Samarium 3,5-dinitrobenzoate dihydrate

The coordination around the Sm atom in the title compound, catena-poly[[[te traaqua-1 kappa(2)O,2 kappa(2)O-tetrakis(mu-3,5-dinitrobenzoato-O:O')disama rium]-bis(mu-3,5-dinitrobenzoato-O:O')] dihydrate], [Sm-2(C7H3N2O6)(6)(H2O) (4)].-2H(2)O. is eightfold, The irregular square-antiprism coordination of the Sm ion is provided by six O atoms from six carboxylate groups and two w ater O atoms. The Sm ions are bridged alternately by four and two Ligands, resulting in linear polymeric chains with two different Sm ... Sm distances of 4.2476(7) and 5.0831(8) Angstrom, and Sm-O distances in the range 2.355 (4)-2.559 (4) Angstrom. A set of hydrogen bonds exists between the nitro g roups and the water molecules.