Diphosphate−Zinc Complexes with Encapsulating Tripodal Coligands

Abstract

Tris(benzimidazolylmethyl)amine (TBA) and tris(pyrazolyl)borate (Tp) ligands have been used to prepare ternary zinc complexes with triorganodiphosphates (R3POP−), triorgano‐methylenediphosphonates (R3PCP−), and diorganodiphosphates (R2POP2−). The complex types [(TBA)Zn(R3POP)]+ and [(TBA)Zn(R3PCP)]+ have been assigned as containing trigonal‐bipyramidal zinc with monodentate diphosphate ligands. By X‐ray structure determination, the complex type [(TBA)Zn(R2POP)] has been found to contain the same ZnN4O coordination pattern, which has also been assigned to the dinuclear complexes [(TBA)Zn(R2POP)Zn(TBA)]2+ incorporating the diphosphates as bis‐monodentate bridging ligands. The same monodentate and bis‐monodentate attachment of the diphosphates, but with tetrahedral zinc in a ZnN3O environment, has been identified in the pyrazolylborate complexes TpZn(R3POP) and TpZn(R2POP)ZnTp.