Synthesis and characterization of a novel spirocyclic aromatic derivative: unique roles of phenothiazine
作者:Hongji Jiang、Jian Sun
DOI:10.1039/c3nj00635b
日期:——
In order to investigate the explicit effects of phenothiazine on the general properties of a spirocyclic aromatic derivative with a sterically perpendicular configuration for electro-optical applications, a novel spirocyclic aromatic derivative SPIS, based on fluorene and phenothiazine, was synthesized and fully characterized by 1H NMR, 13C NMR, elemental analysis and matrix assistant laser desorption/ionization time-of-flight mass, respectively. The photophysical properties, thermal stability and energy levels of compound SPIS were further compared with those of 2,7-dibromo-9,9,-diethyl fluorene. The experimental results indicated that compound SPIS displayed a high thermal stability with a decomposition temperature of 386 °C at 5% mass loss and a melting temperature of 221 °C, which was a notable improvement compared to those of 2,7-dibromo-9,9,-diethyl fluorene. Compound SPIS took on a band gap of about 2.63 eV with blue-green emission in the thin solid film. The introduction of phenothiazine into the spirocyclic aromatic derivative can lower the lowest unoccupied molecular orbital level to −3.05 eV, while increasing the highest occupied molecular orbital level to −5.68 eV relative to those of 2,7-dibromo-9,9,-diethyl fluorene. In conclusion, it is obviously illustrated that the introduction of a rigid segment of phenothiazine into the skeleton of a spirocyclic aromatic derivative can improve the thermal stability, and effectively adjust the photophysical properties and energy levels of fluorene-based monomers over a wide range.
为了研究酚噻嗪对具有立体正交配置的螺环芳香衍生物在电光应用中的一般性质的显性影响,合成了一种基于氟苯和酚噻嗪的新型螺环芳香衍生物SPIS,并通过1H NMR、13C NMR、元素分析以及矩阵辅助激光解吸/电离飞行时间质谱进行全面表征。进一步将化合物SPIS的光物理性质、热稳定性和能级与2,7-二溴-9,9-二乙基氟苯进行了比较。实验结果表明,化合物SPIS展现出较高的热稳定性,在5%质量损失时的分解温度为386°C,熔点为221°C,相比于2,7-二溴-9,9-二乙基氟苯有显著改善。化合物SPIS在薄固体薄膜中呈现出约2.63 eV的带隙,并且具有蓝绿发光。将酚噻嗪引入螺环芳香衍生物中,可以使最低未占分子轨道能级降低至−3.05 eV,同时使最高占有分子轨道能级相对于2,7-二溴-9,9-二乙基氟苯提高至−5.68 eV。总之,显然引入刚性酚噻嗪部分到螺环芳香衍生物的骨架中,可以改善热稳定性,并在较广范围内有效调节基于氟苯单体的光物理性质和能级。