It is to be explained why IR spectroscopy does not distinguish very well between isomers I and J. It is to be explained how UV-vis spectroscopy could be used to distinguish between them. Concept introduction: In UV-vis spectroscopy, absorption of a photon promotes an electron from a lower-energy MO to a higher-energy MO. The λ max for the longest-wavelength absorption in the spectrum corresponds to the HOMO-LUMO. Conjugation decreases the energy difference between the HOMO-LUMO and thus increases the wavelength of the photon absorbed. IR spectroscopy enables to identify different functional groups in the given molecule. One of the greatest advantages of IR spectroscopy is that the frequency of a particular type of vibration is typically found within a characteristic range of frequencies, regardless of the functional group with which the vibration is associated. The fact that absorptions by certain vibrations appear with characteristic frequency ranges enables us to use IR spectroscopy to obtain structural information about a molecule.

Question

Want to see the full answer?

Answer 1

Question

Chapter 15, Problem 15.57P

Interpretation Introduction

Interpretation:

It is to be explained why IR spectroscopy does not distinguish very well between isomers I and J. It is to be explained how UV-vis spectroscopy could be used to distinguish between them.

Concept introduction:

In UV-vis spectroscopy, absorption of a photon promotes an electron from a lower-energy MO to a higher-energy MO. The λmax for the longest-wavelength absorption in the spectrum corresponds to the HOMO-LUMO. Conjugation decreases the energy difference between the HOMO-LUMO and thus increases the wavelength of the photon absorbed.

IR spectroscopy enables to identify different functional groups in the given molecule.

One of the greatest advantages of IR spectroscopy is that the frequency of a particular type of vibration is typically found within a characteristic range of frequencies, regardless of the functional group with which the vibration is associated. The fact that absorptions by certain vibrations appear with characteristic frequency ranges enables us to use IR spectroscopy to obtain structural information about a molecule.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Students have asked these similar questions

Protecting Groups and Carbonyls 6) The synthesis generates allethrolone that exhibits high insect toxicity but low mammalian toxicity. They are used in pet shampoo, human lice shampoo, and industrial sprays for insects and mosquitos. Propose detailed mechanistic steps to generate the allethrolone label the different types of reagents (Grignard, acid/base protonation, acid/base deprotonation, reduction, oxidation, witting, aldol condensation, Robinson annulation, etc.) III + VI HS HS H+ CH,CH,Li III I II IV CI + P(Ph)3 V ༼ Hint: no strong base added VI S VII IX HO VIII -MgBr HgCl2,HgO HO. isomerization aqeuous solution H,SO, ༽༽༤༽༽ X MeOH Hint: enhances selectivity for reaction at the S X ☑

Draw the complete mechanism for the acid-catalyzed hydration of this alkene. esc 田 Explanation Check 1 888 Q A slock Add/Remove step Q F4 F5 F6 A བྲA F7 $ % 5 @ 4 2 3 & 6 87 Click and drag to start drawing a structure. © 2025 McGraw Hill LLC. All Rights Reserved. Terms of Use | Privacy Ce W E R T Y U S D LL G H IK DD 요 F8 F9 F10 F1 * ( 8 9 0 O P J K L Z X C V B N M H He command

Explanation Check F1 H₂O H₂ Pd 1) MCPBA 2) H3O+ 1) Hg(OAc)2, H₂O 2) NaBH4 OH CI OH OH OH hydration halohydrin formation addition halogenation hydrogenation inhalation hydrogenation hydration ☐ halohydrin formation addition halogenation formation chelation hydrogenation halohydrin formation substitution hydration halogenation addition Ohalohydrin formation subtraction halogenation addition hydrogenation hydration F2 80 F3 σ F4 F5 F6 1 ! 2 # 3 $ 4 % 05 Q W & Å © 2025 McGraw Hill LLC. All Rights Reserved. F7 F8 ( 6 7 8 9 LU E R T Y U A F9