Propose a molecular formula for a compound that exhibits the following peaks in
ID: 943283 • Letter: P
Question
Propose a molecular formula for a compound that exhibits the following peaks in its mass spectrum. M+ at m/z = 72, relative height = 38.3% of base peak M + 1 at m/z=73, relative height = 1.8% of base peak M+ at m/z = 96, relative height = 19.0% of base peak M+1 at m/z=97, relative height = 1.5% of base peak M+ at m/z = 108, relative height = 100% of base peak M+1 at m/z=109, relative height = 2.2% of base peak M+2 at m/z = 110, relative height = 97.5% of base peak A compound gives an IR spectrum with a broad signal between 3200 and 3600 cm-1 and two signals between 1600 and 1700 cm-1. In the mass spectrum of this compound, the molecular ion peak appears at m/z = 196, and the relative abundance of the molecular ion and the M+1 peak are 27.2 and 3.9% respectively. What functional groups are present in this compound? How many carbon atoms are present in this compound? Based on the information give, propose a molecular formula for the compound.Explanation / Answer
1.
(a). C5H12
(b)
(c) C6H5-CH2OH
2
(a)
3500–3200 - O–H stretch, H–bonded alcohols, phenols
3400–3250 - N–H stretch 1, 2 amines, amides
1710–1665 - C=O stretch , –unsaturated aldehydes, ketones
1680–1640 - –C=C– stretch alkenes 1650–1580 (m) N–H bend 1 amines
(b) Number of carbon cannot be determined with FTIR and mass spectra. To get the exact number of carbon present in a compound, 13C NMR has to be recorded.
(c) Can't be determined the molecular formula with FTIR and mass spectra. For molecular formula, elemental analysis experiment has be to performed.