Transition Metal Cluster Compounds

On the variation of cluster core characteristics by an endohedral atom. Shape variation in 8-ce [EAu4(PPh3)4]2+ (E = N, P, As, Sb) clusters

“…33 The term ''porcupine'' clusters was introduced earlier to denote their architecture as a core and ligand layer in 1972 by King. 34 Generally, size-dependent properties that are due to the increase of metal atoms ascribed to the central core enable an understanding of the effects according to the number of metallic atoms, which differs greatly from individual atoms and bulk gold. 35 However, modifications within a certain atomic precision have been evaluated to a lesser extent, which is relevant to unraveling shape-dependent characteristics, favoring the increase of structural diversity.…”

“…33 The term “porcupine” clusters was introduced earlier to denote their architecture as a core and ligand layer in 1972 by King. 34…”

[Nb6Cl14(pyrazine)4], a Versatile Precursor for Ligand-Supported Hexanuclear Niobium Cluster Compounds: Synthesis, Characterization, Follow-Up Reactions, and Intermolecular Interactions

“…Niobium cluster compounds, which contain ligand-surrounded octahedral Nb 6 metal atom cores, have been investigated for a long time. − Because of a large variety of possible compositions, structures, and properties, the synthesis of new compounds and their physicochemical characterization have been and still are being intensively investigated. − Unfortunately, for the synthesis of new Nb 6 cluster compounds, a number of obstacles have to be conquered. One originates in the property of Nb 6 cluster compounds to be oxidized easily with the need to avoid contact with air, the low solubility of the so far used starting materials in common solvents resulting in long reaction times or high reaction temperatures, and elaborate workup procedures. − A further difficulty is the growth of (single) crystalline samples, because often a large salt and side product concentration exists, aggravating the crystallization of the target material.…”