Chirality in mononuclear square planar complexes

The aim of this paper is to draw chemists' attention to the chirality of square planar complexes and to ensure that authors of publications take this chemical aspect into consideration. Some simple prochiral or chiral complexes of Pd(II) or Pt(II) with 2-methyl or 2-ethylpyridine were prepared and structurally characterized by X-ray diffraction methods in order to prove that the chirality in square planar complexes is a rather common event. The situation regarding the stereodescriptors for axial chirality, planar chirality and helicity is both confused and confusing and in our opinion it would be better to adopt only the P and M terms that are related to the sign of the appropriate torsion angles.