Four crystal structures of the title complexes have been analyzed by X-ray crystallography. 1:  C80H68N17Nd, a = 17.0545(6) Å, c = 22.807(3) Å, tetragonal, P4/ncc, Z = 4. 2:  C80H68N17Gd, a = 17.399(8) Å, c = 11.377(6) Å, tetragonal, P4212, Z = 2. 3:  C80H70N17OHo, a = 18.096(5) Å, c = 11.079(6) Å, tetragonal, P4212, Z = 4. 4:  C80H70N17OLu, a = 18.171(3) Å, c = 10.987(4) Å, tetragonal, P4/nmm, Z = 2. The [LnIIIPc2]- and [NBu n 4]+ ions in each crystal stack alternately in a column along the 4-fold axis. The Ln(III) cation of each [LnIIIPc2]- is eight-coordinated by two phthalocyanato dianions (Pc). The interplanar distances between the two Pc rings have a linear relationship to the ionic radii of the central Ln(III) cations. The skew angles between the two Pc rings are 6.2, 34.4, 43.2, and 45.0° for the Nd, Gd, Ho, and Lu complexes, respectively. The skew angle seems to depend on the strength of the π−π interaction between the two Pc rings.

The electrochemical behavior of peroxyacetic acid (PAA) in the presence of hydrogen peroxide (H2O2) has been investigated using cyclic voltammetry and hydrodynamic techniques [rotating disk electrode (RDE) voltammetry and rotating ring-disk electrode (RRDE) voltammetry]. The results have been analyzed aiming at simultaneous electroanalysis of both species. Glassy carbon and gold electrodes were used for this investigation. It was found that the reduction of PAA, as well as H2O2, is highly sensitive to the electrode material; for example, at 100 mV s-1, the reduction peak potentials of PAA were 0.2 and -1.1 V at gold and glassy carbon electrodes, respectively. The well-separated steady-state limiting currents were obtained using a gold electrode for the reduction of both PAA and H2O2 and also a well-defined one for the oxidation of H2O2. On the basis of the RDE experiments, good calibration curves were obtained for both species over a wide range of their concentrations, for PAA and H2O2 in the range of 0.36 to 110 and 0.11 to 34 mM, respectively. The simultaneous and selective electroanalysis of PAA and H2O2 in their coexistence is demonstrated for the first time.

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