Chiral complexes of PdCl2 with hydroxypyrazolylquinoline and pyrazolylquinoline based on the monoterpenoid (+)-3-carene: Synthesis and structures

The chiral complexes [(PdLCl2)-Cl-1] (I) and [(PdLCl2)-Cl-2] (II) (where L-1 and L-2 are hydroxypyrazolylquinoline and pyrazolylquinoline, respectively, based on the monoterpenoid (+)-3-carene) were obtained and examined using X-ray diffraction. The crystal structures of complexes I and II are built from mononuclear acentric molecules. The Pd2+ ions coordinate two N atoms of the chelating bidentate ligand L-1 or L-2 and two Cl atoms. The coordination polyhedron Cl2N2 is a square distorted in a tetrahedral manner. In structure I, adjacent molecules are linked by intermolecular contacts and hydrogen bonds Cl center dot center dot center dot H-O, which gives rise to chains aligned with the axis x. In structure II, contacts that are substantially shorter than the van der Waals interactions were not detected.