Substitution effects on the UV–vis and 1H NMR spectra of the dications of meso and/or β substituted porphyrins with trifluoroacetic acid: Electron-deficient porphyrins compared to the electron-rich ones

meso-Aryl-substituted free-base porphyrins: formation, structure and photostability of diprotonated species

“…1) undergoes protonation at one or both of the pyrrole nitrogen atoms, which results in formation of either a monocation or dication, respectively [6][7][8][9][10][11][12][13][14][15][16][17][18]. Although the existence of the mono-protonated cation was reported elsewhere, the diprotonated porphyrin form was practically the only stable product found in acidic media [9][10][11][12][13][14][15][16][17]. The dication, H 4 Por 2?…”

Electrochemical study of the dication of porphyrins with carboxylic acids: Shift of the absorption bands compared to that of the redox potentials

“…Electrochemical properties of porphyrins and metalloporphyrins were found to be influenced by the electronic effects of substituents at the periphery of the porphyrin ring and nonplanar distortion of the macrocycle [3,[18][19][20]. We have previously investigated the shifts of the Soret and Q(0,0) bands and change in the chemical shift of different protons upon core protonation of porphyrins with different carboxylic acids [15,21]. In the present work, the shifts in the redox potentials of some meso-tetra(aryl)porphyrins ( Fig.…”

“…All electrochemical experiments were carried out at room temperature using a scan rate of 0.01 Vs − 1 . The porphyrin dications were prepared according to the literature methods [11,15,17,21].…”

“…Protonation of meso-tetraaryl-and mesotetraalkylporphyrins with protic acids in dichloromethane (or chloroform) affords the diprotonated species as the sole product. Although Aronoff's spectrophotometric titration of H 2 TPP with CF 3 COOH in nitrobenzene has given an intermediate spectrum attributed to a monoprotonated species (H 3 TPP + ) [26], but so far no evidence has been found for the formation of a stable monoprotonated intermediate between the free base and the diprotonated porphyrin in chloroform and dichloromethane [13,17,21].…”

Porphyrin-vancomycin: A highly promising conjugate for the identification and photodynamic inactivation of antibiotic resistant Gram-positive pathogens

“…To afford Van carboxamide, HATU was employed as the coupling reagent. In the subsequent purification procedure, by judging the characteristic UVevisible absorbance of the parent moieties at 280 (l max of 3), 428, 525, 567 and 660 nm (l max of 2, B band approximately 400 nm, Q bands between 500 and 680 nm) [36,37], purified 4 was identified and collected. As shown in Fig.…”