Aggregation patterns in the crystal structures of organometallic Group XV 1,1-dithiolates: the influence of the Lewis acidity of the central atom, metal- and ligand-bound steric bulk, and coordination potential of the 1,1-dithiolate ligands upon supramolecular architecture

Abstract

Supramolecular association operating in the crystal structures of organo-phosphorus, -arsenic, -antimony and -bismuth 1,1-dithiolate compounds is surveyed with the purpose of delineating the factors that dictate the formation of the resultant range of aggregates. Primary considerations for the formation of secondary M⋯S interactions relate to the Lewis acidity of the central atom that can be moderated by i) the nature of the metal atom itself, e.g. the Lewis acidity of P < As < Sb < Bi, ii) the number of metal-bound organic substituents, e.g. the Lewis acidity of R₂M < RM, and iii) the coordination potential of the 1,1-dithiolate ligand, e.g. the Lewis acidity of M(S₂CNR₂) < M(S₂COR). Another vital factor is the steric profile of the metal- and/or ligand-bound R groups, i.e. when R is large, M⋯S interactions are precluded. When M⋯S interactions are absent, for whatever reason, the crystal packing is invariably dominated by C–H⋯S interactions that usually lead to chain motifs.