Branching ratio and L-2+L-3 intensities of 3d-transition metals in phthalocyanines and the amine complexes

L-2,L-3 inner-shell excitation spectra were obtained by electron energy-los s spectroscopy (EELS) for the divalent first transition series metals in ph thalocyanine complexes (MPc) such as titanium oxide phthalocyanine (TiOpc), fluoro-chromium phthalocyanine (CrFPc), manganese phthalocyanine (MnPc), i ron phthalocyanine (FePc), cobalt phthalocyanine (CoPc), nickel phthalocyan ine (NiPc) and copper phthalocyanine (CuPc). It was found that the value of normalized total intensity of I(L-2 + L-3) was nearly proportional to the formal electron vacancies of each 3d-state, and the values of the branching ratio, I(L-3)/I((L-2 + L-3), represented a high-spin-state rather than low -spin-state for MnPc, FePc and NiPc. EELS was also applied to charge-transf er complexes of FePc with an amine such as pyridine or gamma-picoline. It w as concluded that their I(L-2 + L-3) intensity of Fe showed the decrease in vacancies of 3d-states on the formation of the charge-transfer complex wit h these amines, which suggests some electron transfer from the amine to Fe in phthalocyanine. The EELS study provides beneficial information for inves tigating the electronic states of the specific metal sites in organic mater ials: (C) 2000 Elsevier Science Ltd. All rights reserved.