Reactivity of hydride bridges in a high-spin [Fe3(μ-H)3]3+ cluster: reversible H2/CO exchange and Fe–H/B–F bond metathesis. Issue 5 (11th April 2017)

• Record Type: Journal Article
• Authors: Anderton, Kevin J.; Knight, Brian J.; Rheingold, Arnold L.; Abboud, Khalil A.; García-Serres, Ricardo; Murray, Leslie J.
• Is Part Of: Chemical science. Volume 8:Issue 5(2017)
• Page Start: 4123
• Page End: 4129
• Publication Date: 2017-04-11
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6sc05583d
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : The triiron trihydride complex Fe3 H3 L (1 ) [whereL 3− is a tris(β-diketiminate)cyclophanate] reacts with CO and with BF3 ·OEt2 to afford (Fe I CO)2 Fe II (μ3 -H)L (2 ) and Fe3 F3 L (3 ), respectively. Abstract : The triiron trihydride complex Fe3 H3 L (1 ) [whereL 3− is a tris(β-diketiminate)cyclophanate] reacts with CO and with BF3 ·OEt2 to afford (Fe I CO)2 Fe II (μ3 -H)L (2 ) and Fe3 F3 L (3 ), respectively. Variable-temperature and applied-field Mössbauer spectroscopy support the assignment of two high-spin (HS) iron(i ) centers and one HS iron(ii ) ion in2 . Preliminary studies support a CO-induced reductive elimination of H2 from1, rather than CO trapping a species from an equilibrium mixture. This complex reacts with H2 to regenerate1 under a dihydrogen atmosphere, which represents a rare example of reversible CO/H2 exchange and the first to occur at high-spin metal centers, as well as the first example of a reversible multielectron redox reaction at a designed high-spin metal cluster. The formation of3 proceeds through a previously unreported net fluoride-for-hydride substitution, and3 is surprisingly chemically inert to Si–H bonds and points to an unexpectedly large difference between the Fe–F and Fe–H bonds in this high-spin system.