Transformation of Perovskite BaBiO3 into Layered BaBiO2.5 Crystals Featuring Unusual Chemical Bonding and Luminescence
Hong Li+,[a], Qing Zhao+,[b] ,Bo-Mei Liu+,[a] ,Jun-Ying Zhang+,[c] ,Zhi-Yong Li[a], Shao-Qiang Guo[c],Ju-Ping Ma[a], Yoshihiro Kuroiwa[b], Chikako Moriyoshi[b], Li-Rong Zheng[d], and Hong-Tao Sun*[a](孙洪涛)
[a] College of Chemistry, Chemical Engineering and Materials Science
Soochow University, Suzhou 215123 (P.R. China)
[b] Department of Physical Science, Hiroshima University,Higashihiroshima, Hiroshima 739-8526 (Japan)
[c] Department of Physics, Beihang University,Beijing 100191 (P.R. China)
[d] Beijing Synchrotron Radiation Facility,Institute of High Energy Physics,Chinese Academy of Sciences, Beijing 100049 (P.R. China)
[+] These authors contributed equally to this work.
Chem. Eur. J. 2018, 24, 8875-- 8882
Engineering oxygen coordination environments of cations in oxides has received intense interest thanks to the opportunities for the discovery of novel oxides with unusual properties. Herein, the synthesis of stoichiometric layered BaBiO2.5by a nontopotactic phase transformation of perovskite BaBiO3is presented. By analyzing the synchrotron X‐ray diffraction data by the maximum‐entropy method/Rietveld technique, it was found that Bi is involved in an unusual chemical bonding situation with four oxygen atoms featuring one ionic bond and three covalent bonds, which results in an asymmetric coordination geometry. Photophysical characterization revealed that this peculiar structure shows near‐infrared luminescence differing from that of conventional Bi‐containing compounds. Experimental and theoretical results led to the proposal of an excitonic nature of the luminescence. This work highlights that synthesizing materials with uncommon Bi−O bonding and Bi coordination geometry provides a pathway to the discovery of systems with new functionalities. This could inspire interest in the exploration of a range of materials containing heavier p‐block elements with prospects for finding systems with unusual properties.
链接:https://onlinelibrary.wiley.com/doi/abs/10.1002/chem.201801257