Zero‐Valent Palladium Complexes with Monodentate Nitrogen σ‐Donor Ligands

The facile synthesis and isolation of the stable zero-valent complexes [Pd(L)2(maleic anhydride)] with σ-donor N ligands (L=ammonia, aniline, diethylamine, and pyridine) is remarkable in light of the fact that according to the HSAB principle, low-valent palladium compounds with donor groups such as simple amines should be difficult to prepare. The X-ray crystal structure of the pyridine complex is shown (Pd gold, O orange, N blue).