Variable nitric oxide reactivity of tropocoronand cobalt(III) nitrite complexes as a function of the polymethylene linker chain length.
The size-dependent reactivity of cobalt tropocoronands [TC-n,n](2-) is manifest in the NO chemistry of the cobalt(III) nitrite complexes [Co(η(2)-NO(2))(TC-n,n)] (n = 4-6), the synthesis and characterization of which are reported for the first time. Complete conversion of [Co(η(2)-NO(2))(TC-4,4)] to the cobalt mononitrosyl [Co(NO)(TC-4,4)] occurs upon exposure to NO(g). In contrast, addition of NO(g) to [Co(η(2)-NO(2))(TC-5,5)] generates both cobalt mono- and dinitrosyl adducts, and addition of nitric oxide to [Co(η(2)-NO(2))(TC-6,6)] converts this complex to the dicobalt tetranitrosyl species [Co(2)(NO)(4)(TC-6,6)]. In the latter complex, two tetrahedral cobalt dinitrosyl units are bound to the aminotroponeiminate poles of the [TC-6,6](2-) ligand. These results significantly broaden the chemistry of cobalt tropocoronands with nitric oxide and the nitrite anion.
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Julia
J
Kozhukh
Stephen J
SJ
Lippard
D003035:Cobalt / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D009569:Nitric Oxide / Q000737:chemistry*; D009573:Nitrites / Q000737:chemistry*
D009573:Nitrites; D009569:Nitric Oxide; D003035:Cobalt