Tuning the Structural and Photophysical Properties of Cationic Pt(II) Complexes Bearing Neutral Bis(triazolyl)pyridine Ligands

The emission properties of a series
of cationic Pt­(II) complexes bearing neutral tridentate 2,6-bis-(1H-1,2,3-triazol-5-yl)­pyridine and monoanionic ancillary
ligands (Cl– or CN–) are described.
By varying the substitution pattern on the 1,2,3-triazole moieties
of the tridentate luminophore and the nature of the ancillary ligand,
we were able to tune the intermolecular interactions between the complexes
and therefore the electronic interactions between the metal centers.
Indeed, all the compounds possessing Cl– as ancillary
ligand are nonluminescent at room temperature, while the complexes
containing CN– are luminescent. Interestingly, the
π-accepting nature of this ancillary ligand induces Pt­(II)–Pt­(II)
interactions irrespectively of bulky substitution patterns on the
tridentate ligand.