6.9.4
Hydrogen-1 NMR 2 (A2 Only)
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- Deuterated solvents are the same as many protonated solvents but each 1H has been replaced by a deuterium (2D) atom.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
1.1Atomic Structure
1.1.1Fundamental Particles
1.1.2Isotopes & Mass Number
1.1.3Mass Spectrometry
1.1.4Electron Shells, Sub-Shells & Orbitals
1.1.5Electron Configuration
1.1.6Ionisation Energy
1.1.7Factors Affecting Ionisation Energies
1.1.8Trends of Ionisation
1.1.9Specific Impacts on Ionisation Energies
1.1.10End of Topic Test - Atomic Structure
1.1.11A-A* (AO3/4) - Atomic Structure
1.2Amount of Substance
1.3Bonding
1.3.1Ionic Bonding
1.3.2Covalent & Dative Bonding
1.3.3Carbon Structures
1.3.4Metallic Bonding
1.3.5Physical Properties
1.3.6Shapes of Molecules
1.3.7Polarity
1.3.8Intermolecular Forces
1.3.9Intermolecular Forces 2
1.3.10End of Topic Test - Bonding
1.3.11Exam-Style Question - Shape of Molecules
1.3.12A-A* (AO3/4) - Bonding
1.4Energetics
1.5Kinetics
1.6Equilibria
2Physical Chemistry 2 (A2 Only)
2.1Thermodynamics (A2 Only)
2.2Rate Equations (A2 Only)
2.3The Equilibrium Constant Kp (A2 Only)
2.4Electrochemical Cells (A2 Only)
2.5Acids & Bases (A2 Only)
2.5.1Brønsted-Lowry Acids & Bases (A2 Only)
2.5.2pH (A2 Only)
2.5.3The Ionic Product of Water (A2 Only)
2.5.4Weak Acids & Bases (A2 Only)
2.5.5pH Curves & Titrations (A2 Only)
2.5.6pH Curves & Titrations 2 (A2 Only)
2.5.7Buffer Solutions (A2 Only)
2.5.8End of Topic Test - Acids & Bases
2.5.9Exam-Style Question - Weak Acids
2.5.10A-A* (AO3/4) - Acids & Bases
3Inorganic Chemistry
3.1Periodicity & Trends
4Inorganic Chemistry 2 (A2 Only)
4.1Period 3 (A2 Only)
4.2Transition Metals (A2 Only)
4.2.1General Properties (A2 Only)
4.2.2Substitution Reactions (A2 Only)
4.2.3Shapes of Complex Ions (A2 Only)
4.2.4Colours of Ions (A2 Only)
4.2.5Variable Oxidation States (A2 Only)
4.2.6Titrations (A2 Only)
4.2.7Homogeneous Catalysts (A2 Only)
4.2.8Heterogeneous Catalysts (A2 Only)
4.2.9End of Topic Test - Transition Metals
4.2.10A-A* (AO3/4) - Transition Metals
4.3Reactions of Ions in Aqueous Solutions (A2 Only)
5Organic Chemistry 1
5.1Introduction
5.2Alkanes
5.3Halogenoalkanes
5.4Alkenes
5.5Alcohols
5.6Organic Analysis
5.7A-A* (AO3/4) - Organic 1
6Organic Chemistry 2 (A2 Only)
6.1Optical Isomerism (A2 Only)
6.2Aldehydes & Ketones (A2 Only)
6.3Carboxylic Acids & Esters (A2 Only)
6.4Aromatic Chemistry (A2 Only)
6.5Amines (A2 Only)
6.6Polymers (A2 Only)
6.7Biological Organic (A2 Only)
6.8Organic Synthesis (A2 Only)
6.9NMR Spectroscopy (A2 Only)
6.10Chromatography (A2 Only)
6.11A-A* (AO3/4) - Organic 2
Jump to other topics
1Physical Chemistry
1.1Atomic Structure
1.1.1Fundamental Particles
1.1.2Isotopes & Mass Number
1.1.3Mass Spectrometry
1.1.4Electron Shells, Sub-Shells & Orbitals
1.1.5Electron Configuration
1.1.6Ionisation Energy
1.1.7Factors Affecting Ionisation Energies
1.1.8Trends of Ionisation
1.1.9Specific Impacts on Ionisation Energies
1.1.10End of Topic Test - Atomic Structure
1.1.11A-A* (AO3/4) - Atomic Structure
1.2Amount of Substance
1.3Bonding
1.3.1Ionic Bonding
1.3.2Covalent & Dative Bonding
1.3.3Carbon Structures
1.3.4Metallic Bonding
1.3.5Physical Properties
1.3.6Shapes of Molecules
1.3.7Polarity
1.3.8Intermolecular Forces
1.3.9Intermolecular Forces 2
1.3.10End of Topic Test - Bonding
1.3.11Exam-Style Question - Shape of Molecules
1.3.12A-A* (AO3/4) - Bonding
1.4Energetics
1.5Kinetics
1.6Equilibria
2Physical Chemistry 2 (A2 Only)
2.1Thermodynamics (A2 Only)
2.2Rate Equations (A2 Only)
2.3The Equilibrium Constant Kp (A2 Only)
2.4Electrochemical Cells (A2 Only)
2.5Acids & Bases (A2 Only)
2.5.1Brønsted-Lowry Acids & Bases (A2 Only)
2.5.2pH (A2 Only)
2.5.3The Ionic Product of Water (A2 Only)
2.5.4Weak Acids & Bases (A2 Only)
2.5.5pH Curves & Titrations (A2 Only)
2.5.6pH Curves & Titrations 2 (A2 Only)
2.5.7Buffer Solutions (A2 Only)
2.5.8End of Topic Test - Acids & Bases
2.5.9Exam-Style Question - Weak Acids
2.5.10A-A* (AO3/4) - Acids & Bases
3Inorganic Chemistry
3.1Periodicity & Trends
4Inorganic Chemistry 2 (A2 Only)
4.1Period 3 (A2 Only)
4.2Transition Metals (A2 Only)
4.2.1General Properties (A2 Only)
4.2.2Substitution Reactions (A2 Only)
4.2.3Shapes of Complex Ions (A2 Only)
4.2.4Colours of Ions (A2 Only)
4.2.5Variable Oxidation States (A2 Only)
4.2.6Titrations (A2 Only)
4.2.7Homogeneous Catalysts (A2 Only)
4.2.8Heterogeneous Catalysts (A2 Only)
4.2.9End of Topic Test - Transition Metals
4.2.10A-A* (AO3/4) - Transition Metals
4.3Reactions of Ions in Aqueous Solutions (A2 Only)
5Organic Chemistry 1
5.1Introduction
5.2Alkanes
5.3Halogenoalkanes
5.4Alkenes
5.5Alcohols
5.6Organic Analysis
5.7A-A* (AO3/4) - Organic 1
6Organic Chemistry 2 (A2 Only)
6.1Optical Isomerism (A2 Only)
6.2Aldehydes & Ketones (A2 Only)
6.3Carboxylic Acids & Esters (A2 Only)
6.4Aromatic Chemistry (A2 Only)
6.5Amines (A2 Only)
6.6Polymers (A2 Only)
6.7Biological Organic (A2 Only)
6.8Organic Synthesis (A2 Only)
6.9NMR Spectroscopy (A2 Only)
6.10Chromatography (A2 Only)
6.11A-A* (AO3/4) - Organic 2
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