TETRAAQUA[2,6-DIACETYLPYRIDINEDI(ACETIC ACID HYDRAZONE)]YTTRIUM(III) NITRATE TRIHYDRATE - SYNTHESIS, CRYSTAL-STRUCTURE AND Y-89, C-13, H-1-NMR

The synthesis, crystal structure, and Y-89. C-13, and H-1 NMR spectra of tetraaqua[2.6-diacrtylpyridinedi(acetic acid hydrazone)]yttrium(III ) nitrate trihydrate, [Y(H(2)dapaah)(H2O)(4)](3+) 3NO(3)(-). 3H(2)O (1 ), the first reported complex of Y-III With a planar pentadentate liga nd is presented. The Y-III ion coordinates to the pyridyl nitrogen. th e two hydrazone nitrogens, and the two carbonyl oxygens of the pentade ntate ligand and three water molecules above and one below the ligand plane to give a nine-coordinated complex. The geometry around the Y-II I is a slightly distorted tricapped trigonal prism. The Y-89 chemical shift was determined to provide additional data on the relationship of the chemical shift to the coordination polyhedron for Y complexes sin ce Y-89 NMR has been suggested as a probe for biological systems. The Y-89, spectrum shows a peak at +1.53 ppm from the YCl3, standard. one of the smallest chemical shifts relative to the standard reported to d ate and is the first example where the Y-III is coordinated to a neutr al ligand. Copyright (C) 1996 Elsevier Science Ltd