π-complexes of phthalocyanines and metallophthalocyanines

Addition of [Cp*Ru(MeCN)(3)]PF6 to M(PcOEt) (PcOEt = octakis(ethoxy)phthalocyanine; M = H-2,H- Ni (1), Cu, VO) in dichloromethane results in the formation of {Cp*Ru[eta (6)-M(PcOEt)]}PF6. The molecular structure of 1 reveals eta (6)-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 Angstrom. In [Cp*Ru(eta (6)-H2PcOEt)]PF6, two distinct N-H sites are apparent in the H-1 NMR and IR spectra, but only one is exchangeable. The coordinated macrocycle can be metalated. The UV and electrochemical data indicate that the pi -bonded metal center functions as an electron-donating substituent. Luminescence studies indicate that the eta (6)-coordination quenches fluorescence to a lesser degree than coordination of metals into the N-4 pocket of the phthalocyanine subunit.