A comparative study on the bond features in CO, CS, and PbS
A comparative study on the bond features in CO, CS, and PbS
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CO、CS和PbS中键特性的比较研究
DOI：
10.1063/1.5067006
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发表时间：
2018-12-14
影响因子：
4.4
通讯作者：
Tang, Zichao
中科院分区：
文献类型：
--
作者：
Jiao, Chengxiang;Qin, Zhengbo;Tang, Zichao
共价和非共价相互作用主导了大多数化合物的凝聚相和气相。对于经典的双原子分子CO，通常认为它是一个具有一个共轭键的三键体系。本文首次测量了CS和PbS阴离子的光电子速度图成像光谱。通过对CO、CS和PbS的静电势（ESP）和键特征的比较研究，直观地理解了这两种相互作用。结果表明，CO分子中静电相互作用和与价相互作用相互竞争，CS分子中以与价相互作用为主，PbS分子中以静电相互作用为主。因此，CO具有非常小的偶极矩（类似于0.1 D），而CS （>1.8 D）和PbS （>4 D）具有较大的偶极矩。结果表明，随着偶极矩的增大，电子亲和值依次为CO < CS < PbS。此外，通过与CS和PbS的对比，还揭示了CO中具有负键端和正键圆柱表面的有趣ESP。在后一种情况下，两种分子呈现相反的ESP图谱。分子轨道分析表明，尽管Pb属于主族元素，但Pb 5d轨道参与了Pb- s化学键。利用电子定位函数、自然共振理论和键序方法进一步的键分析表明，共价在CS中占主导地位，离子性是PbS的主要成分，而CO分子则介于两者之间。通过本工作的比较研究，揭示了CS分子是一种很有前途的过渡金属配位化学合成配体分子。AIP出版社出版。
Covalent and noncovalent interactions dominate most compounds in the condensed phase and gas phase. For a classical diatomic molecule CO, it is usually regarded as a triple-bond system with one dative bond. In this work, the photoelectron velocity-map imaging spectra of the CS and PbS anions were first measured. The two interactions have been intuitively understood by a comparative investigation of electrostatic potential (ESP) and bond features in CO, CS, and PbS. It is suggested that both electrostatic and dative covalent interactions compete in CO molecules, while dative covalent interaction prevails in CS molecules and electrostatic interaction dominates in PbS molecules. As a consequence, CO has a very small dipole moment (similar to 0.1 D) compared to the large dipole moment in CS (>1.8 D) and PbS (>4 D). It is indicated that the electron affinity value increases with the increasing dipole moment in the order of CO < CS < PbS. In addition, intriguing ESP with negative bond-ends and positive bond-cylindrical-surface in CO is also revealed by comparing with that in CS and PbS. In the latter, the two molecules present opposite ESP maps. Molecular orbital analyses indicate surprising participation of Pb 5d orbitals in the Pb-S chemical bonding although Pb belongs to main-group elements. Further bond analyses using electron localization function, natural resonance theory, and bond order methods suggest that covalence is dominant in CS and ionicity is a major component in PbS, but somewhere in between for CO molecules. By a comparative study in this work, the CS molecule is also revealed as a promising ligand molecule for the transition-metal coordination chemical synthesis. Published by AIP Publishing.