Syntheses and Characterization of One-Dimensional Antimony(III) Diphosphonates: [NH3(CH2)nNH3][Sb{CH3C(O)(PO3)2}] (n=4, 5)

This paper describes the hydrothermal syntheses and characterization of two antimony(III) diphosphonates: [NH₃(CH₂)_nNH₃]Sb{CH₃C(O)(PO₃)₂} [n=4 (1), 5 (2)]. The two compounds are isostructural based on their XRD measurements. Single-crystal structure determination of compound 1 revealed a one-dimensional linear chain structure where the distorted {SbO₅E} octahedra (E is the lone pair electrons occupying an axial position) are corner-shared by {CPO₃} tetrahedra. The protonated diamines are located between the chains, with their nitrogen atoms locked by the hydrogen bonds with the phosphonate oxygens. Crystal data for 1: orthorhombic, space group Pnma, a=13.426(4), b=17.149(4), c5.4496(14) Å, V=1254.7(6) Aų, Z=4.