π-Complexes of Phthalocyanines and Metallophthalocyanines

Abstract

Addition of [Cp*Ru(MeCN)3]PF6 to M(PcOEt) (PcOEt = octakis(ethoxy)phthalocyanine; M = H2, Ni (1), Cu, VO) in dichloromethane results in the formation of {Cp*Ru[η6-M(PcOEt)]}PF6. The molecular structure of 1 reveals η6-coordination of Cp*Ru2+ to one of the isoindole subunits of the phthalocyanine ligand. The crystal structure reveals the presence of two cofacially stacked Pc units in the asymmetric unit separated by 3.27−3.36 Å. In [Cp*Ru(η6-H2PcOEt)]PF6, two distinct N−H sites are apparent in the 1H NMR and IR spectra, but only one is exchangeable. The coordinated macrocycle can be metalated. The UV and electrochemical data indicate that the π-bonded metal center functions as an electron-donating substituent. Luminescence studies indicate that the η6-coordination quenches fluorescence to a lesser degree than coordination of metals into the N4 pocket of the phthalocyanine subunit.