Three new chromophores with triphenylamine as molecular focal point bearing one, two, or three 4-(n-butyloxystyryl) group(s) at the periphery respectively, (named as T1, T2, and T3) have been synthesized and characterized. It is interesting to find that the fluorescence quantum yield increases from T1 (0.489), to T3 (0.535), and to T2 (0.628) in cyclohexane, meanwhile the lifetime for T3 is shorter than T1 and T2, which is an important characteristic for applications in light emitting diode. Also PMMA (polymethyl methacrylate) film doped with T3 gives stronger fluorescence than T1, and T2. Cyclic voltammetry showed that T3 exhibited lowest oxidation potential of 0.52 V vs SCE, suggesting its better hole-transport property.
Two novel V-shaped symmetric chromophores： E-2,8-bis（4-vinyl-4-carbazol-9-yl）diben- zothiophene （abbreviated as SK-G1） and E-2,8-bis（4-vinyl-4-triphenylamino） dibenzothiophene （abbreviated as ST-G1） have been synthesized and characterized. Their two photon absorption properties were measured by the open-aperture femtosecond Z-scan technique and the nanosecond nonlinear optical transmission （NLT）, respectively, when pumped by Ti： sapphire laser at 750 nm and 800 nm.
Jian Wei CHENGXiao Mei WANGJin XUChang Gui LUYi Ping CUIBo LIShi Xiong QIANPing YANG
Two new symmetric chromophores: 2, 8-bis-[(2-4′-ethoxy phenyl-5-4′-styryl)-1, 3, 4- oxadiazole] didibenzothiophene (abbreviated as SO-G1) and 2, 8-bis-[(2-4′-ethoxy phenyl-5-4′- styryl)-1, 3, 4-oxadiazole]-N-ethyl carbazole (abbreviated as NO-G1) have been synthesized and characterized. Both chromophores exhibit strong two-photon absorption (TPA) with the cross-sections of 2.99×10-48 and 3.48×10-48 cm4?s?photon-1 in THF and large up-conversion emission, when pumped by Ti:sapphire femto-second laser at 720 nm.
