title: Imido Analogues of Common Oxo Anions: A New Episode in the Chemistry of Cluster Compounds.
abstract: Oxo anions of p- and d-block elements, for example, SiO(4)(4-), PO(4)(3-), SO(4)(2-), and CrO(4)(2-), are commonly encountered species. The full or partial replacement of the oxo ligands by isoelectronic imido (NR) groups generates homoleptic polyimido anions of the type [E(NR)(x)](z-) or heteroleptic imidooxo anions with the general formula [O(y)E(NR)(x-y)](z-) (where E=main group element or transition metal). The alkali metal derivatives of this new class of anions form ternary or quaternary cluster systems, respectively. The structures of these clusters can be rationalized in terms of the self-assembly of fundamental building blocks. An understanding of the factors that control this process may allow the design of functional materials with specific properties. In addition, these anions are attracting attention as multidentate ligands with unique electronic and stereochemical properties that may engender novel metal-centered chemistry.
authors.affiliation: Department of Chemistry University of Calgary Calgary, AB, T2N 1N4 (Canada).
authors.forename: Justin K.
authors.initials: JK
authors.lastname: Brask
authors.forename: Tristram
authors.initials: T
authors.lastname: Chivers