Access to Stable Metalloradical Cations with Unsupported and Isomeric Metal–Metal Hemi‐Bonds |
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| Authors: | Xin Zheng Dr Xingyong Wang Dr Zaichao Zhang Yunxia Sui Prof Xinping Wang Prof Philip P Power |
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| Affiliation: | 1. State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China);2. School of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an 223300 (China);3. Department of Chemistry, University of California, Davis, CA 95616 (USA) |
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| Abstract: | Metalloradical species Co2Fv(CO)4].+ ( 1 .+, Fv=fulvalenediyl) and Co2Cp2(CO)4].+ ( 2 .+, Cp=η5‐C5H5), formed by one‐electron oxidations of piano‐stool cobalt carbonyl complexes, can be stabilized with weakly coordinating polyfluoroaluminate anions in the solid state. They feature a supported and an unsupported (i.e. unbridged) cobalt–cobalt three‐electron σ bond, respectively, each with a formal bond order of 0.5 (hemi‐bond). When Cp is replaced by bulkier Cp* (Cp*=η5‐C5Me5), an interchange between an unsupported radical Co2Cp*2(CO)4].+ (anti‐ 3 .+) and a supported radical Co2Cp*2(μ‐CO)2(CO)2].+ (trans‐ 3 .+) is observed in solution, which cocrystallize and exist in the crystal phase. 2 .+ and anti‐ 3 .+ are the first stable thus isolable examples that feature an unsupported metal–metal hemi‐bond, and the coexistence of anti‐ 3 .+ and trans‐ 3 .+ in one crystal is unprecedented in the field of dinuclear metalloradical chemistry. The work suggests that more stable metalloradicals of metal–metal hemi‐bonds may be accessible by using metal carbonyls together with large and weakly coordinating polyfluoroaluminate anions. |
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| Keywords: | cations metalloradicals metal– metal bonds unsupported bonds X‐ray diffraction |
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