Zinc and cadmium 2-pyrazinephosphonates: Syntheses, structures and luminescent properties

Abstract

Three new metal(II) 2-pyrazinephosphonates have been synthesized by hydrothermal reactions based on 2-pyrazinephosphonic acid (C₄H₃N₂PO₃H₂1) as ligand, namely, Zn(C₄H₃N₂PO₃) (2), Cd[(C₄H₃N₂PO₃)(H₂O)] (3) and Cd[(C₄H₃N₂PO₃H)Cl]·H₂O (4). In compound 2, the O–P–O bridged inorganic layers are pillared by pyrazinyl groups into a three-dimensional network. In compound 3, the {CdO₅N} and {CPO₃} polyhedra are interconnected via edge and corner-sharing into a metal phosphonate layer. In compound 4, the {Cd₂Cl₂} dimers are linked by O–P–O bridges into a one-dimensional double chain, and the chains are joined into a layer by pyrazinyl groups. Here we employ pyrazinephosphonic acids as structure directing motifs to form extended structures and materials with interesting luminescent properties. The luminescent properties studied have also been described.