IR and Mass Spectrometer Webquest

1. PUT YOUR HEADPHONES ON FOR SOME CHEMISTRY RELATED MUSIC… IR andMass Spectrometer Webquest Chris Tharakan Miss Turner

2. Before I begin • I am not an expert at this topic whatsoever !!! • I have understood most of this topic , during the creation of this PowerPoint • Special thanks to Miss Turner for putting up with my questions on this subject matter

3. The molecules… 1.Propanone 2.Propanal 3.Propanoic acid 4.Propan-1-ol

4. M/z spectrums analysis

5. 1.Propanone At 43 the peak suggests that a + ion part of the molecule . This is the most significant peak in this spectrum . Thus , we can assume that this molecule is likely to propanone as it is closest to its Mr The Ion peak represent the molecular mass , which is 58 , the same mass of Propanone. At 15 m/z ,the peak represents the part of the molecule.

6. Tip : Circle the part of the molecule which correlates to the m/z peak Above the peak represents the part of the molecule which displays …wait for it … !!!

7. 2.Propanal The peak here is the 58 , which is quite clearly made obvious from the protruding peak at 58m/z Here the peak is not to significant for the presence of a ion At 29 the peak shows the presence of a ion , this can be seen using the highlighting method previously mentioned

8. 3.Propanoic acid The 45 peak always represents the Part of the molecule which is present in the molecule The peak here is the 74 . TIP : “make sure that you look at the most significant peak on the right” quote courtesy of Miss Turner At 57 the peak is firstly not extending enough to be classed as a potential ion . At 29 the peak shows the presence of a ion which is outlined on the molecule above. TIP : ENSURE YOU READ THE SCALES CORRECTLY !!

9. 4. Propan-1-ol The peak here is the 58 , which is similar to Mr of Propan-1-ol … The +( ion part of the molecule). At 43 the most significant peak on the spectra represents the+ ion part of the molecule. *HIGHLIGHTED* TIP : Some of the fragment peaks are more difficult to understand , as they may arise from molecular arrangements

10. IR Spectrum analysis

11. PROPANONE As ketones do not consist of C-O bonds ,thus we deduce that these absorptions are part of the finger print regions . This spectrum highlights the close relationship of aldehydes and ketones , in terms of IR characteristics . The peak at approx. wave number suggests that a C=O bond is present . The absence of broad peaks and /or peaks around regions (N-H, 0-H) , shows that the molecule is an aldehyde

12. PROPANAL The infra –red characteristics here are not significant , thus we can conclude that C-O bond are absent in this molecule. The corresponding peaks Shows the presence of a C-H bond. It is evident that a C=O is present from the major peak at . The significant peaks (C-H and C=O bonds) in this IR suggests that this molecule is an aldehyde.

13. PROPANOIC ACID At its evident that C=O group is present in the molecule . The O-H, C=O, and C-O absorptions suggest that the molecule is a carboxylic avid This absorption at (very broad) represents an O-H group in a carboxylic acid . The characteristics that relate to the wave number , a C-O bond (part of the functional group –OH highlighted on the displayed formula above.

14. PROPAN-1-OL The trough , somewhere between 3230 - 3550 cm-1negates that the molecule contains an O-H functional group. This peak and the peak just before , shows that energy is being absorbed , evident from the stretching , As can be seen there is no absorptions in the 1640-1750 sector. This shows that the molecule is likely to be an alcohol The peaks after wavenumber , displays the presence of a C-O bond . This in conjunction with the absence of a peak at reinforces that molecule is likely to be an alcohol

15. The END… CHRIS THARAKAN