Monsch G, Klüfers P. [Fe(H
2 O)
5 (NO)]
2+ , the "Brown-Ring" Chromophore.
Angew Chem Int Ed Engl 2019;
58:8566-8571. [PMID:
31017715 DOI:
10.1002/anie.201902374]
[Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Indexed: 11/12/2022]
Abstract
Although the "brown-ring" ion, [Fe(H2 O)5 (NO)]2+ (1), has been a research target for more than a century, this poorly stable species had never been isolated. We now report on the synthesis of crystals of a salt of 1 which allowed us to tackle the unique bonding situation on an experimental basis. As a result of the bonding analysis, two stretched, spin-polarised π-interactions provide the Fe-NO binding-and challenge the concept of "oxidation state".
Collapse