A novel 3D framework indium phosphite-oxalate based on a pcu-type topology

Abstract

A new inorganic–organic hybrid indium phosphite-oxalate, formulated as H[In5(HPO3)6(H2PO3)2(C2O4)2]·(C4N2H11)2·H2O 1 has been hydrothermally synthesized in the presence of piperazine acting as a structure directing agent (SDA). The single crystal X-ray diffraction reveals that compound 1 shows three-dimensional open-framework with intersecting 12-ring channels along the [010] and [001] directions, which is constructed from strictly alternating double 6-ring units (D6Rs), [C2O4]2− groups and [H2PO3]− pseudo-pyramids. It is noted that the classical D6R SBU is firstly reported in main metal phosphite/phosphite-oxalate. By regarding D6R as the 6-connected nodes, the inorganic–organic hybrid framework is based on a pcu-type topology. The as-synthesized product was characterized by single-crystal X-ray diffraction, powder X-ray diffraction, IR spectroscopy, thermogravimetric analysis (TGA), ICP-AES and elemental analyses.