1000-fold enhancement of luminescence lifetimes via energy-transfer equilibration with the T1 state of Zn(TPP).
The new zinc porphyrin/tungsten alkylidyne dyad Zn(TPP)-C[triple bond]CC(6)H(4)C[triple bond]W(dppe)(2)Cl (1) possesses novel photophysical properties that arise from a tunable excited-state triplet-triplet equilibrium between the porphyrin and tungsten alkylidyne units. Dyad 1 exhibits (3)(d(xy) <-- pi*(WCR)) phosphorescence with a lifetime that is 20 times longer than that of the parent chromophore W(CC(6)H(4)CCPh)(dppe)(2)Cl (2). The triplet-triplet equilibrium can be tuned by the addition of ligands to the Zn center, resulting in phosphorescence lifetimes for 1(L) that are up to 1300 times longer than that of 2. The "lifetime reservoir" effect exhibited by 1(L) is approximately 1 order of magnitude larger than previously reported examples of the phenomenon.
Cohen
Brian W
BW
Department of Chemistry, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.
Lovaasen
Benjamin M
BM
Simpson
Cheslan K
CK
Cummings
Scott D
SD
Dallinger
Richard F
RF
Hopkins
Michael D
MD