NMR basics Flashcards
When does NMR happen?
When nuclei are placed in a static magnetic field and exposed to a second oscillating magnetic field
What can NMR be used for?
Characterise compounds
Monitor reactions
Analyse sample mixtures
How can NMR be used to distinguish isomers of butanol?
Look at the different proton environments to determine the connectivity of the isomer
What do you look at for H1 NMR?
The integrals as there are no splitting patterns
What are the three things an NMR spectra tells you?
Chemical shift
Integral
Splitting pattern
What does the chemical shift tell you about?
The chemical environment
What does the integral tell you?
The amount of protons in each environment
What does the splitting pattern of the peaks tell you?
The proximity to other NMR active nuclei
When do nuclei have the property of spin?
When they have an odd mass or an odd atomic number
Out of carbon 12 and carbon 13 which is easily detected and why?
Carbon 13
Odd neutron number so it is easily detected
What do nuclei with spin generate?
A tiny magnetic field
What do NMR active nuclei have?
Different possible spin states
What do different spin states give rise to?
Different energy levels
What do nuclei with spin have?
Spin quantum number (I)
Each isotope has its own value, except carbon and hydrogen
What are the two possible spin states of carbon13?
-1/2
+1/2
