Long-lived, red-emitting excited state of a Ru(II) complex of a diaminotriazine ligand

Heteroleptic complexes of Ru(II) with tridentate ligand Py-DAT2 (2,6-bis(4,6-diamino-1,3,5-triazin-2-yl)pyridine) and with derivatives of tridentate ligands tpy (2,2′:6′,2″-terpyridine) or dpt (2,6-dipyridyltriazine) have been synthesized and characterized. Changing the second ligand from tpy to dpt was found to profoundly alter the electronic and photophysical properties of the complexes. Structural analysis of the Py-DAT2/tpy complex by single-crystal XRD revealed the presence of a 2D terpyridyl embrace and an extended array of hydrogen bonds involving water of crystallization and the amino groups of Py-DAT2