Efficient aqueous-phase aldol condensation, Michael addition, and solvent-free Wittig reactions were successfully employed to synthesize two two-photon initiators 9-ethyl-3-[4-(2,2′:6′,2″-terpyridinyl-4′-yl)styryl]carbazole (T1) and 9-4-[4-(2,2′:6′,2″-terpyridinyl-4′-yl)styryl]phenyl}carbazole (T2). The two initiators with carbazolyl moiety attached to 2,2′:6′,2″-terpyridine present D–π–A-type framework, where A is a π-deficient terpyridine ring. The crystal structures were determined by single-crystal X-ray diffraction determination. The experimental results confirmed that the two initiators have sensitive single-photon-excited fluorescence (SPEF) and two-photon-excited fluorescence (TPEF) properties. The experimental and theoretical two-photon absorption (TPA) cross-sections were investigated. Two-photon initiation polymerization (TPIP) microfabrication experiments were carried out, and possible polymerization mechanisms are discussed based on the theoretical evaluation.
高效的
水相羟醛缩合、Michael加成和无溶剂Wittig反应成功合成了两种双光子
引发剂9-乙基-3-[4-(2,2′:6′,2″-terpyridinyl-4) '-基)
苯乙烯基]
咔唑(T1)和9-4-[4-(2,2':6',2"-三联
吡啶基-4'-基)
苯乙烯基]苯基}
咔唑(T2)。两种带有
咔唑基部分连接到2,2':6',2"-三联
吡啶的
引发剂呈现D-π-A型骨架,其中A是缺π的三联
吡啶环。通过单晶X射线衍射测定确定了晶体结构。实验结果证实两种
引发剂均具有灵敏的单光子激发荧光(
SPEF)和双光子激发荧光(TPEF)特性。研究了实验和理论双光子吸收(
TPA)截面。进行了双光子引发聚合(
TPIP)微加工实验,并在理论评估的基础上讨论了可能的聚合机理。