Institute of Chemistry, The Jan Kochanowski University, Swietokrzyska 15G, 25-406, Kielce, Poland.
Institute of Chemistry, Faculty of Food Technology, University of Agriculture, Balicka St. 122, 31-149, Kraków, Poland.
J Fluoresc. 2019 Nov;29(6):1393-1399. doi: 10.1007/s10895-019-02446-5. Epub 2019 Nov 21.
The new derivative of coumarin (E)-3-[7-(diethyloamino)-2-oxo-chromen-3yl]-2-(tiophene-2-carbonyl)prop-2-enenitrile (NOSQ) was easy synthesized with commercial substrates as a result of the search of new Michael type addition sensors based on coumarins. Spectral properties of highly emissive NOSQ were investigated by steady state analysis (absorption and fluorescence measurements) and time-resolved analysis (fluorescence lifetime measurements). The effect of water-methanol mixture on the photophysical properties of the NOSQ molecule was analyzed. With increasing of volumetric fraction of water the intensity of absorbance and fluorescence was strongly reduced. The NOSQ quantum yield in methanol was quite high and the first portions of water caused a significant increase in this value. Water, which is usually a quencher, in this case caused the increase in the quantum yield. The fluorescence lifetimes had second-order decay and the values of fluorescence lifetime increased with increasing alcohol content. Density functional theory (DFT) calculations and experimental data remained in agreement and showed that the interaction between the NOSQ molecule and the solvent affects the appearance of the new conformer.
香豆素（E）-3-[7-（二乙氨基）-2-氧代色烯-3-基]-2-（噻吩-2-羰基）丙烯腈（NOSQ）的新衍生物是通过寻找基于香豆素的新型迈克尔型加成传感器，利用商业底物很容易合成的。通过稳态分析（吸收和荧光测量）和时间分辨分析（荧光寿命测量）研究了高发光 NOSQ 的光谱性质。分析了水-甲醇混合物对 NOSQ 分子光物理性质的影响。随着水体积分数的增加，吸光度和荧光强度大大降低。NOSQ 在甲醇中的量子产率相当高，前几部分水会显著增加该值。在这种情况下，通常为猝灭剂的水会导致量子产率增加。荧光寿命呈二级衰减，并且荧光寿命的值随醇含量的增加而增加。密度泛函理论（DFT）计算和实验数据一致，表明 NOSQ 分子与溶剂之间的相互作用会影响新构象的出现。
