Magnetic circular dichroism spectroscopy of cobalt tetraphenyltetraacenaphthoporphyrin
John Mack, Yoshiaki Asano, Nagao Kobayashi, Martin J. Stillman
Journal of Inorganic Biochemistry
The first MCD spectral data for an open shell first row transition metal complex of tetraphenyltetraacenaphthoporphyrin (TPTANP) are reported. The B (or Soret) band of cobalt tetraphenyltetraacenaphthoporphyrin (CoIITPTANP(−2)) exhibits an anomalous negative Faraday A1 term as was reported previously in the case of ZnTPTANP, while a positive A1 term is observed for the Q band. INDO/1 geometry optimizations predict that the TPTANP ligand is saddled due to steric hindrance at the ligand periphery to a slightly lesser extent than is the case with ZnTPTANP. The Q and B bands of CoTPTANP arising from the π-system are blue shifted relative to those of ZnTPTANP, based on the “hypso” effect reported previously for planar porphyrin complexes of d6–9 transition metals.
Magnetic circular dichroism, Inorganic chemistry, Biochemistry