HOMO: higher, Lower, same energy LUMO: higher, Lower, same energy Keto-enol curc

Question

HOMO: higher, Lower, same energy

LUMO: higher, Lower, same energy

Keto-enol curcurmin or diketo curcurmin or both are responsible for the yellow color

Curcurmin is a highly conjugated molecule responsible for turmeric's yellow color and stubborn curry stains. The two tautomers of curcurmin are shown below. O OH tautomerization HO OH HO OH H3 keto-enol curcurmin CH3 H3 diketo curcurmin CHs How would you expect the energies of the HOMO and LUMO to change between these two tautomers? Which tautomer do you suspect is responsible for the yellow color of curcurmin? The HOMO is [Select] in the keto-enol tautomer and the LUMO is [Select Select] is(are) responsible for the yellow color of turmeric

Explanation / Answer

The keto-enol form has the lower HOMO-LUMO energy gap due to conjugation which again get facilitated more by the keto-enol hydrogen bonding but in the diketo form the conjugation will dis appear. Hence HOMO-LUMO energy gap will be higher.

So keto-enol form is responsible for yellow colour.

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.