[摘要]：Photographic and Other Reprographic Processes) Section The two isomeric bis(hydroxystyryl)benzenes HO-p-C6H4-CH=CH-C6H4-p-OH (I) and HO-m-C6H4-CH=CH-C6H4-m-OH (II) show dramatically different photophys. properties that are distinct from each other and from smaller 3- and 4-hydroxystilbenes. A dianion of I is highly fluorescent when dianion of II is completely nonfluorescent. The large quantum yield of fluorescence of I and its dianion reflects a planarized and quite rigid excited-state with quinoidal resonance contribution, while the quenching of the dianion of II maybe explained by the presence of an intermediate 3(n-p*) state combined with poor Franck-Condon overlap between the HOMO and LUMO of this double phenolate.
