Nicoud Sarah, Mentré Olivier, Kabbour Houria
Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois , UMR 8181-UCCS-Unité de Catalyse et Chimie du Solide , F-59000 Lille , France.
Inorg Chem. 2019 Jan 22;58(2):1349-1357. doi: 10.1021/acs.inorgchem.8b02893. Epub 2019 Jan 8.
The new oxysulfide BaVSO, which can be written as BaS(VOS), was prepared by solid state reaction. It crystallizes in noncentrosymmetric space group P6 with the following unit cell parameters: a = 18.3018(2) Å and c = 8.6525(2) Å ( R = 3.21%). This original phase exhibits (VOS) units separated by Ba cations; the latter delimit one-dimensional (1D) hexagonal-like cavities filled by disordered sulfur S anions and arranged into two kinds of sulfur-deficient 1D channels. Density functional theory calculations were employed to gain insights into the chemical bonding and parameters that determine the structure, particularly the V-O versus V-S bonding inside the mixed anion VOS tetrahedra, and the contribution of the S of the cavities. The title compound can be decomposed with three components mainly interacting by ionic bonds as follows, BaVSO → [Ba][S] [(VOS)]; this description may pave the way for the design of other phases related to this system with adjusted band gap features. In particular, the effect of the V(O,S):Ba ratio is discussed to emphasize the presence of the [S] component, in comparison with related structures such as BaVOS [Ba(VOS)(VSO)(VS)], as it contributes strongly just below the Fermi level with subsequent alteration of the band gap.
新型硫氧化物BaVSO（可写成BaS(VOS)）通过固态反应制备而成。它结晶于非中心对称空间群P6，其晶胞参数如下：a = 18.3018(2) Å，c = 8.6525(2) Å（R = 3.21%）。这一原始相呈现出由Ba阳离子分隔的(VOS)单元；后者界定了由无序硫S阴离子填充的一维（1D）类六边形空腔，并排列成两种硫缺陷的1D通道。采用密度泛函理论计算来深入了解化学键以及决定结构的参数，特别是混合阴离子VOS四面体内部的V - O与V - S键，以及空腔中S的贡献。标题化合物可分解为主要通过离子键相互作用的三个组分，如下所示，BaVSO → [Ba][S] [(VOS)]；这种描述可能为设计具有调整带隙特征的与该体系相关的其他相铺平道路。特别是，讨论了V(O,S):Ba比例的影响，以强调[S]组分的存在，与相关结构如BaVOS [Ba(VOS)(VSO)(VS)]相比，因为它在费米能级以下有强烈贡献，随后改变了带隙。
