This work reports a complementary descriptor to acidity for metal cations - oxygen affinity, to scale the interaction strength of metal cations with oxygenate groups. A method for measuring oxygen affinity is developed in alkyl methylimidazolium chloride solvents using in-situ far infrared (FIR) spectroscopy. The relative oxygen affinity values of metal cations in metal chlorides with model compounds including cyclopentanol (for alcohols), cyclohexanone (for ketones), ethylene glycol diethyl ether (for ethers), and H₂O are measured from the dissociation kinetics of the metal-oxygenate complexes. The concentrations of metal-chloride and metal-oxygenate complexes are determined during evaporative removal of oxygenate molecules according to the FIR absorbance of metal-Cl bonds. The oxygen affinity values are shown to reasonably account for the catalytic performances of metal cations in furfural-acetone condensation and glucose isomerization reactions. The oxygen affinity descriptor could be potentially exploited as an intrinsic property of metal cation broadly for metal chloride or metal oxide.

这项工作报告了金属阳离子酸度的补充描述符 - 氧亲和力，以衡量金属阳离子与含氧化合物基团的相互作用强度。使用原位远红外 (FIR) 光谱在烷基甲基咪唑氯化物溶剂中开发了一种测量氧亲和力的方法。金属氯化物中金属阳离子与模型化合物的相对氧亲和力值，包括环戊醇（用于醇）、环己酮（用于酮）、乙二醇二乙醚（用于醚）和 H ₂O 由金属-氧化物配合物的解离动力学测量。根据金属-Cl 键的 FIR 吸光度，在蒸发去除含氧化合物分子的过程中确定金属-氯化物和金属-氧合物络合物的浓度。氧亲和力值合理地解释了金属阳离子在糠醛-丙酮缩合和葡萄糖异构化反应中的催化性能。氧亲和描述符可能被潜在地用作金属阳离子的固有特性，广泛用于金属氯化物或金属氧化物。