Stable compounds containing heavier group 15 elements in the +1 oxidation state

This review provides an oxidation state model that emphasizes the similarities in the structural features, bonding and reactivities of molecules containing main group elements in a particular oxidation state. Using this model, the syntheses, structural features and selected aspects of the chemistry of stable compounds containing group 15 elements (pnictogens) in the +1 oxidation state are examined. Molecular types that are considered include: triphosphenium salts, phosphamethine cyanine dyes, phosphide anions, certain pnictaalkenes, certain phosphinidenes and their heavier analogues, among others. Theoretical models are presented to rationalize the factors that render such molecules stable.