Synthesis and spectroscopic investigation of tetranitro-, tetraamino-, tetrahydroxy-, and tetracyanophthalocyanine-iron(III) chloride

The synthesis of peripherally tetrasubstituted phthalocyaninciron(III) chlo ride derivatives, (R)(4)PcFe(III)Cl (R=NO2, NH2, OH. and CN at the position s 2,9,16,23 or 1,8,15,22) is described. The complexes were characterized by magnetic susceptibility measurements, electronic and infrared spectra and X-ray powder diffraction patterns. The effects of substituents at the perip hery, and the solvents used on the electronic spectra are discussed. The Q band of the electronic spectra for the symmetrically functionalized derivat ives are red-shifted compared to that of unsubstituted PcFeCl. The substitu ents at positions 2,9,16,23 are more effectively involved in the extension of the pi -cloud delocalization than at the positions 1,8,15,22. The LMCT t ransitions superimposed on the Q band are found to be shifted to an interme diate region of 414-497nm depending on the basicity of the solvent. The sha rp IR signals of the C-H bond and metal-ligand vibrations appears to be dim inished for the 2,9,16,23-substituted derivatives than for the 1,8,15,22-su bstituted ones.