β-to-β Directly linked cyclic Ni(II) porphyrin trimer, tetramer, and pentamer (CP, CP, and CP) have been synthesized by reaction of a 2,12-diborylated Ni(II) porphyrin with Pt(cod)Cl2 followed by reductive elimination. The structures of these cyclic porphyrin arrays have been revealed by X-ray diffraction analysis. The strain energies of these cyclic oligomers are calculated to be 77, 57, and 47 kcal/mol for CP, CP, and CP, respectively. Intramolecular excitation energy hopping was observed between the 3(d,d) states of the Ni(II) porphyrins with rates of 3.0, 4.4, and 4.6 ps for CP, CP, and CP, respectively, reflecting the close proximity of the Ni(II) centers.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry