强双光子吸收化合物NT-G1和NO-G1合成与性能研究  

Synthesis and strong two-photon absorption of carbazole derivatives: NT-G1 and NO-G1

作　　者：刘国华[1] 杨平[2] 蒋宛莉[3] 郭晓稚[2] 许贵宝[3] 蒋雪璋[1] 沈梁[1] 王筱梅[1] 

机构地区：[1]苏州大学材料科学与工程学院,江苏苏州215021 [2]苏州大学化学化工系,江苏苏州215006 [3]山东大学晶体材料国家重点实验室,山东济南250100

出　　处：《功能材料》2005年第4期600-603,共4页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(50273024);江苏省自然科学基金资助项目(BK2002041;BK2003031);江苏省教育厅自然科学基金资助项目(02KJB430001;03KJB150115)

摘　　要：选择氮杂芴(咔唑)为π中心,分别以三苯胺和二唑取代基为“枝”,合成了两个强双光子吸收的氮杂芴衍生物2,8 双(4 三苯胺乙烯基) N 乙基氮杂芴(简称NT G1)和2,8 双(2 (4’乙氧基) 5 (4’苯乙烯) 1,3,4 二唑) N 基氮杂芴(简称NO G1),进行了核磁共振谱和质谱等表征。飞秒钛宝石激光器泵浦下,NT G1 和NO G1 溶液发出强双光子上转换荧光,且后者的双光子荧光发射截面是前者的7倍;双光子荧光法计算出NT G1 和NO G1 双光子吸收截面分别为215GM和454GM。分子构型优化表明,NT G1分子中心“氮杂芴”所在平面与两端苯环呈螺旋桨式排布;而NO G1 分子共轭长度增大,且中心的“氮杂芴”与两端延伸的“枝”呈平面构型;从结构上看,NO G1分子属“D A πA D”型,具有明显的pn 结模式,这些都使NO G1 分子具有更好的分子内电荷转移能力,因而有较高的双光子吸收截面。Two new chromophores with carbazole as molecular focal point bearing ether triphenylamine or oxadiazole unit at the periphery respectively (named as NT-G1 and NO-G1, respectively) have been synthesized and characterized. To comparatively investigate their linear and two-photon optical properties, absorption/steady-state and time-resolved fluorescence spectra as well as relative fluorescence quantum yields were examined. Pumped by femto-second laser at 730-800 nm, strong up-conversion emissions with the central wavelength at 453 nm for NT-G1 and 500 nm for NO-G1 in DMF have been observed. Chromophore NO-G1 possesses strong two-photon absorption (TPA) with the cross-section (δTPA) AS high as 454 GM and two-photon emission cross-section (δTPF) being as 21 times as that of fluorescein reference. As compared with NT-G1, NO-G1 has more than 2-fold increase in the two-photon absorption (TPA) cross section, which was probably accounted for the resonance enhancement in the excited states due to its longer conjugation length, planar geometry and molecular pn-structure alike.

关 键 词：2 8-双(4-三苯胺乙烯基)氮杂芴 2 8-双(2-(4’-乙氧基)-5-(4’-苯乙烯)-1 3 4-噁二唑)-N-乙基氮杂芴 双光子吸收 双光子荧光 

分 类 号：O64[理学—物理化学]