Electrochemistry of Quinoxalino- and Bis-Quinoxalino-Porpbyrins Containing Metal(II) Ions

摘要

The electrochemistry of t-butyl-tetraphenylporphyrin and t-butyl-tetraphenyl-quinoxalinoporphyrin,represented as (P)M and (PQ)M (see Figure 1) were investigated in the different nonaqueous solvents.Electrochemical data showed that the fusion of an electroactive quinoxaline group to an electroactive porphyrin (P=>PQ) results in easier reductions of the porphyrin part of the molecule while the quinoxaline-centered redox processes shifts to more negative potentials.The investigated (P)M complexes undergo one or two ring-centered reductions and one or two ring-centered oxidations while additional reductions are seen in the case of (PQ)M.The average HOMO-LUMO gaps for the (P)M and (PQ)M derivatives are 2.26+-0.09 V and 2.14+-0.08 V,respectively.Both values are smaller than the average separation of 2.33 +-0.13 V for the corresponding derivatives of (TPP)M.