[andy719]

http://www3.picturepush.com/photo/a/12620876/640/12620876.png

I have tried to subtract these frequencies to get the J coupling constants: 6,3,3,3,3,3,3,3,3,3,6. But I can't pair up them into something like doublets or triplets.
Can someone tell me how I should correlate them together please?Thank you so much!

[discodermolide]

Looks to me as if some signals are overlapping each other. I see a doublet, a quartet, an AB system? and ?

[andy719]

Looks to me as if some signals are overlapping each other. I see a doublet, a quartet, an AB system? and ?

But what can I do to link those J constants in to a whole tree diagrams?I really have no idea of it..

[sjb]

Looks to me as if some signals are overlapping each other. I see a doublet, a quartet, an AB system? and ?

But what can I do to link those J constants in to a whole tree diagrams?I really have no idea of it..

Take, for instance, the peaks at 1602, 1596. What could they go with?

[andy719]

Looks to me as if some signals are overlapping each other. I see a doublet, a quartet, an AB system? and ?

But what can I do to link those J constants in to a whole tree diagrams?I really have no idea of it..

Take, for instance, the peaks at 1602, 1596. What could they go with?

J constant is 6 and it is the same as that between 1569 and 1563.I think they are mutual and they may form two doublets.

I try to draw this out and I get a sextet of doublets?Is it correct?
http://www5.picturepush.com/photo/a/12631898/640/12631898.png

[Dan]

J constant is 6 and it is the same as that between 1569 and 1563.I think they are mutual and they may form two doublets.

Doublets have a 1:1 pattern. The peaks you refer to do not, which suggests that they do not form a doublet.

You have 12 peaks, this narrows down your options. Factorise it:

12 = 2 x 2 x 3 (ddt, dtd or tdd)
12 = 3 x 4      (tq or qt)
12 = 2 x 6      (dsext or sextd)

So there are 7 possible ways of generating 12 peaks in the signal.

Look for tell-tale intensity patterns associated with the different individual splitting patterns.

d - 1:1
t - 1:2:1
q - 1:3:3:1
etc...

Can you spot anything that looks like a doublet, triplet, quartet etc. that allows you to narrow down the possible solutions?


     

[andy719]

I use the above method and I find out 4 triplets with J constant (6).I think it would be a quartet of triplets and show all 12 lines.Is it reasonable?

[Dan]

I use the above method and I find out 4 triplets with J constant (6).I think it would be a quartet of triplets and show all 12 lines.Is it reasonable?

I agree with qt, and that the t coupling constant is 6.0 Hz. You should also calculate the q coupling constant.