Beijing Key Laboratory for Green Catalysis and Separation, Laboratory for Self-Assembly Chemistry, Department of Chemistry and Chemical Industry, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China.
College of Materials Science and Opto-electronic Technology and Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100049, China.
Nat Chem. 2017 Feb;9(2):188-193. doi: 10.1038/nchem.2637. Epub 2016 Oct 24.
Developing homogeneous catalysts that convert CS and COS pollutants into environmentally benign products is important for both fundamental catalytic research and applied environmental science. Here we report a series of air-stable dimeric Pd complexes that mediate the facile hydrolytic cleavage of both CS carbon-sulfur bonds at 25 °C to produce CO and trimeric Pd complexes. Oxidation of the trimeric complexes with HNO regenerates the dimeric starting complexes with the release of SO and NO. Isotopic labelling confirms that the carbon and oxygen atoms of CO originate from CS and HO, respectively, and reaction intermediates were observed by gas-phase and electrospray ionization mass spectrometry, as well as by Fourier transform infrared spectroscopy. We also propose a plausible mechanistic scenario based on the experimentally observed intermediates. The mechanism involves intramolecular attack by a nucleophilic Pd-OH moiety on the carbon atom of coordinated µ-OCS, which on deprotonation cleaves one C-S bond and simultaneously forms a C-O bond. Coupled C-S cleavage and CO release to yield (bpy)Pd(µ-S) (bpy, 2,2'-bipyridine) provides the thermodynamic driving force for the reaction.
开发能将 CS 和 COS 污染物转化为环境友好产物的均相催化剂，对于基础催化研究和应用环境科学都很重要。在此，我们报告了一系列空气稳定的二聚钯配合物，它们能在 25°C 下轻易地水解断裂 CS 的两个碳-硫键，生成 CO 和三聚钯配合物。用 HNO 氧化三聚配合物，释放出 SO 和 NO，同时再生出起始的二聚配合物。同位素标记证实 CO 的碳和氧原子分别来自 CS 和 HO，气相和电喷雾电离质谱以及傅里叶变换红外光谱也观察到了反应中间体。我们还根据实验中观察到的中间体提出了一个合理的反应机理。该机理涉及由亲核 Pd-OH 部分对配位的 µ-OCS 碳原子的分子内进攻，这导致一个 C-S 键断裂，同时形成一个 C-O 键。耦合的 C-S 断裂和 CO 释放生成 (bpy)Pd(µ-S)（bpy，2,2'-联吡啶），为反应提供了热力学驱动力。
