1H NMR Predicting signal position
1H NMR have signals in the range 0 - 12 δ where the signal due to the hydrogens in (CH3)4Si (TMS - tetramethylsilane) is at 0 δ.
The exact position of a signal due to a particular hydrogen(s) depends on the electronic environment of the hydrogen(s). Elements (groups) that withdraw electron density from around the hydrogen cause the nucleus to absorb at lower field strengths (higher δ).
The position of the absorption depends on the type of carbon that the hydrogen is bonded to.
The exact position of the absorption of hydrogen(s) bonded to an sp3 carbon depends on the other atom(s) bonded to the sp3 carbon .
The exact position of a signal due to a particular hydrogen(s) depends on the electronic environment of the hydrogen(s). Elements (groups) that withdraw electron density from around the hydrogen cause the nucleus to absorb at lower field strengths (higher δ).
The position of the absorption depends on the type of carbon that the hydrogen is bonded to.
Hydrogens bonded to sp3 carbons absorb between 0-5 δ.
Hydrogens bonded to sp2 carbons absorb between 5-12 δ.
Hydrogens bonded to sp2 carbons absorb between 5-12 δ.
The exact position of the absorption of hydrogen(s) bonded to an sp3 carbon depends on the other atom(s) bonded to the sp3 carbon .
As shown below, if the other atom is sp2 carbon or is more electronegative than carbon (O, N or halogen) the hydrogen absorbs at higher δ.