Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

16. Conjugated Systems

HOMO LUMO

Organic Chemistry

16. Conjugated Systems

HOMO LUMO

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Multiple Choice

Consider the MO's of allyl anion. Which of the following are HOMO and LUMO?

HOMO = B, LUMO = C

HOMO = B, LUMO = A

HOMO = C, LUMO = A

HOMO = A, LUMO = C

HOMO = C, LUMO = B

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Verified step by step guidance

Identify the molecular orbitals (MOs) of the allyl anion. The allyl anion has three p orbitals that combine to form three molecular orbitals: one bonding, one non-bonding, and one antibonding.

Examine the images provided. Image A shows a molecular orbital with alternating phases, indicating a non-bonding orbital. Image B shows a bonding orbital with consistent phases across the molecule. Image C shows an antibonding orbital with nodes between each atom.

Understand the concept of HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital). The HOMO is the highest energy orbital that contains electrons, while the LUMO is the lowest energy orbital that does not contain electrons.

Determine the HOMO and LUMO based on the energy levels of the orbitals. The bonding orbital (Image B) is typically lower in energy and occupied, making it a candidate for HOMO. The antibonding orbital (Image C) is higher in energy and unoccupied, making it a candidate for LUMO.

Match the correct HOMO and LUMO to the options provided. Based on the analysis, HOMO = B and LUMO = C is the correct identification of the orbitals.