Français
5. UV band intensity
For some bands, we can find hypochromatic (decrease in ε ) or hyperchromatic (increase in ε ) effects.
5.1 Steric hindrance of conjugation. Rotation around a single bond
In a conjugated system, the introduction of a substituent that causes steric hindrance leads to deconjugation of the two unsaturations, resulting in a change in the UV absorption spectrum of the chromophore.
If steric hindrance is low, the system can still remain coplanar. A hypochromatic effect is observed (a simple decrease in the intensity of the conjugation band, which is broadened).
in the case of dimethylanilines, we have the following values :
The Ultimate Scientific and Technical Reference
This article is included in
Characterization and properties of matter
This offer includes:
Knowledge Base
Updated and enriched with articles validated by our scientific committees
Services
A set of exclusive tools to complement the resources
Practical Path
Operational and didactic, to guarantee the acquisition of transversal skills
Doc & Quiz
Interactive articles with quizzes, for constructive reading
UV band intensity
References
The Ultimate Scientific and Technical Reference
