Zinc complexes of condensed phosphates, 4 - Diphosphate-zinc complexes with encapsulating tripodal coligands

Tris(benzimidazolylmethyl)amine (TBA) and tris(pyrazolyl)borate (Tp) ligand s have been used to prepare ternary zinc complexes with triorganodiphosphat es (R3POP-), triorganomethylenediphosphonates (R3PCP-), and diorganodiphosp hates (R2POP2-), The complex types [(TBA)Zn(R3POP)](+) and [(TBA)Zn(R3PCP)] (+) have been assigned as containing trigonal-bipyramidal zinc with monoden tate diphosphate ligands, By X-ray structure determination, the complex typ e [(TBA)Zn(R2POP)] has been found to contain the same ZnN4O coordination pa ttern, which has also been assigned to the dinuclear complexes [(TBA)Zn(R2P OP)Zn(TBA)](2+) incorporating the diphosphates as bis-monodentate bridging Ligands. The same monodentate and bis-monodentate attachment of the diphosp hates, but with tetrahedral zinc in a ZnN3O environment, has been identifie d in the pyrazolylborate complexes TpZn(R3POP) and TpZn(R2POP)ZnTp.