Question

splitting patterns lastly let’s discuss

Splitting Patterns Lastly, let's discuss why some signals are comprised of only a single peak, called a singlet, while other signals exhibit splitting, and may appear as a doublet, triplet, quartet, quintet, sextet, septet, octet, nonet, etc. Splitting is due to neighboring H's. That is, H's that are separated by 3 covalent bonds are called "neighbors". Each neighbor splits a signal, and the pattern observed matches the N+1 rule: the number of peaks observed is one more than the number of neighbors. Thus, neighboring protons are what give rise to splitting patterns. Triplet Doublet Singlet Quarte Sextet Quintet Septet Note: if splitting is detected, but the pattern is not one of these recognizable patterns, we call the signal a multiplet. Multiplets can result from complex splitting and/or overlapping signals. Activity Hbi Why are there three H's and only two signals? bocause thare Cre of Hs only 2 groups Label the H's (H, or Hb) according to the assigned peaks. Br Br -H What is the area under the curve for each signal? Does the integration ratio match what you expect it to be? Br H Ha For Ha, how many neighboring H's are on the adjacent carbon atom? Does the splitting pattern of Ha follow the N+1 Rule? For Hb, how many neighboring H's are on the adjacent carbon atom? Does the splitting pattern of Ha follow the N+1 Rule? 4.0 6.0 4.5 5.5 5.0 fn (ppm) Page 106

Answer 1

HNMR spectra contains two peaks with splitting patterns. This indecates that the compound contains two tog types of magnetically different Protons. Ho Ha MA Now as to protons, splitted into doablets, so it contains one neighboring hydrogenaton. - 6.0 ppm 4.2 ppm Similarly Ha, protons splitted (Not to the scale.) into triplets, so, it contains two neighboring protons. Now, the chemical shift of Ha is higher than Hb. So, Ha protons are highly deshilded than ito. Now, the compound structure is Br Br AM Ha Activith. 0 Although there are three it's, but Ho are magnetically equivalent, so, these two it's will be in the same chemical shift. . There will be two Protons, signals. Bro Ab

The area under the curve area . . . for Ha = 1.00 unit the . Ho = 1.99 urib ratio = His/Ha = 1.99 = 2:1 Ha Number of Ho is twice than tha. hich is the expected value the course no. of H₂=2 no.it Haal. J. Neighboring it's et stt rule de conse a=2 . It Ha splitted follows the into triplet. 6 Neighboring 4 Nil rule, becouse of Hoat, It follows the Ho is splitted into doublet.