Traustason Hrafn, Bell Nicola L, Caranto Kiana, Auld David C, Lockey David T, Kokot Alex, Szymanowski Jennifer E S, Cronin Leroy, Burns Peter C
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.
School of Chemistry, University of Glasgow, University Avenue, Glasgow, G12 8QQ, United Kingdom.
J Am Chem Soc. 2020 Nov 17. doi: 10.1021/jacs.0c10133.
Room temperature calorimetry methods were developed to describe the energy landscapes of six polyoxometalates (POMs), Li-U, Li-U, K-U, Li/K-U, Mo, and Mo, in terms of three components: enthalpy of dissolution (Δ), enthalpy of formation of aqueous POMs (Δ), and enthalpy of formation of POM crystals (Δ). Δ is controlled by a combination of cation solvation enthalpy and the favorability of cation interactions with binding sites on the POM. In the case of the four uranyl peroxide POMs studied, clusters with hydroxide bridges have lower Δ and are more stable than those containing only peroxide bridges. In general for POMs, the combination of calorimetric results and synthetic observations suggest that spherical topologies may be more stable than wheel-like clusters, and Δ can be accurately estimated using only Δ values owing to the dominance of the clusters in determining the energetics of POM crystals.
室温量热法被开发用于从三个组分描述六种多金属氧酸盐（POMs），即Li-U、Li-U、K-U、Li/K-U、Mo和Mo的能量景观：溶解焓（Δ）、水合POMs的生成焓（Δ）和POM晶体的生成焓（Δ）。Δ由阳离子溶剂化焓与阳离子与POM上结合位点相互作用的有利性共同控制。在所研究的四种过氧化铀酰POMs中，具有氢氧化物桥的簇具有较低的Δ，并且比仅含过氧化物桥的簇更稳定。一般对于POMs而言，量热结果与合成观察结果的结合表明球形拓扑结构可能比轮状簇更稳定，并且由于簇在决定POM晶体能量学方面的主导作用，仅使用Δ值就能准确估计Δ。
