proton nmr
Compounds E and F are both esters with the molecular formula C4H8O2 In their 1H n.m.r. spectra, E has a quartet at δ = 2.3 ppm and F has a quartet at δ*=*4.1*ppm.
mark scheme says
E CH3CH2COOCH3
F CH3COOCH2CH3
I actually draw two structure but what mark scheme shows for E I draw that for F & vice versa . is that MAKES DIFFERENCE?
please explain to me
mark scheme says
E CH3CH2COOCH3
F CH3COOCH2CH3
I actually draw two structure but what mark scheme shows for E I draw that for F & vice versa . is that MAKES DIFFERENCE?
please explain to me
Yes, it makes a difference. 2.3 gives chemical environment HC-CO, so it is that specific hydrogen which has 3 adjacent H atoms.
4.1 gives environment HC-O, which is the hydrogen on the other side of the ester group.
4.1 gives environment HC-O, which is the hydrogen on the other side of the ester group.
Original post by ambershell27
Yes, it makes a difference. 2.3 gives chemical environment HC-CO, so it is that specific hydrogen which has 3 adjacent H atoms.
4.1 gives environment HC-O, which is the hydrogen on the other side of the ester group.
4.1 gives environment HC-O, which is the hydrogen on the other side of the ester group.
can you please explain me more.I am still confused
Why they show only ONE hydrogen with carbon?
and how we decide that we have to put the remaining part on the left of a carbonyl group(c=o) or right
and similarly
how we know that where to add a remaining part on left or right of COO))
I AM ALWAYS CONFUSED with that ...please explain these things to me
(edited 6 years ago)
The H that is highlighted simply shows the position. Other H atoms may share the same environment.
What's important is the splitting, because this tells you what is NEXT to the H atom. If it is a quartet, there are 3 H atoms next to it (n+1 rule). This suggests the presence of a CH3 group next to the atom.
What's important is the splitting, because this tells you what is NEXT to the H atom. If it is a quartet, there are 3 H atoms next to it (n+1 rule). This suggests the presence of a CH3 group next to the atom.
Original post by ambershell27
The H that is highlighted simply shows the position. Other H atoms may share the same environment.
What's important is the splitting, because this tells you what is NEXT to the H atom. If it is a quartet, there are 3 H atoms next to it (n+1 rule). This suggests the presence of a CH3 group next to the atom.
What's important is the splitting, because this tells you what is NEXT to the H atom. If it is a quartet, there are 3 H atoms next to it (n+1 rule). This suggests the presence of a CH3 group next to the atom.
yeah i know that
in question, they told us that at 2.3 there is the quartet. and the quartet is due to 3 adjacent H atoms ...i know that
2.3 chemical shift suggest R-C=O-CH
so we know that there is CH3 adjacent to R-C=O-CH
if we do that CH3CH2COOCH3 we get quartet at 2.1
if we do that CH3COOCH2CH3 we get quartet at 4.1
yeah GOT IT FINALLY ...
it is very simple at the end...
thanks a lot
No problem 
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