Where are you guys up to in Chemistry?

[thushan]

Not yet. Actually I'll just quickly read the NMR notes and actually try this qn properly.

[thushan]

I might have the answer...but there's an issue with it.

I worked out that a R-CH2-CH2-OH is needed. I have a feeling that there are more than 4 proton environments, but that the 7.25 one (which is the aromatic one I think) is really 3 environments 'fused' into one...

I propose that it could be Ph-CH2-CH2-OH.

I just need to do a little reading - I don't get NMR. Properly.

[Jdog]

tush you have you guys done all the bio-molecules stuff in chem? peters is still up to organic, just starte

[Mao]

I might have the answer...but there's an issue with it.

I worked out that a R-CH2-CH2-OH is needed. I have a feeling that there are more than 4 proton environments, but that the 7.25 one (which is the aromatic one I think) is really 3 environments 'fused' into one...

I propose that it could be Ph-CH2-CH2-OH.

I just need to do a little reading - I don't get NMR. Properly.

post spectrum.

[luken93]

I might have the answer...but there's an issue with it.

I worked out that a R-CH2-CH2-OH is needed. I have a feeling that there are more than 4 proton environments, but that the 7.25 one (which is the aromatic one I think) is really 3 environments 'fused' into one...

I propose that it could be Ph-CH2-CH2-OH.

I just need to do a little reading - I don't get NMR. Properly.

post spectrum.

It's alright, we are quite sure we have it now!!!

But anyway, confirmation from you would be nice

BTW, it's CHM1011
"(b) An unknown organic compound has a molecular formula of C8H10O and the
following spectral data;
IR: 3340 cm-1, 13C NMR: δ140, 128, 127, 124, 62, and 39, 1H NMR: δ 2.01 (1H,
broad singlet, exchanges with D2O), 2.87 (2H, triplet), 4.85 (2H, triplet), 7.25 (5H,
multiplet). [chemical shift (integration, splitting)]."

Attached was the preliminary and now final structure that we think it could be...

[Mao]

Yeah, you've nailed it.

[luken93]

Yeah, you've nailed it.

Yay!

The thing we were unsure of, is that the difference between the H environments of the ring is negligible/small enough that it wouldn't produce separate peaks? Or is it that they do, hence the multiplicity?

[Mao]

Yeah, you've nailed it.

Yay!

The thing we were unsure of, is that the difference between the H environments of the ring is negligible/small enough that it wouldn't produce separate peaks? Or is it that they do, hence the multiplicity?

They would produce different peaks, but of course there are complications. In an aromatic ring, spin-spin coupling occurs for neighbouring nuclei at 3 bonds away as well as 4 bonds away. These peaks however are all at very similar chemical shifts. What you end up with is quite a few 'doubly' coupled peaks right on top of each other. The resulting peaks are quite complex, and often our machines are not good enough to clearly see the shape of the peaks to allow us to assign them (due to limited resolution of the instruments). So we just note this complex peak pattern as a 'multiplet' (I prefer to call it 'cluster-fuck', most lecturers don't appreciate it though).

[luken93]

Hahaha fair enough, just wondering how you derived that name?

And yeah, it seemed too complex to have 5 equivalent 1H environments when it wasn't a ring, hence why I kept going back to that structure...

Cheers

[cranberry]

What's everyone up to now in chem? ive done chaps..1-9 excluding 8..(maybe some motivation to cover 1 or 2 more chapters tomorrow )

[nemolala]

AOS 2 is the best part of chem

AOS 1 is just quite wacky and harder

[Andiio]

I might have the answer...but there's an issue with it.

I worked out that a R-CH2-CH2-OH is needed. I have a feeling that there are more than 4 proton environments, but that the 7.25 one (which is the aromatic one I think) is really 3 environments 'fused' into one...

I propose that it could be Ph-CH2-CH2-OH.

I just need to do a little reading - I don't get NMR. Properly.

post spectrum.

It's alright, we are quite sure we have it now!!!

But anyway, confirmation from you would be nice

BTW, it's CHM1011
"(b) An unknown organic compound has a molecular formula of C8H10O and the
following spectral data;
IR: 3340 cm-1, 13C NMR: δ140, 128, 127, 124, 62, and 39, 1H NMR: δ 2.01 (1H,
broad singlet, exchanges with D2O), 2.87 (2H, triplet), 4.85 (2H, triplet), 7.25 (5H,
multiplet). [chemical shift (integration, splitting)]."

Attached was the preliminary and now final structure that we think it could be...

That is Uni Chem, right?

[luken93]

Yerp, don't worry about it haha

[Christiano]

You know how worried I was getting when you guys were talking about NMR .. I didn't understand what was going on 

[The Detective]

half way through IR spectroscopy