Macrocycle threading using solvatochromic squaraine dyes
Macrocycle threading using solvatochromic squaraine dyes
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DOI：
10.1080/10610278.2019.1568433
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发表时间：
2019-03-04
影响因子：
3.3
通讯作者：
Smith, Bradley D.
中科院分区：
文献类型：
--
作者：
Jarvis, Tia S.;Smith, Bradley D.
非共价组装是制备用于生物成像的深红色荧光探针的一种有吸引力的方法。合成了四种新的溶剂化变色方酸菁染料，并证明它们在氯仿溶剂或水溶液中均能被四内酰胺大环化合物包封。氯仿中的大环穿线在吸收波长中产生相对小的20 nm红移。相比之下，水中的大环穿线产生类似于80 nm的吸收波长的红移，表明溶剂化显色方酸菁周围的极性发生了很大的变化，因为它从本体水溶液转移到相对非极性的大环内部。吸收最大值的大红移转化为方酸荧光的非常大的70倍增强。研究了两种同源方酸在水中对大环化合物的穿线反应，发现穿线动力学存在较大差异。在结构末端具有N-甲基取代基的方酸的大环穿线比具有N-丙基取代基的方酸的穿线快500万倍。[图形]。
Non-covalent assembly is an attractive way to fabricate deep-red fluorescent probes for biological imaging. Four new solvatochromic squaraine dyes with unsymmetric structures are prepared and shown to exhibit macrocyclic encapsulation by tetralactam macrocycle in chloroform solvent or in water. Macrocycle threading in chloroform produces a relatively small 20 nm red-shift in absorption wavelength. In contrast, macrocycle threading in water produces similar to 80 nm red-shift in absorption wavelength, indicating a large change in polarity surrounding the solvatochromic squaraine as it transfers from bulk water solution to the relatively non-polar macrocycle interior. The large red-shift in absorption maxima translates into a very large 70-fold enhancement of squaraine fluorescence. Macrocycle threading in water by two homologous squaraines was studied and there was a large difference in threading kinetics. Macrocycle threading by a squaraine with an N-methyl substituent at the end of the structure was 5 million times faster than threading by a squaraine with an N-propyl substituent.[GRAPHICS].