Synthesis and X-ray diffraction study of a chiral bis-phosphahelicene palladium (II) complex

As a complement to our previous studies on the development of a class of chiral phosphahelicenes, this article discloses the synthesis, spectroscopic, and structural characterizations of a new phosphahelicene transition metal complex. It demonstrates the ability of these hindered chiral ligands to coordinate Pd (II) in trans-complexes Cl2Pd(L*)(2). In the solid state, the complex adopts a C2-symmetric arrangement with two ligands facing each other on the same face of the coordination plane. X-Ray data highlight bending of the Pd (II) unit from the expected planar coordination geometry that might be due to a significant pi-pi stacking effect between the central rings of two helical units.