Fufa Tesfa Oluma, Ma Hongwei, Ayub Ali R, Nabat Karim Y, Khan Yaqoot, Li Hui
Key Laboratory of Clusters Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology 100081 Beijing P. R. China
RSC Adv. 2025 Jul 10;15(30):24192-24201. doi: 10.1039/d5ra03383g.
A novel Schiff base ligand, 2-amino-3-((()-2,5-dihydroxybenzylidene)amino)maleonitrile hemihydrate (CHNO·½HO or HL), was synthesized by a condensation reaction of diaminomaleonitrile and 2,5-dihydroxybenzaldehyde in ethanol. Its crystal structure, fluorescence (FL) emission and Zn(ii)-detection properties were studied. The crystal structure of HL belongs to a face-centered orthorhombic space group (2), confirming its crystalline nature. HL emitted green-colored fluorescence in MeCN, EtOH, and DMF, with varying FL yields of 0.53, 0.68, and 0.95, respectively. This suggests that the solvent environment plays a crucial role in modulating the FL properties of HL. In DMF, the gradual addition of Zn(ii) to the HL solution resulted in a color change from yellow to orange, accompanied by the appearance of new absorbance bands at 494 nm and two isosbestic points at 300 and 440 nm. These phenomena were not observed either in MeCN or EtOH, indicating that Zn(ii)-HL binding was more pronounced in DMF. Thus, HL demonstrated sensitive Zn(ii) binding, with a 1 : 1 binding stoichiometry, a high binding constant (3.745 × 10 μM), and a low limit of detection (3.455 × 10 μM). Overall, the findings highlight the potential of the novel crystalline HL for efficient FL emission and sensitive Zn(ii) detection in DMF, suggesting its potential utilization for fabricating light-emitting organic devices and metal-ion sensors.
通过二氨基马来腈与2,5 - 二羟基苯甲醛在乙醇中发生缩合反应，合成了一种新型席夫碱配体2 - 氨基 - 3 - ((()-2,5 - 二羟基亚苄基)氨基)马来腈半水合物（CHNO·½HO或HL）。研究了其晶体结构、荧光（FL）发射和锌（ii）检测性能。HL的晶体结构属于面心正交空间群（2），证实了其晶体性质。HL在乙腈、乙醇和N,N - 二甲基甲酰胺中发出绿色荧光，其FL产率分别为0.53、0.68和0.95。这表明溶剂环境在调节HL的FL性质方面起着关键作用。在N,N - 二甲基甲酰胺中，向HL溶液中逐渐加入锌（ii）会导致颜色从黄色变为橙色，同时在494 nm处出现新的吸收带以及在300和440 nm处出现两个等吸收点。在乙腈或乙醇中均未观察到这些现象，表明锌（ii）与HL的结合在N,N - 二甲基甲酰胺中更为明显。因此，HL表现出对锌（ii）的敏感结合，结合化学计量比为1∶1，结合常数高（3.745×10 μM），检测限低（3.455×10 μM）。总体而言，这些发现突出了新型晶体HL在N,N - 二甲基甲酰胺中实现高效FL发射和灵敏锌（ii）检测的潜力，表明其在制造发光有机器件和金属离子传感器方面的潜在应用价值。
