Electrocrystallization and X-ray Structure of Partially Oxidized Stacked Porphyrin Trimers of the Form 3F2(BF4)2*C7H8

Article abstract of DOI:10.1021/ja00195a023

The sunthesis, structural characterization, and electrical conductivity of a fluorogallium porphyrin trimer, <(OEP)Ga>3F2(BF4)2*C7H8, are described.Single crystals of this compound suitable for X-ray analysis were obtained by a slow galvanostatic electrolysis of (OEP)GaF in toluene/acetonitrile.The monoclinic cell of this compound, space group P2₁/c with Z = 2, has parameters a = 14.968(3) Angstroem, b = 24.80 (1) Angstroem, c = 15.268(6) Angstroem, β = 78.82(3) deg, and V = 5518 Angstroem³.The structure was refined by a full-matrix least-squares technique leading to final residuals of R_w = 0.064 and R = 0.060 for the 431 variables and the 3508 unique reflections for which I >= 3?(I).The structure is described as segregated linear stacks of trimers separated by one toluene of solvation along <1, 0, 0>.ESR data indicate one ligand-centered oxidation site per trimer.Direct current conductivity measurements give small values of ? between 1E-7 and 1E-8 Ω^-1 cm^-1, but these values increase at high ac frequency (? = 1.24-1.5 Ω^-1 cm^-1 at 10 GHz).