T-Shaped Cationic Cu^I Complexes with Hemilabile PNP-Type Ligands

The versatile coordination behavior of the PNP ligands <b>1A</b> (2,6-bis[(di-<i>tert</i>-butylphosphino)methyl]pyridine) and <b>1B</b> (2,6-bis[(diphenylphosphino)methyl]pyridine) to Cu^I is described, whereby a hemilabile interaction of the pyridine N-donor atom to the copper center resulted in a rare T-shaped complex with <b>1A</b>, while with <b>1B</b> also a tetracoordinated species could be isolated. Theoretical calculations support the weak interaction of the pyridine N donor in <b>1A</b> with the Cu center.