Dominance of broken bonds and nonbonding electrons at the nanoscale.
Dominance of broken bonds and nonbonding electrons at the nanoscale.
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DOI：
10.1039/c0nr00245c
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发表时间：
2010-10
期刊：
影响因子：
6.7
通讯作者：
Chang Q. Sun
中科院分区：
文献类型：
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作者：
Chang Q. Sun
尽管它们在人体和我们的环境中无处不在，但非成键孤电子和孤电子对的影响长期以来一直被低估。最近的进展表明：(1)当物质变成纳米级时，在配位不足的原子之间形成更短更强的键，引发了原本恒定的体性质的尺寸趋势，而在断裂键附近存在的孤电子产生了体材料没有表现出来的迷人现象；（ii）在生物、有机和无机样品中，与C、N、O和F四面体配位键相关的孤电子对和孤电子偶极子形成官能团。本文将以表面空位、原子链端和阶地边缘态、催化增强、金属团簇的导电绝缘跃迁、缺陷磁性、纳米接触处的库仑排斥、Cu(3)C(2)H(2)和Cu(3)O(2)表面偶极子形成、孤对中和界面应力等为例，重点介绍非键电子能量学和动力学理论的发展和应用。旨在提高人们对他们对社会的革命性影响的认识。讨论还将扩展到非键电子对催化增强和催化剂设计、冰的密度异常和负热膨胀、B、C、N、O和F诱导的高温超导、CF(4)在合成血液抗凝中的分子结构和功能、NO信号和酶端粒等方面的潜在影响。同时，强调了从键和非键形成、解离、弛豫和振动以及电荷重居、极化、致密化和局域化等相关能量学和动力学角度理解物质性质的必要性和有效性。在不久的将来，发现和掌握控制非键态的因素，并将其用于功能材料的设计，并确定其局限性，将形成一个“非键电子学和能量学”的主题领域，这可能比单独处理核心或价电子更具挑战性，更迷人，更有前途，更有回报。
Although they exist ubiquitously in human bodies and our surroundings, the impact of nonbonding lone electrons and lone electron pairs has long been underestimated. Recent progress demonstrates that: (i) in addition to the shorter and stronger bonds between under-coordinated atoms that initiate the size trends of the otherwise constant bulk properties when a substance turns into the nanoscale, the presence of lone electrons near to broken bonds generates fascinating phenomena that bulk materials do not demonstrate; (ii) the lone electron pairs and the lone pair-induced dipoles associated with C, N, O, and F tetrahedral coordination bonding form functional groups in biological, organic, and inorganic specimens. By taking examples of surface vacancy, atomic chain end and terrace edge states, catalytic enhancement, conducting-insulating transitions of metal clusters, defect magnetism, Coulomb repulsion at nanoscale contacts, Cu(3)C(2)H(2) and Cu(3)O(2) surface dipole formation, lone pair neutralized interface stress, etc, this article will focus on the development and applications of theory regarding the energetics and dynamics of nonbonding electrons, aiming to raise the awareness of their revolutionary impact to the society. Discussion will also extend to the prospective impacts of nonbonding electrons on mysteries such as catalytic enhancement and catalysts design, the density anomalies of ice and negative thermal expansion, high critical temperature superconductivity induced by B, C, N, O, and F, the molecular structures and functionalities of CF(4) in anti-coagulation of synthetic blood, NO signaling, and enzyme telomeres, etc. Meanwhile, an emphasis is placed on the necessity and effectiveness of understanding the properties of substances from the perspective of bond and nonbond formation, dissociation, relaxation and vibration, and the associated energetics and dynamics of charge repopulation, polarization, densification, and localization. Finding and grasping the factors controlling the nonbonding states and making them of use in functional materials design and identifying their limitations will form, in the near future, a subject area of "nonbonding electronics and energetics", which could be even more challenging, fascinating, promising, and rewarding than dealing with core or valence electrons alone.