Reaction of μ-oxobis(phthalocyaninatoiron(III)) in pyridine/water. Evidence for a slow reacting oxophthalocyaninatoiron(IV) compound
作者:Fabrizio Monacelli
DOI:10.1016/s0020-1693(96)05174-2
日期:1997.1
The reaction of mu-oxobis(phthalocyaninatoiron(III)) in pyridine containing small amounts of water has been investigated. The reaction occurs in two consecutive steps. The first step is a disproportionation equilibrium (K = 1.0X10(-3) mol dm(-3) at 35 degrees C) yielding [(py)(2)Fe(II)(pc)] and the ferryl compound [(py)Fe(IV)(pc)O]. The spectrum of the latter in the 600-700 nm range shows the shape characteristic of phthalocyaninato derivatives with a high intensity Q band (epsilon = 7.5 X 10(4)) at 670 nm. During the succeeding step, that requires several hours to be completed, the Fe=O oxygen is transferred to peripheral sites of the macrocycle, very likely to form C-OH groups. This fact does not modify appreciably the electronic properties of the complex, if compared to those of [(py)(2)Fe(pc)], and can be revealed only by FAB experiments which show the presence of phthalocyaninato derivatives of mass 568 + 16 and 568 + 32 (568 being the mass of the molecular ion [Fe(pc)(+)]. The first step of this reaction represents a convenient method for preparing pyridine solutions of the ferrylic species, suitable for reactivity studies.