6.5.1 Nuclear Magnetic Resonance (NMR) spectroscopy

• $^{1}H$ NMR focuses on hydrogen
• What happens to atomic nuclei in a magnetic field in NMR spectroscopy?

  They absorb and emit energy
• Resonance frequency depends on the chemical environment of the nucleus


  True
• What does $^{1}H$ NMR measure in a molecule?


  Hydrogen environments
• $^{1}H$ NMR reveals the types and number of hydrogen atoms in a molecule.


  True
• The position of resonance on the NMR spectrum is called the chemical shift.
• ^{1}H NMR focuses on hydrogen environments within a molecule.

  True
• When placed in a strong magnetic field, certain nuclei can absorb and emit energy at specific resonance frequencies.
• Match the type of NMR with its focus:

  ^{1}H NMR ↔️ Hydrogen environments

  ^{13}C NMR ↔️ Carbon environments
• Steps in the principles of NMR spectroscopy:

  1️⃣ Place nuclei in magnetic field

  2️⃣ Nuclei absorb energy at resonance frequency

  3️⃣ Chemical environment affects resonance

  4️⃣ Chemical shift is measured on spectrum
• What does ^{13}C NMR primarily focus on measuring?

  Carbon atom arrangements
• What key information does ^{13}C NMR provide about a molecule?

  Carbon atom arrangements
• $^{1}H$ NMR and $^{13}C$ NMR both utilize the magnetic properties of their nuclei to provide insights into molecular structure.


  True
• What does $^{13}C$ NMR reveal information about?


  Carbon atom arrangements
• Interpreting NMR spectra involves examining chemical shift and signal splitting
• The chemical shift reflects the chemical environment of the nuclei in a molecule.


  True
• What rule predicts the number of peaks formed from splitting?

  n+1 rule
• Order the splitting patterns based on the number of adjacent hydrogen atoms:

  1️⃣ Singlet (0 adjacent H atoms)

  2️⃣ Doublet (1 adjacent H atom)

  3️⃣ Triplet (2 adjacent H atoms)

  4️⃣ Quartet (3 adjacent H atoms)
• $^{13}C$ NMR spectra show the number and types of carbon atoms in a molecule.


  True
• What does the chemical shift indicate in an NMR spectrum?

  Chemical environment
• Match the splitting pattern with the number of peaks it produces:

  Singlet ↔️ 1 peak

  Doublet ↔️ 2 peaks

  Triplet ↔️ 3 peaks

  Quartet ↔️ 4 peaks
• What does signal splitting in $^{1}H$ NMR reveal about a molecule?


  Connectivity
• Which type of analysis in organic chemistry uses NMR to distinguish between stereoisomers?

  Stereochemical analysis
• What is NMR used to determine?

  Molecular structure
• $^{13}C$ NMR measures carbon environments


  True
• The position of a signal on the NMR spectrum is called the chemical shift.
• Match the NMR type with what it measures:

  $^{1}H$ NMR ↔️ Hydrogen environments

  $^{13}C$ NMR ↔️ Carbon environments
• $^{13}C$ NMR measures carbon environments.
• What is the definition of resonance frequency in NMR spectroscopy?

  Frequency at which nuclei absorb energy
• Match the NMR type with its key information:

  ^{1}H</latex> NMR ↔️ Types of hydrogen atoms

  $^{13}C$ NMR ↔️ Carbon atom arrangements
• What information does ^{13}C NMR provide about a molecule?

  Carbon atom arrangements
• The chemical shift in NMR depends on the chemical environment of the nucleus.

  True
• What is the role of the chemical environment in NMR spectroscopy?

  Affects resonance frequency
• ^{13}C NMR reveals the types and number of hydrogen atoms in a molecule.

  False
• ^{1}H NMR measures hydrogen environments using the ¹H nucleus, while ^{13}C NMR measures carbon environments using the ¹³C nucleus.
• What are the two primary types of NMR spectroscopy?

  $^{1}H$ NMR and $^{13}C$ NMR
• What does $^{1}H$ NMR focus on within a molecule?


  Hydrogen environments
• Match the type of NMR with what it measures:

  $^{1}H$ NMR ↔️ Hydrogen environments

  $^{13}C$ NMR ↔️ Carbon environments
• What unit is chemical shift measured in?

  ppm
• What causes signal splitting in $^{1}H$ NMR?


  Spin-spin coupling