Account for the following observations: (a) The 1H NMR spectrum of cyclohexane shows a single peak at room temperature, but when the temperate is lowered significantly the peak starts to broaden and then separates into two. (b) At room temperature, the 19F NMR spectrum of PF5 shows two lines, and even at the lowest experimentally accessible temperatures the spectrum is substantially unchanged. (c) In the 1H NMR spectrum of a casually prepared sample of ethanol a triplet and a quartet are seen. These multiplets show additional splittings if the sample is prepared with the careful exclusion of water.

Account for the following observations: (a) The 1H NMR spectrum of cyclohexane shows a single peak at room temperature, but when the temperate is lowered significantly the peak starts to broaden and then separates into two. (b) At room temperature, the 19F NMR spectrum of PF5 shows two lines, and even at the lowest experimentally accessible temperatures the spectrum is substantially unchanged. (c) In the 1H NMR spectrum of a casually prepared sample of ethanol a triplet and a quartet are seen. These multiplets show additional splittings if the sample is prepared with the careful exclusion of water.

Principles of Instrumental Analysis

7th Edition

ISBN:9781305577213

Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Chapter19: Nuclear Magnetic Resonance Spectroscopy

Section: Chapter Questions

Problem 19.20QAP

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