3.9.11
Proton NMR II
Making Spectra Clear
Making Spectra Clear
The choice of solvent before the spectra is recorded makes the process easier. The process of integration after also makes interpretation of the spectra easier.


Solvent choice
Solvent choice
- The solvent choice in 1H NMR is crucial because many solvents contain 1H's.
- If a solvent contains 1H's, they will appear in the spectrum and this will cause confusion.
- This can be solved by using solvents without any 1H's (e.g. CCl4) or deuterated solvents (e.g. CDCl3, D2O).


Deuterated solvents
Deuterated solvents
- Deuterated solvents are the same as many protonated solvents but each 1H has been replaced by a deuterium (2D) atom.
- Deuterium atoms have an even nucleon number and so will not interfere with the NMR.


Integration
Integration
- The area ratios of signals in spectra are hard to evaluate at first glance when signal splitting happens.
- E.g. It is hard to compare the area ratio under a quartet and a singlet.
- To make it easier, many NMR machines integrate the peaks to then give an accurate ratio.
Examples of 1H NMR
Examples of 1H NMR
Below are some examples to demonstrate interpreting 1H NMR spectra.


Example 1: 1,1-dichloroethane
Example 1: 1,1-dichloroethane
- The spectrum is shown above and the interpretation is on the next slide.


Example 1: 1,1-dichloroethane
Example 1: 1,1-dichloroethane
- The spectrum shows two peaks representing the two different proton environments.
- The peak on the left represents the 1H on the -CCl2H because it is deshielded.
- It is a quartet because the adjacent carbon has three protons attached.


Example 2: Bromo-dimethyl ether
Example 2: Bromo-dimethyl ether
- The spectrum is shown above and the interpretation is on the next slide.


Example 2: Bromo-dimethyl ether
Example 2: Bromo-dimethyl ether
- The spectrum shows two peaks representing the two different proton environments.
- Both peaks are singlets because neither of them are adjacent to any carbons with any protons.


Example 3: Ethanol
Example 3: Ethanol
- The spectrum is shown above and the interpretation is on the next slide.


Example 3: Ethanol
Example 3: Ethanol
- The spectrum shows two peaks representing the two different proton environments.
- The peak on the left represents the 1Hs on the -CH2OH because it is deshielded.
- The splittings are a triplet and a quartet as expected.
1Physical Chemistry
1.1Atoms, Molecules & Stoichiometry
1.2Atomic Structure
1.2.1Fundamental Particles
1.2.2Isotopes & Mass Number
1.2.3Electron Shells, Sub-Shells & Orbitals
1.2.4Electron Configuration
1.2.5Ionisation Energy
1.2.6Factors Affecting Ionisation Energies
1.2.7Trends of Ionisation
1.2.8Specific Impacts on Ionisation Energies
1.2.9Electron Affinity
1.2.10End of Topic Test - Atomic Structure
1.2.11A-A* (AO2/3) - Atomic Structure
1.3Chemical Bonding
1.3.1Ionic Bonding
1.3.2Covalent & Dative Bonding
1.3.3Shapes of Molecules
1.3.4Intermolecular Forces
1.3.5Intermolecular Forces 2
1.3.6Electronegativity
1.3.7Bond Length, Bond Energy, & Bond Polarity
1.3.8Metallic Bonding
1.3.9Physical Properties
1.3.10End of Topic Test - Bonding
1.3.11A-A* (AO2/3) - Bonding
1.4States of Matter
1.5Chemical Energetics
1.6Electrochemistry
1.7Equilibria
1.7.1Dynamic Equilibrium & Le Chatelier
1.7.2Kc
1.7.3Kp
1.7.4pH
1.7.5The Ionic Product of Water
1.7.6Weak Acids & Bases
1.7.7Introduction to Solubility Equilibria
1.7.8Solubility Equilibria Calculations
1.7.9Free Energy of Dissolution
1.7.10pH and Solubility
1.7.11Common-Ion Effect
1.7.12End of Topic Test - Kp & Electrochemistry
1.7.13A-A* (AO2/3) - Electrochemical Cells
1.8Partition Coefficient
1.9Reaction Kinetics
1.9.1Collision Theory
1.9.2Orders, Rate Constants & Equations
1.9.3Rate Graphs
1.9.4Rate Determining Step
1.9.5Maxwell-Boltzmann Distribution
1.9.6Catalysts
1.9.7Homogeneous Catalysts
1.9.8Heterogeneous Catalysts
1.9.9End of Topic Test - Kinetics
1.9.10End of Topic Test - Rate Equations
1.9.11A-A* (AO2/3) - Rate Equations
2Inorganic Chemistry
2.1The Periodic Table
2.2Group 2
2.3Group 17
2.4Transition Metals
3Organic Chemistry & Analysis
3.1Introduction to Organic Chemistry
3.2Hydrocarbons
3.2.1Fractional Distillation
3.2.2Cracking
3.2.3Combustion
3.2.4Chlorination
3.2.5End of Topic Test - Alkanes
3.2.6Introduction to Alkenes
3.2.7Reactions of Alkenes
3.2.8Polymerisation Reactions
3.2.9End of Topic Test - Alkenes
3.2.10Arenes
3.2.11Evidence for Structure of Arenes
3.2.12Reactions of Benzene
3.2.13End of Topic Test -Arenes
3.3Halogen Derivatives
3.4Hydroxy Compounds
3.5Carbonyl Compounds
3.6Carboxylic Acids & Derivatives
3.7Nitrogen Compounds
3.8Polymerisation
3.9Analytical Techniques
3.9.1Chromatography
3.9.2High-Performance Liquid Chromatography
3.9.3Gas Chromatography
3.9.4IR Spectroscopy
3.9.5Uses of IR Spectroscopy
3.9.6Mass Spectrometry
3.9.7Mass Spectrometry Analysis
3.9.8Nuclear Magnetic Resonance
3.9.9Carbon-13 NMR
3.9.10Proton NMR I
3.9.11Proton NMR II
3.9.12End of Topic Test - Analytical Techniques
3.9.13A-A* (AO2/3) - Analytical Techniques
Jump to other topics
1Physical Chemistry
1.1Atoms, Molecules & Stoichiometry
1.2Atomic Structure
1.2.1Fundamental Particles
1.2.2Isotopes & Mass Number
1.2.3Electron Shells, Sub-Shells & Orbitals
1.2.4Electron Configuration
1.2.5Ionisation Energy
1.2.6Factors Affecting Ionisation Energies
1.2.7Trends of Ionisation
1.2.8Specific Impacts on Ionisation Energies
1.2.9Electron Affinity
1.2.10End of Topic Test - Atomic Structure
1.2.11A-A* (AO2/3) - Atomic Structure
1.3Chemical Bonding
1.3.1Ionic Bonding
1.3.2Covalent & Dative Bonding
1.3.3Shapes of Molecules
1.3.4Intermolecular Forces
1.3.5Intermolecular Forces 2
1.3.6Electronegativity
1.3.7Bond Length, Bond Energy, & Bond Polarity
1.3.8Metallic Bonding
1.3.9Physical Properties
1.3.10End of Topic Test - Bonding
1.3.11A-A* (AO2/3) - Bonding
1.4States of Matter
1.5Chemical Energetics
1.6Electrochemistry
1.7Equilibria
1.7.1Dynamic Equilibrium & Le Chatelier
1.7.2Kc
1.7.3Kp
1.7.4pH
1.7.5The Ionic Product of Water
1.7.6Weak Acids & Bases
1.7.7Introduction to Solubility Equilibria
1.7.8Solubility Equilibria Calculations
1.7.9Free Energy of Dissolution
1.7.10pH and Solubility
1.7.11Common-Ion Effect
1.7.12End of Topic Test - Kp & Electrochemistry
1.7.13A-A* (AO2/3) - Electrochemical Cells
1.8Partition Coefficient
1.9Reaction Kinetics
1.9.1Collision Theory
1.9.2Orders, Rate Constants & Equations
1.9.3Rate Graphs
1.9.4Rate Determining Step
1.9.5Maxwell-Boltzmann Distribution
1.9.6Catalysts
1.9.7Homogeneous Catalysts
1.9.8Heterogeneous Catalysts
1.9.9End of Topic Test - Kinetics
1.9.10End of Topic Test - Rate Equations
1.9.11A-A* (AO2/3) - Rate Equations
2Inorganic Chemistry
2.1The Periodic Table
2.2Group 2
2.3Group 17
2.4Transition Metals
3Organic Chemistry & Analysis
3.1Introduction to Organic Chemistry
3.2Hydrocarbons
3.2.1Fractional Distillation
3.2.2Cracking
3.2.3Combustion
3.2.4Chlorination
3.2.5End of Topic Test - Alkanes
3.2.6Introduction to Alkenes
3.2.7Reactions of Alkenes
3.2.8Polymerisation Reactions
3.2.9End of Topic Test - Alkenes
3.2.10Arenes
3.2.11Evidence for Structure of Arenes
3.2.12Reactions of Benzene
3.2.13End of Topic Test -Arenes
3.3Halogen Derivatives
3.4Hydroxy Compounds
3.5Carbonyl Compounds
3.6Carboxylic Acids & Derivatives
3.7Nitrogen Compounds
3.8Polymerisation
3.9Analytical Techniques
3.9.1Chromatography
3.9.2High-Performance Liquid Chromatography
3.9.3Gas Chromatography
3.9.4IR Spectroscopy
3.9.5Uses of IR Spectroscopy
3.9.6Mass Spectrometry
3.9.7Mass Spectrometry Analysis
3.9.8Nuclear Magnetic Resonance
3.9.9Carbon-13 NMR
3.9.10Proton NMR I
3.9.11Proton NMR II
3.9.12End of Topic Test - Analytical Techniques
3.9.13A-A* (AO2/3) - Analytical Techniques
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