Photoinduced electron transfer in supramolecular assemblies involving saddle-distorted porphyrins and phthalocyanines

Takahiko Kojima, Tatsuaki Nakanishi, Tatsuhiko Honda, Shunichi Fukuzumi

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Unique supramolecular assemblies are constructed based on a saddle-distorted non-planar porphyrin, dodecaphenylporphyrin (H2DPP), and its metal complexes. The saddle distortion facilitates protonation of pyrrole nitrogens to afford a stable diprotonated porphyrin, which can act as an electron acceptor. A diprotonated hydrochloride salt of a saddle-distorted dodecaphenylporphyrin ([H4DPP]Cl2) forms a nano-sized channel structure called a "porphyrin nanochannel". Electron-donating molecules such as hydroquinones are included as guest molecules in the porphyrin nanochannel. Photoinduced electron transfer from the guest molecules to the singlet state of H4DPP2+ occurs, producing H 4DPP+• and cation radicals of the guest molecules. The saddle distortion also results in higher Lewis acidity at a metal center to maintain axial coordination of ligands, due to poor overlap of the lone-pair orbitals with the d orbitals of the metal center. By taking advantage of saddle distortion of both H4DPP2+ and zinc phthalocyanine, 1,4,8,11,15,18,22,25-octaphenylphthalocyanine (ZnOPPc), a discrete supramolecular assembly composed of H4DPP2+ and ZnOPPc, is obtained using 4-pyridinecarboxylate (4-PyCOO-) that connects the two components by hydrogen bonding and coordination bonding, respectively. Photoexcitation of the assembly results in efficient electron transfer from ZnOPPc to H4DPP2+ in the supramolecular complex.

Original languageEnglish
Pages (from-to)14-21
Number of pages8
JournalJournal of Porphyrins and Phthalocyanines
Issue number1
StatePublished - Jan 2009

Bibliographical note

Funding Information:
The authors gratefully acknowledge the contributions of collaborators and co-workers mentioned in the references. The authors also acknowledge support of their study by Grants-in-Aid and a Global COE program, “The Global Education and Research Center for BioEnvironmental Chemistry” from the Ministry of Education, Culture, Sports, Science and Technology, Japan and Japanese Society of Promotion of Science. T. K. appreciates support from Japan Society of Science and Technology through “the potentiality verification stage” program.


  • Photoinduced electron transfer
  • Saddle-distorted phthalocyanine
  • Saddle-distorted porphyrin
  • Supramolecular assembly


Dive into the research topics of 'Photoinduced electron transfer in supramolecular assemblies involving saddle-distorted porphyrins and phthalocyanines'. Together they form a unique fingerprint.

Cite this