Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States.
Department of Chemistry, Reed College, Portland, Oregon 97202, United States.
ACS Appl Mater Interfaces. 2021 Apr 28;13(16):19497-19506. doi: 10.1021/acsami.1c03269. Epub 2021 Apr 15.
Polyoxometalate (POM)-based ionic liquids, with nearly infinite compositional variations to fine-tune antimicrobial and physical properties, function as water purification filters, anticorrosion/antibacterial coatings for natural stones, self-repairing acid-resistant coatings, catalysts, and electroactive, stable solvents. By combining hydrophobic quaternary ammonium cations (QACs; tetraheptylammonium and trihexyltetradecylammonium) with butyltin-substituted polyoxotungstates [(BuSn)(α-SiWO)] via repeated solvent extraction-ion exchange, we obtained phase-pure hybrid POM salts (referred to as such because they melt above room temperature). If the solvent extraction process is performed only once, then solids with high salt contamination and considerably lower melting temperatures are obtained. Solution-phase behavior, based on POM-QAC interactions, was similar for all formulations in polar and nonpolar organic solvents, as observed by X-ray scattering and multinuclear magnetic resonance spectroscopy. However, solid thin films of the butyltin-functionalized hybrid POM salts were significantly more stable and adhesive than their inorganic analogues. We attribute this to the favorable hydrophobic interactions between the butyltin groups and the QACs. All synthesized hybrid POM salts display a potent antimicrobial activity toward . These studies provide fundamental form-function understanding of hybrid POM salts, based on interactions between ions in these complex hybrid phases.
多金属氧酸盐（POM）基离子液体具有几乎无限的组成变化，可以精细调整抗菌和物理性能，可用作水净化过滤器、天然石材的防腐/抗菌涂层、自修复耐酸涂层、催化剂以及电活性、稳定的溶剂。通过将疏水性季铵阳离子（QAC；四庚基铵和三己基十四烷基铵）与丁基锡取代的多钨酸盐[（BuSn）（α-SiWO）]通过反复溶剂萃取-离子交换结合，我们获得了纯相混合 POM 盐（之所以这样称呼，是因为它们在室温以上熔化）。如果仅进行一次溶剂萃取过程，则会获得高盐污染且熔化温度低得多的固体。基于 POM-QAC 相互作用的溶液相行为在极性和非极性有机溶剂中对所有配方均相似，这可以通过 X 射线散射和多核磁共振波谱观察到。然而，丁基锡功能化混合 POM 盐的固体薄膜比它们的无机类似物稳定且具有较强的附着力。我们将其归因于丁基锡基团与 QAC 之间有利的疏水相互作用。所有合成的混合 POM 盐对 均显示出很强的抗菌活性。这些研究提供了基于这些复杂混合相中离子相互作用的混合 POM 盐的基本形态-功能理解。
