Hydrated neodymium(III) and europium(III) picrate complexes with pyrazine- N-oxide

Abstract

Compounds with composition Ln(pic) 3·2pyzNO·7H 2O (Ln=Nd, Eu; pic=picrate; pyzNO=pyrazine- N-oxide) were obtained by reaction of the hydrated lanthanide picrate with pyrazine- N-oxide in ethanol (molar ratio 1:4). The adducts were characterized by elemental analyses and IR spectra. X-ray single crystal data for the neodymium complex indicate that the crystal system is triclinic, space group P 1̄. Nd unit cell dimensions are: a=7.930(1) Å; b=12.869(1) Å; c=20.833(1) Å; α=106.414(7) Å; β=92.574(7) Å; γ=92.202(9) Å; V=2034.4(3) Å; Z=2. Europium cell parameter are a=7.882(1) Å, b=12.880(1) Å, c=20.788(2) Å, α=106.224(8)°, β=92.055(7)°, γ=93.140(7)°. One picrate is bidentate, coordinated through the phenoxo oxygen and one oxygen of an o-nitro group and two are not coordinated. One pyrazine- N-oxide is bonded through the oxygen and the other is out of sphere. Six water molecules are bonded and a seventh is not coordinated. The coordination polyhedron is a distorted tricapped trigonal prism.