3.4.2 and 3.4.3: Organic Analysis (more) Flashcards
Types of mass spectrometry to find Mr
2
High resolution mass spectrometry
Low resolution mass spectrometry
Low resolution mass spectrometry
to one dp.
High resolution mass spectrometry
to several dp.
High resolution mass spectrometry
advantage over low resolution
useful to identify compounds that appear to have the same Mr when they are rounded to the nearest whole number
How to work out Mr from mass spectrum
Peak with largest M/Z ratio
Molecular ion peak
Whole number molecule with one electron removed
Tallest peak on mass spectrum
most stable ion
IR spectroscopy
A beam of infrared radiation passed through a sample of a chemical
IR radiation absorbed by what
covalent bonds
How do covalent bonds absorb radiation
if they are polar they will absorb IR radiation
bonds will vibrate
Wavenumber
frequency
What does the wavenumber do
The wavenumber of IR absorbed corresponds to a characteristic functional group
Wavenumber equation
and units
1/wavelength
cm-1
Wavenumber depends on
3
mass of atoms
dipole strength
bond strength
Fingerprint region
Below 1500cm-1, the fingerprint region of an unknwon substance can be compared to the spectra in a database to find an EXACT MATCH
