Three yttrium crotonate complexes with diimines

The synthesis and crystal structures of three new yttrium crotonate (crot) compounds, associated with three different nitro­genous bases, namely 1,10-phenanthroline (phen), 4-­methyl-1,10-phenanthroline (mphen) and 2,2′-bipyridyl­amine (bpa), are presented. All three compounds organize as centrosymmetric dimers, to give tetra-μ-crotonato-bis[croto­nato(1,10-phenanthroline)yttrium(III)] dihydrate, [Y₂(C₄H₅O₂)₆(C₁₂H₈N₂)₂]·2H₂O or [Y(crot)₃(phen)]₂·2H₂O, (I), tetra-μ-crotonato-bis­[crotonato(4-methyl-1,10-phenan­throline)­yttrium(III)] dihydrate, [Y₂(C₄H₅O₂)₆(C₁₃H₁₀N₂)₂]·2H₂O or [Y(crot)₃(mphen)]₂·2H₂O, (II), and tetra-μ-crot­onato-bis­[di­aqua(crotonato)yttrium(III)] 2,2′-bipyridyl­amine tetrasolvate, [Y₂(C₄H₅O₂)₆(H₂O)₄]·4C₁₀H₉N₃ or [Y(crot)₃(aq)₂]₂·4(bpa), (III). Complexes (I) and (II) are isomorphous, with the bases acting as chelating ligands. In complex (III), the coordination sphere is built up of carboxyl­ate and aqua ligands, with the non-coordinated di­imine acting as included solvent.