Zinc complexes of condensed phosphates, 2 - Diphosphate-zinc complexes with chelating coligands

Zinc perchlorate, diorganodiphosphates (POP2-), and chelating Ligands L (L = 1,10-phenanthroline, neocuproine, 2,2'-bipyridine, oxinate) yield three t ypes of ternary complexes. Type 1 (L2Zn . POP) contains octahedral zinc bou nd by the diphosphate as an OPOPO chelate ligand. Type 2 (LZn . POP) consis ts of dimeric complexes containing five-coordinate zinc, with the diphospha tes acting as OPOPO chelate Ligands for one zinc ion and as OPO bridges bet ween two zinc ions. Type 3 (L2Zn2. POP), observed only for oxinate, is prop osed to contain two five-coordinate zinc ions bridged by the diphosphate as a tetradentate ligand.