photochemical funnel

Molecular structure where the excited-state reactant or intermediate is delivered to the ground state to initiate product formation.

Note:

For a broad class of organic reactions, the structure of the funnel can take the form of a conical intersection or a singlet–triplet crossing.

Source:

PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 385