A quadruply azulene-fused porphyrin with intense near-IR absorption and a large two-photon absorption cross section.

@article{Kurotobi2006AQA,
  title={A quadruply azulene-fused porphyrin with intense near-IR absorption and a large two-photon absorption cross section.},
  author={Kei Kurotobi and Kil Suk Kim and Su Bum Noh and Dongho Kim and Atsuhiro Osuka},
  journal={Angewandte Chemie},
  year={2006},
  volume={45 24},
  pages={3944-7}
}