Abstract A new complex, Co(Htpc)2(H2O)2 (1) (Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid), has been synthesized and characterized by X-ray single-crystal diffraction, elemental analysis, infrared spectral analysis, and thermogravimetric analysis. Meanwhile, the optimized geometric structure of the ligand was determined using the M06-2X functional of density functional theory (DFT) with the 6-311 + G(d, p) basis set. The gap energies ΔE between the frontier molecular orbitals were computed in different solvent media (water, methanol and ethanol) using the time dependent density functional theory (TD-DFT)/M06-2X by applying the Polarizable Continuum Model (PCM). The coordination sphere around Co(II) is distorted octahedral with two chelating tpc- ligands and two coordinated water molecules. Bovine serum albumin (BSA) binding properties of the ligand, CoCl2·6H2O and 1 were investigated by fluorescence and UV–Vis absorption spectroscopy, revealing 1 exhibits higher binding affinity with BSA than free ligand and CoCl2·6H2O. ΔG, ΔH and ΔS at 298 and 308 K manifested that van der Waals interactions and hydrogen bonds were the main forces in the binding process. Graphical Abstract

中文翻译：

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基于 5-(三氟甲基)吡啶-2-羧酸的新型 Co(II) 配合物的合成、晶体结构和 BSA 相互作用

摘要 合成了一种新的配合物 Co(Htpc)2(H2O)2 (1) (Htpc = 5-(trifluoromethyl)pyridine-2-carb acid)，并通过 X 射线单晶衍射、元素分析、红外光谱分析和热重分析。同时，使用密度泛函理论（DFT）的M06-2X泛函以6-311 + G（d，p）基组确定配体的优化几何结构。通过应用极化连续模型 (PCM)，使用时间相关密度泛函理论 (TD-DFT)/M06-2X 在不同溶剂介质（水、甲醇和乙醇）中计算前沿分子轨道之间的间隙能 ΔE。Co(II) 周围的配位球是扭曲的八面体，带有两个螯合 tpc-配体和两个配位的水分子。通过荧光和紫外-可见吸收光谱研究了配体 CoCl2·6H2O 和 1 的牛血清白蛋白 (BSA) 结合特性，表明 1 与 BSA 的结合亲和力高于游离配体和 CoCl2·6H2O。298 和 308 K 处的 ΔG、ΔH 和 ΔS 表明范德华相互作用和氢键是结合过程中的主要作用力。图形概要