Palladium (II) and nickel (II) complexes with tetradentate ligands derived from pyrrole 2- carboxaldehyde and various diamines have been synthesized and characterized. The complexes are neutral and the coordination around the metal is square-planar; they are able to activate the molecular hydrogen and to catalyse the homogenous hydrogenation of phenylacetylene. The X-ray structures of N, N′-cycloexylenebis (pyrrol-2- ...
