由1-(2,4-二羟基苯基)乙酮和吡啶衍生物合成了两种新的席夫碱。这两种化合物都用红外线表征,UV-Vis。,1HNMR,13CNMR和质谱研究。对具有6-31G(d,P)作为基础设置。用理论方法计算的振动频率与实验值吻合良好。两种席夫碱本质上都是高度荧光的。在含水甲醇介质中研究了化合物的阳离子识别特征。发现席夫碱4-(1-(吡啶-4-亚氨基)乙基)苯-1,3-二醇(PYEB)与Fe(III)和Cu(II)离子相互作用,而席夫碱4,4'-((吡啶-2,3-二基双(氮杂烷基))双(乙-1-基-1-基))双(苯-1,3-二醇)(PDEB)被发现检测Cu(II)离子。建立了结合激发态分子内质子转移(ESIPT)-螯合增强荧光(CHEF)效应和螯合增强猝灭(CHEQ)过程检测Fe(III)和Cu(II)离子的识别机制,分别。确定了在传感过程中形成的金属络合物的稳定常数。发现Fe(III)和Cu(II)离子相对于席夫碱PYEB的检测限为1.64×10-6和2.16×10-7M,分别。关于席夫碱PDEB,发现Cu(II)离子的检测限为4.54×10-4M。Schiff碱PDEB的Cu(II)离子传感特性用于检测HeLa细胞的生物成像研究。
Two new Schiff bases were synthesized from 1-(2,4-dihydroxyphenyl)ethanone and pyridine derivatives. Both compounds were characterized using infrared, UV-Vis., 1H NMR, 13C NMR and mass spectral studies. Density functional theory (DFT) calculations were performed for both the Schiff bases with 6-31G(d, p) as the basis set. Vibrational frequencies calculated using the theoretical method were in good agreement with the experimental values. Both the Schiff bases were highly fluorescent in nature. The cation-recognizing profile of the compounds was investigated in aqueous methanol medium. The Schiff base 4-(1-(pyridin-4-ylimino)ethyl)benzene-1,3-diol (PYEB) was found to interact with Fe(III) and Cu(II) ions, whereas the Schiff base 4,4\'-((pyridine-2,3-diylbis(azanylylidene))bis(ethan-1-yl-1-ylidene))bis(benzene-1,3-diol) (PDEB) was found to detect Cu(II) ions. The mechanism of recognition was established as combined excited state intramolecular proton transfer (ESIPT)-chelation-enhanced fluorescence (CHEF) effect and chelation-enhanced quenching (CHEQ) process for the detection of Fe(III) and Cu(II) ions, respectively. The stability constant of the metal complexes formed during the sensing process was determined. The limit of detection for Fe(III) and Cu(II) ions with respect to Schiff base PYEB was found to be 1.64 × 10-6 and 2.16 × 10-7 M, respectively. With respect to Schiff base PDEB, the limit of detection for Cu(II) ion was found to be 4.54 × 10-4 M. The Cu(II) ion sensing property of the Schiff base PDEB was applied in bioimaging studies for the detection of HeLa cells.