meso-Pentafluorophenyl-substituted nonaphyrin-(184.108.40.206.220.127.116.11.1) 3 has been prepared by using a stepwise ring-size-selective synthesis, and has been reduced with NaBH4 to nonaphyr-in(18.104.22.168.22.214.171.124.1) 5. Structurally, 3 is characterized by a figure-of-eight shape, consisting of a porphyrin-like tetrapyrrolic segment and a hexaphyr-in-like hexapyrrolic segment, whereas 5 has been found to adopt a distorted nonplanar butterfly-like shape. In the mono-metal complexes 6 and 7, a ZnII or CuII ion is bound by the porphyrin-like tetrapyrrolic segment, maintaining the overall structure of 3. Similarly to 3. complexes 6 and 7 are interconvertible with the corresponding complexes 9 and 10 through two-electron reduction with NaBH4 and oxidation with DDQ. The metal-free hexaphyrin-like segments of 6 and 7 have been shown to serve as a suitable platform for the complexation of two palladium ions, providing hetero-trinuclear metal complexes 11 (Zn II-PdII-PdII) and 13 (CuII-Pd II-PdII) in high yields, in which the Zn or Cu ion resides at the same porphyrin-like segment, and one Pd ion is bound in an NNCC fashion through double C-H bond activation while the other is bound in an NNC fashion with single C-H bond activation. Multi-metal complexes 11, 12. and 13 exhibit small electrochemical HOMO-LUMO gaps (<0.6eV). despite their nonplanar conformations.
All Science Journal Classification (ASJC) codes
- Organic Chemistry