Novel Model Compounds for Photoinduced Electron Transfer: Structures of the Folded Conformers of Zinc(II)–Pyropheophytin– Anthraquinone Dyads

✍ Scribed by Juho Helaja; Andrei Y. Tauber; Ilkka Kilpeläinen; Paavo H. Hynninen

• Book ID: 101256313
• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 477 KB
• Volume: 35
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/(sici)1097-458x(199709)35:9<619::aid-omr143>3.0.co;2-r

✦ Synopsis

The solution structures of the P4-epimers of Zn(II)-pyropheophytin-anthraquinone dyads (ZnPQ1 and ZnPQ2) were determined using two-dimensional NMR spectroscopy and molecular modeling. The mutual orientation of the anthraquinone and Zn-pyropheophytin rings was found to be di †erent in the two P4-epimeric dyads on the basis of the ROESY correlations, observed between the quinone and phorbin protons. The anthraquinone ring is situated below the phorbin macrocycle in both dyads, ZnPQ1 and ZnPQ2. In ZnPQ1, the ring planes show tilting, the anthraquinone ring being in a sloping position below subrings B, C and E of the phorbin macrocycle. In ZnPQ2, the two p-systems are almost parallel with the anthraquinone ring being located approximately below the center of the phorbin macrocycle.