Coordination Abilities of Di-2-picolylphenylphosphane Judged on the Basis of Charge Density Investigations

Abstract

The hindered reactivity of PhP(CH2Py)(2)LiCl (2) compared to the coordination behavior of the lithium chloride free ligand PhP(CH2Py)(2) (Py = 2-pyridyl) (1) could be elucidated by means of experimental electron density studies. According to the successful synthesis of metal complexes containing the dianionic Janus Head ligand PhP(CHPy)(2), the formation and the coordination pattern of the monoanionic ligand PhP{C(H)Py}(CH2Py) was examined. The reaction of ligand 1 with n-butyllithium/PMDETA and the superbase n-butyllithium/NaOtBu, respectively, led to the alkali metal complexes [(PMDETA)Li{C(H)Py}P(CH2Py)Ph] (5) and (PyCH2)PhP{C(H)Py}Na(Et2O) (6).