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

Luminescent complexes, [(C (N) over cap(N) over cap )Pt(C CR)](HC (N) over cap(N) over cap = 4-(1-phenyl)-6-phenyl-2,2'-bipyridine, R = Ph (1, PPPt); HC (N) over cap(N) over cap = 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 (IL)-I-3 triplet state of the molecules could be acquired through the intersystem crossing directly from (MLCT)-M-1 state and the triplet-triplet internal conversion from the (MLCT)-M-3 state to the (IL)-I-3 state was negligible in the molecules. (C) 2007 Elsevier B.V. All rights reserved.