Straus Daniel B, Mitchell Warden Hillary E, Cava Robert J
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States.
Inorg Chem. 2021 Sep 6;60(17):12676-12680. doi: 10.1021/acs.inorgchem.1c01277. Epub 2021 Aug 10.
In lead(II) halide compounds including virtually all lead halide perovskites, the Pb 6s lone pair results in distorted octahedra, in accordance with the pseudo-Jahn-Teller effect, rather than generating hemihedral coordination polyhedra. Here, in contrast, we report the characterization of an organic-inorganic hybrid material consisting of one-dimensional edge-sharing chains of Pb-Br square pyramids, separated by [Mn(DMF)] (DMF = dimethylformamide) octahedra. Molecular orbital analysis and density-functional theory calculations indicate that square pyramidal coordination about Pb results from the occupancy of the empty ligand site by a Pb lone pair that has both s and p orbital character rather than the exclusively 6s lone pair. These results demonstrate that a Pb lone pair can be exploited to behave like a ligand in lead halide compounds, greatly expanding the realm of possible lead halide materials to include extended solids with nonoctahedral coordination environments.
在包括几乎所有卤化铅钙钛矿的卤化铅（II）化合物中，根据赝 Jahn-Teller 效应，Pb 6s 孤对电子会导致八面体畸变，而不是产生半面配位多面体。相比之下，我们在此报道了一种有机-无机杂化材料的表征，该材料由 Pb-Br 四方锥的一维边共享链组成，这些链由 [Mn(DMF)]（DMF = 二甲基甲酰胺）八面体隔开。分子轨道分析和密度泛函理论计算表明，Pb 的四方锥配位是由具有 s 和 p 轨道特征的 Pb 孤对电子占据空的配体位点所致，而不是仅由 6s 孤对电子引起。这些结果表明，在卤化铅化合物中，Pb 孤对电子可被利用来表现得像一个配体，从而极大地扩展了可能的卤化铅材料的范围，使其包括具有非八面体配位环境的扩展固体。
