning

confidence: 99%

“…[23] A simple analysis of the frontier orbitals of the fully oxidized molecules helped us to rationalize the first two examples of non-blue, non-mixed-valent singly reduced clusters. Calculations performed on the reduced structures confirmed our hypothesis (Supporting Information, Tables S1, S2).…”

mentioning

confidence: 99%

Polyoxometalate {W₁₈O₅₆XO₆} Clusters with Embedded Redox‐Active Main‐Group Templates as Localized Inner‐Cluster Radicals

et al. 2013

View full text Add to dashboard Cite

Polyoxometalates (POMs) [1] are an exceptional family of polynuclear molecular oxide anions usually formed by W, Mo, or V.[2] POMs offer a wide range of structures with diverse physical properties, electronic structures, and applications, such as in catalysis, [3] medicine, [4] materials science, [5] or nanotechnology. Heteropolyoxometalates (HPOMs) are a significant and widely explored subset of POMs. Within this class, the choice of the heteroelement not only determines certain physical properties of the cluster, but increasingly has been found to control the range and connectivity of the building blocks.[6] Amongst the structural diversity of HPOMs architectures, Keggin [7] . In general, POMs exhibit significant stability for both the oxidized and oneelectron-reduced form, [9] and the electrochemistry of HPOMs has been extensively studied.[10] In this respect, in an effort to tune the redox properties of POMs, we have been able to engineer clusters that incorporate redox-active anions and expand the classic WD family. [11] Electrochemical studies demonstrated that classic WD anions are reduced through multiple steps of two electrons (at pH 7) without degradation of the heteropoly structure.The process generates reduced species, known as heteropoly blues owing to their characteristic blue color, [12] with the WD structures having two types of metal sites: cap and the belt (Figure 1). In the classic WD structures, these "blue" electrons are delocalized only over the belt metal atoms. [13] NMR spectroscopy experiments on the reduced species show that electron delocalization is restricted to the two hexagonal belts and are completely spin-paired at room temperature. [14] Herein, we present the first Dawson-like {W 18 O 56 XO 6 } clusters (X = I or Te) with localized redox active inner-cluster templates, and we show that these moieties can adopt different oxidation states; for example, IVII/VI or Te VI/V , respectively. To investigate this in detail, we used cyclic voltammetry, UV and EPR spectroscopy combined with experimental comparison to a control, non-heteroatom embedded Dawson-like cluster. We also evaluated the electronic structure of both the oxidized and reduced forms of the clusters using DFT based upon X-ray data of the oxidized forms.[11] As a built-in control we used a

show abstract

Electronic and Magnetic Properties of α-Keggin Anions: A DFT Study of [XM₁₂O₄₀]ⁿ^-, (M = W, Mo; X = Al^III, Si^IV, P^V, Fe^III, Co^II, Co^III ) and [SiM₁₁VO₄₀]^m^- (M = Mo and W)

Cited by 223 publications

References 52 publications

A DFT Study on the Electronic and Redox Properties of [PW₁₁O₃₉(ReN)]^n–(n = 3, 4, 5) and [PW₁₁O₃₉(OsN)]^2–

A DFT Study on the Electronic and Redox Properties of [PW₁₁O₃₉(ReN)]^n–(n = 3, 4, 5) and [PW₁₁O₃₉(OsN)]^2–

Are the solvent effects critical in the modeling of polyoxoanions?

Polyoxometalate {W₁₈O₅₆XO₆} Clusters with Embedded Redox‐Active Main‐Group Templates as Localized Inner‐Cluster Radicals

Contact Info

Product

Resources

About

Electronic and Magnetic Properties of α-Keggin Anions: A DFT Study of [XM12O40]n-, (M = W, Mo; X = AlIII, SiIV, PV, FeIII, CoII, CoIII ) and [SiM11VO40]m- (M = Mo and W)

Cited by 223 publications

References 52 publications

A DFT Study on the Electronic and Redox Properties of [PW11O39(ReN)]n–(n = 3, 4, 5) and [PW11O39(OsN)]2–

A DFT Study on the Electronic and Redox Properties of [PW11O39(ReN)]n–(n = 3, 4, 5) and [PW11O39(OsN)]2–

Are the solvent effects critical in the modeling of polyoxoanions?

Polyoxometalate {W18O56XO6} Clusters with Embedded Redox‐Active Main‐Group Templates as Localized Inner‐Cluster Radicals

Contact Info

Product

Resources

About

Electronic and Magnetic Properties of α-Keggin Anions: A DFT Study of [XM₁₂O₄₀]ⁿ^-, (M = W, Mo; X = Al^III, Si^IV, P^V, Fe^III, Co^II, Co^III ) and [SiM₁₁VO₄₀]^m^- (M = Mo and W)

A DFT Study on the Electronic and Redox Properties of [PW₁₁O₃₉(ReN)]^n–(n = 3, 4, 5) and [PW₁₁O₃₉(OsN)]^2–

A DFT Study on the Electronic and Redox Properties of [PW₁₁O₃₉(ReN)]^n–(n = 3, 4, 5) and [PW₁₁O₃₉(OsN)]^2–

Polyoxometalate {W₁₈O₅₆XO₆} Clusters with Embedded Redox‐Active Main‐Group Templates as Localized Inner‐Cluster Radicals