Controlling solid-state optical properties of stimuli responsive dimethylamino-substituted dibenzoylmethane materials
Controlling solid-state optical properties of stimuli responsive dimethylamino-substituted dibenzoylmethane materials
复制标题
DOI：
10.1039/c7qm00157f
复制
发表时间：
2017-09-01
影响因子：
7
通讯作者：
Fraser, Cassandra L.
中科院分区：
文献类型：
--
作者：
Butler, Tristan;Wang, Fang;Fraser, Cassandra L.
硼配位β -二酮（BF(2)bdks）的机械致变色发光（ML）性质已被广泛研究，而非配位β -二酮（bdks）的刺激响应性质尚不清楚。虽然bdk染料显示出有希望的特性，包括高对比度ML，快速室温自擦，溶剂化变色和聚集诱导发射（AIE），但先前报道的染料显示出在窄波长范围内（类似于420-500 nm）的发射。为了在更宽的颜色范围内调节发光，二甲胺（DMA）取代的β -二酮用一系列供电子和吸电子取代基合成。研究了溶剂致变色、聚集致发光（AIE）、ML和热致变色。大多数染料表现出正的溶剂化变色，并对机械和热刺激有反应。固体发射波长与对取代基的吸电子强度相关，范围从蓝色到橙色（488-578 nm）。采用粉末x射线衍射（XRD）和差示扫描量热法（DSC）对其进行了结构和热表征。这些数据表明，刺激响应特性是晶体到非晶相变的结果。此外，还测定了碘和氰取代染料在THF/H2O溶液中的聚集诱导发射（AIE）性能。两者都表现出聚集引起的强烈发射。通过增加染料和非发射极性掺杂剂樟脑酸酐的浓度制备聚苯乙烯薄膜，进一步研究了这些染料对基质极性的敏感性。在这些薄膜中观察到发射红移，这表明基质效应可以用来调节dma取代的二酮的发射。
The mechanochromic luminescent (ML) properties of boron coordinated beta-diketones (BF(2)bdks) have been widely studied, however the stimuli responsive properties of uncoordinated beta-diketones (bdks) are less known. While bdk dyes show promising properties, including high contrast ML, rapid room temperature self-erasure, solvatochromism, and aggregation induced emission (AIE), previously reported dyes exhibit emission over a narrow range of wavelengths (similar to 420-500 nm). To tune luminescence over a broader color range, dimethylamino (DMA) substituted beta-diketones were synthesized with a series of electron donating and withdrawing substituents. Solvatochromism, aggregation induced emission (AIE), ML, and thermochromism were investigated. Most dyes showed positive solvatochromic shifts and were responsive to mechanical and thermal stimuli. The solid-state emission wavelengths correlated with the electron withdrawing strength of the para substituent and ranged from blue to orange (488-578 nm). Structural and thermal characterization was performed by powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC) respectively. These data indicate that stimuli responsive properties are the result of a crystalline to amorphous phase transition. Additionally, the aggregation induced emission (AIE) properties of iodo and cyano substituted dyes were measured in THF/H2O solutions. Both showed intense emission resulting from aggregation. The sensitivity of these dyes toward matrix polarity was further investigated by fabricating polystyrene films with increasing concentrations of dye and camphoric anhydride, a non-emissive polar dopant. A red-shift in emission was observed in these films which demonstrated that matrix effects can be used to tune the emission of DMA-substituted diketones.