Hydrothermal synthesis, crystal structure, and thermal stability of a novel 3D cadmium phosphonate with double-stranded helical channels

A novel 3D cadmium phosphonate, [enH2]0.5[Cd2(HL)(L)] 1 (H3L = 2-hydroxyphosphonoacetic acid; en = ethylenediamine) has been synthesized under hydrothermal reaction conditions. The structure of compound 1 comprises right-handed double-stranded helical channels, left-handed double-stranded helical channels and achiral channels that are connected through cadmium atoms and L3−ligands to form a meso compound, and the protonated ethylenediamine cations are located inside the achiral channels.