SYNTHESIS AND CHARACTERIZATION OF QUINONE-SUBSTITUTED OCTAALKYL PORPHYRIN MONOMERS AND DIMERS

The synthesis and characterization of a variety of selectively metalated quinone-substituted zinc-containing octaalkyl porphyrin dimers, designed to mimic certain key electronic and structural aspects of the photosynthetic reaction centers of Rhodopseudomonas viridis and Rhodobacter sphaeroides, and appropriate control monomers and dimers are described. These new compounds have been characterized by 1H NMR, 13C NMR, UV-visible spectroscopy, mass spectrometry, and microanalysis. Electrochemical data arc also given for representative dimers and monomers and X-ray structural information is provided for a 1,3-phenyl-linked and a 1,4-phenyl-linked functionalized copper-containing dimer (Cu25 and Cu29, respectively) and for a quinone-substituted metal-free monomer (H220). Crystallographic data for H220 is as follows: monoclinic, P21/c, a = 8.241 (6), b = 30.34 (3), c = 13.502 (12) Å, β = 92.86 (1)°, t = -162 °C, Z = 4, R(F) = 0.069, NV = 434, NO = 5894. Crystallographic data for Cu25(1.5CHCl3MO.5CH3OH) is as follows: triclinic, Pī a = 19.015 (4), b = 19.043 (6), c = 12.957 (5) Å, α = 109.90 (2)°, β = 108.84 (2)°, γ = 101.86 (2)°, t = -162°C, Z = 2, R(F) = 0.085, NV = 1015, NO = 11574. Crystallographic data for Cu29(2CHC13) is as follows: triclinic, Pī, a = 12.036 (3), b = 12.762 (3), c = 14.353 (3) Å, α = 94.64 (1)°, β = 103.54 (1)°, γ= 104.68 (1)°, t = -115 °C, Z = 1 (molecule has a crystallographically imposed center of symmetry), R(F) = 0.067, NV = 505, NO = 8318. © 1990, American Chemical Society. All rights reserved.