In this paper, we demonstrate the synthesis and enhanced two-photon absorption (TPA) properties of two novel tetradonor-containing anthracene-centered cross-conjugated polymers with a 2,6-diarylenevinylene/9,10-diaryleneethynylene motif, poly[9,10-bis(p-didecylaminophenylethynyl)-2,6-anthracenevinylene-alt-N-octyl-3,6-/2,7-carbazolevinylene] (P1/P2). P1 and P2 are synthesized by means of a Sonogashira coupling of 9,10-dibromo-2,6-bis(diethylphosphorylmethyl)anthracene with arylethynylene followed by a Wittig–Horner reaction with arylene-dicarbaldehyde. They have number average molecular weights of 1.82 × 104 and 2.15 × 104 g mol-1, respectively, and are readily soluble in common organic solvents and emit strong orange one- and two-photon excitation fluorescence with peaks around 555 nm. The maximal TPA cross sections (δ) of P1 and P2 in toluene, measured by the two-photon-induced fluorescence method, are 2360 and 1520 Gm per repeating unit, respectively. These δ values are significantly larger than the sum of that of the two corresponding linear analogues, indicating that the cooperatively enhanced δ has been achieved in the anthracene-centered cross-conjugated polymers, which are different from the reported characteristics of benzene- and pyrazine-centered cross-conjugated chromophores that show no enhancement of δ. These results underline that an anthracene ring is a promising cross π-center and can be used to construct novel cross-conjugated polymers exhibiting distinctive optoelectronic properties.
在本文中,我们展示了聚[9,10-双(对-二癸基
氨基
苯乙炔基)-2,6-
蒽乙炔-alt-N-辛基-3,6-/2,7-
咔唑烯](P1/P2)这两种具有 2,6-二芳基
乙烯/9,10-二芳基
乙炔主题的新型含四价
蒽中心交叉共轭聚合物的合成和增强双光子吸收(
TPA)特性。P1 和 P2 是通过 9,10-二
溴-2,6-双(
二乙基磷酰甲基)
蒽与芳基
乙炔的 Sonogashira 偶联,然后与芳基二
甲醛进行 Wittig-Horner 反应合成的。它们的平均分子量分别为 1.82 × 104 和 2.15 × 104 g mol-1,易溶于普通有机溶剂,能发出强烈的橙色单光子和双光子激发荧光,峰值在 555 nm 附近。通过双光子诱导荧光法测得的 P1 和 P2 在
甲苯中的最大
TPA 截面(δ)分别为每重复单位 2360 和 1520 Gm。这些δ值明显大于两个相应的线性类似物的δ值之和,表明
蒽中心交叉共轭聚合物实现了协同增强δ,这与所报道的苯中心和
吡嗪中心交叉共轭发色团的特点不同,苯中心和
吡嗪中心交叉共轭发色团的δ没有增强。 这些结果突出表明,
蒽环是一种很有前途的交叉π中心,可用于构建新型交叉共轭聚合物,从而表现出独特的光电特性。