B4 Organic Analysis Flashcards
What does the furthest right peak on a mass spectrometer show
Total molecular mass
What to look for on a mass spectrometer
- Peak furtherst right
- Frangmentation peaks with high relative intensisites
What do fragmentation peaks with high relative intensisites show on a mass spectrometer
Common fragments
How to explain mass spectrometry fragmentation
- Molecular ion of X shows total molecular mass
- M/Z of 29 suggests Ch3Ch2+
- Include all peaks with high relative intensities
What must be included on all mass spectrometry annotations
A positive charge
What does infrared do to covalent bonds
Causes them to vibrate more and absorb more energy
What is the issue with methane
Causes and contributes to global warming
What in infrared spectroscopy used in
- Monitor gases causing air pollution
- Breathelysers to measure ethanol in the breath
What must you always ignore in infrared anaysis
The fingerprint reigon to the right
What to always look out for in infrared analysis
- C=O (aldehyde or ketone)
- O-H (alcohol)
- C=O and Broad O-H (carboxylic acid)
When explaining in infrared, what must always be included with each point
- Peak range and where peak is present
- Type of bond
- Functional group
What type of functional group and bond is shown of this infrared
- C=O
- Aldehyde or ketone
What type of functional group and bond is shown of this infrared
- C=O
- C-O (BROAD)
- Carboxylic Acid
What type of functional group and bond is shown of this infrared
- O-H (Not broad)
- Alcohol
On C-13 NMR, what does the number of peaks tell you
The number of carbon environments
On a C-13 NMR, what does the ppm shift indicate
What atom each carbon in each enviroment is bonded to
On a C-13 NMR, what are all ppm shifts relative to
The TMS peak
On a Proton-NMR, what do the number of peaks on the spectrum tell you
The number of proton enviroments
On a Proton-NMR, what does the ppm shift indicate
To what atom, each proton in the environment is bonded to
On a Proton-NMR, what does the length of the peak indicate
How many protons are part of that environment (done as a ratio)
On a Proton-NMR, what does the splitting pattern indicate
How many hydrogens are on the neighbouring carbon atom
On a Proton-NMR, what rule is used to determine splitting patterns
n+1 rule
Splitting Pattern: 1 peak
Singlet
Splitting Pattern: 2 peak
Doublet
Splitting Pattern: 3 peak
Triplet
Splitting Pattern: 4 peak
Quartet
On a Proton-NMR, what does a large splitting pattern indicate
Methyl groups
Why are deuterated solvents used in NMR spectras
They don’t have hydrogen in, so don’t show up on the spectrum
What region of the electromagnetic spectrum is used on in Proton-NMR
Radiowaves
What is D2O added to Proton-NMR spectras sometimes, and why
- O-H and N-H peaks can appear anywhere
- D2O removes these peaks
What solvent is most commonly used in NMR
CDCl3
Proton NMR: What does symmetry in environments at c7-8ppm suggest
Benzene ring
Proton NMR: What does a singlet with 3H in the enviroment suggest
Methyl group (-CH3)
Proton NMR: What does a environment with 2H in by itself suggest
-CH2
Before fully developing an NMR response, what must always be stated first
The number of environments that there are
After the whole number of environments have been given, what information must be given about each environment for a thorough explaination
- Splitting patter - so how many H on adjacent C atoms
- Peak area - so how many H in that enviroment
- PPM of peak - due to which bond present
