Structural systematics of rare earth complexes. XXI Polymeric sodium bis(thiodiglycolato)neodymiate(III)

A single-crystal, room-temperature, X-ray structure determination is record ed for the title compound, NaNd(tdga)(2) ('tdga(2-)' = -OCOCH2SCH2COO-). Cr ystals are monoclinic, space group Pc, a 9.5058(4), b 7.323(1), c 9.402(4) Angstrom, beta 97.71(2)degrees, Z = 2 f.u., conventional R on \F\ being 0.0 28 for N-o 1054 independent 'observed' (I > 3 sigma(I)) diffractometer refl ections. The compound is a novel polymeric array; the neodymium atom is eig ht-coordinated by ligand oxygen atoms at distances ranging from 2.43(2) to 2.54(1) Angstrom. A redetermination of the parent thiodiglycolic acid is al so recorded (orthorhombic Pnam, a 5.0444(8), b 6.690(1), c 17.73(1) Angstro m, Z = 4, R 0.038 for N-o 866).