Optical exaltation

The molar rtfraction [R] and magnetic rotation [M] were measured with the sodium D line the value of [R] for the azido group was derived from alkyl azides. In phenyl derivatives it increases to about 10-2 . This results from conjugation of N3 with the aromatic ring optical exaltation effect) [M] is related to the Faraday effect (sec reference 16 for a simple discussion, and reference 18a for a recent review. 

Briihl (1886a) had noted that the effect of unsaturation on molecular refraction could not always be represented by the increments previously deduced two olefinic bonds when situated conjugatively increased the refraction abnormally, the difference between observed and calculated R s being regarded as optical anomaly . In 1907 he introduced the terms optical exaltation and optical depression to refer respectively to cases where the observed R exceeded or fell short of that calculated numerically, depressions are commonly small but exaltations may be very large (see Smiles, 1910 von Auwers, 1924) ... 

In many respects, chiral compounds have been regarded as special entities within the tine chemical community. As we will see, the possession of chirality does not, in many respects, make the compound significantly more expensive to obtain. Methods for the preparation of optically active compounds have been known for more than 100 years (many based on biological processes). The basic chemistry to a substrate on which an asymmetric transformation is then performed can offer more challenges in terms of chemistry and cost optimization than the exalted asymmetric step. 

The action of sodium molybdate (NajMoOi) on a-hydroxy acids is interesting since it produces an exaltation in the optical rotation. This... 

Equally debatable are the interpretations of the catalase optical spectrum 78, 81) (Table III), which is distinguished by a band near 880 nm 74, 89) and an exaltation of the transition at 625 nm. These features, although not typical of aquo hemoproteins when L = His, are apparent in their anionic complexes (Table III) 74, 79, 80, 89-98) and should also characterize high-spin hydroxo derivatives 99, 100). For these reasons, it seems premature to accept the thesis of Williams et cd. 76, 81) that Ls = carboxyl. 

Some of the effects produced by adding such acids or salts to solutions of polyhydroxy compounds are increased conductivity and acidity of the solution, exaltation of the rotation of optically active substances, and marked changes of volume. For an example, see Table III, above. 

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