Abstract
The synthesis and characterization of divalent [Fe(TC-5,5)] (1) and trivalent [Fe(OTf)(TC-5,5)] (2) tropocoronand complexes are described. Compound 1 reacts with 1 equiv of NO to form the {FeNO}7 complex 3. A single-crystal X-ray structure determination of 3 reveals a trigonal bipyramidal geometry with a linearly coordinated nitrosyl (Fe−N−O = 174.3(4)°) having a short Fe−N distance of 1.670(4) A. EPR and Mossbauer spectroscopy, SQUID susceptometry, and normal coordinate analysis indicate 3 to be a low-spin {FeIII(NO-)}2+ species. In the presence of excess NO, 3 converts to a metastable nitrosyl−nitrito complex that decomposes by losing NO2, which subsequently nitrates the aromatic tropolone rings of the ligand. The final products of the NO disproportionation reaction are N2O and [Fe(NO)(TC-5,5-NO2)] (4). The νNO stretching band of 4 is increased to 1716 cm-1 from its value of 1692 cm-1 in 3, owing to the electron-withdrawing nitro groups on the ligand, and the compound no longer promotes the disproportio...
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
