What could be the compound in this spectra with peaks at 154 and 154+2?

AI Thread Summary
The discussion centers on analyzing a spectrum with peaks at 154 and 154+2, suggesting the presence of a compound likely containing an ester and an alkyl chloride. Key observations include a strong IR band at ~1700 indicating a carbonyl, a ~1200 band suggesting a saturated ester, and a ~2900 peak also indicative of an ester. The mass spectrum shows a molecular ion peak at 154, with a +2 isotope peak confirming the presence of chlorine due to its isotopic abundance. It is noted that the peak at 118, resulting from HCl loss, does not show a significant +2 peak because the chlorine isotope is no longer present after the loss. The analysis emphasizes the importance of understanding the relationships between the peaks in both IR and mass spectra for accurate compound identification.
Respect-rometry
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Hi guys

As part of my degree I've got to analyses a set of spectras unknown compounds. I've managed to do them all so far, but seem to be struggling on this one particular set.

Here's the spectra that I have to analyse: http://imgur.com/a/oVNYe

So far I think it might be an ester with a Alkyl chloride in it.

Any help is greatly appreciated!
 
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Please elaborate on what you see and how you get to the conclusions.
 
Borek said:
Please elaborate on what you see and how you get to the conclusions.
Sure.

Strong IR band at ~1700 indicates presence of carbonyl oxygen. In a Spectroscopy book I've got from the library, the band at ~1200 is supposedly indicative of a saturated ester. The band at ~2900 also suggests an ester

In the mass spec. The molecular ion peak is 154, with an M+2 showing a +2 isotope is present. The 3:1 peak ratio shows its Chlorine due to the 75:25 relative abundances of 35Cl& 37Cl. The peak at 118 is indicative of loss of HCl

There is a peak at 43 which I thought what a C-H group with two methyl groups and a C=O group attached. This is because there is a multiplet peak in the 1H NMR with 7 peaks and an integration of 1. So that would come from the H atom coupling to the two equivalent methyl groups.

The 13C NMR shows which environments are CH3, CH2, CH and quaternary C environments.

This is what I've got so far, so any help would be great
 
Respect-rometry said:
The peak at 118 is indicative of loss of HCl

MS is not something I feel confident about, but if you have peaks at 154 and 154+2, and HCl is lost, shouldn't you have a similar pair at 118 and 118+2?
 
Borek said:
MS is not something I feel confident about, but if you have peaks at 154 and 154+2, and HCl is lost, shouldn't you have a similar pair at 118 and 118+2?
No there shouldn't be a significant 118+2 peak, because Cl is being lost and so the 37Cl isotope won't be present anymore. Hence there is no 3:1 peak ratio in the mass spectra at 118 & 120
 
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