六氧金属酸锂Li7MO6（M = Nb、Ta、Sb、Bi）结构与动力学特征的新见解

New insights into the structural and dynamical features of lithium hexaoxometalates Li7MO6 (M = Nb, Ta, Sb, Bi).

作者信息

Mühle Claus, Dinnebier Robert E, van Wüllen Leo, Schwering Georg, Jansen Martin

机构信息

Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.

出版信息

Inorg Chem. 2004 Feb 9;43(3):874-81. doi: 10.1021/ic030208w.

DOI:10.1021/ic030208w

PMID:14753807

Abstract

We present a (re)investigation of the hexaoxometalates Li(8)MO(6) (M = Sn, Pb, Zr, Hf) and Li(7)MO(6) (M = Nb, Ta, Sb, Bi). Lithium motion and ionic conductivity in the hexaoxometalates were studied using impedance spectroscopy (for Li(7)MO(6), M = Sb, Bi, Ta) and (6)Li and (7)Li solid-state nuclear magnetic resonance (for Li(7)TaO(6)). The NMR data indicate a considerable exchange of Li among the tetrahedral and octahedral voids even at ambient temperature. In an investigation of the crystal structures using laboratory and synchrotron X-ray powder diffraction techniques, the structures of Li(7)TaO(6), Li(7)NbO(6), and Li(7)SbO(6) could be solved and refined. All three reveal a triclinic metric (Li(7)SbO(6), triclinic, P1, a = 5.38503(6) A, b = 5.89164(7) A, c = 5.43074(6) A, alpha = 117.2210(6) degrees, beta = 119.6311(6) degrees, gamma = 63.2520(7) degrees, V = 127.454(3) A(3), Z = 1; Li(7)NbO(6), triclinic, P1, a = 5.37932(9) A, b = 5.91942(11) A, c = 5.37922(9) A, alpha = 117.0033(9) degrees, beta = 119.6023(7) degrees, gamma = 63.2570(9) degrees, V = 126.938(4) A(3), Z = 1; Li(7)TaO(6), triclinic, P1, a = 5.38486(2) A, b = 5.92014(3) A, c = 5.38551(2) A, alpha = 117.0108(2) degrees, beta = 119.6132(2) degrees, gamma = 63.2492(2) degrees, V = 127.208(1) A(3), Z = 1.

摘要

我们对六氧金属酸盐Li₈MO₆（M = Sn、Pb、Zr、Hf）和Li₇MO₆（M = Nb、Ta、Sb、Bi）进行了（重新）研究。利用阻抗谱（针对Li₇MO₆，M = Sb、Bi、Ta）以及⁶Li和⁷Li固态核磁共振（针对Li₇TaO₆）研究了六氧金属酸盐中的锂迁移和离子电导率。核磁共振数据表明，即使在室温下，锂在四面体和八面体空隙之间也有相当程度的交换。在使用实验室和同步加速器X射线粉末衍射技术对晶体结构进行的研究中，Li₇TaO₆、Li₇NbO₆和Li₇SbO₆的结构得以解析和精修。所有这三种化合物均呈现三斜晶系度量（Li₇SbO₆，三斜晶系，P1，a = 5.38503(6) Å，b = 5.89164(7) Å，c = 5.43074(6) Å，α = 117.2210(6)°，β = 119.6311(6)°，γ = 63.2520(7)°，V = 127.454(3) Å³，Z = 1；Li₇NbO₆，三斜晶系，P1，a = 5.37932(9) Å，b = 5.91942(11) Å，c = 5.37922(9) Å，α = 117.0033(9)°，β = 119.6023(7)°，γ = 63.2570(9)°，V = 126.938(4) Å³，Z = 1；Li₇TaO₆，三斜晶系，P1，a = 5.38486(2) Å，b = 5.92014(3) Å，c = 5.38551(2) Å，α = 117.0108(2)°，β = 119.6132(2)°，γ = 63.2492(2)°，V = 127.208(1) Å³，Z = 1）。