Department of Biosciences and Biomedical Engineering, School of Engineering, Indian Institute of Technology Indore, Khandwa Road, Simrol, Indore 453552, India.
Department of Chemistry, School of Basic Sciences, Indian Institute of Technology Indore, Khandwa Road, Simrol, Indore 453552, India.
Dalton Trans. 2022 Aug 30;51(34):13071-13084. doi: 10.1039/d2dt01726a.
In this work, four new ruthenium complexes [Ru(η--cymene)(L1)Cl] 1, [Ru(η--cymene)(L2)Cl] 2, [Ru(η--cymene)(L3)Cl] 3 and [Ru(η--cymene)(L4)Cl] 4 [HL1 = (2-cyanophenyl)glycine; HL2 = (5-chloro-2-cyanophenyl)glycine; HL3 = (2-cyano-3-fluorophenyl)glycine; HL4 = (4-cyanophenyl)glycine] were synthesized and well characterized by several spectroscopic and analytical techniques. Complexes 1 and 3 were found to be fluorescent in most of the solvents; however, 2 and 4 were found to be fluorescent mostly in EtOAc, DMF and ethanol. Amongst these four complexes, 3 has shown selective sensing against CO and SO anions by quenching of fluorescence. The LOD values are found to be in the sub-micromolar range. Investigations of the sensing mechanism performed by computation and NMR studies indicate a possible adduct formation between the NH group of the ligand and the anion(s) through hydrogen bond formation, which ultimately might lead to proton transfer to the bi-negative anion. The quantum yield of the complex 3 was found to decrease on addition of CO and SO anions from 0.46 to 0.13 and 0.12, respectively. The Job's plot indicates the binding between the probe and anion in a 1 : 1 ratio for both CO and SO anions. Along with that, all the complexes were found to be biocompatible when tested against several cell lines showing very high IC values. It can also be observed that 1 is capable of penetrating within the cells and can act as a cell imaging agent showing fluorescence, and thus can be used for bio-imaging purposes.
在这项工作中，合成了四个新的钌配合物[Ru(η--cymene)(L1)Cl]1、[Ru(η--cymene)(L2)Cl]2、[Ru(η--cymene)(L3)Cl]3和[Ru(η--cymene)(L4)Cl]4[HL1=(2-氰基苯基)甘氨酸；HL2=(5-氯-2-氰基苯基)甘氨酸；HL3=(2-氰基-3-氟苯基)甘氨酸；HL4=(4-氰基苯基)甘氨酸]，并通过多种光谱和分析技术对其进行了很好的表征。复合物 1 和 3 在大多数溶剂中都具有荧光性；然而，2 和 4 在 EtOAc、DMF 和乙醇中主要具有荧光性。在这四个配合物中，3 对 CO 和 SO 阴离子表现出选择性传感，通过荧光猝灭。LOD 值被发现处于亚微米范围。通过计算和 NMR 研究进行的传感机制研究表明，配体的 NH 基团可能通过氢键形成与阴离子（s）形成加合物，这最终可能导致质子转移到双负阴离子。复合物 3 的量子产率在添加 CO 和 SO 阴离子后分别从 0.46 降低到 0.13 和 0.12。Job 图表明，探针与阴离子之间以 1：1 的比例结合，对于 CO 和 SO 阴离子都是如此。除此之外，所有的配合物在对几种细胞系进行测试时都被发现是生物相容的，显示出非常高的 IC 值。还可以观察到 1 能够穿透细胞内部，并可以作为细胞成像剂显示荧光，因此可用于生物成像目的。
