Pressure-induced new chemistry

It has long been recognized that the valence electrons of an atom dominate the chemical properties, while the innershell electrons or outer empty orbital do not participate in chemical reactions. Pressure, as a fundamental thermodynamic variable, plays an important role in the preparation of new materials. More recently, pressure stabilized a series of unconventional stoichiometric compounds with new oxidation states, in which the inner-shell electrons or outer empty orbital become chemically active. Here, we mainly focus on the recent advances in high-pressure new chemistry including novel chemical bonding and new oxidation state, identified by first-principles swarm intelligence structural search calculations.The aim of this review is to provide an up-to-date research progress on the chemical bonding with inner-shell electrons or outer empty orbital, abnormal interatomic charge transfer, hypervalent compounds, and chemical reactivity of noble gases.Personal outlook on the challenge and opportunity in this field are proposed in the conclusion.

高压下氟化钒的结构预测

五氟化钒是很强的氟化剂之一,主要用作强氧化剂和有机合成的氟化剂,也是某些科研项目的必需原料。研究者通过实验证实了四氟化钒能自发歧化成五氟化钒和三氟化钒,但是所需要的实验条件为真空条件。作者利用第一性原理以及粒子群优化算法对V-F二元化合物进行广泛的结构搜索,发现了新的VF和VF2组分,发现了VF5在高压下发生了复杂的相变,所呈现的压力组分相图也为实验合成提供了有力的理论支撑。

离子液体在超级电容器中的应用

超级电容器作为一种清洁和可持续的能源储存设备,因其功率密度高、循环使用寿命长及应用温度范围宽等特点被广泛应用于军事装备、航空航天、交通运输等领域。本文介绍了超级电容器和离子液体的特性,综述了离子液体作为超级电容器电解质材料的应用,同时特别介绍了近年来在实验以及分子动力学模拟方面的一些重要研究成果,并分析了离子液体基超级电容器的优势以及不足。