Abstract

A palladium(II) complex, [Pd(L)Cl] (1) with a new ONS donor azo–thioether ligand (L) (where L = 2,4-dihydroxy-5-((2-(methylthio)phenyl)diazenyl)(phenyl)(phenyl)methanone) is successfully synthesized. The ligand and complex are thoroughly characterized by several spectroscopic techniques. The geometry of the complex is confirmed by single-crystal X-ray analysis. Electronic structure and spectral properties are interpreted by DFT and TDDFT calculations. The interaction of the complex with CT DNA was investigated by UV-vis method and binding constant is found to be 5.42 × 10⁴ M⁻¹. Competitive binding titration with ethidium bromide (EB) by fluorescence titration method was carried out to understand the efficiency of the complex to displace EB from EB-DNA complex. From fluorescence titration Stern-Volmer dynamic quenching constants, K_sv was calculated and is found to be 4.15 × 10⁴ M⁻¹. Cyclic voltammogram of the complex exhibits significant shifting of the reduction couple to the negative potential region and decrease in current height in the presence of CT DNA.

Graphic Abstract

SYNOPSIS A palladium(II) complex, [Pd(L)Cl] (1) with a new ONS donor azo–thioether ligand (L) (where L = 2,4-dihydroxy-5-((2-(methylthio)phenyl)diazenyl)(phenyl)(phenyl)methanone) is successfully synthesized and characterized. The geometry of the complex is confirmed by single-crystal X-ray analysis. Electronic structure and spectral properties are interpreted by DFT and TDDFT calculations. The interaction of the complex with CT DNA is investigated by UV-vis, fluorescence and cyclic voltammetric method.

中文翻译：

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钯（II）与新型含ONS供体配体硫醚的配合物的合成，表征，X射线结构和DNA结合研究

摘要

钯（II）配合物[Pd（L）Cl]（1），具有新的ONS供体偶氮-硫醚配体（L）（其中L = 2,4-二羟基-5-（（2-（甲硫基）苯基）二氮烯基）（苯基）（苯基）甲酮已成功合成。配体和配合物通过几种光谱技术进行了全面表征。配合物的几何形状通过单晶X射线分析确认。电子结构和光谱特性通过DFT和TDDFT计算来解释。通过UV-vis方法研究了复合物与CT DNA的相互作用，发现结合常数为5.42×10 ⁴  M ^-1。进行了荧光滴定法与溴化乙锭（EB）的竞争结合滴定，以了解该复合物从EB-DNA复合物中置换EB的效率。根据荧光滴定Stern-Volmer动态猝灭常数，计算出K _sv为4.15×10 ⁴  M ^-1。复合物的循环伏安图显示，在存在CT DNA的情况下，还原对明显转移至负电位区，电流高度降低。

图形摘要

提要一种钯（II）配合物[Pd（L）Cl]（1），具有新的ONS供体偶氮-硫醚配体（L）（其中L = 2,4-二羟基-5-（（2-（甲硫基）苯基） ）二氮烯基）（苯基）（苯基）甲酮已成功合成并表征。配合物的几何形状通过单晶X射线分析确认。电子结构和光谱特性通过DFT和TDDFT计算来解释。通过紫外可见，荧光和循环伏安法研究了配合物与CT DNA的相互作用。