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