The determination of stoichiometric ratios and stability constants of metal–ligand complexes is of great importance for physical, chemical, biochemical, and environmental studies and often require relatively expensive and sophisticated instruments. Herein, we introduce a simple, accurate, and low-cost method for determining these parameters by a conventional digital camera. The stoichiometric ratios and stability constants of iron complexes of 1,10-phenanthroline, 2,4,6-Tris(2-pyridyl)-s-triazine, and salicylate were determined, as model examples, using the molar ratio and the continuous variation methods. Digital images of solutions with various metal–ligand ratios were captured and analyzed, and the Y_xy color absorbance and the ΔE_LUV color difference parameters were used as convenient analytical signals that favorably compete with conventional spectrophotometric signals. For the three studied iron complexes, the results of stoichiometric ratios and stability constants obtained from digital images were in excellent agreement with the spectrophotometric and the previously reported literature’s data.

中文翻译：

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用数码相机测定菲咯啉，三（2-吡啶基）-s-三嗪和水杨酸酯的铁配合物的化学计量和稳定性常数

金属-配体配合物的化学计量比和稳定常数的确定对于物理，化学，生物化学和环境研究非常重要，并且通常需要相对昂贵和复杂的仪器。在此，我们介绍一种简单，准确且低成本的方法，用于通过常规数码相机确定这些参数。作为模型实例，使用摩尔比和连续变化，确定了1,10-菲咯啉，2,4,6-Tris（2-吡啶基）-s-三嗪和水杨酸酯的铁配合物的化学计量比和稳定常数。方法。捕获并分析了具有各种金属配体比率的溶液的数字图像，以及Y _xy色吸收和ΔE _LUV色差参数用作方便的分析信号，可与常规分光光度信号竞争。对于三种研究的铁配合物，从数字图像获得的化学计量比和稳定性常数的结果与分光光度法和先前报道的文献数据高度吻合。