Metal Cation Induced Modulation of the Photophysical Properties of a Platinum(II) Complex Featuring a Dipicolylanilino-Acetylide Ligand

We report the synthesis of a new, luminescent, cyclometalated platinum complex 1 incorporating a bis(2-picolyl) anilino (DPA) group. The complex has the form LPt-C C-C6H4-N(CH(2)py)(2), where L is a (CNN)-N-boolean AND-N-boolean AND-coordinating ligand based on phenylbipyridine. The ground-state absorption and excited-state luminescence of complex 1 are modulated by the binding of selected divalent metal ions (Zn2+, Cd2+, Ni2+, and Pb2+) to the DPA unit; the extent of the observed changes are dependent upon the identity of the metal ion. In particular, binding of Zn2+ leads to a substantial enhancement in the emission intensity.