21. Measurement and analysis

21. Measurement and analysis

21.1 Spectroscopic identification of organic compounds

Nature of science:

• Improvements in modern instrumentation - advances in spectroscopic techniques (IR, ¹H NMR and MS) have resulted in detailed knowledge of the structure of compounds.

Understandings:

• Structural identification of compounds involves several different analytical techniques including IR, ¹H NMR and MS.

• In a high resolution ¹H NMR spectrum, single peaks present in low resolution can split into further clusters of peaks.

• The structural technique of single crystal X-ray crystallography can be used to identify the bond lengths and bond angles of crystalline compounds.

Applications and skills:

• Explanation of the use of tetramethylsilane (TMS) as the reference standard.

• Deduction of the structure of a compound given information from a range of analytical characterization techniques (X-ray crystallography, IR, ¹H NMR and MS).