Using the bidirectional NICS scan method in conjunction with two-photon absorption (TPA) measurements, it has proved possible to determine the relationship between pi-conjugation and aromaticity in two structurally related expanded porphyrin systems, sapphyrin and inverted sapphyrin, and establish that differences in these defining factors depend on the presence or absence of a key sp3 hybrid molecular orbital within the macrocyclic periphery.
No takes yet. Share an insight, caveat, or question.
Yoon et al. (2007) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: