基于席夫碱配体的锰羰基配合物可见光诱导释放一氧化碳性能

利用五羰基溴化锰和2-吡啶甲醛以及卤代苯胺通过一步法合成得到了3个含席夫碱配体的锰羰基配合物Mn (CO)₃(py (CH=N) ph-X) Br]，其中X=Cl (1)、Br (2)、I (3)，并采用核磁、X射线单晶衍射、红外光谱、紫外可见光谱和荧光光谱对其进行了表征。这类配合物在非光照下稳定，在可见光(LED蓝光、绿光和红光)作用下分解释放CO，可以作为光诱导的一氧化碳释放剂(photoCORMs)。研究表明蓝光是促进配合物分解释放CO的最有效光源。此外，CO释放动力学分析显示配合物分解释放CO过程符合一级动力学模型。配合物3的释放研究表明脱氧肌红蛋白能够捕捉所释放的CO。尽管这些配合物本身的细胞毒性(IC₅₀)达到微摩尔级，但光照下的细胞兼容性有显著改善，上升为接近100微摩尔级。这些配合物具有荧光性质，在450 nm激发波长下在500~700 nm范围内发射一定强度的荧光，可以作为荧光标记物用以监测细胞或生物体内释放剂分布及CO释放情况。

Visible light-induced CO-release from manganese carbonyl complexes based on Schiff base ligand

Three manganese carbonyl complexes Mn(CO)₃(py(CH=N)ph -X)Br], where X=Cl (1), Br (2), I (3), containing Schiff base ligands were synthesized by a one-step method using manganese pentacarbonyl bromide, 2-pyridine formaldehyde, and halogenated aniline. They were characterized by NMR, X-ray single crystal diffraction, IR spectrum, UV-Vis spectrum, and fluorescence spectrum. These complexes were stable under non-illumination, but they could decompose to release CO under visible light (LED blue, green, and red light), which can be used as photo-induced carbon monoxide release molecules (photoCORMs). The CO release rate could be conveniently con-trolled by selecting different lights. It has been shown that blue light was the most effective light source to promote the decomposition of these complexes to release CO. The differences in the electronic effects of the halogenated ligands in these complexes also contribute to the differences in their reaction rates. In addition, the kinetic analysis of CO release shows that the process conforms to the first-order kinetic model. The carbon monoxide release of com-plex 3 was also studied by standard myoglobin assay, showing that deoxymyoglobin was able to capture the released CO. Although the cytotoxicity of these complexes itself reached the micromolar level, the cell compatibility under light was significantly improved, rising to nearly 100 micromolar levels. These complexes had fluorescent proper-ties, emitting a certain intensity of fluorescence in a range of 500-700 nm at the excitation wavelength of 450 nm, which can be used as fluorescent markers to monitor the distribution of release agents and CO release in cells or organisms. CCDC: 2216419, 1; 2216420, 2.