5-Co-ordination of Divalent Copper

Abstract

CONSIDERABLE attention has recently been given to the co-ordination of additional ligands along the axis normal to the molecular plane of planar 4-co-ordinated complexes. Ballhausen and Liehr, for example, explain the blue and yellow isomers of Lifschitz's nickel stilbene-diamine salts in terms of co-ordination of the associated anions in this way¹; Harris, Nyholm and Stevenson have shown by X-ray analysis the analogous attachment of iodide ions in bis-(o-phenylene-bis-dimethylarsine)palladous iodide² and Sacconi, Lombardo and Paoletti have determined stability constants for the adducts of heterocyclic bases with the planar inner-complex nickel diacetyl-bis-(benzoylhydrazone) in benzene solution³.