Reactivity of pyrrole pigments, XX. On the structure of Cu(II) and Zn(II) tripyrrin-1-one chelates in solution

Tripyrrindione as a Redox‐Active Ligand: Palladium(II) Coordination in Three Redox States

“…For instance, tripyrrins (Scheme ) are typically stable as protonated salts in neat trifluoroacetic acid, but decompose rapidly in the presence of nucleophiles 18. In addition, tripyrrane19 and tripyrrin‐1‐one20 scaffolds, as well as pyrrolyldipyrrin prodigiosin21, 22 (Scheme ), undergo oxidative ligand degradation in the presence of Cu II ions.…”

meso-Aryl substituted free-base tripyrrins: preparation and electrochemically induced protonation/deprotonation reactions. Single crystal X-ray analysis of (2,6-diFPh)2TriPyH

“…Tripyrrins and the related tripyrranes (Chart 1) are intermediates in the synthesis of porphyrins 1 and expanded porphyrins, 2 which have been mentioned in the literature for over four decades. The tripyrrins can be considered as formally derived from the macrocyclic parent porphyrins by the loss of one of the four pyrrole rings [3][4][5][6][7][8][9][10][11][12] and have potential applications in the eld of coordination polymers 20 and uorescent materials. 25,26 However, due to the high propensity of the nonmetallated compounds to decompose in the presence of weak nucleophiles, their characterization in solution has been limited in a large part to methyl terminated species, 13 meso-oxo derivatives 9 or stable tripyrrinones with enolizable terminal hydroxy functionalities.…”

“…25,26 However, due to the high propensity of the nonmetallated compounds to decompose in the presence of weak nucleophiles, their characterization in solution has been limited in a large part to methyl terminated species, 13 meso-oxo derivatives 9 or stable tripyrrinones with enolizable terminal hydroxy functionalities. [6][7][8][9]11,12 The diprotonated form of b-substituted tripyrrins has been characterized in solution by NMR spectroscopy 13,[16][17][18] and one free-base b-substituted tripyrrin has been structurally characterized. 23 However, almost nothing is known about free-base meso-substituted tripyrrins due to the instability of these compounds.…”

Case history of porphyrin J-aggregates: a personal point of view

“…The nice and expected zwitterionic behavior of sulfonato-substituted tripyrrinones [2] (published later in 1996) lead us to spectrometric pKa measurements of the analogous series of the meso-substituted 4-sulfonatophenyl-and-phenyl substituted porphyrins ( Fig. 1) in order to study the electronic effect of the sulfonato substituents on the basicity of the pyrrolenic nitrogens.…”