Other Facts About H NMR Spectroscopy

How many signals are present in the H NMR spectrum for each molecule What splitting is observed in each signal (a) (CH3)3CCH20H (b) CH3CH2CH2OH 

How does the rotation around carbon-carbon o bonds and the ring flip of cyclohexane rings affect an NMR spectrum Because these processes are rapid at room temperamre, an NMR spectrum records an average of all conformations that interconvert. 

even though each cyclohexane carbon has two dilferent types of hydrogens—one axial and one equatorial— the two chair forms of cyclohexane rapidly interconvert them, and an NMR spectrum shows a single signal for the average environment that it sees.  

Axial and equatorial H s rapidly interconvert. NMR sees an average environment and shows one signal. 

We will learn more about the spectroscopic absorptions of benzene derivatives in Chapter 17. 

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