A 2D lanthanum coordination polymer with π-π Stacking

A 2D lanthanum coordination polymer La2(1,10-phen)2(e,a-cis-1,4-chdc) 3·2.5H2O (chdc = cyclohexanedicarboxylic acid; phen = 1,10-phenanthroline) 1 which contains two-dimensional (2-D) lanthanum-organic sheets, was prepared under hydrothermal conditions and characterized by elemental analyses, IR spectra, TG analysis, and single-crystal X-ray diffraction. In the structure of 1, the La site is nine-coordinate by two nitrogen atoms from 1,10-phen and seven oxygen atoms from several 1,4-chdc ligands, connected into a 2-D coordination polymer, with the flexible 1,4-chdc spacers. The 2-D layers are extended into a 3-D framework by π-π interactions between adjacent layers.