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In-situ FTIR spectroelectrochemistry has been applied to determine difference spectra in the region 1800 to 1000 cm−1 associated with the oxidation of TPPH2, TPPMg, TPPCu, TPPZn, TPPCo, TPPMnCl, and TPPFeCl. In all cases, formation of the π-cation radical results in two characteristic absorbance decreases near 1600 and 1485 cm−1, and five characteristic absorbance increases near 1415, 1350, 1285, 1225, and 1005 cm−1. Formation of the π-dication was observed for TPPZn, TPPMg, and TPPCo, and gave rise to a new absorbance increase near 1600 cm−1, and a shift to higher frequency of bands in the 1200 to 1400 cm−1 region. Perchlorate coordination to oxidized TPPZn, TPPMg, and TPPCo gives rise to bands near 1140 and 1030 cm−1.

A . SCOTT HINMAN and BRAD J. PAVELICH. Can. J. Chem. 65, 919 (1987). A versatile thin layer spectroelectrochemical cell employing specular reflection of the incident light beam from the electrode surface is described. Its application to in-situ uv-vis and FTIR characterization of the products of electrochemical reactions and to thin layer voltammetry and coulometry as well as conventional cyclic voltammetry is demonstrated for the oxidation of tetraphenylporphinatozinc in dichloroethane/tetrabutylammonium perchlorate solution. The advantages and disadvantages of this type of cell as compared to more conventional sandwich type optically transparent thin layer electrodes are discussed.A. SCOTT HINMAN et BRAD J. PAVELICH. Can. J. Chem. 65, 919 (1987). On dtcrit une cellule spectroClectrochimique cn couche mince qui est versatile et qui utilise la riflexion sptculaire d'un faisceau de lumikre incidente provenant de la surface de I'ilectrode. Utilisant l'oxydation du titraphtnylporphinatozinc dans une solution de dichloroithane/perchlorate de tCtrabutylammonium, on a dCmontrC l'application de cette cellule i la caractkrisation par uv-vis et FTIR in-situ des produits des riactions tlectrochimiques, ii la voltamitrie et i la coulomCtrie en couche mince ainsi qu'i la voltamttrie cyclique conventionnelle. On compare les avantages et les disavantages de ce type de cellule avec ceux des Clectrodes en couches minces plus conventionnelles, de type sandwiches et optiquement transparentes.[Traduit par la revue]

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A. SCOTT HINMAN, KAREN MCGARTY, CLEMENT TANG, and BRAD J. PAVELICH. Can. J. Chem. 67, 545 (1989). Perchlorato(tetraphenylporphinato)manganese(III) (TPPMnC104) is shown to be a useful reagent for the determination of a variety of anions in nonaqueous media. The analysis is based on the displacement of coordinated perchlorate by more strongly coordinating anions as monitored spectrophotometrically. The procedure is demonstrated for the determination of tetraalkylammonium salts of nitrate, nitrite, chloride, bromide, iodide, acetate, trifluoroacetate, cyanate, and thiocyanate in acetonitrile. Relative precisions and accuracies of the order of five parts per thousand are indicated.Key words: perchlorato(tetraphenylporphinato)manganese(III), specrophotometric determination of anions, anions in nonaqueous media.A. SCOTT HINMAN, KAREN MCGARTY, CLEMENT TANG et BRAD J. PAVELICH. Can. J. Chem. 67,545 (1989). On dCmontre que le perchlorato(tCtraphCnylporphinato)manganese(III) (TPPMnC104) est un reactif utile pour dtterminer divers anions dans des milieux non-aqueux. L'analyse est bade ssu une dttermination spectrophotomCtrique du dkplacement du perchlorate par des anions qui se coordonnent plus fortement. On dCmontre I'utilitC de la mCthode par la determination du nitrate, du nitrite, du chlorure, du bromure, de l'iodure, de I'acCtate, du trifluoroacttate, du cyanate et du thiocyanate de tttraalkylamrnonium dans l'acetonitrile. On a CvaluC que les prCcisions et les exactitudes relatives sont de l'ordre de cinq parties par mille.Mots cle's : perchlorato(tCtraphCnylporphinato)manganese(III), dktermination spectrophotomCtrique des anions, anions dans des milieux non-aqueux.[Traduit par la revue] Introduction In nonaqueous solvents, a great number of common anions can be solubilized through the use of large organic countercations. Tetraalkylammonium ions are probably the most frequently employed in this regard, and a great number of tetraalkylammonium salts are commercially available. Many such salts are either deliquescent, or extremely hygroscopic, and it can thus be difficult to prepare solutions with accurately known concentrations. In this paper, we report on the use of perchlorato(tetraphenylporphinato)manganese(III) (TPPMn-C104, I) as a reagent for spectrophotometric assay of a number of anions in nonaqueous solvents.