inorganic chemistry

conversion, rate constantkic); radiative decay to the ground state
(fluorescence, kfl); conversion to the lowest triplet state T 1
(intersystem crossing,kisc). In its turn,T 1 can undergo deactiva-
tion via nonradiative (intersystem crossing, k^0 isc) or radiative
(phosphorescence,kph) decay to the ground stateS 0.

E

(a)

(b)

S 2

S 1

S 0

ket

kd

*A-B

A-B

1/τ

A+-B-

or other

quenching

processes

A-*B

100 % efficiency

kisc

kfl

kph

T 1

T 2

kic k′

isc

FIG. 3. (a) Schematic energy level diagram for a generic molecule.
For more details, see text. (b) Schematic deactivation processes of an
excited state in a supramolecular species.

PHOTOCHEMISTRY & PHOTOPHYSICS OF METAL COMPLEXES 109