Worksheet: NMR Splitting Patterns
In this worksheet, we will practice determining molecular structure from NMR splitting patterns and assigning multiplicities based on peak intensities.
Q1:
Which of the following correctly describes the relative intensities of splitting of an NMR peak?
- AQuartet—
- BTriplet—
- CPentet—
- DSextet—
Q2:
The splitting of energy levels in the presence of a magnetic field is caused by which of the following?
- ASymmetry degeneracy
- BPauli exclusion principle
- CFermi contact interaction
- DThe Zeeman effect
- EBose-Einstein effect
Q3:
A NMR spectrum at room temperature reveals one well-defined peak. When cooled slightly, the peak becomes broadened. At temperatures, two well defined peaks are apparent. What is responsible for these observations?
- AInteger quantum spin numbers
- BSpin-spin coupling interactions
- CFractional quantum spin numbers
- DDynamic fluxionality
- ELow natural abundances of the nucleus
Q4:
What is the most likely cause of fluxional behavior in the NMR spectrum of , iron pentacarbonyl?
- ARotation of a hindered carbonyl bond
- BDissociation and recoordination of the carbonyl ligands
- COpening and closing of bridging carbonyls
- DIsomerism between trigonal bipyramidal and square pyramidal configurations
- EMonomer-dimer formation with a bridging carbonyl