University of Monastir, Laboratory of Physico-Chemistry of Materials LR01ES19, Faculty of Sciences of Monastir, Tunisia.
Department of Chemistry, Faculty of Sciences, University of Gabes, Tunisia.
Dalton Trans. 2022 May 31;51(21):8303-8317. doi: 10.1039/d2dt00690a.
Two novel bicapped Keggin polyoxidovanadates with organic cations, (CHN)[HPVO]·5HO (1) and (CHN)(NH)[HPVO]·11HO (2), (PVO = PV14, CHN = 3-picoline and CHN = methenamine) were synthesized. These compounds were isolated and characterized in the solid state and in solution by elemental analysis, powder X-ray diffraction, FTIR, UV-vis, V, P, C and H NMR, and fluorescence spectroscopy. Further confirmation of the PV14 structures was obtained by single-crystal X-ray diffraction studies of 1 and 2. The Hirshfeld surface analysis was performed to confirm that within the intermolecular interactions occurring in the two crystals, the O⋯H/H⋯O, O⋯O and H⋯H interactions dominate. The protonation and one-electron reduction of the PV14 moiety were also analysed by means of DFT calculations; besides confirming the protonation sites and correctly predicting the p values, the DFT results also indicate that molecular reduction is energetically more favourable in protonated PV14 anions. Upon the addition of PV14 anions to bovine serum albumin (BSA) up to a ratio of 1 : 1, the fluorescence decreased by 45% for both 1 and 2, indicating that the interaction of vanadium-containing species with this protein takes place; log() values of 5.5 were obtained in both systems. Upon the addition of 1 or 2 to solutions of calf-thymus DNA (ctDNA), changes were observed in the UV-vis absorption and circular dichroism spectra. The significance of the changes observed is discussed considering the several V-containing species that form in the solution.
两种新型含有机阳离子的双帽 Keggin 多氧化钒酸盐，(CHN)[HPVO]·5H2O (1) 和 (CHN)(NH)[HPVO]·11H2O (2)（PVO = PV14，CHN = 3-皮考啉和 CHN = 乌洛托品），被合成出来。这些化合物在固态和溶液中通过元素分析、粉末 X 射线衍射、FTIR、UV-vis、V、P、C 和 H NMR 以及荧光光谱进行了分离和表征。通过 1 和 2 的单晶 X 射线衍射研究进一步证实了 PV14 结构。Hirshfeld 表面分析被用来确认在两个晶体中发生的分子间相互作用中，O⋯H/H⋯O、O⋯O 和 H⋯H 相互作用占主导地位。通过 DFT 计算还分析了 PV14 部分的质子化和单电子还原；除了确认质子化位点和正确预测 p 值外，DFT 结果还表明，在质子化的 PV14 阴离子中，分子还原在能量上更有利。当 PV14 阴离子与牛血清白蛋白（BSA）的比例达到 1:1 时，1 和 2 的荧光都降低了 45%，表明含钒物种与这种蛋白质的相互作用发生了；在这两个系统中都得到了 log()值为 5.5。当 1 或 2 加入小牛胸腺 DNA（ctDNA）溶液中时，观察到紫外可见吸收和圆二色性光谱的变化。考虑到溶液中形成的几种含 V 物种，讨论了观察到的变化的意义。
