Effects of axial pyridine coordination on a saddle-distorted porphyrin macrocycle: stabilization of hexa-coordinated high-spin Fe(iii) and air-stable low-spin iron(ii) porphyrinates
We have reported here the effect of axial ligand L (L: pyridine/substituted pyridine) on FeIII(tn-OEP)Cl/FeIII(tn-OEP)ClO4 that first form high-spin FeIII(tn-OEP)(L)2.X (X: Cl, ClO4) which, on longer exposure, spontaneously auto reduce to a series of air stable FeII(tn-OEP)(L)2 complexes. The introduction of four nitro groups into the meso-positions of octaethyl porphyrin (tn-OEP), severely distorts