Crystal Structure of a Polysamarium (III) Nitrate Chain Crosslinked by a Di-CMPO Ligand

Abstract

In the title compound poly[aqua­bis­(-nitrato-4O,O\u27:O,O\u27\u27)tetra­kis­(nitrato-2O,O\u27){4-tetra­ethyl [(ethane-1,2-diyl)bis(aza­nedi­yl)bis­(2-oxo­ethane-2,1-di­yl)]di­phospho­nate-2O,O\u27}disamarium(III)], [Sm2(NO3)6(C14H30N2O8P2)(H2O)]n, a 12-coordinate SmIII and a nine-coordinate SmIII cation are alternately linked via shared bis-bidentate nitrate anions into a corrugated chain extending parallel to the a axis. The nine-coordinate SmIII atom of this chain is also chelated by a bidentate, yet flexible, carbamoyl­methyl­phoshine oxide (CMPO) ligand and bears one water mol­ecule. This water mol­ecule is hydrogen bonded to nitrate groups bonded to the 12-coordinate SmIII cation. The CMPO ligand, which lies about an inversion center, links neighboring chains along the c axis, forming sheets parallel to the ac plane. Hydrogen bonds between the amide NH group and metal-bound nitrate anions are also present in these sheets. The sheets are packed along the b axis through only van der Waals inter­actions