Magnetic circular dichroism spectroscopy of cobalt tetraphenyltetraacenaphthoporphyrin.
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 (Co(II)TPTANP(-2)) exhibits an anomalous negative Faraday A(1) term as was reported previously in the case of ZnTPTANP, while a positive A(1) 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 pi-system are blue shifted relative to those of ZnTPTANP, based on the "hypso" effect reported previously for planar porphyrin complexes of d(6-9) transition metals.
Mack
John
J
Department of Chemistry, University of Western Ontario, London, Ontario, Canada N6A 5B7.
Asano
Yoshiaki
Y
Kobayashi
Nagao
N
Stillman
Martin J
MJ
D002942:Circular Dichroism / Q000379:methods*; D003035:Cobalt / Q000737:chemistry*; D008280:Magnetics; D008958:Models, Molecular; D011166:Porphyrins / Q000737:chemistry*
D011166:Porphyrins; D003035:Cobalt