Illustrated Glossary of Organic Chemistry - Delta E

Illustrated Glossary of Organic Chemistry

ΔE: An energy difference. In Chem 14C and Chem 14D refers to the energy difference between quantum mechanical energy states (rotational, vibrational, electronic, nuclear spin, etc.).

The HOMO-LUMO ΔE (the HOMO-LUMO gap) is an important property for conjugated molecules.

In ¹H-NMR spectroscopy, the ground state-excited state ΔE controls the energy of radio wave photon required for nuclear spin flip, and hence the proton's chemical shift.