Asymmetric Spin Density Distribution in the Copper( II ) Complex of N‐Confused Tetraphenylporphyrin: A Multifrequency Continuous‐Wave and Pulse EPR Study

The magnetic interactions between the unpaired electron and the nitrogen donors of the porphyrin ring in the copper(II) complex of N-confused tetraphenylporphyrin, [CuII(nctpp)], were studied by continuous-wave (cw) and pulse EPR methods (see picture). A pronounced asymmetric distribution of the spin density on the three core nitrogen nuclei was found, in contrast to the spin density distribution in the symmetric [CuII(tpp)] complex.