Nitrilotris(methylenephosphonic) Complexes of Lanthanides [Na(H2O)x]2[LnIIINa6H(H2O)10{N(CH2PO3)3}2] · nH2O (LnIII = Pr, Nd)

Abstract

The sodium salts of lanthanide nitrilotris(mehylenephosphonate) complexes [Na(H₂O)_x]₂[Ln^IIINa₆H(H₂O)₁₀{N(CH₂PO₃)₃}₂] · nH₂O, where Ln^III = Pr (I), and Nd (II), were prepared, isolated, and studied. The isostructural crystals are monoclinic, space group P2₁/c, Z = 2; for complex I, a = 11.8168(7), b =  10.5403(9), c = 19.8094(10) Å, β = 94.232(5)°; for complex II, a = 11.7999(2), b = 10.5495(2), c = 19.7976(3) Å, β = 94.158(2)°. The lanthanide ions are coordinated at the center of a cage consisting of two {N(CH₂PO₃)₃} acid residues and six sodium ions, which form P–O–Na–O–P bridges. The Ln coordination polyhedron is a regular rhombohedron (CIF files CCDC nos. 1825702 (I), 1825700 (II)).