Mashkoori Amineh, Mohamadi Maryam, Ebrahimipour S Yousef, Castro Jesus
Department of Chemistry, Faculty of Science, Shahid Bahonar University of Kerman, Kerman, Iran.
Molecular Medicine Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
J Fluoresc. 2025 Apr 2. doi: 10.1007/s10895-025-04283-1.
This study synthesizes and characterizes the mononuclear complex [Cu(phen)₂(NO₃)]NO₃·H₂O using analytical techniques such as infrared spectroscopy (FT-IR), elemental analysis, molar conductivity measurements, and single-crystal X-ray crystallography. The complex exhibited 1:1 electrolyte behavior. X-ray crystallography revealed a distorted trigonal bipyramidal geometry around Cu(II), stabilized by two 1,10 phenanthroline ligands and a nitrate ion. Crystallographic data were further analyzed using Hirshfeld surface analysis to quantify intermolecular interactions. The analysis revealed the following percentages: O…H (30.3%) and H…H (25.6%). DNA binding studies using UV-vis absorption spectroscopy demonstrated a hypochromic effect, suggesting a partial intercalative or groove-binding mode due to steric hindrance. The binding constant (K) was determined to be 3.74 × 10 M⁻, indicating a relatively high affinity for DNA. The interaction of the complex with BSA was investigated using UV-vis absorption and fluorescence spectroscopy. Hyperchromism in UV-vis spectra and fluorescence quenching of BSA tryptophan residues were observed, indicating complex binding and conformational changes in BSA. Stern-Volmer analysis revealed a binding-dominated quenching mechanism. Thermodynamic parameters calculated from fluorescence data suggested that van der Waals forces and hydrogen bonding are the dominant interactions in the complex-BSA binding, which was found to be spontaneous and enthalpy-driven. Cyclic voltammetry confirmed the complex's interaction with DNA, showing a decrease in peak currents and negative shifts in peak potentials, further supporting the proposed binding mode.
本研究使用红外光谱（FT-IR）、元素分析、摩尔电导率测量和单晶X射线晶体学等分析技术，对单核配合物[Cu(phen)₂(NO₃)]NO₃·H₂O进行了合成与表征。该配合物表现出1:1电解质行为。X射线晶体学表明，Cu(II)周围存在扭曲的三角双锥几何结构，由两个1,10-菲咯啉配体和一个硝酸根离子稳定。使用 Hirshfeld 表面分析对晶体学数据进行了进一步分析，以量化分子间相互作用。分析结果显示以下百分比：O…H（30.3%）和H…H（25.6%）。使用紫外可见吸收光谱进行的DNA结合研究显示出减色效应，表明由于空间位阻导致部分插入或沟槽结合模式。结合常数（K）被确定为3.74×10 M⁻¹，表明对DNA具有相对较高的亲和力。使用紫外可见吸收光谱和荧光光谱研究了该配合物与牛血清白蛋白（BSA）的相互作用。观察到紫外可见光谱中的增色现象和BSA色氨酸残基的荧光猝灭，表明配合物与BSA结合并导致其构象变化。Stern-Volmer分析揭示了以结合为主导的猝灭机制。根据荧光数据计算的热力学参数表明，范德华力和氢键是配合物与BSA结合中的主要相互作用，发现该结合是自发的且由焓驱动。循环伏安法证实了该配合物与DNA的相互作用，显示出峰电流降低和峰电位负移，进一步支持了所提出的结合模式。
