CrIII-Phthalocyaninate: Darstellung und spektroskopische Eigenschaften von Di(halogeno)phthalocyaninatochromaten(III)

Cr^III Phthalocyaninates: Synthesis and Spectroscopical Properties of Di(halo)phthalocyaninato(2 –)chromates(III) [Cr(H₂O)₂Pc^2?]⁺ reacts in acetone with (ⁿBu₄N)X to yield less soluble tetra(n-butyl)ammonium di(halo)phthalocyaninato(2 –)chromate(III), (ⁿBu₄N)[Cr(X)₂Pc^2?] (X = F, Cl, Br, I). In the differential pulse voltammograms the first ring oxidation is observed at 0,80 V, the ring reduction at ?1,48 V and the metal reduction (Cr(III)/Cr(II)) at ?0,80 V (averaged potentials). The last is followed by a partial dissociation of one of the halo ligands. In the UV-VIS-NIR spectra there are three weakly absorbing spin-allowed trip-quarter(TQ) transitions (TQ1 (8,4) < TQ2 (11,5) < TQ3 (20,6); averaged values (av) in 10³ cm^?1), a (Pc + X)-CrCT transition (31,3; av in 10³ cm^?1) and the characteristic π-π* transitions of the Pc^2? ligand (B (14,5) < Q₁ (24,5) < Q₂ (29,2) < N (36,0) < L (41,0); av in 10³ cm^?1). Q₁ and (Pc + X)-CrCT depend strongly on the halo ligands. Prominent luminescence spectra are obtained by excitation within the TQ1 region, in which the spin-forbidden trip-sextet transition (8330 (X = F), 7680 (Cl), 7460 (Br) 7450 cm^?1 (I)) dominates at low temperatures (T < 50 K). The vibrational spectra are discussed. In coincidence of the excitation lines with TQ3, v_s(Cr? X) at 458 (X = F) < 246 (Cl) < 157 (Br) < 107 cm^?1 ( I ) is selectively resonance Raman enhanced. v_as(Cr? X) is observed in the FIR spectrum at 522 (X = F) < 283/326 (Cl) < 227 (Br) < 205 cm^?1 ( I ).