Le Thi Hong Hai, Nguyen Thi Ngoc Vinh, Ngo Tuan Cuong, Le Van Co, Bui Thi Yen Hang, Da Tran Thi, Nguyen Huu Dinh, Van Meervelt Luc
Department of Chemistry, Hanoi National University of Education, 136 Xuan Thuy - Cau Giay, Hanoi, Vietnam.
Department of Science, Hong Duc University, 565 Quang Trung- Tan Son, Thanh Hoa, Vietnam.
J Fluoresc. 2021 Jan;31(1):195-208. doi: 10.1007/s10895-020-02648-2. Epub 2020 Nov 16.
Starting from eugenol (4-allyl-2-methoxyphenol) three new quinoline derivatives, namely 5-bromo-7-(carboxymethoxy)-6-hydroxy-1-methylquinolin-1-ium-3-sulfonate (Q2, CHBrNOS), 5-amino-7-(carboxymethoxy)-6-hydroxyquinolin-1-ium-3-sulfonate (Q4, CHNOS) and 7-(carboxymethoxy)-5,6-dihydroxylquinolin-1-ium-3-sulfonate (Q6, CHNO), have been synthesized and crystallised as dihydrate. The best planes through the quinoline ring and the carboxymethoxy substituent is 6.60 (14), 7.28 (6) and 4.73 (7)° for Q2, Q4 and Q6, respectively. The crystal packing of Q2 is characterised by O-H…O, π …π and Br …pyridine interactions. The two water molecules bridge three sulphate groups. Infinite chains of Q4 running in the direction [021] are formed by O/N-H …O hydrogen bonds at both ends of the molecule. Parallel chains interact by O/N-H…O hydrogen bonds and π…π and C=O…phenyl stacking. The -NH substituent bridges two sulphate groups, while the two water molecules bridge the other functional groups. The packing of Q6 consists of sheets of molecules interaction through O/N-H…O hydrogen bonds while the two water molecules bridge all function groups present. Parallel sheets interact through π…π and C=O…pyridine stacking. An aqueous solution of Q2 and its precursor 7-(carboxymethoxy)-6-hydroxyquinolin-1-ium-3-sulfonate (Q) exhibits fluorescence which is pH dependent. The fluorescence intensity of a 10 μM solution of Q containing Zn reaches its maximum for a [Zn]:[Q] ratio of 1:1. The fluorescence properties of Q, Q2, Q4 and Q6 were further investigated by DFT calculation methods.
从丁香酚（4-烯丙基-2-甲氧基苯酚）出发，合成了三种新的喹啉衍生物，即5-溴-7-（羧基甲氧基）-6-羟基-1-甲基喹啉-1-鎓-3-磺酸盐（Q2，CHBrNOS）、5-氨基-7-（羧基甲氧基）-6-羟基喹啉-1-鎓-3-磺酸盐（Q4，CHNOS）和7-（羧基甲氧基）-5,6-二羟基喹啉-1-鎓-3-磺酸盐（Q6，CHNO），并以二水合物形式结晶。对于Q2、Q4和Q6，穿过喹啉环和羧基甲氧基取代基的最佳平面分别为6.60（14）、7.28（6）和4.73（7）°。Q2的晶体堆积以O-H…O、π…π和Br…吡啶相互作用为特征。两个水分子桥连三个硫酸根。Q4沿[021]方向的无限链由分子两端的O/N-H…O氢键形成。平行链通过O/N-H…O氢键、π…π和C=O…苯基堆积相互作用。-NH取代基桥连两个硫酸根，而两个水分子桥连其他官能团。Q6的堆积由通过O/N-H…O氢键相互作用的分子片组成，而两个水分子桥连所有存在的官能团。平行片通过π…π和C=O…吡啶堆积相互作用。Q2及其前体7-（羧基甲氧基）-6-羟基喹啉-1-鎓-3-磺酸盐（Q）的水溶液表现出pH依赖性荧光。含锌的10μM Q溶液的荧光强度在[Zn]:[Q]比为1:1时达到最大值。通过密度泛函理论（DFT）计算方法进一步研究了Q、Q2、Q4和Q6的荧光性质。
