Chemical structure

Its determination includes a chemist's specifying the molecular geometry and, when feasible and necessary, the electronic structure of the target molecule or other solid.

[2][3] Structure determination can be applied to a range of targets from very simple molecules (e.g., diatomic oxygen or nitrogen) to very complex ones (e.g., such as protein or DNA).

Theories of chemical structure were first developed by August Kekulé, Archibald Scott Couper, and Aleksandr Butlerov, among others, from about 1858.

Concerning chemical structure, one has to distinguish between pure connectivity of the atoms within a molecule (chemical constitution), a description of a three-dimensional arrangement (molecular configuration, includes e.g. information on chirality) and the precise determination of bond lengths, angles, and torsion angles, i.e. a full representation of the (relative) atomic coordinates.

These methods include: Additional sources of information are: When a molecule has an unpaired electron spin in a functional group of its structure, ENDOR and electron-spin resonance spectroscopes may also be performed.