研究室工作进展 Aug. 10th, 2019

Synthesis and Reactivity of Asymmetric Cr(I) Dinitrogen Complexes

Supported by Cyclopentadienyl-phosphine Ligands

Jiapeng Li,# Jianhao Yin,# Gao-Xiang Wang,# Zhu-Bao Yin,

Wen-Xiong Zhang* and Zhenfeng Xi* (#共同一作)

Chem. Commun. 2019, 55, 9641-9644.

Transition metal complex-based dinitrogen fixation has been a central research theme in chemistry. Although some successful examples have been reported in the literature, the search for novel bonding diversity of structurally well-defined transition metal-dinitrogen complexes is still in great demand and of great challenge. Compared with Mo and W congeners, only a limited number of Cr-dinitrogen complexes are known.

In this work, as shown in the scheme, unprecedented structurally well-defined trinuclear and dinuclear Cr(I) dinitrogen complexes (I, II) and mixed-valence dinuclear Cr dinitrogen complex (III), with novel asymmetric N2 ligand coordination modes, are realized via the reduction of their corresponding Cr(II) chlorides bearing cyclopentadienyl-phosphine ligands. Oxidative addition reactions of single, double and triple bonds are found to take place on the low-valent Cr(I) centre.

本工作是本研究室在固氮化学研究方面的第三个工作，与我们近期发表的论文（Dinitrogen Functionalization Affording Chromium Hydrazido Complex. J. Am. Chem. Soc. 2019, 141, 4241−4247）密切相关。这两个工作表明，在固氮化学中，small changes in ligand design can result in dramatic changes in N2 coordination and reactivity. 本研究室另外一个固氮化学论文工作报道了首例稀土金属促进的C-N键生成反应（Scandium-Promoted Direct Conversion of Dinitrogen into Hydrazine Derivatives via N−C Bond Formation. J. Am. Chem. Soc. 2019, 141, 8773−8777）。