Class / Semester.; IG(Chemistry) / 6th semester Paper : Basic Spectroscopic Technique Unit III (Uv visible Spectroscopy)

1. Woodward Fieser Rule
PGDepartmentofChemistry,ClusterUniversitySrinagar
P G Department of Chemistry, SP College
Cluster University Srinagar
Online Lecture By
Dr. Syed Raashid Maqsood
Assistant Professor
Class / Semester.; IG(Chemistry) / 6th semester
Paper : Basic Spectroscopic Technique
Unit III (Uv visible Spectroscopy)

2. Why we are Here
PGDepartmentofChemistry,ClusterUniversitySrinagar
#StayHomeStaySafe
#BreakTheChain

3. PGDepartmentofChemistry,ClusterUniversitySrinagar
Woodward Fiser Rules
Woodward–Fieser rules ,(named after Robert Burns Woodward and Louis Fieseralso) are
sets of empirically derived rules which predict the wavelength of the absorption
maximum (λmax) in an ultraviolet–visible spectrum of a given organic molecule.
Inputs used in the calculation are the type of chromophores present, the auxochromes
(substituents on the chromophores), extended conjugation and solvent.
These rules are mostly applicable to two types of organic molecules:
i) conjugated dienes,and polyenes.
ii) conjugated carbonyl compounds
ƛmax (Cal.) = Base Value for diene + Ʃcontribution for substituents
+ Ʃcontribution from other factors
For a good number of examples
ƛmax (Cal.) ᴝ ƛmax (Exp.)
conjugated dienes, and polyenes.

4. PGDepartmentofChemistry,ClusterUniversitySrinagar
Assigning the Base Value
Type of Diene Unit Base ValueStructure
Acyclic Diene
Homoannular Diene
Hetroannular Diene
214 /215 nm
214 / 215 nm
253 nm
(Cissoid)
(transoid)

5. PGDepartmentofChemistry,ClusterUniversitySrinagar
Contribution from various factors

6. PGDepartmentofChemistry,ClusterUniversitySrinagar
Examples

7. PGDepartmentofChemistry,ClusterUniversitySrinagar
Examples

8. PGDepartmentofChemistry,ClusterUniversitySrinagar
Examples

9. PGDepartmentofChemistry,ClusterUniversitySrinagar
Examples

10. PGDepartmentofChemistry,ClusterUniversitySrinagar
Woodward Fieser Rule for Enones

11. PGDepartmentofChemistry,ClusterUniversitySrinagar
Woodward Fieser Rule for Enones

12. PGDepartmentofChemistry,ClusterUniversitySrinagar
Woodward Fieser Rule for Enones

13. PGDepartmentofChemistry,ClusterUniversitySrinagar
Woodward Fieser Rule for Enones

14. PGDepartmentofChemistry,ClusterUniversitySrinagar
Woodward Fieser Rule for Enones

15. PGDepartmentofChemistry,ClusterUniversitySrinagar
Woodward Fieser Rule for Enones

16. PGDepartmentofChemistry,ClusterUniversitySrinagar
Drop your quarries and responses in the comment section of Google class room
StayHomeStaySafe