Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
Laboratory for Innovative Key Materials and Structures (LINK), IRL 3629, CNRS-Saint-Gobain-NIMS, National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan.
Molecules. 2022 Nov 2;27(21):7473. doi: 10.3390/molecules27217473.
In an attempt to isolate boron-containing tri-niobium polychalcogenide species, we have carried out prolonged thermolysis reactions of [CpNbCl] (Cp = -CMe) with four equivalents of Li[BHE] (E = Se or S). In the case of the heavier chalcogen (Se), the reaction led to the isolation of the tri-niobium cubane-like cluster [(NbCp*)(-Se)(BH)(-Se)] () and the homocubane-like cluster [(NbCp*)(-Se)(-Se)(BH)(-Se)] (). Interestingly, the tri-niobium framework of stabilizes a selenaborate {SeBH} ligand. A selenium atom is further introduced between boron and one of the selenium atoms of to yield cluster . On the other hand, the reaction with the sulfur-containing borate adduct [LiBHS] afforded the trimetallic clusters [(NbCp*)(-S){-S(BH)}] () and [(NbCp*)(-S){-S(S)}] (). Both clusters and have an NbS core, which further stabilizes {BH} and mono-sulfur units, respectively, through bi-chalcogen coordination. All of these species were characterized by B{H}, H, and C{H} NMR spectroscopy, mass spectrometry, infrared (IR) spectroscopy, and single-crystal X-ray crystallography. Moreover, theoretical investigations revealed that the triangular Nb framework is aromatic in nature and plays a vital role in the stabilization of the borate, borane, and chalcogen units.
为了分离含硼的三铌多杂化物物种，我们对[CpNbCl]（Cp=-CMe）与四当量的 Li[BHE]（E=Se 或 S）进行了长时间的热解反应。在较重的杂原子（Se）的情况下，反应导致了三铌类似立方烷的簇[(NbCp*)(-Se)(BH)(-Se)]（()）和类似同核立方烷的簇[(NbCp*)(-Se)(-Se)(BH)(-Se)]（()）的分离。有趣的是，三铌框架稳定了一个硒硼酸盐{SeBH}配体。另一个硒原子进一步被引入硼和（）中一个硒原子之间，生成了簇（）。另一方面，与含硫的硼酸盐加合物[LiBHS]的反应生成了三金属簇[(NbCp*)(-S){-S(BH)}]（()）和[(NbCp*)(-S){-S(S)}]（()）。簇（）和（）都具有 NbS 核，通过双杂原子配位，分别进一步稳定了{BH}和单硫单元。所有这些物种都通过 B{H}、H 和 C{H} NMR 光谱、质谱、红外（IR）光谱和单晶 X 射线晶体学进行了表征。此外，理论研究表明，三角形 Nb 框架具有芳香性，在稳定硼酸盐、硼烷和杂原子单元方面起着至关重要的作用。
