Giang Ninh Thi Minh, Duong Trinh Hong, Cuong Ngo Tuan, Hai Le Thi Hong
Faculty of Chemistry, Hanoi National University of Education, Hanoi, Vietnam.
Faculty of Natural Science and Technology, Tay Nguyen University, Đăk Lăk, Vietnam.
J Fluoresc. 2025 Mar 4. doi: 10.1007/s10895-025-04204-2.
Four new dinuclear complexes Zn1-Zn4 were synthesized by the interaction of Zn(NO).4HO with Schiff bases containing p-phenylenediamine. The data of ESI-MS, IR and H NMR spectroscopy showed that the ligands coordinated with Zn(II) via two sets of O, N atoms. In DMSO, ligands exhibit weak luminescence while the complex solutions emit strongly at maximum wavelength in the range 409-513 nm. Notably, electron-donating groups enhance the quantum yield of the complex solutions. Particularly, Zn2 containing NEt substitutes has outstanding quantum yields of 74%. Besides, the lifetimes of the complexes increase in the order Zn2 < Zn4 < Zn1 < Zn3 in DMSO. Along with the experiment, the structure, absorption and emission spectra of Zn1-Zn4 have been investigated by TD-DFT calculation. The result reproduces well the experimental absorption wavelengths and shows that the absorptions of the complexes are due to the singlet S → S transition from the π to the π* orbital of the ligand in complexes and the emission occurs from minimum of the S state to the ground singlet state S. The calculation results also support for the fact that Zn2 has profoundly quantum yields.
通过Zn(NO₃)₂·4H₂O与含对苯二胺的席夫碱相互作用合成了四种新型双核配合物Zn1-Zn4。电喷雾电离质谱（ESI-MS）、红外光谱（IR）和核磁共振氢谱（¹H NMR）数据表明，配体通过两组O、N原子与Zn(II)配位。在二甲基亚砜（DMSO）中，配体发出微弱的荧光，而配合物溶液在409-513 nm范围内的最大波长处发出强烈荧光。值得注意的是，供电子基团提高了配合物溶液的量子产率。特别是，含有N(Et)₂取代基的Zn2具有74%的出色量子产率。此外，在DMSO中，配合物的寿命按Zn2＜Zn4＜Zn1＜Zn3的顺序增加。结合实验，通过含时密度泛函理论（TD-DFT）计算研究了Zn1-Zn4的结构、吸收光谱和发射光谱。结果很好地再现了实验吸收波长，并表明配合物的吸收是由于配合物中配体从π轨道到π*轨道的单重态S→S跃迁引起的，发射是从S态的最小值到基态单重态S发生的。计算结果也支持Zn2具有高量子产率这一事实。
