Nitrones and Oxaziridines. XLI. Chromophoric Systems Based on 1-Pyrroline 1-Oxides and 2H-Pyrrole 1-Oxides

Abstract

1-Pyrroline 1-oxides and 2H-pyrrole 1-oxides have been shown to be suitable compounds for the development of extended chromophoric systems. 1-Pyrroline 1-oxides (31, (5) and (7) have conjugated systems in which a nitrone group is conjugatively linked to a dimethylamino group. The 2H-pyrrole 1-oxides (10), (13), (14) and (19) provide cross-conjugated systems incorporating the same structural features. The most extensive delocalization arises in the distyryl compound (19), which on protonation gives an extended cyanine chromophore. The bis nitrone (21) shows a chromophore with nitrone groups at each end of the conjugated system. Some general structural principles affecting the chromophoric systems are discussed.