High-spin five-coordinate Fe

Metathetical reactions on the complex [Fe(Me6[14]-4,ll-dieneN4) (CH3CN)2] lead to a series of low-spin six-coordinate (with coordinated NCS") and high-spin five-coordinate (Br", 1", OFT) complexes. Low-spin iron(lll) complexes are also known. 

Five-coordinate Fe complexes of tetra-(/He5o-hepta-fluoro-n-propyl)porphyrin have pyrrole-H peaks at 101.5 and 86.4 ppm as a result of 5 4-distortion of the porphyrin ring, probably a ruffling distortion, since the structure of the bis-pyridine Fe complex is highly ruffled. Five-coordinate Fe complexes of reduced porphyrins have also been reported NMR spectra of high-spin Fe complexes... 

SERRS and voltammetry techniques were used to elucidate the mechanism of oxygen reduction on a silver electrode with iron(III) tetra-4-iV-methylpyridyl-porphyrin " . The results indicate that after the oxidation-reduction cycle at pH 10 and pH 4 the iron porphyrin is adsorbed on the Ag surface as a high-spin, five-coordinated -oxo-bridged dimer. SERRS spectra show that the first electron transfer forms a mixed-valence Fe(n)-0-Fe(III) //- oxo-bridged dimer. 

In 50 the strain resulting from tridentate coordination of 48 is alleviated by the >NH bridge between the thiazole and one of the pyridine rings, creating one six-membered and one five-membered chelate ring. This is evident from the structure of the high spin fluoroborate salt [Fe 502](BF4)2.3H2O in... 

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