Assembly of one-dimensional AlP₂O₈^3- chains into three-dimensional MAlP₂O₈·C ₂N₂H₉ frameworks through transition metal cations (M = Ni²⁺, Co²⁺ and Fe²⁺)

Three-dimensional (3D) MAlP₂O₈·C ₂N₂H₉ open-frameworks have been successfully generated from 1D AlP₂O₈^3- chains using transition metal cations M²⁺ (M = Ni, Co and Fe). The 1D AlP ₂O₈^3- chain compound whose chain structure is made up of corner-sharing Al₂P₂ four-membered rings is prepared solvothermally using ethylenediamine as a template; to the reactant mixture in which the one-dimensional AlP₂O₈^3- chain compound has already crystallized, transition metal cations are added. Structural analysis indicates that the terminal oxygen atoms attached to the one-dimensional AlP₂O₈^3- chains are exclusively coordinated to M²⁺ forming O-M-O bonds. XRD, DRS, ICP, CHN and Mössbauer techniques have been used to characterise the products. This work provides a new approach to the synthesis of 3D open-frameworks through the assembly of low-dimensional structures via transition metal cations.