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The synthesis and characterization of a new series of relatively flexible cofacial donor-acceptor dyads for singlet-singlet energy transfer with the corrole or etio-porphyrin free base and zinc porphyrin is described, as the acceptor and donor. The results show that the presence of a bulky group located between the acceptor and the donor moiety influences the energy transfer rate.

The formation of a [pi]-complex of a free-base bisporphyrin (H4DPOx) with acridinium perchlorate (Ac[H.sup.}Cl[O4.sup.-]) and the photodynamics in benzonitrile (PhCN) is reported. Results reveal that a 1:1 [pi]-complex is formed between H4DPOx and Ac[H.sup.} in PhCN with a large binding constant.

The electrochemistry and pyridine binding reactions of different porphyrin-crrole dyads are investigated by cyclic voltammetry and thin-layer spectroelecrochemistry in pyridine. Up to four pyridine ligands can be coordinated to each dyad, with the exact value depending upon the metal oxidation state and type of spacer.

The synthesis of a novel family of heterobinuclear cofacial biphenylene (B), anthracene (A), 9,9-dimethylxanthene (X) or dibenzofuran (O) bridged porphyrin-corrole complexes, (PCY)MCICoCl, is reported, M being either an iron(III) or manganese(III) ion. Each complex is characterized by electrochemistry, mass spectrometry, UV-vis, IR, and electron spin resonance spectroscopy.

The synthesis and characterization of cofacial copper biscorroles and porphyrin-corroles linked by a biphenylenyl or anthracenyl spacer are described. The comparative study of four cofacial copper bis-corrole) BC and porphyrin-corrole (PC) dyads and their related monomeric corrole and porphyrin units shows that electron interaction between the two face-to-face macrocycles of these cofacial derivatives depends critically on the type and size of rigid spacer.

The diprotonated form of a fluorinated free base porphyrin, 5-(p-aminophenol)-10,15,20-tris(pentafluorophenyl)porphyrin ([H.sub.2]FAP), has catalyzed the reduction of oxygen by a weak electron donor like ferrocene (Fc). Spectrophotometric measurements performed in 1,2-dichloroethane solutions have shown that reduction of oxygen by Fc catalyzed by [H.sub.4][FAP.sup.2+] has occurred in the presence of the tetrakis(pentafluorophenyl)borate ([TB.sup.-]) counteranion in the organic phase.

Molecular electrocatalysis for oxygen reduction at a polarized water/1,2-dichloroethane (DCE) interface is analyzed, which has involved aqueous protons, ferrocene (Fc) in DCE and amphiphilic cobalt porphyrin catalysts adsorbed at the interface. The reaction is shown to be electrocatalytic as its rate has depended on the applied Galvani potential difference between the two phases.

Cobalt porphine (CoP) dissolved in the organic phase of a biphasic system is used for catalyzing [O.sub.2] reduction by an electron donor, ferrocene (Fc). Voltammetry is used at the interface between two immiscible electrolyte solutions (ITIES) to drive this catalytic reduction at the interface as a function of the applied potential difference, where aqueous protons and organic electron donors have combined to reduce [O.sub.2].

The catalytic mechanisms of the dehydrogenation vs the oxygenation of 10-methyl-9,10-dihydroacridine (AcrHR) in the two electron and four-electron reduction of O2, catalyzed by monomeric cobalt porphyrins and cofacial dicobalt porphyrins, respectively, are discussed in relation to the C(9)-H or C(9)-C bond cleavage of AcrHR radical cations produced in the electron-transfer oxidation of AcrHR.