A
potential-energy surface for a process
A + B–C in which the initial descent of the system into the product valley is associated
with a substantial decrease in the
A–B distance and with little separation between the products
A–B and
C. In terms of a
potential-energy profile, the energy barrier occurs in the early stage of the
reaction path. Attractive surfaces are also called early-downhill surfaces, and the barrier in
such a surface is called a Type-I barrier.
Source:
PAC, 1996, 68, 149
(A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC
Recommendations 1996))
on page 153