Polyoxomolybdate-Supported Bismuth Trihalides [Mo₈O₂₆(BiX₃)₂]^4– (X = Cl, Br, I): Syntheses and Study of Polymorphism

Abstract

Octamolybdate complexes TBA4[Mo8O26(BiX3)2] (TBA = n-tetrabutylammonium, X = Cl (1), Br (2), I (3)) were obtained by straightforward syntheses from TBA4[Mo8O26] and corresponding Bi(III) halides in MeCN. All compounds were structurally characterized; in all cases, {BiX3} fragments are coordinated by two oxygen atoms of polyoxometalate core. Occurring polymorphism is also discussed.

Charge Makes a Difference: Molecular Ionic Bismuth Compounds

“…[23] Heterometallic clusters with bismuth can be found in the form of polyoxometalate clusters [24] used in catalysis [25] and photocatalysis. [26] Special attention is directed toward compounds featuring MoÀ OÀ Bi-moieties, [9,27] as they represent molecular models for Bi 2 O 3 •MoO 3 catalysts used in the industrial SOHIO process, the oxidation or ammoxidation of propylene to make acrolein or acrylonitrile. [7] The biochemistry of bismuth complexes, [28] and the structure and reactivity of molecular bismuth compounds with transition-metal-based ligands [29] including ionic species, have recently been reviewed.…”

“…Bismuth compounds have gained attraction during the past years as a consequence of a diversity of reasons, which have served to introduce the corresponding species into research areas ranging from fundamental chemical, physical and material sciences to fields of applied chemistry—prominently realized in the use of bismuth phosphomolybdate and related compounds as catalysts in the industrial oxidation of propene (SOHIO process) [7–9] …”

“…Heterometallic clusters with bismuth can be found in the form of polyoxometalate clusters [24] used in catalysis [25] and photocatalysis [26] . Special attention is directed toward compounds featuring Mo−O−Bi‐moieties, [9, 27] as they represent molecular models for Bi 2 O 3 ⋅MoO 3 catalysts used in the industrial SOHIO process, the oxidation or ammoxidation of propylene to make acrolein or acrylonitrile [7] …”

Assembly of a coordination polymer with sulphate-capped pentamolybdate units and copper: synthesis, structure, magnetic and catalytic studies

“…Within the overall literature of CP-POMs, assemblies with polyoxomolybdates constitute an important sub-class. Some of the important polyoxomolybdates reported within such compounds include both the iso-polyoxometalate types, such as the tetramolybdate {Mo 4 O 13 }, 23,24 the hexamolybdate {Mo 6 O 24 }, [25][26][27] the octamo-lybdate {Mo 8 O 26 }, [28][29][30][31] and the decamolybdate {Mo 10 O 33 } assemblies, [32][33][34] and the hetero-polyoxometalate types, especially those based on the {XMo 12 O 40 }-type (X = Si IV , P V ) Keggin unit derivatives, [35][36][37][38][39] and the {(AO 3 X) 2 Mo 5 O 15 }-type pentamolybdate unit derivatives (X = O, C; A = P V , S VI , As V , Se VI , Te VI ). 40 The pentametalate ion is a unique hetero-polyoxometalate structure, wherein a circular and nearly planar five metal polyhedral unit assembly, {M 5 O 15 } (M = Mo, W), is coordinated on either side by tetrahedral hetero-groups from main-group elements.…”

Bismuth(III)‐Containing Heteropolytungstates [Bi(XW11O39)2]n– (X = Si, Ge, n = 13; X = P, n = 11) and [Bi(P2W17O61)2]17–

“…Several Bi‐containing POMs have been synthesized in the last few decades, but in nearly all of them Bi 3+ plays the role of a central heteroatom with a trigonal‐pyramidal coordination geometry . Very few heteropolytungstates are known with Bi 3+ ion as a linking, addenda‐substituting, terminally coordinated, or capping atom . In these cases the trivalent Bi 3+ ion assumes a tetrahedral or pentagonal‐pyramidal coordination geometry.…”