{"title":"Hypervalency in sulfur? ab initio and DFT studies of the structures of thiosulfate and related sulfur oxyanions","authors":"A. Nishimoto, Daisy Y. Zhang","doi":"10.1080/02786110310001622767","DOIUrl":null,"url":null,"abstract":"The structures of thiosulfate (S2O3 2−) and four other isovalent sulfur oxyanions, S m O n 2− have been investigated at the MP2, MP4, and B3LYP levels of theory, with 6−31+G* as the basis set. By comparing the bond lengths in the dianions with those in the doubly protonated molecules, H2S m O n , the sulfur–oxygen and sulfur–sulfur bond orders have been estimated, based on a valence bond theory model. The conventional Lewis structures, which represent the central S atom as forming six covalent bonds with the four ligands, consistently give accurate descriptions of the structures for all the dianions. Natural bond order analyses, however, show that the 3d orbitals do not participate in valence bonding to any significant degree. Chemically, the peripheral sulfur atoms in all the dianions are predicted to be stronger nucleophiles as well as stronger bases than the oxygen atoms in the gas phase.","PeriodicalId":22122,"journal":{"name":"Sulfur Letters","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"7","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Sulfur Letters","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1080/02786110310001622767","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 7
Abstract
The structures of thiosulfate (S2O3 2−) and four other isovalent sulfur oxyanions, S m O n 2− have been investigated at the MP2, MP4, and B3LYP levels of theory, with 6−31+G* as the basis set. By comparing the bond lengths in the dianions with those in the doubly protonated molecules, H2S m O n , the sulfur–oxygen and sulfur–sulfur bond orders have been estimated, based on a valence bond theory model. The conventional Lewis structures, which represent the central S atom as forming six covalent bonds with the four ligands, consistently give accurate descriptions of the structures for all the dianions. Natural bond order analyses, however, show that the 3d orbitals do not participate in valence bonding to any significant degree. Chemically, the peripheral sulfur atoms in all the dianions are predicted to be stronger nucleophiles as well as stronger bases than the oxygen atoms in the gas phase.
以6−31+G*为基础,在MP2、MP4和B3LYP理论水平上研究了硫代硫酸盐(S2O3 2−)和其他四个同价硫氧离子(S2O3 2−)的结构。通过比较双质子化分子(H2S m O n)和双质子化分子(H2S m O n)的键长,根据价键理论模型估计了硫氧键和硫硫键的键序。传统的路易斯结构,表示中心的S原子与四个配体形成六个共价键,一致地准确描述了所有阴离子的结构。然而,自然键序分析表明,三维轨道不参与任何程度的价键。化学上,在所有的离子中,外围的硫原子被预测为比气相中氧原子更强的亲核试剂和更强的碱。