.mu.-Oxo iron(III) phthalocyanine. Electronic structure of the solid form obtained from a dihydroxoiron(III) precursor

Further Studies on the Oxidation State of Iron in μ-Oxo Dimeric Phthalocyanine Complexes

“…Thus the Q-band has been observed at 627 nm for PyPcMn-O-MnPcPy [26,48] R is an unsubstituted or a tetra-4-tert-butyl-or tetra-4-ethylsubstituted phthalocyanine [46,[51][52][53][54][55]. Form '690' obtained either by direct reaction [8][9][10][11][12] or by reaction of iron phthalocyanine with oxygen [13][14][15] has the Qband at $690 nm (Fig. 1A) [8][9][10][11][12][23][24][25].…”

“…), were proposed for two isolated forms of m-oxo-bridged complexes with postulated Fe(II) ions [8][9][10][11][12]. On the other hand, many authors consider these complexes to be m-oxo-bis(phthalocyanine iron(III)), (PcFe) 2 O, and axially coordinated m-oxobis(phthalocyanine iron(III)), (LPcFe) 2 O [13][14][15]. By analogy with other iron(III) m-oxo dimers [2][3][4][5][6][7], a high-spin, strongly antiferromagnetically coupled (J b À100 cm À1 ) Fe(III) pair has been postulated for (PcFe) 2 O [13][14][15][16], while a weakly coupled (J % À6 cm…”

“…Most attention has been concentrated on the study of m-oxo-bridged complexes based on the unsubstituted phthalocyanine ligand, which are only slightly soluble in common organic solvents [13][14][15][16][17][18][19][20]. Regarding more soluble compounds, only a few works have been carried out [8][9][10][11][12]21].…”

“…Regarding more soluble compounds, only a few works have been carried out [8][9][10][11][12]21]. The use of lowsolubility phthalocyanine m-oxo dimers leads to difficulties with their purification, and in all cases the presence of monomeric or dimeric impurities has been observed [13][14][15], misrepresenting the spectral characteristics of the studied complexes. On the other hand, tert-butyl-substituted phthalocyanine complexes show good solubility in common organic solvents, and the effect of the alkyl groups on the electronic structure of the corresponding complexes is very weak [8][9][10][11][12]22].…”

The cathodic reduction of oxygen at metal tetrasulfonato-phthalocyanines: influence of adsorption conditions on electrocatalysis

“…In addition, UV-vis spectra were recorded to determine the reaction of the water-soluble phthalocyanines with oxygen. It is generally accepted that peroxy species are formed [13- For FePc, even the subsequent formation of an oxo-bridged species has been reported [16,17]:…”