Photochromic nitrogen-containing

Topics that have formed the subjects of reviews this year include contemporary issues in electron transport research, dynamics of bimolecular photoelectron transfer reactions, photophysical properties of functionalised fullerene derivatives, carbon-carbon bond formation via radical ions, photoinduced electron transfer processes in ketone, aldehyde, and ester synthesis, photochemical reactions between arenenitriles and benzylic donors, photo-oxidation of conjugated dienes, photoredox reactions of aromatic nitro compounds, electron transfer-mediated photochemistry of some unsaturated nitrogen-containing compounds, reactions of 02( Ag), carbon dioxide activation by aza-macrocyclic complexes, and photochromism of chalcone derivatives. ... 

During photochromic studies of dithienylethene-containing imidazolium derivative. Yam and co-workers prepared 4,5-di(thienyl)-2-trifluoromethylimid-azoles and related hexafluorophosphates (Scheme 5) [14]. The condensation of a 1,2-diketone or a-aminoketone with trifluoroacetaldehyde hemiacetal afforded the desired 3,4-disubstituted-2-(trifluoromethyl)imidazoles. The A-methylation of the unsubstituted nitrogen(s) followed by treatment with ammonium hexafluorophosphate afforded the corresponding imidazolium salts. 

---