Electrosynthesis and X-ray Crystallographic Structure of Zn-II meso-Triaryltriphenylphosphonium Porphyrin and Structural Comparison with Mg-II meso-Triphenylphosphonium Porphine

The electrochemical oxidation of Zn-II 5,15-bis(p-tolyl)-10-phenylporphyrin (1-Zn) in the presence of triphenylphosphine (PPh3) leads to the meso-substituted triphenylphosphonium porphyrin, coordinated by one P(O)Ph-3 molecule [1-Zn-PPh3+,PF6-center dot P(O)Ph-3] in good yield (84 %). This cationic porphyrin was characterized by NMR, MALDI-TOF mass spectrometry, UV/Vis. absorption spectroscopy and X-ray diffraction analyses. The molecular structure of this compound was compared with already published meso- and beta-triphenylphosphonium porphyrins but also with an unpublished X-ray crystallographic structure of Mg-II 5-triphenylphosphoniumporphine (MgP-PPh3+,PF6-) previously obtained by electrosynthesis.