Two New Chromium(III) Complexes with the Pincer-type Pyridine-2,6-dicarboxylate Ligand

The synthesis and crystal structures of two new salts of chromium(III) with pyridine-2,6-dicarboxylic acid H2Pda (and 2,2’-bipyridyl, Bpy, as a co-ligand) are reported, (HPyz)[Cr(Pda)2](H2Pda)-(H2O)5 (1) and [Cr(Pda)(Bpy)(H2O)][Cr(Pda)2](H2O)2 (2). Both crystal structures contain the octahedral [Cr(Pda)2]− anion with the pincer-type O,N,O-Pda2− ligand. In 1, the pyrazole additive does not act as a ligand, rather it is included as a mono-protonated cation. In 2, both Pda2−, the neutral 2,2’-bipyridyl and water are coordinating Cr3+ in the cation [Cr(Pda)(Bpy)(H2O)]+.