Das Anish Kumar, Biswas Sourav, Manna Surya Sekhar, Pathak Biswarup, Mandal Sukhendu
School of Chemistry, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala 69551, India.
Department of Chemistry, Indian Institute of Technology, Indore, Madhya Pradesh 453552, India.
Inorg Chem. 2021 Dec 6;60(23):18234-18241. doi: 10.1021/acs.inorgchem.1c02867. Epub 2021 Nov 6.
Unraveling the total structure of the atom-precise silver cluster-assembled materials (CAMs) is extremely significant to elucidating the structure-property correlation, but it is a very challenging task. Herein, a new silver CAM is synthesized by a facile synthetic pathway with a unique distorted elongated square-bipyramid-based Ag core geometry. The core is protected by two different kinds of the surface protecting ligands (adamantanethiolate and trifluoroacetate) and connected through a bidentate organic linker. The crystallographic data show that this material embraces a one-dimensional periodic structure that orchestrates by various noncovalent interactions to build a thermally stable supramolecular assembly. Further characterization confirms its n-type semiconducting property with an optical band gap of 1.98 eV. The impact of an adamantanethiol-protected silver core on the optical properties of this type of periodic framework is analyzed by the UV-vis absorbance and emission phenomena. Theoretical calculations predicted that the occupied states are majorly contributed by Ag-S. Solvent-dependent photoluminescence studies proved that a polar solvent can significantly perturb the metal thiolate and thiolate-centered frontier molecular orbitals that are involved in the electronic transitions.
解析原子精确的银簇组装材料(CAMs)的整体结构对于阐明结构-性质关系极为重要,但这是一项极具挑战性的任务。在此,通过简便的合成途径合成了一种新型银CAM,其具有独特的基于扭曲细长正方双锥的Ag核几何结构。该核由两种不同的表面保护配体(金刚烷硫醇盐和三氟乙酸盐)保护,并通过双齿有机连接体相连。晶体学数据表明,这种材料具有一维周期性结构,通过各种非共价相互作用构建热稳定的超分子组装体。进一步表征证实其为n型半导体性质,光学带隙为1.98 eV。通过紫外可见吸收和发射现象分析了金刚烷硫醇保护的银核对这种周期性框架光学性质的影响。理论计算预测,占据态主要由Ag-S贡献。溶剂依赖性光致发光研究证明,极性溶剂可显著扰动参与电子跃迁的金属硫醇盐和以硫醇盐为中心的前沿分子轨道。