Interplay between the Reorientational Dynamics of the B3H8- Anion and the Structure in KB3H8

被引：13

作者：

Andersson, M. S. ^{[7
,8
]}

Grinderslev, J. B. ^{[1
,2
]}

Chen, X-M ^{[3
]}

Chen, X. ^{[3
,4
,5
]}

Haussermann, U. ^{[6
]}

Zhou, W. ^{[7
]}

Jensen, T. R. ^{[1
,2
]}

Karlsson, M. ^{[8
]}

Udovic, T. J. ^{[7
,9
]}

机构：

[1] Aarhus Univ, Interdisciplinary Nanosci Ctr iNANO, DK-8000 Aarhus, Denmark

[2] Aarhus Univ, Dept Chem, DK-8000 Aarhus, Denmark

[3] Henan Normal Univ, Henan Key Lab Boron Chem & Adv Energy Mat, Sch Chem & Chem Engn, Xinxiang 453007, Henan, Peoples R China

[4] Zhengzhou Univ, Coll Chem, Zhengzhou 450001, Henan, Peoples R China

[5] Zhengzhou Univ, Green Catalysis Ctr, Zhengzhou 450001, Henan, Peoples R China

[6] Stockholm Univ, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden

[7] NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA

[8] Chalmers Univ Technol, Dept Chem & Chem Engn, SE-41296 Gothenburg, Sweden

[9] Univ Maryland, Dept Mat Sci & Engn, College Pk, MD 20742 USA

来源：

JOURNAL OF PHYSICAL CHEMISTRY C | 2021年 / 125卷 / 07期

基金：

瑞典研究理事会; 美国国家科学基金会;

关键词：

Synchrotron radiation - Negative ions - Boron - Calculations - Differential scanning calorimetry - Neutron scattering - Rotation;

D O I：

10.1021/acs.jpcc.0c10186

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The structure and reorientational dynamics of KB3H8 were studied by using quasielastic and inelastic neutron scattering, Raman spectroscopy, first-principles calculations, differential scanning calorimetry, and in situ synchrotron radiation powder X-ray diffraction. The results reveal the existence of a previously unknown polymorph in between the alpha'- and beta-polymorphs. Furthermore, it was found that the [B3H8](-) anion undergoes different reorientational motions in the three polymorphs alpha, alpha', and beta. In alpha-KB3H8, the [B3H8](-) anion performs 3-fold rotations in the plane created by the three boron atoms, which changes to a 2-fold rotation around the C-2 symmetry axis of the [B3H8](-) anion upon transitioning to alpha'-KB3H8. After transitioning to beta-KB3H8, the [B3H8](-) anion performs 4-fold rotations in the plane created by the three boron atoms, which indicates that the local structure of beta-KB3H8 deviates from the global cubic NaCl-type structure. The results also indicate that the high reorientational mobility of the [B3H8](-) anion facilitates the K+ cation conductivity, since the 2-orders-of-magnitude increase in the anion reorientational mobility observed between 297 and 311 K coincides with a large increase in K+ conductivity.

引用

页码：3716 / 3724

页数：9

共 31 条

[1] Interplay of NH4+ and BH4- reorientational dynamics in NH4BH4 [J].