Solvothermal synthesis and structures of one-and two-dimensional zinc phosphates

Abstract

Two new zinc phosphates, [C₈N₄H₂₆][Zn₂ (HPO₄)₄] (I) and [C₈N₄H₂₆] [Zn₆(PO₄)₄(HPO₄)₂] (II) have been synthesized employing solvothermal reactions in the presence of N,N'(3-bisaminopropyl)-1,2-ethylenediamine. The structure of I consists of ZnO₄ and HPO₄ tetrahedra, forming four-membered rings, which are connected edgewise giving rise to the one-dimensional ladders. HPO₄ units also hang from the Zn center into the inter-ladder spaces along with the organic amine molecules. In II, the connectivity between ZnO₄, PO₄ and HPO₄ tetrahedral units gives rise to a two-dimensional layered structure with eight-membered apertures. The amine molecule occupies the center of these apertures and interacts with the layer through hydrogen bonds. The formation of one-dimensional tube-like structure in II is noteworthy. The self-complementary three-dimensional hydrogen bonded framework formed between the ladders in I,[C₈N₄H₂₆] [Zn₆(HPO₄)₄]. The view is down the ladder axis. Note that the amine molecules are situated within the channels. Dotted lines are the possible hydrogen bond interactions.