Date of Award
1987
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Abstract
The absorption and magnetic circular dichroism (MCD) spectra of a series of phthalocyanine (Pc) complexes (CoPc, ZnPc, FePc, RuPc, MnPc and MgPc) have been recorded. Axial ligation to CoPc, ZnPc, FePc and RuPc complexes results in the species that are soluble in methylene chloride, and hence, for the first time, allows for the observation of the high energy bands in the solution spectra of the MPc complexes.;Although, the Q band is well separated from the rest of the bands, configuration interaction results in a considerable overlap of bands in the Soret region. Band deconvolution calculations are thus, used to provide information on the positions and widths of the bands in the spectra of the CoPc, ZnPc, FePc, RuPc, MnPc and MgPc complexes. The spectra of the ZnPc complexes, which should be free of charge transfer transitions, are used as models in assigning the spectra of the other MPc complexes. The Q, B, N, L and C bands of the ZnPc complexes are centered near, 14 900, 27 513, 29 778, 35 437 and 40 655 {dollar}{lcub}\rm cm \sp{lcub}-1{rcub}{rcub},{dollar} respectively. Charge transfer transitions complicate the spectra of the CoPc, FePc, MnPc, and RuPc complexes, while solvent absorptions obscure the high energy bands in MgPc complexes.;The chemical, electrochemical and photochemical oxidation products of CoPc, ZnPc, FePc and RuPc complexes are characterized by the absorption, MCD and electron paramagnetic resonance (EPR) spectroscopies. In Zn(II)Pc, Ru(II)Pc and Co(II)Pc complexes, oxidation occurs at the phthalocyanine ligand forming the M(II)Pc({dollar}-1){dollar} {dollar}\pi{dollar} cation radical species. In Fe(II)Pc complexes, however, the formation of the {dollar}\pi{dollar} cation radical complex only occurs after the oxidation of Fe(II) to Fe(III). The {dollar}\pi{dollar} cation radical spectra consists of many overlapping bands and band deconvolution calculations are used to give an estimate of the number and positions of the individual bands. The formation of the {dollar}\pi{dollar} cation radical species is identified by the formation of degenerate transitions near 12 050, 14 300 and 23 000 and a nondegenerate transition near 20 000 {dollar}{lcub}\rm cm\sp{lcub}-1{rcub}{rcub}.{dollar} The 14 300 {dollar}{lcub}\rm cm\sp{lcub}-1{rcub}{rcub}{dollar} band is assigned to the Q band of the MPc{dollar}(-1){dollar} {dollar}\pi{dollar} cation radical species. The bands near 12 050, 20 000 and 23 000 {dollar}{lcub}\rm cm\sp{lcub}-1{rcub}{rcub}{dollar} are associated with {dollar}\pi\to\pi{dollar} transitions.
Recommended Citation
Nyokong, Tebello, "Electrochemical And Photochemical Properties Of Metallophthalocyanines" (1987). Digitized Theses. 1607.
https://ir.lib.uwo.ca/digitizedtheses/1607