Synthesis and properties of novel excited-state intramolecular proton transfer (ESIPT) materials recently developed in our group are described. Highly efficient ESIPT in polymeric system has been investigated theoretically and experimentally with a semi-rigid polyquinoline possessing an intramolecular tautomerizable hydrogen bond. Poly(aryl ether) dendrimers of three different generations that are cored with photo-tautomerizable quinoline (QGn, n=1,2,3) were also synthesized and characterized to investigate the effect of dendritic architecture on the ESIPT activity. Stimulated emission and amplified spontaneous emission in these organic materials system are discussed in terms of ESIPT activity.
Strongly fluorescent organic nonlinear optical materials containing triphenyl amine as a core and 1-(2-ethyl-hexane-1-sulfonyl)-4-vinylbenzene or 4-[4-(2-ethyl-hexane-1-sulfonyl)-1-ethyl] styrene group as the arms which were mono-,di-, and tri-substituted at the para position of nitrogen were synthesized. Photorefractivity of these molecular glasses were measured and correlated with their structure and symmetry. Large two-photon absorption cross-section and strong up-conversion fluorescence emission were also observed in these materials.