P–C Bond Cleavage-Assisted Lanthanide Phosphate Coordination Polymers

The reaction of lanthanide­(III) salts with an organodiphosphonic acid under hydrothermal conditions resulted in a P–C bond cleavage affording [{Eu4(PO4)­(PO4)0.5×4(PO4)0.25×4(H2O)2}·6H2O]n (1), [{Dy4(PO4)­(PO4)0.5×4(PO4)0.25×4(H2O)2}·6H2O]n (2), and [{Gd­(PO4)0.5(PO4)0.5(H2O)3}·2H2O]n (3). 1 and 2 are porous 3D coordination polymers whose repeating units possess a dimeric motif. While one lanthanide ion in the dimer is eight-coordinate in a distorted square-antiprismatic geometry, the other is nine-coordinate and present in a distorted monocapped square-antiprismatic geometry. In contrast to 1 and 2, 3 possesses a 2D architecture; the asymmetric unit contains a monomeric GdIII center which is nine-coordinate in a distorted monocapped square-antiprismatic geometry.