Application of MCD spectroscopy to porphyrinoids

A Core‐Expanded Subphthalocyanine Analogue with a Significantly Distorted Conjugated Surface and Unprecedented Properties

“…In the magnetic circular dichroism (MCD) spectra, Faraday B terms corresponding to the split Q bands were observed for both compounds, thus indicating nondegenerate excited states of 1 a and 2 a. [22] Compounds 1 a and 2 a also exhibited fluorescence at 710 and 706 nm with fluorescence quantum yields of 0.08 and 0.006, respectively. The smaller quantum yield of 2 a relative to that of 1 a is reasonable if the more flexible structure of 2 a indicated by the variable-temperature 1 H NMR spectroscopic measurements is taken into consideration.…”

Interaction of Fe3+meso-tetrakis (2,6-dichloro-3-sulfonatophenyl) porphyrin with cationic bilayers: magnetic switching of the porphyrin and magnetic induction at the interface

“…PP does not exhibit circular dichroism (CD) signal. The presence of a magnetic field results in the magnetic circular dichroism signal as resulting from orbital splitting (Faraday A term contribution) and mixing (Faraday B term contribution) [38,[66][67][68].…”

Photophysical properties of tetraphenylporphyrinsubphthalocyanine conjugates

“…The Q band of the subPc chromophore is slightly blue shifted to 562 nm on coordination to both porphyrins. Magnetic circular dichroism (MCD) spectroscopy can be used to identify the main electronic Q(0,0) and B(0,0) bands of porphyrinoids, due to the presence of intense Faraday A1 terms or coupled pairs of oppositely-signed Faraday B0 terms [20,21]. In the context of the TPP-O-subPc conjugates, the two chromophores can be viewed as retaining their four-fold and three-fold axes of symmetry, since they are linked at the axial position of the boron atom of subPc and a meso-phenyl ring of TPP rather than being directly linked to the two core chromophores, so the spectra are dominated by pseudo-A1 terms.…”