Nonmolecular Metal Chalcogenide/Halide Solids and Their Molecular Cluster Analogues

Abstract

A variety of transition-metal cluster structures are found within the extended arrays of solidstate materials. Although molecular analogues of some of these clusters have been synthesized-ither by the self-assembly of smaller components in solution or by the excision of intact cluster units directly from the solid-state phase-molecular chemists are often unaware of the rich structural variety expressed in solid-state clusters. This article presents these diverse structural types as potential targets for synthetic molecular chemistry by describing fundamental solid-state cluster topologies in transition-metal chalcogenide/halide phases and detailing cases where molecular counterparts have been prepared. Particular emphasis is placed on cluster excision as a method of molecular cluster synthesis.

Characterization of Catalytically Active Octahedral Metal Halide Cluster Complexes

“…Extensive efforts have been directed at the synthesis of new halide clusters or the combination of known halide clusters with new networks. Presently, more than a hundred types of halide clusters have been synthesized by combining nineteen kinds of Group 3-7 metal atoms and four kinds of π-donor halogen ligands [11][12][13].…”

Octahedral Metal Clusters [Nb6Cl12(CN)6]4– as Molecular Building Blocks: From Supramolecular Assemblies to Coordination Polymers

“…The materials described herein are all built from diamagnetic cyanochloride cluster anions [Nb 6 Cl 12 (CN) 6 ] 4-and coordinatively unsaturated metal complexes such as [Mn(salen)] + and their derivatives. The overall structures are largely determined by the number of coordination sites available for linkage to the cluster unit and coordination preferences of the metal complexes.…”

“…[3] Progress in supramolecular chemistry has led to the use of more complex molecular building units to prepare materials with novel structures and properties. Inspired by the success of using hexacyanometalate anions [M(CN) 6 ] n-as building units to construct functional solids with diverse structures, [4] several groups are actively exploring the use of their expanded analogues, such as octahedral transition metal clusters, as building units to investigate the effect of the metal-metal bonds on their physicochemical properties. Octahedral transition metal clusters based on an M 6 octahedron in which six metal atoms are linked to each other through metal-metal bonds and µ 2 or µ 3 ligands to give a M 6 L 12 or M 6 L 8 cluster core (Figure 1) have received considerable interest since the discovery of the Chevrel phases which consist of 3D frameworks based on the 6-8 type clusters.…”

“…[5] Different synthetic methodologies have been developed to excise these clusters from their solid-state precursors through solution chemistry routes. [6] The cluster core [M 6 L 12 ] n+ or [M 6 L 8 ] n+ has an atom-or ion-like behavior. It is larger in size compared with mononuclear metal complexes, has versatile electronic structures, multiple coordination sites, and potential catalytic properties that make them promising candidates as building units of supramolecular structures.…”

“…It is larger in size compared with mononuclear metal complexes, has versatile electronic structures, multiple coordination sites, and potential catalytic properties that make them promising candidates as building units of supramolecular structures. [7] Face-capped octahedral cluster units [W 6 S 8 (CN) 6 ] 6-and [Re 6 Q 8 (CN) 6 ] n-(Q = S, Se and Te) have been used as building units of supramolecular structures, some of which show functional properties such as catalysis and molecular sieves. [8] The use of edge-capped octahedral niobium halide clusters as building units remains largely unexplored compared with the extensive work that has been reported on octahedral face-capped rhenium and tungsten clusters.…”