Watson Alexander E R, Grant Michael J, Boyle Paul D, Ragogna Paul J, Gilroy Joe B
Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, London, Ontario N6A 5B7, Canada.
Inorg Chem. 2022 Nov 21;61(46):18719-18728. doi: 10.1021/acs.inorgchem.2c03216. Epub 2022 Nov 10.
While they are often encountered as reaction intermediates, phosphenium cations are not commonly incorporated into π-conjugated systems. We report the synthesis and characterization of donor-stabilized phosphenium cations supported by pyridylhydrazonide ligands. The preparation of these cations relies on precise control of ligand - isomerism. The heterocycles were treated with a variety of transition metals, with [Rh(COD)Cl] yielding the only well-defined organometallic products. The optoelectronic properties of the phosphenium heterocycles and their transition-metal complexes were examined using UV-vis absorption spectroscopy, cyclic voltammetry, and modeling by density functional theory (DFT). Computations support the description of these compounds as phosphenium cations and corroborate our observation of a weak P-N bond, which was manifested experimentally as the Rh adducts undergo selective insertion of Rh into the P-N bond, depending on the substituent at phosphorus. The reported compounds provide a framework for further study of π-conjugated, ,'-chelated phosphenium cations and their transition-metal adducts.
虽然磷鎓阳离子常作为反应中间体出现，但它们并不常被并入π共轭体系。我们报道了由吡啶腙配体支持的供体稳定磷鎓阳离子的合成与表征。这些阳离子的制备依赖于对配体异构现象的精确控制。用多种过渡金属处理这些杂环化合物，其中[Rh(COD)Cl]产生了唯一明确的有机金属产物。使用紫外可见吸收光谱、循环伏安法以及密度泛函理论（DFT）建模研究了磷鎓杂环化合物及其过渡金属配合物的光电性质。计算结果支持将这些化合物描述为磷鎓阳离子，并证实了我们观察到的弱P-N键，这在实验中表现为Rh加合物根据磷上的取代基选择性地将Rh插入P-N键。所报道的化合物为进一步研究π共轭、,'-螯合磷鎓阳离子及其过渡金属加合物提供了一个框架。
