DEPT (Distortionless Enhancement by Polarization Transfer) NMR is a ¹3C-NMR technique thatprovides information about the number of hydrogens attached to a carbon in a ¹3C-NMR spectrum.Through a series of rf pulses, primary (-CH3, 1°), secondary (-CH₂, 2°) and tertiary (-CH=, 3°) carbonscan be assigned in the ¹³C-NMR spectrum. Quaternary (4°) carbons do not appear in a DEPT spectrum.In a DEPT spectrum, you will see four spectra (from top to bottom): DEPT-135, DEPT-90, DEPT-45,and the original ¹C spectrum. NOTE: Our NMR does NOT print the original "C spectrum at thebottom. In a DEPT-135 scan, primary and tertiary carbons have positive peaks, and secondarycarbons have negative peaks.thekDEPT-135DEPT-90DEPT-4513C spectrumTertiary (CH) and primary (CH3)groups are positive, secondary(CH₂) groups are negative.Only tertiary (CH)groups show up.All protonatedcarbons show up.220 200 180 160d140 120 100 80 60PPMe40 20Note that in 2,5,5-trimethylhexan-3-one, there is one tertiary carbon (b), one secondary carbon (d), twodifferent types of primary carbons (a, f). Carbon b is negative in the DEPT-135 spectrum. Carbon b isthe only tertiary carbon, so it is the only peak in the DEPT-90 spectrum. Carbon c and carbon e haveno hydrogens attached, so those peaks are missing in all DEPT spectra. Match the DEPT component spectrum with the information gleaned.DEPT-135 (top spectrum)DEPT-90 (middle spectrum)DEPT-45 (bottom spectrum)[Choose ][Choose ]2° groups only1° groups, 2° groups, and 3° groups2° groups and 3° groups are positive, 1° groups are negative1° and 3° groups are positive, 2° groups are negative.3° groups only[Choose]

We know that DEPT provides the information about the number of hydrogen atoms attached to the carbon…

Match the DEPT component spectrum with the information gleaned. DEPT-135 (top spectrum) DEPT-90 (middle spectrum) DEPT-45 (bottom spectrum) [Choose ] [Choose ] 2° groups only 1° groups, 2° groups, and 3° groups 2° groups and 3° groups are positive, 1° groups are negative 1° and 3° groups are positive, 2° groups are negative. 3° groups only [Choose ]

Match the DEPT component spectrum with the information gleaned. DEPT-135 (top spectrum) DEPT-90 (middle spectrum) DEPT-45 (bottom spectrum) [Choose ] [Choose ] 2° groups only 1° groups, 2° groups, and 3° groups 2° groups and 3° groups are positive, 1° groups are negative 1° and 3° groups are positive, 2° groups are negative. 3° groups only [Choose ]

Organic Chemistry: A Guided Inquiry

2nd Edition

ISBN:9780618974122

Author:Andrei Straumanis

Publisher:Andrei Straumanis

ChapterL4: Proton (1h) Nmr Spectroscopy

Section: Chapter Questions

Problem 15E

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Similar questions

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