<title>Localized vibrations: moles in structure-land</title>

Abstract

Functional groups reveal specific information about their direct surroundings; in fact they form the moles, the undercoveragents, in molecules. However, like with agents, the information is produced in coded form (spectral data) so one has to know the code into detail before the message is completely understood.The substantially improved accuracy (wavenumber, intensity) and sensitivity brought about by Fr-instruments, in combination with computer software, offer extended spectral information. Functional groups can now be examined in great detail. Obviously the amount of deducible structural items is group dependent, implying that one has to pursue the probing qualities of a functionality prior to use. The OH-group, and more in particular the OH-stretching vibration, proves to be an extremely good mole. Its potentials are demonstrated on conformational studies of various saturated alcohols, the presence of OHit bridges, the strength and type of OH<) bridges, all in an apolar solvent, and on the disclosure of different hydrogen bonds in some solid samples.