Neodymium, erbium, and europium complexes with 1,6-bis(diphenylphosphoryl)-2,5-dioxahexane (L): The crystal structure of [Nd2(NO3)6L3]

Solid complexes M(NO3)3 · 1.5L (M = Nd, Er, Eu; L is 1,6-bis(diphenylphosphoryl)-2,5-dioxahexane) have been synthesized. A new, convenient method of synthesis of L has been suggested. The crystal structure of [Nd2(NO3)6L3] has been determined by single-crystal X-ray diffraction. The nonacoordination environments of the Nd(1) and Nd(2) atoms are composed each of six O atoms of bidentate nitrate ions and three phosphoryl O atoms of the L molecules (av. Nd-O, 2.543 and 2.374 Å, respectively). Two independent L molecules act as bridges linking the Nd atoms to form centrosymmetric tetramers [L-Nd(NO3)3-L-Nd(NO3)3-L2-Nd(NO3)3-L-Nd(NO3)3L]. The third L molecule is disordered over two positions with site occupancy factors of 0.602(4) and 0.398(4) so that most of the molecules chelate the terminal Nd atoms in the tetramer, and the other molecules combine tetramers into longer associates. On the basis of elemental analysis data and IR spectra, it has been assumed that the Er and Eu complexes have the same structure as [Nd2(NO3)6L3].