Ciprofloxacin hydrochloride (CPFH) is a very common antibiotic drug for the treatment of different types of bacterial infections. The activity of the drug depends on the complexation of the employed drug with different metals present in the body. In the current investigation, the complexation behavior of CPFH drug with numerous metal ions was explored by means of UV-Visible spectroscopic and density functional theory (DFT) techniques at various temperatures. The binding constants (K_f) of CPFH+metal ions complexes were determined from the Benesi-Hildebrand equation. The K_f values experience an alteration with the nature of metal ions employed and the change of temperature. The binding of CPFH with alkali earth metals decreases with the increase of metal size and increases with the increase of temperature, while the opposite effect of temperature was observed for transition metals. The Gibbs free energy of binding (ΔG^o) for the complexation between CPFH and metal ions was negative in all cases, which reveals that the complexation phenomenon is spontaneous. The values of enthalpy and entropy connote the presence of both hydrophobic and electrostatic interactions. The complexation of CPFH was observed to be endothermic in the case of alkali earth metals while exothermic for transition metals. The intrinsic enthalpy gain (ΔII^{o, *}) values signify the higher stability of metal-drug complexes. The compensation temperature (T_C) values were found to be comparable to the biological systems. DFT studies show the formulation of 1:1 complexes with transition metals as well as the square planar geometry of the complexes. HOMO and LUMO analyses reveal that the stability of CPFH-Ni complexes is higher than that of CPFH-Co/CPFH-Zn complexes.

盐酸环丙沙​​星 (CPFH) 是一种非常常见的抗生素药物，用于治疗不同类型的细菌感染。药物的活性取决于所用药物与体内存在的不同金属的络合。在目前的研究中，CPFH 药物与多种金属离子的络合行为通过紫外-可见光谱和密度泛函理论 (DFT) 技术在不同温度下进行了探索。CPFH+金属离子复合物的结合常数 ( K _f ) 由 Benesi-Hildebrand 方程确定。K _f值会随着所用金属离子的性质和温度的变化而发生变化。CPFH与碱土金属的结合随着金属尺寸的增加而降低，随着温度的升高而增加，而温度对过渡金属的影响则相反。CPFH与金属离子络合的吉布斯结合自由能（ΔG ^o）均为负值，表明络合现象是自发的。焓和熵的值意味着疏水和静电相互作用的存在。观察到 CPFH 的络合在碱土金属的情况下是吸热的，而在过渡金属的情况下是放热的。固有焓增益 (ΔII ^{o , *}) 值表示金属-药物配合物的稳定性更高。发现补偿温度 (T _C ) 值与生物系统相当。DFT 研究显示了与过渡金属的 1:1 配合物的配方以及配合物的方形平面几何形状。HOMO和LUMO分析表明CPFH-Ni配合物的稳定性高于CPFH-Co/CPFH-Zn配合物。