Photophysical properties of cyclometalated Pt(II) complexes attached with pyrene by CC single bond

Luminescent complexes, [(C^N^N)Pt(C≡CR)](HC^N^N = 4-(1-phenyl)-6-phenyl-2,2′-bipyridine, R = Ph (1, PPPt); HC^N^N = 4-(1-pyrene)-6-phenyl-2, 2′-bipyridine; R = Ph (2, PyPPt), p-Et-Ph (3, PyEPPt)), were synthesized and their photophysical properties were investigated in acetonitrile liquid solution and butyronitrile glasses at 77 K. These complexes display steady state dual emissions at room temperature and 77 K. The emission lifetime and transient absorption of these complexes illustrated that the 3IL triplet state of the molecules could be acquired through the intersystem crossing directly from 1MLCT state and the triplet–triplet internal conversion from the 3MLCT state to the 3IL state was negligible in the molecules.