Solution NMR and X-Ray Structural Studies on Model Iron Phthalocyaninato-Complexes for Use as Optical Sensors

The addition of primary amines as solubilizing reagents for phthalocyaninatoiron complexes is shown to afford six-coordinate bis(amine)phthalocyaninato complexes, i.e., [Fe(amine)2(pc)] 2 (amine = decan-1-amine) and 3 (amine = benzylamine), with the two new N-donors occupying the trans-axial positions. The new complexes were characterized by extensive NMR measurements in THF solution. For complex 3 with the benzylamine ligand, the solid-state structure was determined by X-ray diffraction methods. Complex 2 is sufficiently labile in THF solution to exchange one amine ligand against CO (gas) affording an equilibrium mixture containing [Fe(amine)(CO)(pc)] 4.