[janovic]

Please, would somebody be so kind to help me with compound identification based on MASS, NMR, IR and UV spectra? I need it till Thursday evening and just can't move forward with this myself. I'm still not experienced enough.

PDF is attached below. It's from the book Spectroscopy Chemistry NMR FTIR MS - Silverstein, assigned problems, compound 9.43. Maybe somebody has already solved this before.

I would be incredibly grateful for any help. I would even pay something if it's necessary, because I'm aware these identifications can be quite time consuming.

Thank you in advance for any advice or possible help.

Best regards
Jan Janovic

[Borek]

You have to show your attempts at solving the problem, this is a forum policy.

[janovic]

Please delete the thread. Already found help elsewhere.

[sjb]

Please delete the thread

Why not instead post your answer and the way you got there (in a few days, once you've confirmed it's the right way forward etc) so that others can learn from your experience?

[MOTOBALL]

There is a systematic way to analyze MS data; try this procedure to organize the data and your thoughts.

Capital letters are only for EMPHASIS.

Step 1

Perform a visual inspection of the mass spectrum.
The PRESUMED molecular ion, m/z 152, shows the presence or absence (WHICH ??) of Br, Cl and S atoms (WHY )
The given molecular weight (MW 152 Da) is EVEN, and therefore the molecule contains an ODD or EVEN (WHICH ??) number of N atoms (odd = 1,3,5,7 OR even = 0, 2, 4, 6...etc) Google "the NITROGEN RULE in mass spectrometry". VERY, VERY important !
Check for absence/presence of "characteristic" m/z values; a "characteristic" ion is one that suggests the presence of a certain structural feature.
For instance, a (usually strong) m/z 77 is a characteristic ion (C6H5)+. ; indicates a phenyl ring.  Is this in your spectrum ?  Is it intense ?
 
Step 2

Set up a table with 4 columns.
Column 1: list m/z values from highest (m/z 152) to lowest. GENERALLY, as a first pass, ignore low intensity (< 5%) m/z values.
Column 2: mass difference to next highest m/z value OR next-but-one group of ions.
Column 3: possible elemental compositions for the mass difference (e.g. 28 could be C2H4 or CO or N2).
Column 4: possible structural feature that corresponds to the elemental composition.

Step 3

On a piece of paper, draw the possible structural elements that you have derived from your analysis.  Try to connect them such that all of the major m/z values can be formed from the structure; be aware that sometimes, two (or more) different structures (isomers) can be constructed that will generate very similar mass spectra.

Step 4

Check that the elemental composition (C, H, N, O, etc) of the assembled molecule gives MW 152.
Further, use an accurate mass calculator (available on-line) to see which of the possible C, H, N, O, etc. combinations is closest to MW 152.0125.

YOU CAN DO THIS !!!!