Odor theory, functional group

The aforementioned theories arc concerned wilh Ihc size and shape of odorant molecules, but differ in certain underlying concepts. For example, accommodating for functional groups, electron donor-acceptor characteristics, as well as Ihc sorptive nature of odorants on sensor sites. The vibration Iheory largely concentrates on the far-infrared and Raman spectral characteristics of odoriferous substances. The remaining theories concentrate on structural and behavior characteristics of odorant molecules, stressing direct interactions physically, chemically, and biologically wilh the olfactory sensor system. 

Several theories relating molecular properties to perceived odor quality have been advanced. Examples include the work of Wright (16,] ) who links odor quality to molecular vibrations in the far-infrared, and of Amoore (18) who links odor quality to molecular shape, size, and electronic nature and who introduced the concept of primary class. Beets (19) has discussed odor quality relative to molecular shape as represented by oriented profiles, chirality, and functional groups. In a recently published book (20) he has expanded these discussions. Theimer and coworkers (, , 23) have discussed the Importance of the molecular cross-sectional areas, free energies of desorption, and chirality in relation to odor. A discussion of musk odor quality and molecular structure has been presented by Teranishi (24). Laffort and coworkers ( ) have related odor quality to four molecular properties derived from gas chromatographic retention indices measured on four stationary phases. 

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