ABSTRACT

Present paper reports on the interactions between four hydrazones derived from pyridoxal and hydrazides of 2-furoic, thiophene-2-carboxylic, pyrazinoic and pyridine-3-carboxylic acids and 10 different anions (F⁻, Cl⁻, I⁻, PO₄^3-, HPO₄^2-, H₂PO₄^3-, NO₃⁻, SO₃^2-, SO₄^2-, CH₃COO⁻) and three cations (Co²⁺, Ni²⁺, Zn²⁺). Hydrazones are sensitive towards anion presence in non-buffered DMSO only, thus, indicating that the proton transfer from ligand towards anion is responsible for the changes in colour, UV-Vis and fluorescent spectra. Buffered solutions of ligand mixture with any anion are indistinguishable from free hydrazone. The addition of d-metal ions to pyridoxal-derived hydrazones dissolved in buffered DMSO changes the solution colour, UV-Vis and fluorescent spectra. Conditional rate constants of Co²⁺ oxidation, as well as the apparent stability constants of Co²⁺, Co³⁺ complexes with Schiff bases, were determined from kinetic experiments, while Ni²⁺, Zn²⁺ complexes stability constants were calculated from UV-Vis and fluorimetry titration data.

摘要

本论文报告了衍生自吡哆醛的四种腙与 2-呋喃、噻吩-2-羧酸、吡嗪酸和吡啶-3-羧酸的酰肼与 10 种不同阴离子（F ^-、Cl ^-、I ^-、PO ₄ ^3）之间的相互作用^- , HPO ₄ ^2- , H ₂ PO ₄ ^3- , NO ₃ ^- , SO ₃ ^2- , SO ₄ ^2- , CH ₃ COO ^- )和三种阳离子（Co ²⁺ , Ni ²⁺ , Zn ²⁺）。腙仅对非缓冲 DMSO 中存在的阴离子敏感，因此，表明从配体向阴离子的质子转移是颜色、UV-Vis 和荧光光谱变化的原因。带有任何阴离子的配体混合物的缓冲溶液与游离腙无法区分。将 d-金属离子添加到溶解在缓冲 DMSO 中的吡哆醛衍生腙中会改变溶液颜色、UV-Vis 和荧光光谱。Co ²⁺氧化的条件速率常数以及Co ²⁺、Co ³⁺与席夫碱配合物的表观稳定常数由动力学实验确定，而Ni ²⁺、Zn ²⁺ 配合物稳定性常数由紫外-可见光和荧光滴定数据计算。