X-Ray crystal structure of ?-Oxo-bis[(1-methylimidazole)-phthalocyaninatoiron(III)] and comments on the molecular structure and chemistry of Oxo-bridged iron phthalocyaninate dimers

Single-crystal X-ray work has been carried out on crystals containing the 1-methylimidazole adduct of µ-oxo-bis[(phthalocyaninato)iron(III)], [{Fe(pc)(mim)}2O]·[Fe(pc)(mim)2]·3Me2CO. The crystals are monoclinic, space group C2/c, with a= 35.236(5), b= 14.173(2), c= 23.220(3)Å, ?= 103.56(10)° and Z= 4. The structure was solved and refined using all data including zero intensities (5739). Only the atoms of the µ-oxo dimer were refined anisotropically because of data limitations. The Fe atoms in [{Fe(pc)(mim)}2O] are nominally centred in the phthalocyanine plane, with an average Fe-N(pc) of 1.92(3)Å and six-co-ordinate, with Fe-O 1.749(1)Å and Fe-N(mim) 2.039(7)Å. The Fe-O-Fe angle is 175.1°. X-Ray data for [Fe(pc)(mim)2] are as expected for six-co-ordinate low-spin nitrogen-containing base adducts of [Fe(pc)]. The crystal data are discussed in the light of similar results on [{Fe(pc)(mim)}2C] and related compounds.