Heterocyclic Amine Derivatives of Zinc Organophosphonates

A series of novel zinc(II) organophosphonates with coordinated 2,2ʹ-bipyridyl (2,2ʹ-bipy, C10H8N2) and 1,10-phenanthroline (phen, C12H8N2) ligands (with the proposed formulations: Zn(O3PC6H5)(C12H8N2), Zn2(O3PR)2(C12H8N2) (R = C6H5CH2, C2H5, CH3), and Zn2(O3PR)2(C10H8N2)(H2O) (R = C6H5, C6H5CH2)) has been prepared and characterized. The amine derivatives have the same 1:1 metal/phosphorus ligand ratio as the parent zinc(II) organophosphonates, and, with the exception of the phen derivative of zinc(II) phenylphosphonate, Zn(O3PC6H5)(C12H8N2), all of the amine derivatives were found to possess a metal/phosphorus/amine ratio of 2:2:1 where one amine ligand is coordinated to every two zinc atoms. Elemental analyses, FTIR, TGA, XPS, and solid-state 31P/13C MAS NMR data are consistent with the proposed formulations. Powder XRD measurements show Zn(O3PC6H5)(C12H8N2) and Zn2(O3PCH2C6H5)2(C12H8N2) to be layered, whereas the other complexes are nonlamellar materials. XPS data suggests that the nitrogen atoms of the amine ligands are coordinated to the zinc center in an unsymmetrical manner.