Coordination chemistry of the heterotopic 1,2-phenylenebis(thio)diacetic acid ligand: Rhodium(I), palladium(II) and nickel(II) complexes

► Racemic PdII, RhI, and NiII complexes are obtained with 1,2-phenylenebis(thio)diacetic acid. ► In the Pd and Rh complexes, the COOH groups are not coordinated but involved in hydrogen bonding. ► The Ni complex has a tetradentate 1,2-phenylenebis(thio)diacetate ligand (κ4S,S′,O,O′). ► Extended hydrogen bonding is observed (XH···O, X = O, N).