《 Modern Research Methods in Polymer

Science》Drs. Wei Tian & Yanhui Chen

Sep-Dec. 2014

Main Content

Introduction of Nuclear Magnetic Resonance (NMR) Analysis

Modern Research Methods in Polymer Science

One Dimensional NMRs

1H NMR

13C NMR

Others: 15N/19F/29Si/31P NMR

Two Dimensional NMRs

Solid-State NMR

1H NMR

Function Advantages

(1) To determine the micro chemical structure(2) To test the purity of compounds(3) To determine the proportion of each component in the mixture

(1) Analyzing the material

molecular configuration space

(2) Measuring without destroying

samples

(3) Precise Information

1

2

3 1. Chemical Shift

2. Spin Splitting

3. Peak Area

O

O

C=O

13C NMR

Function(1) Determination of molecular

structure

(2) Analysis of organic compound structure

Main differences between 13C-NMR and 1H-NMR13C-NMR 1H-NMR

Study of spin changes of carbon nuclear

Chemical shift ranges from 0-240 ppm

The process is very slow Pulse-fourier transform

technique is used

Study of spin changes of proton nuclear

Chemical shift ranges from 0-14 ppm

The process is very fast Continuous wave method is

used

Two Dimensional NMRs

Function

(1) Analyze the complex organic molecules

(2) Detect the three dimensional structure of polymers in the solution

(3) Research the dynamic procedure of the molecules

Advantages

(1) Putting some parameter of NMR (chemical shift (δ)、 coupling constant（ J） and so on) in a two-dimensional plane

(2) Decreasing the overlap of the spectral line

(3) Providing new information about nuclear spin

J resolved spectroscopy

chemical shift correlation spectroscopy

multiple quantum spectroscopy

core

2D-NMR

homonuclear couple:1H-1H COSY

heterocaryosis couple:HMBC、HMQC

NOE：ROESY、NOESY

chemical exchange

Two Dimensional NMRs

Two Dimensional NMRs

2D NOESY 1H NMR spectra of Ibu-CD2 in D2O

Description

Macromolecules 2009, 42, 640-651.

Solid-State NMR

1. Some samples are not dissolved.

2. Some samples can be dissolved, but the structure could be changed in solvent.

3. Understand the structural changes from liquid to solid.

4. As an important supplement of X – ray.

5. Solid state nuclear magnetic resonance spectroscopy can provide solid state structure of material in the state of aggregation, phase structure, molecular motion information, interaction, etc.

6. The advantage of solid state NMR is to keep the solid state of matter.

Acknowledgement

Wei Tian thanks for the help and source materials from graduate

students of Applied Chemistry Department of School of Science.