Conjugation, ultraviolet spectroscopy

The isoindole-isoindolenine equilibrium has been studied quantitatively only in the case of certain 1-arylisoindoles. Although two structurally different isoindolenines are possible, only that with the carbon-nitrogen double bond conjugated with both aromatic rings was observed. Investigation of the isoindole-isoindolenine ratios for three compounds by NMR and ultraviolet spectroscopy indicated a... [Pg.133]

Ultraviolet spectroscopy Is a conjugated it electron system present ... [Pg.409]

Structure Determination in Conjugated Systems Ultraviolet Spectroscopy 501... [Pg.501]

Aromatic rings are detectable by ultraviolet spectroscopy because they contain a conjugated rr electron system. In general, aromatic compounds show a series of bands, with a fairly intense absorption near 205 nm and a less intense absorption in the 255 to 275 nm range. The presence of these bands in the ultraviolet spectrum of a molecule is a sure indication of an aromatic ring. [Pg.534]

Dienamines derived from A 4-3-oxosteroids give as the final products immonium salts with a system of conjugated double bonds (40), as shown by ultraviolet spectroscopy.32... [Pg.185]

CONJUGATED SYSTEMS, ORBITAL SYMMETRY, AND ULTRAVIOLET SPECTROSCOPY 667... [Pg.13]

Because of the interaction between the double bonds, systems containing conjugated double bonds tend to be more stable than similar systems with isolated double bonds. In this chapter, we consider the unique properties of conjugated systems, the theoretical reasons for this extra stability, and some of the characteristic reactions of molecules containing conjugated double bonds. We also study ultraviolet spectroscopy, a tool for determining the structures of conjugated systems. [Pg.667]

CHAPTER 15 Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy... [Pg.668]

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