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Four aryl-substituted tripyrrinone copper(II) complexes were synthesized and characterized as to their electrochemical and spectroelectrochemical properties. The examined compounds are represented as (YPh)3TPO2Cu, where TPO2 is a dianion of the tripyrrinone and Y is a CH3O, CH3, H or Cl substituent on the para-position of each phenyl ring of the compound. The neutral compounds are ESR active and show a typical d9 Cu(II) signal in frozen CH2Cl2 solution. Each Cu(II) compound undergoes three reductions between −0.61 and −1.90 V and two oxidations between 1.00 and 1.24 V in CH2Cl2 containing 0.1 mol/L tetra-n-butylammonium perchlorate. The potentials for oxidation are similar to those of copper tetraarylporphyrins but the reduction potentials are positively shifted as compared to the corresponding tetraarylporphyrins. Thus, the potential difference between the first one-electron oxidation and first one-electron reduction (the HOMO-LUMO gap) of (YPh)3TPO2Cu, which ranges from 1.68 to 1.75 V, is similar to that of copper corroles (1.73–1.85 V), but smaller than the separation of 2.30–2.37 V for the copper tetraarylporphyrins under the same solution conditions.

A series of N-confused free-base meso-substituted tetraarylporphyrins was investigated by electrochemistry and spectroelectrochemistry in nonaqueous media containing 0.1 M tetra-n-butylammonium perchlorate (TBAP) and added acid or base. The investigated compounds are represented as (XPh)4 NcpH2 , in which "Ncp" is the N-confused porphyrin macrocycle and X is a OCH3 , CH3 , H, or Cl substituent on the para position of each meso-phenyl ring of the macrocycle. Two distinct types of UV/Vis spectra are initially observed depending upon solvent, one corresponding to an inner-2H form and the other to an inner-3H form of the porphyrin. Both forms have an inverted pyrrole with a carbon inside the cavity and a nitrogen on the periphery of the π-system. Each porphyrin undergoes multiple irreversible reductions and oxidations. The first one-electron addition and first one-electron abstraction are located on the porphyrin π-ring system to give π-anion and π-cation radicals with a potential separation of 1.52 to 1.65 V between the two processes, but both electrogenerated products are unstable and undergo a rapid chemical reaction to give new electroactive species, which were characterized in the present study. The effect of the solvent and protonation/deprotonation reactions on the UV/Vis spectra, redox potentials and reduction/oxidation mechanisms is discussed with comparisons made to data and mechanisms for the structurally related free-base corroles and porphyrins.

Multicomponent BaMo2O7 single-crystalline nanowire bundles were synthesized by a hydrothermal crystallization process under mild conditions using cheap and simple bulky oxide and fluoride as precur...