Crystal structure of erbium(3) nitrate complex with acetic acid hydrazide

X-ray study (diffractometer, lambda Mo Ksub(α), 2826 reflections, the method of heavy atom, anisotropic-isotropic (H) least square fit method up to R=0.055) of Er(AH)4(NO3)3xH2O, where AH=NH2NHCOCH3 has been carried out. The crystals are rhombic: a=16.479, b=9.122, c=31.750 A, Z=8. sp.gr. Pbcn. The structure is built of complex cations [Er(AH)4(H2O)]3+ and anions NO3-. Er atom coordinates four O atoms and four N atoms of bidentate-cyclic AH-ligands and O atom of water molecule like in a one-cap square antiprism. Mean distances and angles are as follows: Er-N 2.542, Er-O (AH) 2.337 A, OErN 64.5 deg; Er-Osub(ω) distance is 2.363 A. Distances in hydrazide grouping are the usual ones. Chelate cycles are not flat and have the shape of Er-envelope. Cations and anions are bonded in the structure by the system of H-bonds of the type N-H...O and O-H...O, the shortest ones (2.75 and 2.73 A) are formed with the participation of O atom of water molecule