A Highly Reactive Seven‐Coordinate Osmium(V) Oxo Complex: [OsV(O)(qpy)(pic)Cl]2+ |
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| Authors: | Yingying Liu Dr Siu‐Mui Ng Dr William W Y Lam Dr Shek‐Man Yiu Prof Tai‐Chu Lau |
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| Affiliation: | Department of Biology and Chemistry and Institute of Molecular Functional Materials, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China) |
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| Abstract: | Seven‐coordinate ruthenium oxo species have been proposed as active intermediates in catalytic water oxidation by a number of highly active ruthenium catalysts, however such species have yet to be isolated. Reported herein is the first example of a seven‐coordinate group 8 metal‐oxo species, OsV(O)(qpy)(pic)Cl]2+ (qpy=2,2′:6′,2′′:6′′,2′′′‐quaterpyridine, pic=4‐picoline). The X‐ray crystal structure of this complex shows that it has a distorted pentagonal bipyramidal geometry with an Os?O distance of 1.7375 Å. This oxo species undergoes facile O‐atom and H‐atom‐transfer reactions with various organic substrates. Notably it can abstract H atoms from alkylaromatics with C? H bond dissociation energy as high as 90 kcal mol?1. This work suggests that highly active oxidants may be designed based on group 8 seven‐coordinate metal oxo species. |
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| Keywords: | C H activation osmium oxidation structure elucidation X‐ray diffraction |
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