8.2.2

NMR

IR Spectroscopy

How does it work?

What does it determine about inorganic substances?

What are the benefits and limitations of its use?

Examples of application in industry

What does it determine about inorganic substances?

How does it work?

What are the benefits and limitations of its use?

Examples of application in industry

Investigate molecular structure of organic and inorganic molecules

Analyse composition of mixtures

Study physical properties

Solubility

Diffusion

Determine purity of substances

Design drugs

Screen presence of drugs

QC measure in industry

Study membrane structures

Study metabolic pathways

How chemicals in body are synthesised and broken down

Utilises magnetic properties of nuclei

Samples placed in magnetic field

Electromagnetic radiation is applied

Nuclei absorb radiation

NMR spectrum is produced

Shows absorption

Benefits

Limitations

Relatively low sensitivity

Costly

New technique

Large sample volume

Limited qualitative reuslts

Structural details obtained

Automated

Lower analysis time

High reproducibility

IR light passed through substance

IR Freq matches that of substance -> energy absorbed

Radiation enters sample compared to the one that leaves

spectrum produced compared to that of known substances

Types of vibrational modes

Functional groups molecule has

Almost figure out what the molecule is

Benefits

Limitations

High quality/precise

High speed

Not possible to know molecular weight of substance

does not provide information of positions of functional groups

not possible to know if pure or a mixture

Forensic analysis

Civil and criminal analysis