SYNTHESIS AND SPECTROSCOPICAL PROPERTIES OF THE MIXED-VALENT DI(PHTHALOCYANINATO)LANTHANIDES(III)

Green di(phthalocyaninato)lanthanide(III), [M(Pc)(2)] (M = rare earth metal ion: La..(-Ce, Pm)..Lu) is prepared by anodic oxidation of ((n)B u(4)N)[M(Pc(2-))(2)] dissolved in CH2Cl2/((n)Bu(4)N)ClO4. The UV-Vis-N IR spectra show intense pi-pi transitions at similar to 15000 cm(-1) and 31000 cm(-1), typical for Pc(2-) ligands. Bands at similar to 1100 0 cm(-1) and 22000 cm(-1) indicate the equal presence of a Pc(-) pi-ra dical. The metal dependent NIR band between 4000 and 9000 cm(-1) is ch aracteristic for these mixed-valent complexes and assigned to an inter valence transition (b(1) --> a(2); D-4d symmetry). Most bands are shif ted linearly with the M(III) radius. In the IR and resonance Raman (r. r.) spectra the typical vibrations of the Pc(-) pi-radical are dominan t. These are essentially metal independent excepting the C-C and C-N v ibrations of the inner (CN)(8) ring. The sym. M-N stretching vibration between 141 (La) and 168 cm(-1) (Lu) is selectively r.r.-enhanced whe n excited with 1064 nm.