For my lab I have to identify an organic molecule based on IR, MS, and NMR.
Possible functional groups for this unknown are Aldehyde, Alcohol, Amine,
Carboxylic Acid, Ketone, Phenol, Ester.
List of all the possible chemicals are found:
http://depts.washington.edu/chemcrs/bulkdisk/chem242A_sum09/handout_Unknown-Derivative_List.pdfMS
(91 m/z)-------(105 m/z)--------(184 m/z)
- obviously mass of my compound's mass is 184.
- first fragment 184-105 = 79; which is same as bromine MW
- so I think I definitely have bromine
- I'm not sure about 184-91 fragment.
H NMR
- 3 chemical shifts
1. ~7.4 ppm (Multiplet; Area = 2.4702)
2. ~4.6 ppm (Triplet; Area = 1.0102)
3. ~4.3 ppm (Triplet; Area = 1.0000)
- ppm values from book tells me that ~7.4 is benzene and I'm not quite sure about the other two
IR Spec seems really ambiguous. I cannot seem to identify main functional group from my IR.
3433.8 cm = TA told me to ignore this peak
3028.6 cm = Long
2967.9 cm = Medium
1944.3 cm = Very short
1876.9 cm = Very short
1799.1 cm = Very short
1603.0 cm = Medium
1496.1 cm = Long
1453.8 cm = Long
1431.8 cm = Medium
1314.5 cm = Medium
1262.3 cm = Long
1215.9 cm = Long
1196.4 cm = Medium
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Based on the information above I've concluded that my compound is either p-bromobenzaldehyde or o-bromobenzaldehyde
Reasons
1. MW of bromobenzaldehyde is 185 which is close.
2. First fragment of 105 is same MW as benzaldehyde.
3. ~7.4 ppm is benzene chemical shift
Does it sounds convincing that my compound is either p-bromobenzaldehyde or o-bromobenzaldehyde?