Metallization of a Hypervalent Radical Dimer: Molecular and Band Perspectives
文献类型：期刊论文
| 作者 | Tse, JS ; Leitch, AA ; Yu, XY ; Bao, XZ ; Zhang, SJ ; Liu, QQ ; Jin, CQ ; Secco, RA ; Desgreniers, S ; Ohishi, Y ; Oakley, RT |
| 刊名 | JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
 |
| 出版日期 | 2010 |
| 卷号 | 132期号:13页码:4876 |
| 关键词 | AUGMENTED-WAVE METHOD HIGH-PRESSURE DISELENADIAZOLYL RADICALS ELECTRONIC-PROPERTIES CRYSTAL-STRUCTURE 1 STRUCTURAL-CHARACTERIZATION ELECTRICAL-CONDUCTIVITY PHASE-TRANSITION SULFUR 2 4 6-SELENATRIAZINYL RADICALS |
| ISSN号 | 0002-7863 |
| 通讯作者 | Oakley, RT: Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. |
| 中文摘要 | Variable pressure and temperature conductivity measurements on the bisthiaselenazolyl radical dimer [1a](2) have established the presence of a weakly metallic state over the pressure range 5-9 GPa. To explore the origin of this metallization we have examined the crystal and molecular structure of [1a](2) as a function of pressure. At ambient pressure the dimer consists of two radicals linked by a hypervalent 4-center 6-electron S center dot center dot center dot Se-Se center dot center dot center dot S sigma-bond into an essentially coplanar arrangement. The dimers are packed in cross-braced slipped pi-stack arrays running along the x-direction of the monoclinic (space group P2(1)/c) unit cell. Pressurization to 4 GPa induces little change in the molecular structure of [1a](2) or in the slipped pi-stack crystal architecture. Near 5 GPa, however, stress on the dimer leads to buckling of the two halves of the molecule and a contraction in the metrics of the S center dot center dot center dot Se-Se center dot center dot center dot S unit. These structural changes can be understood in terms of an electronic configurational switch from a 4-center 6-electron sigma-bonded dimer to a more conventional pi-bonded arrangement. At the same time the slipped pi-stack arrays undergo a concertina-like compression, and the crystal structure experiences highly anisotropic changes in cell dimensions. DFT calculations on the molecular electronic structure of the dimer indicate a marked decrease in the HOMO-LUMO gap as the dimer buckles. Related solid-state calculations indicate a rapid closure of the valence/conduction band gap in the same pressure region and the formation of a quasi-metallic state. Metallization of [1a](2) thus arises as much from intramolecular changes, which give rise to a collapse of the HOMO-LUMO gap and near coalescence of the valence and conduction bands, as from increased intermolecular interactions, which cause widening and overlap of the band edges. |
| 收录类别 | SCI |
| 资助信息 | Natural Sciences and Engineering Research Council of Canada (NSERCC); NSF of China; MOST of China; NRC; CIHR; University of Saskatchewan |
| 语种 | 英语 |
| 公开日期 | 2013-09-18 |
| 源URL | [http://ir.iphy.ac.cn/handle/311004/41931]  |
| 专题 | 物理研究所_物理所公开发表论文_物理所公开发表论文_期刊论文 |
| 推荐引用方式 GB/T 7714 | Tse, JS,Leitch, AA,Yu, XY,et al. Metallization of a Hypervalent Radical Dimer: Molecular and Band Perspectives[J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,2010,132(13):4876. |
| APA | Tse, JS.,Leitch, AA.,Yu, XY.,Bao, XZ.,Zhang, SJ.,...&Oakley, RT.(2010).Metallization of a Hypervalent Radical Dimer: Molecular and Band Perspectives.JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,132(13),4876. |
| MLA | Tse, JS,et al."Metallization of a Hypervalent Radical Dimer: Molecular and Band Perspectives".JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 132.13(2010):4876. |
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来源：物理研究所
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