Question

A compound with molecular formula C5H10Br2 displays the following 13C NMR along with the DEPT-90 and DEPT-135 13CNMR spectra. What is the structure for this compound?

Answer 1

Answer:

Explanation:

The correct structure for the compound C5H10Br2 is:

Br -- CH₂ -- CH₂ -- CH₂ -- CH₂ -- CH₂ -- Br

         1          2         3         4         5

The name of the required compound is 1,5-dibromopentane.

The DEPT spectroscopy is applied to differentiate between CH₃, CH₂, and CH groups.

Assuming the DEPT is up, this shows a positive peak which illustrates CH₃ group

Assuming the DEPT is down, this shows a negative peak which illustrates CH₂ or CH group

C-13 NMR with DEPT-135

1. The negative peak in DEPT at 26.77 ppm illustrates CH₂ or CH
2. The negative peak at 31.85 ppm illustrate CH₂ or CH
3. The negative peak at  33.24 ppm illustrate CH₂ or CH

The carbon analysis is:

Assign            ppm

1                     33.24

2                     31.85

3                     26.77

4                     31.85

5                    33.24