TTET
Triplet–triplet energy transfer, abbreviated TTET, is a nonradiative energy transfer process in photochemistry and photophysics. In TTET, a donor molecule that is in its triplet excited state transfers energy to an acceptor molecule that is also in a triplet state. The transfer is typically described as a Dexter-type exchange mechanism, which requires direct orbital overlap and close physical contact between the donor and acceptor, rather than long-range dipole–dipole interactions.
A key condition for TTET is the relative triplet energies of the two species. The donor’s triplet
TTET has several important applications. It is a fundamental step in triplet–triplet annihilation upconversion (TTA-UC), where
Oxygen can quench triplet states, so TTET processes often require inert or controlled environments to minimize