Electronic effects in transition metal porphyrins. The reactions of imidazoles and pyridines with a series of para-substituted tetraphenylporphyrin complexes of chloroiron(III)

Linear free energy relationships predict coordination and π-stacking interactions of small molecules with ferriprotoporphyrin IX

“…Nonetheless, the findings are in agreement with more recent ones of Marques et al where a similar stepwise process was found with imidazole and hematohemin in methanol [41] as well as a number of older studies on other iron porphyrins in organic solvents [48,49]. The effect in hematohemin was seen to involve only subtle changes in the spectrum upon association of the first imidazole, followed by a much larger change when the second ligand binds and converts the iron porphyrin to a low spin complex.…”

Synthesis, properties, and reactivity of a series of non-heme {FeNO}7/8 complexes: Implications for Fe-nitroxyl coordination

“…After a THF blank was recorded at 298 K, the spectrum of the working solution was recorded. The UV-vis spectrum thus obtained was consistent with literature [50] and was monitored over 15 min resulting in no observable change. To this cuvette was then added a 0.025 mL aliquot of a 1 mM stock of the {FeNO} 7 (3 or 4 in THF) or {FeNO} 8 (5 or 6 in acetone) compounds (1:1 ratio of [Fe(TPP)Cl]/{FeNO} 7/8 ) to initiate the reaction.…”

Photoreduction of iron protoporphyrin IX chloride in non‐ionic triton X‐100 micelle studied by electronic absorption and resonance Raman spectroscopy

“…42 Moreover, the absorption spectrum of another similar complex, Fe III TPP(H 2 O) 2 ClO 4 , also shows close similarity to that of Fe III TPPCl complex with both species exhibiting theˇband at 510 nm, characteristic of coordination by Cl . 7,43 Experiments carried out in the presence of 2-MeIm and 1,2-Me 2 Im at ¾100 mM concentration at neutral or basic pH and anaerobic conditions with 441.6 nm excitation give the same spectra as those reported for five-coordinated high-spin ferrous complexes, 18 On laser excitation at 457.9 nm, similar photoreduction is obtained although to a lesser extent, but there is no reduction on excitation at wavelength ½488.0 nm. Similarly, no photoreduction is obtained at acidic pH even in the presence of 2-MeIm or 1,2-Me 2 Im.…”