Palladium complexes bearing the dipyridyl ligand: synthesis, structural studies, and use in the Heck reaction

Two new palladium complexes derived from the di(2-pyridinyl)methanone N-(2-pyridinyl)hydrazone (DPMNPH) ligand are reported. The compounds were characterized by elemental analysis, spectroscopic studies, and, for the DPMNPH ligand, single-crystal X-ray diffraction analysis. The DPMNPH ligand crystallized as orthorhombic with the space group P2(1)2(1)2(1). The H1 atom is intramolecularly bonded to the pyridinic N4 with N1-H1 = 0.92(3) angstrom, H1 center dot center dot center dot N4 = 1.87(2) angstrom, N1 center dot center dot center dot N4 = 2.615(2) angstrom, and N1-H1 center dot center dot center dot N4 = 137(2)degrees. Both complexes were excellent catalysts in the Heck reaction in the presence of base.