Porous lanthanide-organic open frameworks with helical tubes constructed from interweaving triple-helical and double-helical chains

Achiral channels as well as left- and right-handed helical tubes are present in novel lanthanide-organic frameworks prepared under hydrothermal conditions from lanthanide oxides. In the three-dimensional coordination polymers, the Ln atoms (Ln = Eu, Dy, Y, Pr, Nd, Sm, Gd, Tb, Er) are linked by 4,5-imidazoledicarboxylic acid ligands with skew coordination orientation (see picture). (Figure Presented).